Osteoarthritis

SAN DIEGO – Even older, heavier, sicker patients, and those with worse mental health, benefit substantially from total hip replacement when indicated, a study has shown.

It’s just that their outcomes aren’t quite as good as those of their younger, leaner, and healthier peers because they also tend to start out with worse preoperative hip pain and function. Even so, they benefit about as much from the operation, gaining in the range of 20 points on the 48-point Oxford Hip Score (OHS), the study found.

Because of that, perhaps physicians should reconsider basing selection of surgery candidates on negative preoperative characteristics; maybe even "patient [body mass index (BMI)] should not be used, as these patients still get substantial improvement following surgery," lead investigator Andy Judge, Ph.D., said at the World Congress on Osteoarthritis, sponsored by Osteoarthritis Research Society International.

The team compared preoperative OHS scores with postoperative scores collected over a 5-year period from 1,375 hip replacement patients who underwent surgery because of osteoarthritis. Each got a cemented Exeter femoral component. Their mean age was 68; 60% were women.

The OHS asks patients 12 multiple-choice questions about pain and function. The five possible answers are scored 0-4, with 0 being the worst possible overall score, and 48 the best.

In general, and regardless of preoperative factors, surgery gave the majority of patients significant relief in the 1st year that was maintained through the 5th year, said Dr. Judge, a senior statistician at the University of Oxford.

There were "small differences in postoperative OHS observed for age, BMI, comorbidity, mental health, and femoral component size, but these patients still received substantial benefit from surgery," he said.

Preoperative hip pain and function was the biggest predictor of how patients fared after the operation. Patients with worse scores tended to have worse postoperative pain and function.

However, even those who entered the operating room with OHS scores below 5 improved, on average, to about 30. Those who entered with scores in the mid-30s improved to the low 40s.

Between-group magnitudes of improvement were similar for other factors taken into account. For instance, average preoperative OHS scores were in the lower teens for those with BMIs at or above 30 kg/m²; postoperative scores were in the mid-30s. Slimmer peers with BMIs below 30 kg/m² entered the operating room with average OHS scores in the upper teens; their postoperative scores improved to about 40 on average.

It was the same story with poorer preoperative mental health scores and higher numbers of comorbidities; patients started and wound up a few points lower on the OHS, but tended to benefit about as much as patients with better mental health and fewer comorbidities.

Patients who were 60-70 years old had the best postoperative scores by a few points, but also started with OHS scores a few points higher than younger and older patients, who, nonetheless, had comparable, roughly 20-point improvements in postoperative OHS scores.

Similarly, patients with larger femoral component sizes (offset of 44 mm or more) also had slightly better outcomes, but also entered the trial with slightly better hip scores. The trial’s findings were statistically significant.

Dr. Judge said he had no relevant financial disclosures. The study was funded by the British National Institute for Health Research.

SAN DIEGO – Even older, heavier, sicker patients, and those with worse mental health, benefit substantially from total hip replacement when indicated, a study has shown.

It’s just that their outcomes aren’t quite as good as those of their younger, leaner, and healthier peers because they also tend to start out with worse preoperative hip pain and function. Even so, they benefit about as much from the operation, gaining in the range of 20 points on the 48-point Oxford Hip Score (OHS), the study found.

Because of that, perhaps physicians should reconsider basing selection of surgery candidates on negative preoperative characteristics; maybe even "patient [body mass index (BMI)] should not be used, as these patients still get substantial improvement following surgery," lead investigator Andy Judge, Ph.D., said at the World Congress on Osteoarthritis, sponsored by Osteoarthritis Research Society International.

The team compared preoperative OHS scores with postoperative scores collected over a 5-year period from 1,375 hip replacement patients who underwent surgery because of osteoarthritis. Each got a cemented Exeter femoral component. Their mean age was 68; 60% were women.

The OHS asks patients 12 multiple-choice questions about pain and function. The five possible answers are scored 0-4, with 0 being the worst possible overall score, and 48 the best.

In general, and regardless of preoperative factors, surgery gave the majority of patients significant relief in the 1st year that was maintained through the 5th year, said Dr. Judge, a senior statistician at the University of Oxford.

There were "small differences in postoperative OHS observed for age, BMI, comorbidity, mental health, and femoral component size, but these patients still received substantial benefit from surgery," he said.

Preoperative hip pain and function was the biggest predictor of how patients fared after the operation. Patients with worse scores tended to have worse postoperative pain and function.

However, even those who entered the operating room with OHS scores below 5 improved, on average, to about 30. Those who entered with scores in the mid-30s improved to the low 40s.

Between-group magnitudes of improvement were similar for other factors taken into account. For instance, average preoperative OHS scores were in the lower teens for those with BMIs at or above 30 kg/m²; postoperative scores were in the mid-30s. Slimmer peers with BMIs below 30 kg/m² entered the operating room with average OHS scores in the upper teens; their postoperative scores improved to about 40 on average.

It was the same story with poorer preoperative mental health scores and higher numbers of comorbidities; patients started and wound up a few points lower on the OHS, but tended to benefit about as much as patients with better mental health and fewer comorbidities.

Patients who were 60-70 years old had the best postoperative scores by a few points, but also started with OHS scores a few points higher than younger and older patients, who, nonetheless, had comparable, roughly 20-point improvements in postoperative OHS scores.

Similarly, patients with larger femoral component sizes (offset of 44 mm or more) also had slightly better outcomes, but also entered the trial with slightly better hip scores. The trial’s findings were statistically significant.

Dr. Judge said he had no relevant financial disclosures. The study was funded by the British National Institute for Health Research.

SAN DIEGO – Even older, heavier, sicker patients, and those with worse mental health, benefit substantially from total hip replacement when indicated, a study has shown.

It’s just that their outcomes aren’t quite as good as those of their younger, leaner, and healthier peers because they also tend to start out with worse preoperative hip pain and function. Even so, they benefit about as much from the operation, gaining in the range of 20 points on the 48-point Oxford Hip Score (OHS), the study found.

Because of that, perhaps physicians should reconsider basing selection of surgery candidates on negative preoperative characteristics; maybe even "patient [body mass index (BMI)] should not be used, as these patients still get substantial improvement following surgery," lead investigator Andy Judge, Ph.D., said at the World Congress on Osteoarthritis, sponsored by Osteoarthritis Research Society International.

The team compared preoperative OHS scores with postoperative scores collected over a 5-year period from 1,375 hip replacement patients who underwent surgery because of osteoarthritis. Each got a cemented Exeter femoral component. Their mean age was 68; 60% were women.

The OHS asks patients 12 multiple-choice questions about pain and function. The five possible answers are scored 0-4, with 0 being the worst possible overall score, and 48 the best.

In general, and regardless of preoperative factors, surgery gave the majority of patients significant relief in the 1st year that was maintained through the 5th year, said Dr. Judge, a senior statistician at the University of Oxford.

There were "small differences in postoperative OHS observed for age, BMI, comorbidity, mental health, and femoral component size, but these patients still received substantial benefit from surgery," he said.

Preoperative hip pain and function was the biggest predictor of how patients fared after the operation. Patients with worse scores tended to have worse postoperative pain and function.

However, even those who entered the operating room with OHS scores below 5 improved, on average, to about 30. Those who entered with scores in the mid-30s improved to the low 40s.

Between-group magnitudes of improvement were similar for other factors taken into account. For instance, average preoperative OHS scores were in the lower teens for those with BMIs at or above 30 kg/m²; postoperative scores were in the mid-30s. Slimmer peers with BMIs below 30 kg/m² entered the operating room with average OHS scores in the upper teens; their postoperative scores improved to about 40 on average.

It was the same story with poorer preoperative mental health scores and higher numbers of comorbidities; patients started and wound up a few points lower on the OHS, but tended to benefit about as much as patients with better mental health and fewer comorbidities.

Patients who were 60-70 years old had the best postoperative scores by a few points, but also started with OHS scores a few points higher than younger and older patients, who, nonetheless, had comparable, roughly 20-point improvements in postoperative OHS scores.

Similarly, patients with larger femoral component sizes (offset of 44 mm or more) also had slightly better outcomes, but also entered the trial with slightly better hip scores. The trial’s findings were statistically significant.

Dr. Judge said he had no relevant financial disclosures. The study was funded by the British National Institute for Health Research.

SAN DIEGO – Male gender, obesity, pain level, and baseline radiographic severity independently predict the progression of knee osteoarthritis, while race and baseline multiple joint involvement, knee misalignment, and physical inactivity do not, according to the results of a large cohort study.

The findings could help drug developers figure out whom to include in trials of drugs aimed at slowing progression. Also, the blood, DNA, and other samples collected in the study, upon further analysis, may suggest new drug targets in people at risk for progression, said lead investigator Dr. Charles Eaton, professor of family medicine at Brown University, Providence, R.I.

"It may be some of the metabolic factors related to obesity," such as inflammation, "make you progress," and could be targeted in drug development, he said.

Meanwhile, it’s a good idea to encourage obese patients who have knee osteoarthritis (OA) to lose weight. Also, "if you have a male coming in complaining of a lot of knee pain, they might be at high risk for progression. Get an x-ray and see if they actually have arthritis, and see how severe it is," Dr. Eaton said at the World Congress on Osteoarthritis.

He and his colleagues used publicly available data from the Osteoarthritis Initiative, a multicenter longitudinal cohort study looking for biomarkers of incidence and progression, to track 1,842 knees in 1,247 knee OA patients. For each knee, the investigators analyzed x-rays taken at baseline and at 4 years of follow-up to see who had medial joint-space narrowing of 0.5 mm or more. The researchers then looked to see what baseline characteristics predicted progression. Subjects were 45-79 years old. Almost 60% of the knees in the study belonged to women.

Compared with women, the adjusted odds ratio for progression among men was 1.27 (95% confidence interval 1.02-1.59).

Patients who entered the study with Kellgren-Lawrence grade 3 disease, instead of grade 2 disease, had twice the risk of progression (OR 2.09, 95% CI 1.72-2.54). Those who enrolled with a body mass index of 30 kg/m² or higher were about 1.5 times more likely to progress than those who entered with a BMI below 25 kg/m² (OR 1.41, 95% CI 1.02-1.96).

Patients with the worst pain at baseline – WOMAC (Western Ontario and McMaster Universities index) pain scores in the fourth quartile – were twice as likely to progress as those who entered with first quartile pain (OR 2.18, 95% CI 1.69-2.82).

Time itself was a factor, too; 4 years into the trial, patients were nine times as likely as in the first year to have progressed (OR 9.14, 95% CI 7.45-11.22).

"Previously, it was thought that females were more likely to progress. Initial studies suggested that African Americans were more likely to progress. But when we adjusted for everything, that was no longer true," Dr. Eaton said. Baseline income, smoking, depression, and Knee Injury and Osteoarthritis Outcome Score (KOOS) functionality were among the other potential risk-factors that did not pan out on multivariate analysis.

"We are trying to understand" the increased risk for men. Men may have entered the trial with a greater burden of meniscal damage than women, and a greater likelihood of past knee surgery; there was a trend in the data toward increased progression risk for previous knee operations, but it dropped out on multivariate analysis.

The meeting was sponsored by the Osteoarthritis Research Society International.

The Osteoarthritis Initiative is funded by the National Institutes of Health, Merck, GlaxoSmithKline, Novartis Pharmaceuticals, and Pfizer. Dr. Eaton said he had no disclosures.

SAN DIEGO – Male gender, obesity, pain level, and baseline radiographic severity independently predict the progression of knee osteoarthritis, while race and baseline multiple joint involvement, knee misalignment, and physical inactivity do not, according to the results of a large cohort study.

The findings could help drug developers figure out whom to include in trials of drugs aimed at slowing progression. Also, the blood, DNA, and other samples collected in the study, upon further analysis, may suggest new drug targets in people at risk for progression, said lead investigator Dr. Charles Eaton, professor of family medicine at Brown University, Providence, R.I.

"It may be some of the metabolic factors related to obesity," such as inflammation, "make you progress," and could be targeted in drug development, he said.

Meanwhile, it’s a good idea to encourage obese patients who have knee osteoarthritis (OA) to lose weight. Also, "if you have a male coming in complaining of a lot of knee pain, they might be at high risk for progression. Get an x-ray and see if they actually have arthritis, and see how severe it is," Dr. Eaton said at the World Congress on Osteoarthritis.

He and his colleagues used publicly available data from the Osteoarthritis Initiative, a multicenter longitudinal cohort study looking for biomarkers of incidence and progression, to track 1,842 knees in 1,247 knee OA patients. For each knee, the investigators analyzed x-rays taken at baseline and at 4 years of follow-up to see who had medial joint-space narrowing of 0.5 mm or more. The researchers then looked to see what baseline characteristics predicted progression. Subjects were 45-79 years old. Almost 60% of the knees in the study belonged to women.

Compared with women, the adjusted odds ratio for progression among men was 1.27 (95% confidence interval 1.02-1.59).

Patients who entered the study with Kellgren-Lawrence grade 3 disease, instead of grade 2 disease, had twice the risk of progression (OR 2.09, 95% CI 1.72-2.54). Those who enrolled with a body mass index of 30 kg/m² or higher were about 1.5 times more likely to progress than those who entered with a BMI below 25 kg/m² (OR 1.41, 95% CI 1.02-1.96).

Patients with the worst pain at baseline – WOMAC (Western Ontario and McMaster Universities index) pain scores in the fourth quartile – were twice as likely to progress as those who entered with first quartile pain (OR 2.18, 95% CI 1.69-2.82).

Time itself was a factor, too; 4 years into the trial, patients were nine times as likely as in the first year to have progressed (OR 9.14, 95% CI 7.45-11.22).

"Previously, it was thought that females were more likely to progress. Initial studies suggested that African Americans were more likely to progress. But when we adjusted for everything, that was no longer true," Dr. Eaton said. Baseline income, smoking, depression, and Knee Injury and Osteoarthritis Outcome Score (KOOS) functionality were among the other potential risk-factors that did not pan out on multivariate analysis.

"We are trying to understand" the increased risk for men. Men may have entered the trial with a greater burden of meniscal damage than women, and a greater likelihood of past knee surgery; there was a trend in the data toward increased progression risk for previous knee operations, but it dropped out on multivariate analysis.

The meeting was sponsored by the Osteoarthritis Research Society International.

The Osteoarthritis Initiative is funded by the National Institutes of Health, Merck, GlaxoSmithKline, Novartis Pharmaceuticals, and Pfizer. Dr. Eaton said he had no disclosures.

SAN DIEGO – Male gender, obesity, pain level, and baseline radiographic severity independently predict the progression of knee osteoarthritis, while race and baseline multiple joint involvement, knee misalignment, and physical inactivity do not, according to the results of a large cohort study.

The findings could help drug developers figure out whom to include in trials of drugs aimed at slowing progression. Also, the blood, DNA, and other samples collected in the study, upon further analysis, may suggest new drug targets in people at risk for progression, said lead investigator Dr. Charles Eaton, professor of family medicine at Brown University, Providence, R.I.

"It may be some of the metabolic factors related to obesity," such as inflammation, "make you progress," and could be targeted in drug development, he said.

Meanwhile, it’s a good idea to encourage obese patients who have knee osteoarthritis (OA) to lose weight. Also, "if you have a male coming in complaining of a lot of knee pain, they might be at high risk for progression. Get an x-ray and see if they actually have arthritis, and see how severe it is," Dr. Eaton said at the World Congress on Osteoarthritis.

He and his colleagues used publicly available data from the Osteoarthritis Initiative, a multicenter longitudinal cohort study looking for biomarkers of incidence and progression, to track 1,842 knees in 1,247 knee OA patients. For each knee, the investigators analyzed x-rays taken at baseline and at 4 years of follow-up to see who had medial joint-space narrowing of 0.5 mm or more. The researchers then looked to see what baseline characteristics predicted progression. Subjects were 45-79 years old. Almost 60% of the knees in the study belonged to women.

Compared with women, the adjusted odds ratio for progression among men was 1.27 (95% confidence interval 1.02-1.59).

Patients who entered the study with Kellgren-Lawrence grade 3 disease, instead of grade 2 disease, had twice the risk of progression (OR 2.09, 95% CI 1.72-2.54). Those who enrolled with a body mass index of 30 kg/m² or higher were about 1.5 times more likely to progress than those who entered with a BMI below 25 kg/m² (OR 1.41, 95% CI 1.02-1.96).

Patients with the worst pain at baseline – WOMAC (Western Ontario and McMaster Universities index) pain scores in the fourth quartile – were twice as likely to progress as those who entered with first quartile pain (OR 2.18, 95% CI 1.69-2.82).

Time itself was a factor, too; 4 years into the trial, patients were nine times as likely as in the first year to have progressed (OR 9.14, 95% CI 7.45-11.22).

"Previously, it was thought that females were more likely to progress. Initial studies suggested that African Americans were more likely to progress. But when we adjusted for everything, that was no longer true," Dr. Eaton said. Baseline income, smoking, depression, and Knee Injury and Osteoarthritis Outcome Score (KOOS) functionality were among the other potential risk-factors that did not pan out on multivariate analysis.

"We are trying to understand" the increased risk for men. Men may have entered the trial with a greater burden of meniscal damage than women, and a greater likelihood of past knee surgery; there was a trend in the data toward increased progression risk for previous knee operations, but it dropped out on multivariate analysis.

The meeting was sponsored by the Osteoarthritis Research Society International.

The Osteoarthritis Initiative is funded by the National Institutes of Health, Merck, GlaxoSmithKline, Novartis Pharmaceuticals, and Pfizer. Dr. Eaton said he had no disclosures.

SAN DIEGO – It’s not unusual for total knee replacement patients to have arthritis in other joints, and it negatively impacts surgery outcomes, Toronto researchers have found.

In their study, 420 of 494 knee replacement patients (85%) reported problems in at least one other joint. Those with foot or ankle arthritis had a significantly reduced chance of achieving an MCID (Minimally Clinically Important Difference) on postoperative WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) pain and function scores (odds ratio pain 0.32, 95% confidence interval 0.185-0.544; OR function 0.53, 95% CI 0.303, 0.940).

Patients who reported neck problems also had reduced odds of achieving an MCID on physical function WOMAC scores (OR 0.37, 95% CI 0.183, 0.726).

"It’s not surprising that ankles and feet [were] significant. [They] impact activities for which lower-extremity joints are involved. How the upper extremities are associated here, in particular the neck, is unclear," said lead investigator Anthony Perruccio, Ph.D., an epidemiologist and research scientist at the Toronto Western Research Institute.

Because patients with neck problems also saw less improvement in fatigue, anxiety, depression, and pain, there may also be a mental health component, he said.

Whatever the case, the lesson is to treat the whole patient, not just the knee. Referrals to other types of providers are appropriate, including physiotherapists and mental health counselors as needed, said Dr. Perruccio.

"There’s more than just the one joint that’s involved here. Outcomes could be improved if a more holistic approach to osteoarthritis management were considered," he said.

All 494 patients had primary, unilateral knee replacements secondary to osteoarthritis. Their mean age was 65, 65% were women, and almost half were obese.

The patients filled out several surveys before their operations, including WOMAC and other pain and function scales plus the Profile of Mood States (POMS) fatigue scale, the Knee injury and Osteoarthritis Outcome Score (KOOS) sports and recreation scale, and the Hospital Anxiety and Depression Scale (HADS). They also pointed out on a homunculus diagram which joints were causing trouble.

Almost half (46%) reported pain on most days in four or more joints in addition to their operative knee. The nonoperative knee was a problem for 57%, elbows/wrists/hands were problematic for 49%, ankles/feet for 36%, the back for 31%, shoulders for 29%, hips for 25%, and neck for 22%. Just 15% said only their operative knee was symptomatic.

A year after their operation, patients took the surveys again. Those with back problems tended to see less improvement in fatigue at 1 year. Those with ankle or foot arthritis – in addition to diminished returns on pain and function – also saw less improvement than others in depression and sports and recreation scores.

The congress was sponsored by the Osteoarthritis Research Society International. Dr. Perruccio said he had no relevant financial disclosures. The work was funded by the Canadian Institutes of Health Research.

* Correction, 10/21/11: The original headline of this story, "Knee Replacement Worsens Arthritis in Other Joints," misrepresented the findings of this study. The headline has been revised.

SAN DIEGO – It’s not unusual for total knee replacement patients to have arthritis in other joints, and it negatively impacts surgery outcomes, Toronto researchers have found.

In their study, 420 of 494 knee replacement patients (85%) reported problems in at least one other joint. Those with foot or ankle arthritis had a significantly reduced chance of achieving an MCID (Minimally Clinically Important Difference) on postoperative WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) pain and function scores (odds ratio pain 0.32, 95% confidence interval 0.185-0.544; OR function 0.53, 95% CI 0.303, 0.940).

Patients who reported neck problems also had reduced odds of achieving an MCID on physical function WOMAC scores (OR 0.37, 95% CI 0.183, 0.726).

"It’s not surprising that ankles and feet [were] significant. [They] impact activities for which lower-extremity joints are involved. How the upper extremities are associated here, in particular the neck, is unclear," said lead investigator Anthony Perruccio, Ph.D., an epidemiologist and research scientist at the Toronto Western Research Institute.

Because patients with neck problems also saw less improvement in fatigue, anxiety, depression, and pain, there may also be a mental health component, he said.

Whatever the case, the lesson is to treat the whole patient, not just the knee. Referrals to other types of providers are appropriate, including physiotherapists and mental health counselors as needed, said Dr. Perruccio.

"There’s more than just the one joint that’s involved here. Outcomes could be improved if a more holistic approach to osteoarthritis management were considered," he said.

All 494 patients had primary, unilateral knee replacements secondary to osteoarthritis. Their mean age was 65, 65% were women, and almost half were obese.

The patients filled out several surveys before their operations, including WOMAC and other pain and function scales plus the Profile of Mood States (POMS) fatigue scale, the Knee injury and Osteoarthritis Outcome Score (KOOS) sports and recreation scale, and the Hospital Anxiety and Depression Scale (HADS). They also pointed out on a homunculus diagram which joints were causing trouble.

Almost half (46%) reported pain on most days in four or more joints in addition to their operative knee. The nonoperative knee was a problem for 57%, elbows/wrists/hands were problematic for 49%, ankles/feet for 36%, the back for 31%, shoulders for 29%, hips for 25%, and neck for 22%. Just 15% said only their operative knee was symptomatic.

A year after their operation, patients took the surveys again. Those with back problems tended to see less improvement in fatigue at 1 year. Those with ankle or foot arthritis – in addition to diminished returns on pain and function – also saw less improvement than others in depression and sports and recreation scores.

The congress was sponsored by the Osteoarthritis Research Society International. Dr. Perruccio said he had no relevant financial disclosures. The work was funded by the Canadian Institutes of Health Research.

* Correction, 10/21/11: The original headline of this story, "Knee Replacement Worsens Arthritis in Other Joints," misrepresented the findings of this study. The headline has been revised.

SAN DIEGO – It’s not unusual for total knee replacement patients to have arthritis in other joints, and it negatively impacts surgery outcomes, Toronto researchers have found.

In their study, 420 of 494 knee replacement patients (85%) reported problems in at least one other joint. Those with foot or ankle arthritis had a significantly reduced chance of achieving an MCID (Minimally Clinically Important Difference) on postoperative WOMAC (Western Ontario and McMaster Universities Osteoarthritis Index) pain and function scores (odds ratio pain 0.32, 95% confidence interval 0.185-0.544; OR function 0.53, 95% CI 0.303, 0.940).

Patients who reported neck problems also had reduced odds of achieving an MCID on physical function WOMAC scores (OR 0.37, 95% CI 0.183, 0.726).

"It’s not surprising that ankles and feet [were] significant. [They] impact activities for which lower-extremity joints are involved. How the upper extremities are associated here, in particular the neck, is unclear," said lead investigator Anthony Perruccio, Ph.D., an epidemiologist and research scientist at the Toronto Western Research Institute.

Because patients with neck problems also saw less improvement in fatigue, anxiety, depression, and pain, there may also be a mental health component, he said.

Whatever the case, the lesson is to treat the whole patient, not just the knee. Referrals to other types of providers are appropriate, including physiotherapists and mental health counselors as needed, said Dr. Perruccio.

"There’s more than just the one joint that’s involved here. Outcomes could be improved if a more holistic approach to osteoarthritis management were considered," he said.

All 494 patients had primary, unilateral knee replacements secondary to osteoarthritis. Their mean age was 65, 65% were women, and almost half were obese.

The patients filled out several surveys before their operations, including WOMAC and other pain and function scales plus the Profile of Mood States (POMS) fatigue scale, the Knee injury and Osteoarthritis Outcome Score (KOOS) sports and recreation scale, and the Hospital Anxiety and Depression Scale (HADS). They also pointed out on a homunculus diagram which joints were causing trouble.

Almost half (46%) reported pain on most days in four or more joints in addition to their operative knee. The nonoperative knee was a problem for 57%, elbows/wrists/hands were problematic for 49%, ankles/feet for 36%, the back for 31%, shoulders for 29%, hips for 25%, and neck for 22%. Just 15% said only their operative knee was symptomatic.

A year after their operation, patients took the surveys again. Those with back problems tended to see less improvement in fatigue at 1 year. Those with ankle or foot arthritis – in addition to diminished returns on pain and function – also saw less improvement than others in depression and sports and recreation scores.

The congress was sponsored by the Osteoarthritis Research Society International. Dr. Perruccio said he had no relevant financial disclosures. The work was funded by the Canadian Institutes of Health Research.

* Correction, 10/21/11: The original headline of this story, "Knee Replacement Worsens Arthritis in Other Joints," misrepresented the findings of this study. The headline has been revised.

U.S. health care expenditures for mental disorders were 65% higher for women than men in 2008, according to a report from the Agency for Healthcare Research and Quality.

Total spending among adults that year was $37.3 billion for women and $22.6 billion for men, making mental disorders the third most costly condition for women and the fifth most costly for men. Other conditions with large discrepancies between women and men were COPD/asthma (51% higher in women), osteoarthritis (44% higher in women), and back problems (40% higher in women), the AHRQ reported.

Heart disease was the leading source of expenditure for both women ($43.6 billion) and men ($47.3 billion), while cancer was second – $37.7 billion for women and $33.7 billion for men.

The report used data for the U.S. civilian, noninstitutionalized adult population from the Medical Expenditure Panel Survey, which is cosponsored by the AHRQ and the National Center for Health Statistics.

U.S. health care expenditures for mental disorders were 65% higher for women than men in 2008, according to a report from the Agency for Healthcare Research and Quality.

Total spending among adults that year was $37.3 billion for women and $22.6 billion for men, making mental disorders the third most costly condition for women and the fifth most costly for men. Other conditions with large discrepancies between women and men were COPD/asthma (51% higher in women), osteoarthritis (44% higher in women), and back problems (40% higher in women), the AHRQ reported.

Heart disease was the leading source of expenditure for both women ($43.6 billion) and men ($47.3 billion), while cancer was second – $37.7 billion for women and $33.7 billion for men.

The report used data for the U.S. civilian, noninstitutionalized adult population from the Medical Expenditure Panel Survey, which is cosponsored by the AHRQ and the National Center for Health Statistics.

U.S. health care expenditures for mental disorders were 65% higher for women than men in 2008, according to a report from the Agency for Healthcare Research and Quality.

Total spending among adults that year was $37.3 billion for women and $22.6 billion for men, making mental disorders the third most costly condition for women and the fifth most costly for men. Other conditions with large discrepancies between women and men were COPD/asthma (51% higher in women), osteoarthritis (44% higher in women), and back problems (40% higher in women), the AHRQ reported.

Heart disease was the leading source of expenditure for both women ($43.6 billion) and men ($47.3 billion), while cancer was second – $37.7 billion for women and $33.7 billion for men.

The report used data for the U.S. civilian, noninstitutionalized adult population from the Medical Expenditure Panel Survey, which is cosponsored by the AHRQ and the National Center for Health Statistics.

SAN DIEGO – Patients with severe pain in the first 3 months after total knee replacement have worse pain and function outcomes at 1 and 2 years, and are less satisfied with the procedure, Boston researchers have found.

Because of that, severe pain after the operation "is something that we ought to be intervening on," said lead investigator Dr. Jeffrey N. Katz, professor of medicine and orthopedic surgery at Harvard Medical School, Boston.

Depressed, catastrophizing patients and those in severe pain before the operation are all at risk for severe pain afterward. Using cognitive-behavioral therapy and optimizing antidepressant dosages and pain control can help, both before and after the operation, Dr. Katz said at the World Congress on Osteoarthritis.

Also, "people might consider operating sooner," before pain becomes severe, he said.

Of the approximately 600,000 total knee replacements in the United States every year, about 15% of patients have severe pain after the operation, but until now, it wasn’t known "whether that portends poor outcomes over time," Dr. Katz said.

His team found that it did, at least in the 622 unilateral, primary, total knee replacement patients in their study. Overall, 62% were aged older than 65 years, 58% were women, 35% had a body mass index greater than 30 kg/m²; and about half had two or more comorbidities.

Their mean preoperative function score on the WOMAC (Western Ontario and McMaster Universities) osteoarthritis index was 47, and their mean preoperative WOMAC pain score was 41 (with 100 being the best score on the WOMAC index and 0 the worst possible).

Following the surgery, 15% of the patients had WOMAC pain scores lower than 50 at 3 months, which indicated severe pain. Dr. Katz and his team compared these patients with the other 85%.

The patients with severe pain at 3 months had mean WOMAC function scores of about 60 at both the 1- and 2-year follow-up. The 85% of patients without severe pain had function scores in the mid-70s at both points.

Similarly, the severe pain group had WOMAC pain scores in the mid-60s at both 1 and 2 years. The other patients had mean WOMAC scores in the mid-80s at both points.

About 60% in the severe pain group said they couldn’t walk five blocks at both 1 and 2 years. Among those without severe pain, about 40% said that couldn’t walk five blocks at both points.

Finally, about a quarter of patients in the severe pain group were dissatisfied with their surgery at both 1 and 2 years afterward. About 5% of patients without severe postsurgical pain were dissatisfied with their operation at 1 year and about 3% were dissatisfied at 2 years. All the results were statistically significant (P less than .001).

The patients came from 12 referral centers in the United States, the United Kingdom, and Australia. The study did not capture the reasons for the pain, the problems with implants (if any), or the patients’ psychiatric histories.

Dr. Katz said that the 5-year findings appear to be similar to the 1- and 2-year results, but there weren’t enough data to include them in the analysis.

The congress was sponsored by the Osteoarthritis Research Society International. The study was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases. The data used in the analysis came from a multicenter, prospective cohort study sponsored by implant maker Stryker Corp. about a decade ago. Dr. Katz said he has no disclosures.

SAN DIEGO – Patients with severe pain in the first 3 months after total knee replacement have worse pain and function outcomes at 1 and 2 years, and are less satisfied with the procedure, Boston researchers have found.

Because of that, severe pain after the operation "is something that we ought to be intervening on," said lead investigator Dr. Jeffrey N. Katz, professor of medicine and orthopedic surgery at Harvard Medical School, Boston.

Depressed, catastrophizing patients and those in severe pain before the operation are all at risk for severe pain afterward. Using cognitive-behavioral therapy and optimizing antidepressant dosages and pain control can help, both before and after the operation, Dr. Katz said at the World Congress on Osteoarthritis.

Also, "people might consider operating sooner," before pain becomes severe, he said.

Of the approximately 600,000 total knee replacements in the United States every year, about 15% of patients have severe pain after the operation, but until now, it wasn’t known "whether that portends poor outcomes over time," Dr. Katz said.

His team found that it did, at least in the 622 unilateral, primary, total knee replacement patients in their study. Overall, 62% were aged older than 65 years, 58% were women, 35% had a body mass index greater than 30 kg/m²; and about half had two or more comorbidities.

Their mean preoperative function score on the WOMAC (Western Ontario and McMaster Universities) osteoarthritis index was 47, and their mean preoperative WOMAC pain score was 41 (with 100 being the best score on the WOMAC index and 0 the worst possible).

Following the surgery, 15% of the patients had WOMAC pain scores lower than 50 at 3 months, which indicated severe pain. Dr. Katz and his team compared these patients with the other 85%.

The patients with severe pain at 3 months had mean WOMAC function scores of about 60 at both the 1- and 2-year follow-up. The 85% of patients without severe pain had function scores in the mid-70s at both points.

Similarly, the severe pain group had WOMAC pain scores in the mid-60s at both 1 and 2 years. The other patients had mean WOMAC scores in the mid-80s at both points.

About 60% in the severe pain group said they couldn’t walk five blocks at both 1 and 2 years. Among those without severe pain, about 40% said that couldn’t walk five blocks at both points.

Finally, about a quarter of patients in the severe pain group were dissatisfied with their surgery at both 1 and 2 years afterward. About 5% of patients without severe postsurgical pain were dissatisfied with their operation at 1 year and about 3% were dissatisfied at 2 years. All the results were statistically significant (P less than .001).

The patients came from 12 referral centers in the United States, the United Kingdom, and Australia. The study did not capture the reasons for the pain, the problems with implants (if any), or the patients’ psychiatric histories.

Dr. Katz said that the 5-year findings appear to be similar to the 1- and 2-year results, but there weren’t enough data to include them in the analysis.

The congress was sponsored by the Osteoarthritis Research Society International. The study was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases. The data used in the analysis came from a multicenter, prospective cohort study sponsored by implant maker Stryker Corp. about a decade ago. Dr. Katz said he has no disclosures.

SAN DIEGO – Patients with severe pain in the first 3 months after total knee replacement have worse pain and function outcomes at 1 and 2 years, and are less satisfied with the procedure, Boston researchers have found.

Because of that, severe pain after the operation "is something that we ought to be intervening on," said lead investigator Dr. Jeffrey N. Katz, professor of medicine and orthopedic surgery at Harvard Medical School, Boston.

Depressed, catastrophizing patients and those in severe pain before the operation are all at risk for severe pain afterward. Using cognitive-behavioral therapy and optimizing antidepressant dosages and pain control can help, both before and after the operation, Dr. Katz said at the World Congress on Osteoarthritis.

Also, "people might consider operating sooner," before pain becomes severe, he said.

Of the approximately 600,000 total knee replacements in the United States every year, about 15% of patients have severe pain after the operation, but until now, it wasn’t known "whether that portends poor outcomes over time," Dr. Katz said.

His team found that it did, at least in the 622 unilateral, primary, total knee replacement patients in their study. Overall, 62% were aged older than 65 years, 58% were women, 35% had a body mass index greater than 30 kg/m²; and about half had two or more comorbidities.

Their mean preoperative function score on the WOMAC (Western Ontario and McMaster Universities) osteoarthritis index was 47, and their mean preoperative WOMAC pain score was 41 (with 100 being the best score on the WOMAC index and 0 the worst possible).

Following the surgery, 15% of the patients had WOMAC pain scores lower than 50 at 3 months, which indicated severe pain. Dr. Katz and his team compared these patients with the other 85%.

The patients with severe pain at 3 months had mean WOMAC function scores of about 60 at both the 1- and 2-year follow-up. The 85% of patients without severe pain had function scores in the mid-70s at both points.

Similarly, the severe pain group had WOMAC pain scores in the mid-60s at both 1 and 2 years. The other patients had mean WOMAC scores in the mid-80s at both points.

About 60% in the severe pain group said they couldn’t walk five blocks at both 1 and 2 years. Among those without severe pain, about 40% said that couldn’t walk five blocks at both points.

Finally, about a quarter of patients in the severe pain group were dissatisfied with their surgery at both 1 and 2 years afterward. About 5% of patients without severe postsurgical pain were dissatisfied with their operation at 1 year and about 3% were dissatisfied at 2 years. All the results were statistically significant (P less than .001).

The patients came from 12 referral centers in the United States, the United Kingdom, and Australia. The study did not capture the reasons for the pain, the problems with implants (if any), or the patients’ psychiatric histories.

Dr. Katz said that the 5-year findings appear to be similar to the 1- and 2-year results, but there weren’t enough data to include them in the analysis.

The congress was sponsored by the Osteoarthritis Research Society International. The study was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases. The data used in the analysis came from a multicenter, prospective cohort study sponsored by implant maker Stryker Corp. about a decade ago. Dr. Katz said he has no disclosures.

SAN DIEGO – Physicians overall are doing a less than stellar job of recognizing glucocorticoid-induced osteoporosis and prescribing bone-protective medications for affected or high-risk patients.

But some specialties are doing significantly better than others.

“While many rheumatologists and endocrinologists are doing a pretty good job, we know that collectively, internationally, this still continues to be a major therapeutic dilemma, and steroids still constitute the most common form of drug-induced osteoporosis,” said Dr. Kenneth G. Saag.

He cited a recent as-yet-unpublished study led by University of Alabama epidemiologist Ryan C. Outman, who, together with his coinvestigators, analyzed 106,310 patients in the Medco Pharmacy database who were at high risk for glucocorticoid-induced osteoporosis (GIOP) by virtue of having received more than 90 days of systemic corticosteroid therapy during the study years of 2004-2007.

The primary study outcome was prescription of any form of anti-GIOP medication within 12 months after patients reached the 90-day mark of steroid therapy. The 12-month mark is the point on the therapeutic time line when, according to American College of Rheumatology guidelines, physicians are supposed to initiate bone-protective therapy.

The steroids were prescribed by a total of 53,766 physicians. During the 12-month window, the physicians ordered bone mineral density tests in just 4.6% of the patients, and 23.5% of patients received a prescription for an anti-GIOP medication, according to Dr. Saag, professor of medicine and epidemiology at the University of Alabama, Birmingham.

The results varied by physician specialty. In a multivariate analysis adjusted for patient age, gender, and other potential confounders, endocrinologists were 61% more likely to prescribe anti-GIOP medication for patients having more than 90 days of exposure to systemic steroids than were internists, who served as the reference standard. Rheumatologists were 59% more likely than internists to prescribe therapy.

Nephrologists, pulmonologists, and gastroenterologists were 37%, 34%, and 15%, respectively, more likely to have prescribed bone-protective medications for their at-risk patients than were internists.

Dermatologists and physicians in all other specialties who prescribed steroids for longer than 90 days were, collectively, 22% less likely to introduce anti-GIOP therapy than were internists.

Rates of prescription of anti-GIOP medications were particularly low in men of all ages and in premenopausal women. During the 12 months after more than 90 days of exposure to systemic steroids, 36.8% of affected women aged 50 years or older were prescribed bone-protective medication, compared with 11.4% of affected women under age 50 years and 14.7% of men of any age, said Dr. Saag, who was not involved in the study.

“We've got a lot of work to do in terms of initiating therapy, but adherence is a big problem, too. Less than half of patients who start on any bone-protective drug are still taking it a year later,” he said.

Dr. Saag disclosed that he has received research grants from and serves as a paid consultant to Amgen, Eli Lilly, Merck, and Novartis.

SAN DIEGO – Physicians overall are doing a less than stellar job of recognizing glucocorticoid-induced osteoporosis and prescribing bone-protective medications for affected or high-risk patients.

But some specialties are doing significantly better than others.

“While many rheumatologists and endocrinologists are doing a pretty good job, we know that collectively, internationally, this still continues to be a major therapeutic dilemma, and steroids still constitute the most common form of drug-induced osteoporosis,” said Dr. Kenneth G. Saag.

He cited a recent as-yet-unpublished study led by University of Alabama epidemiologist Ryan C. Outman, who, together with his coinvestigators, analyzed 106,310 patients in the Medco Pharmacy database who were at high risk for glucocorticoid-induced osteoporosis (GIOP) by virtue of having received more than 90 days of systemic corticosteroid therapy during the study years of 2004-2007.

The primary study outcome was prescription of any form of anti-GIOP medication within 12 months after patients reached the 90-day mark of steroid therapy. The 12-month mark is the point on the therapeutic time line when, according to American College of Rheumatology guidelines, physicians are supposed to initiate bone-protective therapy.

The steroids were prescribed by a total of 53,766 physicians. During the 12-month window, the physicians ordered bone mineral density tests in just 4.6% of the patients, and 23.5% of patients received a prescription for an anti-GIOP medication, according to Dr. Saag, professor of medicine and epidemiology at the University of Alabama, Birmingham.

The results varied by physician specialty. In a multivariate analysis adjusted for patient age, gender, and other potential confounders, endocrinologists were 61% more likely to prescribe anti-GIOP medication for patients having more than 90 days of exposure to systemic steroids than were internists, who served as the reference standard. Rheumatologists were 59% more likely than internists to prescribe therapy.

Nephrologists, pulmonologists, and gastroenterologists were 37%, 34%, and 15%, respectively, more likely to have prescribed bone-protective medications for their at-risk patients than were internists.

Dermatologists and physicians in all other specialties who prescribed steroids for longer than 90 days were, collectively, 22% less likely to introduce anti-GIOP therapy than were internists.

Rates of prescription of anti-GIOP medications were particularly low in men of all ages and in premenopausal women. During the 12 months after more than 90 days of exposure to systemic steroids, 36.8% of affected women aged 50 years or older were prescribed bone-protective medication, compared with 11.4% of affected women under age 50 years and 14.7% of men of any age, said Dr. Saag, who was not involved in the study.

“We've got a lot of work to do in terms of initiating therapy, but adherence is a big problem, too. Less than half of patients who start on any bone-protective drug are still taking it a year later,” he said.

Dr. Saag disclosed that he has received research grants from and serves as a paid consultant to Amgen, Eli Lilly, Merck, and Novartis.

SAN DIEGO – Physicians overall are doing a less than stellar job of recognizing glucocorticoid-induced osteoporosis and prescribing bone-protective medications for affected or high-risk patients.

But some specialties are doing significantly better than others.

“While many rheumatologists and endocrinologists are doing a pretty good job, we know that collectively, internationally, this still continues to be a major therapeutic dilemma, and steroids still constitute the most common form of drug-induced osteoporosis,” said Dr. Kenneth G. Saag.

He cited a recent as-yet-unpublished study led by University of Alabama epidemiologist Ryan C. Outman, who, together with his coinvestigators, analyzed 106,310 patients in the Medco Pharmacy database who were at high risk for glucocorticoid-induced osteoporosis (GIOP) by virtue of having received more than 90 days of systemic corticosteroid therapy during the study years of 2004-2007.

The primary study outcome was prescription of any form of anti-GIOP medication within 12 months after patients reached the 90-day mark of steroid therapy. The 12-month mark is the point on the therapeutic time line when, according to American College of Rheumatology guidelines, physicians are supposed to initiate bone-protective therapy.

The steroids were prescribed by a total of 53,766 physicians. During the 12-month window, the physicians ordered bone mineral density tests in just 4.6% of the patients, and 23.5% of patients received a prescription for an anti-GIOP medication, according to Dr. Saag, professor of medicine and epidemiology at the University of Alabama, Birmingham.

The results varied by physician specialty. In a multivariate analysis adjusted for patient age, gender, and other potential confounders, endocrinologists were 61% more likely to prescribe anti-GIOP medication for patients having more than 90 days of exposure to systemic steroids than were internists, who served as the reference standard. Rheumatologists were 59% more likely than internists to prescribe therapy.

Nephrologists, pulmonologists, and gastroenterologists were 37%, 34%, and 15%, respectively, more likely to have prescribed bone-protective medications for their at-risk patients than were internists.

Dermatologists and physicians in all other specialties who prescribed steroids for longer than 90 days were, collectively, 22% less likely to introduce anti-GIOP therapy than were internists.

Rates of prescription of anti-GIOP medications were particularly low in men of all ages and in premenopausal women. During the 12 months after more than 90 days of exposure to systemic steroids, 36.8% of affected women aged 50 years or older were prescribed bone-protective medication, compared with 11.4% of affected women under age 50 years and 14.7% of men of any age, said Dr. Saag, who was not involved in the study.

“We've got a lot of work to do in terms of initiating therapy, but adherence is a big problem, too. Less than half of patients who start on any bone-protective drug are still taking it a year later,” he said.

Dr. Saag disclosed that he has received research grants from and serves as a paid consultant to Amgen, Eli Lilly, Merck, and Novartis.

SAN DIEGO – Lateral wedge shoe insoles reduce the gait load on the inside of the knee but fail to lessen pain long term in patients with medial knee osteoarthritis.

A British research team thinks it may have solved the mystery. It seems the inserts work only in the subset of patients who have flatter feet and who plant their heels more squarely when they walk, rather than rolling their foot to the outside, said lead investigator Graham Chapman, Ph.D., at the World Congress on Osteoarthritis.

Previous studies (BMJ 2011;342:d2912) seem to have "grouped everyone together and assumed they are going to respond to wearing a lateral wedge," said Dr. Chapman, a research fellow in biomechanics at the University of Salford (England).

That was not the case when he and his colleagues analyzed 33 patients who had medial knee osteoarthritis (OA) and a Kellgren-Lawrence grade 2 or 3. Their mean age was 59 years, their mean body mass index was 32.2 kg/m², and 42% (14) were women.

Patients "who walked more on the lateral hindfoot and those with pes cavus [high arch] were unlikely to respond to lateral wedges."

In 13 (39%) of the patients, the inserts did not help. Their use actually increased the load on the inside of the knee, as measured by the external knee adduction moment. In the remaining patients, use of the 5-degree lateral wedge insoles – which look much like any shoe insole except for a "fat bit on outside," Dr. Chapman said – reduced the adduction moment by a mean of 4.1%.

The researchers next looked to see how those who did not benefit from the insoles differed from those who did benefit.

The 13 patients who did not benefit were likely to have more contact on their lateral heel as they walked (about 19 cm² vs. about 17.5 cm²) and higher medial arches (with mean subarch angles of about 104 degrees vs. about 111 degrees in those who benefited from the inserts). The findings were statistically significant.

Patients "who walked more on the lateral hindfoot and those with pes cavus [high arch] were unlikely to respond to lateral wedges. Excluding persons whose foot dynamics make them unlikely to respond to insoles may leave a large group of patients who can experience their potential therapeutic benefits," the researchers concluded in their abstract.

The next step is a randomized trial to see if people who fit the profile of responders truly do have less pain when they wear shoes with lateral wedges rather than control shoes.

The ultimate goal is to help clinicians predict who will benefit from the insoles, Dr. Chapman said at the meeting, which was sponsored by the Osteoarthritis Research Society International.

Dr. Chapman said he has no disclosures. The work was funded by Arthritis Research UK.

SAN DIEGO – Lateral wedge shoe insoles reduce the gait load on the inside of the knee but fail to lessen pain long term in patients with medial knee osteoarthritis.

A British research team thinks it may have solved the mystery. It seems the inserts work only in the subset of patients who have flatter feet and who plant their heels more squarely when they walk, rather than rolling their foot to the outside, said lead investigator Graham Chapman, Ph.D., at the World Congress on Osteoarthritis.

Previous studies (BMJ 2011;342:d2912) seem to have "grouped everyone together and assumed they are going to respond to wearing a lateral wedge," said Dr. Chapman, a research fellow in biomechanics at the University of Salford (England).

That was not the case when he and his colleagues analyzed 33 patients who had medial knee osteoarthritis (OA) and a Kellgren-Lawrence grade 2 or 3. Their mean age was 59 years, their mean body mass index was 32.2 kg/m², and 42% (14) were women.

Patients "who walked more on the lateral hindfoot and those with pes cavus [high arch] were unlikely to respond to lateral wedges."

In 13 (39%) of the patients, the inserts did not help. Their use actually increased the load on the inside of the knee, as measured by the external knee adduction moment. In the remaining patients, use of the 5-degree lateral wedge insoles – which look much like any shoe insole except for a "fat bit on outside," Dr. Chapman said – reduced the adduction moment by a mean of 4.1%.

The researchers next looked to see how those who did not benefit from the insoles differed from those who did benefit.

The 13 patients who did not benefit were likely to have more contact on their lateral heel as they walked (about 19 cm² vs. about 17.5 cm²) and higher medial arches (with mean subarch angles of about 104 degrees vs. about 111 degrees in those who benefited from the inserts). The findings were statistically significant.

Patients "who walked more on the lateral hindfoot and those with pes cavus [high arch] were unlikely to respond to lateral wedges. Excluding persons whose foot dynamics make them unlikely to respond to insoles may leave a large group of patients who can experience their potential therapeutic benefits," the researchers concluded in their abstract.

The next step is a randomized trial to see if people who fit the profile of responders truly do have less pain when they wear shoes with lateral wedges rather than control shoes.

The ultimate goal is to help clinicians predict who will benefit from the insoles, Dr. Chapman said at the meeting, which was sponsored by the Osteoarthritis Research Society International.

Dr. Chapman said he has no disclosures. The work was funded by Arthritis Research UK.

SAN DIEGO – Lateral wedge shoe insoles reduce the gait load on the inside of the knee but fail to lessen pain long term in patients with medial knee osteoarthritis.

A British research team thinks it may have solved the mystery. It seems the inserts work only in the subset of patients who have flatter feet and who plant their heels more squarely when they walk, rather than rolling their foot to the outside, said lead investigator Graham Chapman, Ph.D., at the World Congress on Osteoarthritis.

Previous studies (BMJ 2011;342:d2912) seem to have "grouped everyone together and assumed they are going to respond to wearing a lateral wedge," said Dr. Chapman, a research fellow in biomechanics at the University of Salford (England).

That was not the case when he and his colleagues analyzed 33 patients who had medial knee osteoarthritis (OA) and a Kellgren-Lawrence grade 2 or 3. Their mean age was 59 years, their mean body mass index was 32.2 kg/m², and 42% (14) were women.

Patients "who walked more on the lateral hindfoot and those with pes cavus [high arch] were unlikely to respond to lateral wedges."

In 13 (39%) of the patients, the inserts did not help. Their use actually increased the load on the inside of the knee, as measured by the external knee adduction moment. In the remaining patients, use of the 5-degree lateral wedge insoles – which look much like any shoe insole except for a "fat bit on outside," Dr. Chapman said – reduced the adduction moment by a mean of 4.1%.

The researchers next looked to see how those who did not benefit from the insoles differed from those who did benefit.

The 13 patients who did not benefit were likely to have more contact on their lateral heel as they walked (about 19 cm² vs. about 17.5 cm²) and higher medial arches (with mean subarch angles of about 104 degrees vs. about 111 degrees in those who benefited from the inserts). The findings were statistically significant.

Patients "who walked more on the lateral hindfoot and those with pes cavus [high arch] were unlikely to respond to lateral wedges. Excluding persons whose foot dynamics make them unlikely to respond to insoles may leave a large group of patients who can experience their potential therapeutic benefits," the researchers concluded in their abstract.

The next step is a randomized trial to see if people who fit the profile of responders truly do have less pain when they wear shoes with lateral wedges rather than control shoes.

The ultimate goal is to help clinicians predict who will benefit from the insoles, Dr. Chapman said at the meeting, which was sponsored by the Osteoarthritis Research Society International.

Dr. Chapman said he has no disclosures. The work was funded by Arthritis Research UK.

SAN DIEGO – Separating an osteoarthritic knee joint for 2 months – that is, stretching the top of the tibia away from the base of the femur and holding the bones in place with pins set into an external fixation frame – stimulates the joint to produce new cartilage, thereby reducing pain and improving function for at least 2 years, according to findings from a small European pilot study.

The 20 patients in the trial were all facing knee replacement due to osteoarthritis (OA); the technique, known as knee joint distraction, has postponed surgery for 2 years and counting in the subjects. The hope is the patients will never need an artificial knee, according to senior investigator Dr. Floris Lafeber, a professor of experimental rheumatology at the University Medical Center Utrecht (the Netherlands).

Their minimum joint space width increased from a baseline mean of 1.0 mm to 1.8 mm at 2 years. Patients started the trial with, on average, about 22% of their subchondral bone denuded; that dropped to about 8% at 2 years.

In short, there was an "astonishing increase in cartilage volume," Dr. Lafeber said at the World Congress on Osteoarthritis, which was sponsored by the Osteoarthritis Research Society International.

Meanwhile, total WOMAC (Western Ontario and McMaster Universities) osteoarthritis index scores increased from about 45% at baseline to about 78% at 2 years, with improvements in WOMAC pain, function, and stiffness subscales. Visual Analog Scale pain scores improved from 73 at baseline to 28 at 2 years. The results were statistically significant.

The technique, which had been used in the past for ankle OAs, "looks very promising" for osteoarthritic knees, Dr. Lafeber said. The 1 year results have been previously published (Ann. Rheum. Dis. 2011;70:1441-6; Internal Medicine News, August 2011, p. 22).

His team will next pit knee distraction against total knee replacement and osteotomy in two randomized trials. The researchers will keep tracking the original 20 patients as well. "We are now having follow-up of the first patients for more than 4 years, and no prostheses are placed yet," Dr. Lafeber said.

The researchers plan "more sophisticated MRIs to look at the quality of the cartilage," although the increased joint space on weight-bearing x-rays suggests mechanical competence. Biomarker analysis also suggests "the quality of the cartilage has a hyaline aspect," according to Dr. Lafeber.

The 20 patients’ average age was 49 years; 11 were women. All had end-stage, unilateral knee OA with severe pain and cartilage damage. Patients with major problems in both knees were excluded from the study.

In a variation of the Ilizarov procedure, a tube with internal coil springs was placed on each side of the patients’ osteoarthritic knees, bridging the joints. Joints were then distracted to 5 mm over a few days. Full weight bearing was allowed. The tubes and pins were removed after 2 months.

The theory is that temporarily unloading the knee prevents additional wear and tear and allows cartilage to start repairing itself.

Pin sites became infected in 17 of the 20 patients, and were treated with local and oral antibiotics. Dr. Lafeber said he and his colleagues hope that technique refinements will reduce the infection rate.

Dr. Lafeber said he had no disclosures. The work was supported by the Dutch Arthritis Association.

SAN DIEGO – Separating an osteoarthritic knee joint for 2 months – that is, stretching the top of the tibia away from the base of the femur and holding the bones in place with pins set into an external fixation frame – stimulates the joint to produce new cartilage, thereby reducing pain and improving function for at least 2 years, according to findings from a small European pilot study.

The 20 patients in the trial were all facing knee replacement due to osteoarthritis (OA); the technique, known as knee joint distraction, has postponed surgery for 2 years and counting in the subjects. The hope is the patients will never need an artificial knee, according to senior investigator Dr. Floris Lafeber, a professor of experimental rheumatology at the University Medical Center Utrecht (the Netherlands).

Their minimum joint space width increased from a baseline mean of 1.0 mm to 1.8 mm at 2 years. Patients started the trial with, on average, about 22% of their subchondral bone denuded; that dropped to about 8% at 2 years.

In short, there was an "astonishing increase in cartilage volume," Dr. Lafeber said at the World Congress on Osteoarthritis, which was sponsored by the Osteoarthritis Research Society International.

Meanwhile, total WOMAC (Western Ontario and McMaster Universities) osteoarthritis index scores increased from about 45% at baseline to about 78% at 2 years, with improvements in WOMAC pain, function, and stiffness subscales. Visual Analog Scale pain scores improved from 73 at baseline to 28 at 2 years. The results were statistically significant.

The technique, which had been used in the past for ankle OAs, "looks very promising" for osteoarthritic knees, Dr. Lafeber said. The 1 year results have been previously published (Ann. Rheum. Dis. 2011;70:1441-6; Internal Medicine News, August 2011, p. 22).

His team will next pit knee distraction against total knee replacement and osteotomy in two randomized trials. The researchers will keep tracking the original 20 patients as well. "We are now having follow-up of the first patients for more than 4 years, and no prostheses are placed yet," Dr. Lafeber said.

The researchers plan "more sophisticated MRIs to look at the quality of the cartilage," although the increased joint space on weight-bearing x-rays suggests mechanical competence. Biomarker analysis also suggests "the quality of the cartilage has a hyaline aspect," according to Dr. Lafeber.

The 20 patients’ average age was 49 years; 11 were women. All had end-stage, unilateral knee OA with severe pain and cartilage damage. Patients with major problems in both knees were excluded from the study.

In a variation of the Ilizarov procedure, a tube with internal coil springs was placed on each side of the patients’ osteoarthritic knees, bridging the joints. Joints were then distracted to 5 mm over a few days. Full weight bearing was allowed. The tubes and pins were removed after 2 months.

The theory is that temporarily unloading the knee prevents additional wear and tear and allows cartilage to start repairing itself.

Pin sites became infected in 17 of the 20 patients, and were treated with local and oral antibiotics. Dr. Lafeber said he and his colleagues hope that technique refinements will reduce the infection rate.

Dr. Lafeber said he had no disclosures. The work was supported by the Dutch Arthritis Association.

SAN DIEGO – Separating an osteoarthritic knee joint for 2 months – that is, stretching the top of the tibia away from the base of the femur and holding the bones in place with pins set into an external fixation frame – stimulates the joint to produce new cartilage, thereby reducing pain and improving function for at least 2 years, according to findings from a small European pilot study.

The 20 patients in the trial were all facing knee replacement due to osteoarthritis (OA); the technique, known as knee joint distraction, has postponed surgery for 2 years and counting in the subjects. The hope is the patients will never need an artificial knee, according to senior investigator Dr. Floris Lafeber, a professor of experimental rheumatology at the University Medical Center Utrecht (the Netherlands).

Their minimum joint space width increased from a baseline mean of 1.0 mm to 1.8 mm at 2 years. Patients started the trial with, on average, about 22% of their subchondral bone denuded; that dropped to about 8% at 2 years.

In short, there was an "astonishing increase in cartilage volume," Dr. Lafeber said at the World Congress on Osteoarthritis, which was sponsored by the Osteoarthritis Research Society International.

Meanwhile, total WOMAC (Western Ontario and McMaster Universities) osteoarthritis index scores increased from about 45% at baseline to about 78% at 2 years, with improvements in WOMAC pain, function, and stiffness subscales. Visual Analog Scale pain scores improved from 73 at baseline to 28 at 2 years. The results were statistically significant.

The technique, which had been used in the past for ankle OAs, "looks very promising" for osteoarthritic knees, Dr. Lafeber said. The 1 year results have been previously published (Ann. Rheum. Dis. 2011;70:1441-6; Internal Medicine News, August 2011, p. 22).

His team will next pit knee distraction against total knee replacement and osteotomy in two randomized trials. The researchers will keep tracking the original 20 patients as well. "We are now having follow-up of the first patients for more than 4 years, and no prostheses are placed yet," Dr. Lafeber said.

The researchers plan "more sophisticated MRIs to look at the quality of the cartilage," although the increased joint space on weight-bearing x-rays suggests mechanical competence. Biomarker analysis also suggests "the quality of the cartilage has a hyaline aspect," according to Dr. Lafeber.

The 20 patients’ average age was 49 years; 11 were women. All had end-stage, unilateral knee OA with severe pain and cartilage damage. Patients with major problems in both knees were excluded from the study.

In a variation of the Ilizarov procedure, a tube with internal coil springs was placed on each side of the patients’ osteoarthritic knees, bridging the joints. Joints were then distracted to 5 mm over a few days. Full weight bearing was allowed. The tubes and pins were removed after 2 months.

The theory is that temporarily unloading the knee prevents additional wear and tear and allows cartilage to start repairing itself.

Pin sites became infected in 17 of the 20 patients, and were treated with local and oral antibiotics. Dr. Lafeber said he and his colleagues hope that technique refinements will reduce the infection rate.

Dr. Lafeber said he had no disclosures. The work was supported by the Dutch Arthritis Association.

SAN DIEGO – A 3-month exercise program appears to have significantly delayed, and perhaps even prevented, hip replacements in a Norwegian randomized, controlled trial.

Within the first 6 years after participating in the exercise program, 40% (22) of patients had gotten a hip replacement; in the control group, 57% (31) had gotten an artificial hip during the follow-up period.

The 109 patients who started the trial had mild to moderate hip pain and were not yet eligible for surgery. They went through three 90-minute education sessions where they were told to stay active, even if it hurts a bit.

The message was "don’t be afraid of your pain. It won’t damage your cartilage" and might improve symptoms, said researcher Linda Fernandes, Ph.D., a physiotherapist at Diakonhjemmet Hospital in Oslo.

Immediately after the education part of the trial, 55 patients were randomized to a 3-month, supervised strength and flexibility exercise program.

"We pushed them quite hard," Dr. Fernandes said at the World Congress on Osteoarthritis. They "had to exercise at 70-80% of [their] maximum" for over 1 hour. Patients attended, on average, about twice a week; 80% completed 20 sessions.

In spring 2011 – 3.5 to 6 years after the exercise program – Dr. Fernandes and her associates telephoned patients in both arms of the trial to learn if they had a subsequent hip replacement.

The results were "kind of surprising to us," said senior author and physiotherapist May Arna Risberg, Ph.D., a professor in the sport medicine department at the Norwegian School of Sport Sciences in Oslo.

"If you exercise early, maybe you can prevent [hip] surgery long-term."

Among patients who had gotten an artificial hip, the median time to surgery in the exercise group was 5.4 years; it was 3.5 years in the control group. Exercise patients also had significantly less pain and better function, not only in the spring of 2011 but also at earlier follow-up points.

The two groups were evenly balanced, with no significant baseline differences in age, gender, joint space, Harris Hip Score, and self-reported pain and function.

"There is something going on here, although it is hard for me to understand it," Dr. Risberg said. "I think it has something to do with the 12-week program. We also saw that the progression of radiographic osteoarthritis was significantly worse in the patients that did not get supervised exercise. The mechanism for how this works we don’t know."

Perhaps patients in the exercise group learned, instead of just being told, that a reasonable amount of hip pain is tolerable. Maybe they were less afraid to be active and so stayed active, while their peers in the control arm of the study did not, Dr. Fernandes said.

"If you exercise early" in the course of the disease, "maybe you can prevent surgery long-term," she said. "But that is just a theory. We can’t really say anything about cause and effect here."

Patients worked on 26 exercises, including squats, crunches, cycling, and stepping. If they learned how to balance on one foot, patients were put on a balance pad to make it harder. If they got to the point where they could do eight leg curls, "we increased the load," Dr. Fernandes said. If pain got to be too much, they backed off the exercise until it diminished (Phys. Ther. 2010;90:592-601).

The team collected data on cardiovascular and other physiologic parameters in the two groups but has not analyzed them yet. They also surveyed how active patients were at various follow-up points, but lost confidence in their assessment scale – the Physical Activity Scale for the Elderly (PASE) – after one of the researchers determined it was not valid for their setting.

To date, there have been few randomized controlled trials to see if exercise helps hip osteoarthritis, though exercise is known to help knee osteoarthritis, Dr. Risberg said.

Patients in the study were 40-80 years old and had hip pain for more than 3 months, radiographically confirmed hip osteoarthritis, Harris Hip Scores of 60-95, and no previous joint replacements.

The next best step would be a larger randomized trial, Dr. Fernandes said, but in the meantime the team is analyzing patients’ biomechanics to see if they correlate with the outcomes.

"We have to look into this further," Dr. Fernandes said.

The congress was sponsored by the Osteoarthritis Research Society International.

The study was funded by the Norwegian Foundation for Health and Rehabilitation, the Norwegian Rheumatism Association, and the South-Eastern Norway Regional Health Authority. The researchers said they have no disclosures.

SAN DIEGO – A 3-month exercise program appears to have significantly delayed, and perhaps even prevented, hip replacements in a Norwegian randomized, controlled trial.

Within the first 6 years after participating in the exercise program, 40% (22) of patients had gotten a hip replacement; in the control group, 57% (31) had gotten an artificial hip during the follow-up period.

The 109 patients who started the trial had mild to moderate hip pain and were not yet eligible for surgery. They went through three 90-minute education sessions where they were told to stay active, even if it hurts a bit.

The message was "don’t be afraid of your pain. It won’t damage your cartilage" and might improve symptoms, said researcher Linda Fernandes, Ph.D., a physiotherapist at Diakonhjemmet Hospital in Oslo.

Immediately after the education part of the trial, 55 patients were randomized to a 3-month, supervised strength and flexibility exercise program.

"We pushed them quite hard," Dr. Fernandes said at the World Congress on Osteoarthritis. They "had to exercise at 70-80% of [their] maximum" for over 1 hour. Patients attended, on average, about twice a week; 80% completed 20 sessions.

In spring 2011 – 3.5 to 6 years after the exercise program – Dr. Fernandes and her associates telephoned patients in both arms of the trial to learn if they had a subsequent hip replacement.

The results were "kind of surprising to us," said senior author and physiotherapist May Arna Risberg, Ph.D., a professor in the sport medicine department at the Norwegian School of Sport Sciences in Oslo.

"If you exercise early, maybe you can prevent [hip] surgery long-term."

Among patients who had gotten an artificial hip, the median time to surgery in the exercise group was 5.4 years; it was 3.5 years in the control group. Exercise patients also had significantly less pain and better function, not only in the spring of 2011 but also at earlier follow-up points.

The two groups were evenly balanced, with no significant baseline differences in age, gender, joint space, Harris Hip Score, and self-reported pain and function.

"There is something going on here, although it is hard for me to understand it," Dr. Risberg said. "I think it has something to do with the 12-week program. We also saw that the progression of radiographic osteoarthritis was significantly worse in the patients that did not get supervised exercise. The mechanism for how this works we don’t know."

Perhaps patients in the exercise group learned, instead of just being told, that a reasonable amount of hip pain is tolerable. Maybe they were less afraid to be active and so stayed active, while their peers in the control arm of the study did not, Dr. Fernandes said.

"If you exercise early" in the course of the disease, "maybe you can prevent surgery long-term," she said. "But that is just a theory. We can’t really say anything about cause and effect here."

Patients worked on 26 exercises, including squats, crunches, cycling, and stepping. If they learned how to balance on one foot, patients were put on a balance pad to make it harder. If they got to the point where they could do eight leg curls, "we increased the load," Dr. Fernandes said. If pain got to be too much, they backed off the exercise until it diminished (Phys. Ther. 2010;90:592-601).

The team collected data on cardiovascular and other physiologic parameters in the two groups but has not analyzed them yet. They also surveyed how active patients were at various follow-up points, but lost confidence in their assessment scale – the Physical Activity Scale for the Elderly (PASE) – after one of the researchers determined it was not valid for their setting.

To date, there have been few randomized controlled trials to see if exercise helps hip osteoarthritis, though exercise is known to help knee osteoarthritis, Dr. Risberg said.

Patients in the study were 40-80 years old and had hip pain for more than 3 months, radiographically confirmed hip osteoarthritis, Harris Hip Scores of 60-95, and no previous joint replacements.

The next best step would be a larger randomized trial, Dr. Fernandes said, but in the meantime the team is analyzing patients’ biomechanics to see if they correlate with the outcomes.

"We have to look into this further," Dr. Fernandes said.

The congress was sponsored by the Osteoarthritis Research Society International.

The study was funded by the Norwegian Foundation for Health and Rehabilitation, the Norwegian Rheumatism Association, and the South-Eastern Norway Regional Health Authority. The researchers said they have no disclosures.

SAN DIEGO – A 3-month exercise program appears to have significantly delayed, and perhaps even prevented, hip replacements in a Norwegian randomized, controlled trial.

Within the first 6 years after participating in the exercise program, 40% (22) of patients had gotten a hip replacement; in the control group, 57% (31) had gotten an artificial hip during the follow-up period.

The 109 patients who started the trial had mild to moderate hip pain and were not yet eligible for surgery. They went through three 90-minute education sessions where they were told to stay active, even if it hurts a bit.

The message was "don’t be afraid of your pain. It won’t damage your cartilage" and might improve symptoms, said researcher Linda Fernandes, Ph.D., a physiotherapist at Diakonhjemmet Hospital in Oslo.

Immediately after the education part of the trial, 55 patients were randomized to a 3-month, supervised strength and flexibility exercise program.

"We pushed them quite hard," Dr. Fernandes said at the World Congress on Osteoarthritis. They "had to exercise at 70-80% of [their] maximum" for over 1 hour. Patients attended, on average, about twice a week; 80% completed 20 sessions.

In spring 2011 – 3.5 to 6 years after the exercise program – Dr. Fernandes and her associates telephoned patients in both arms of the trial to learn if they had a subsequent hip replacement.

The results were "kind of surprising to us," said senior author and physiotherapist May Arna Risberg, Ph.D., a professor in the sport medicine department at the Norwegian School of Sport Sciences in Oslo.

"If you exercise early, maybe you can prevent [hip] surgery long-term."

Among patients who had gotten an artificial hip, the median time to surgery in the exercise group was 5.4 years; it was 3.5 years in the control group. Exercise patients also had significantly less pain and better function, not only in the spring of 2011 but also at earlier follow-up points.

The two groups were evenly balanced, with no significant baseline differences in age, gender, joint space, Harris Hip Score, and self-reported pain and function.

"There is something going on here, although it is hard for me to understand it," Dr. Risberg said. "I think it has something to do with the 12-week program. We also saw that the progression of radiographic osteoarthritis was significantly worse in the patients that did not get supervised exercise. The mechanism for how this works we don’t know."

Perhaps patients in the exercise group learned, instead of just being told, that a reasonable amount of hip pain is tolerable. Maybe they were less afraid to be active and so stayed active, while their peers in the control arm of the study did not, Dr. Fernandes said.

"If you exercise early" in the course of the disease, "maybe you can prevent surgery long-term," she said. "But that is just a theory. We can’t really say anything about cause and effect here."

Patients worked on 26 exercises, including squats, crunches, cycling, and stepping. If they learned how to balance on one foot, patients were put on a balance pad to make it harder. If they got to the point where they could do eight leg curls, "we increased the load," Dr. Fernandes said. If pain got to be too much, they backed off the exercise until it diminished (Phys. Ther. 2010;90:592-601).

The team collected data on cardiovascular and other physiologic parameters in the two groups but has not analyzed them yet. They also surveyed how active patients were at various follow-up points, but lost confidence in their assessment scale – the Physical Activity Scale for the Elderly (PASE) – after one of the researchers determined it was not valid for their setting.

To date, there have been few randomized controlled trials to see if exercise helps hip osteoarthritis, though exercise is known to help knee osteoarthritis, Dr. Risberg said.

Patients in the study were 40-80 years old and had hip pain for more than 3 months, radiographically confirmed hip osteoarthritis, Harris Hip Scores of 60-95, and no previous joint replacements.

The next best step would be a larger randomized trial, Dr. Fernandes said, but in the meantime the team is analyzing patients’ biomechanics to see if they correlate with the outcomes.

"We have to look into this further," Dr. Fernandes said.

The congress was sponsored by the Osteoarthritis Research Society International.

The study was funded by the Norwegian Foundation for Health and Rehabilitation, the Norwegian Rheumatism Association, and the South-Eastern Norway Regional Health Authority. The researchers said they have no disclosures.

SAN DIEGO – It’s important to pay attention to both knees – the knee that was operated on as well as the knee that wasn’t operated on – after a unilateral, medial, opening-wedge high tibial osteotomy.

Joint load increases in the nonoperative knee following the procedure, which is used to correct varus malalignment, according to researchers at the University of Western Ontario, London.

The findings apply to a subset of opening wedge high tibial osteotomy (HTO) patients, those who present initially with significant bilateral varus, but in whom symptoms were severe enough to require surgery in only one knee.

In 38 such patients, 2 years after surgery "we noted a 0.25% [of body weight times height] increase in peak knee adduction moment in the non-operative limb," as well as a slight increase in vertical ground reaction force, said lead author and physiotherapist Angelo Boulougouris, a biomechanics doctoral candidate at the school. The external knee adduction moment measured during gait is an indicator of tibiofemoral joint osteoarthritis progression.

"The major point is to pay attention to what’s happening to the opposite knee, to make sure you are not ignoring it and focusing your entire treatment plan on just looking at the operative knee," he said.

An unloader brace, for instance, might be appropriate for the nonoperative knee, among other possible interventions, he said. An unloader brace is designed to lessen the stress on a knee with medial compartment knee osteoarthritis. This use of the unloader brace would be to prevent development of knee OA rather than to ease the discomfort associated with established disease

During HTO, a wedge of the cancellous bone allograft is placed in the proximal end of the tibia, correcting both varus deformity and weight distribution through the knee. "Our surgeons are particularly careful to not over-correct," Mr. Boulougouris said.

Of the 38 patients, 32 were men, the average age was about 50 and average body mass index (BMI) about 27 kg/m². Varus malalignment in the operative limb was about 11 degrees and Kellgren-Lawrence grades ranged from 1 to 3. Varus malalignment was about 8 degrees in the nonoperative limb, with Kellgren-Lawrence grades ranging from 0 to 1.

Patients did well overall, reporting decreased pain and improved quality of life at 2 years. Varus malalignment was corrected in the operative limb, and unchanged in the nonoperative limb.

Knee adduction moment had also significantly decreased on the operative side (mean change, –1.99 % of body weight times height), but increased slightly on the nonoperative side. Gait changes also increased load on the nonoperative knee, including increased gait speed (mean change, 0.08 m/sec) and decreased trunk lean to the stance-phase limb (mean change, –1.43 degrees). The findings were statistically significant.

The reasons could include the operation itself, disease progression in the nonoperative knee, or the fact that patients had gained an average of about 4.5 pounds at the 2-year follow-up.

Mr. Boulougouris said that he doubts the weight gain had much to do with it. He and his colleagues hope to tease out the contributing factors in a regression analysis.

The study was funded by the Canadian Institute of Health Research. Mr. Boulougouris reported that he had no relevant financial conflicts of interest to disclose.

SAN DIEGO – It’s important to pay attention to both knees – the knee that was operated on as well as the knee that wasn’t operated on – after a unilateral, medial, opening-wedge high tibial osteotomy.

Joint load increases in the nonoperative knee following the procedure, which is used to correct varus malalignment, according to researchers at the University of Western Ontario, London.

The findings apply to a subset of opening wedge high tibial osteotomy (HTO) patients, those who present initially with significant bilateral varus, but in whom symptoms were severe enough to require surgery in only one knee.

In 38 such patients, 2 years after surgery "we noted a 0.25% [of body weight times height] increase in peak knee adduction moment in the non-operative limb," as well as a slight increase in vertical ground reaction force, said lead author and physiotherapist Angelo Boulougouris, a biomechanics doctoral candidate at the school. The external knee adduction moment measured during gait is an indicator of tibiofemoral joint osteoarthritis progression.

"The major point is to pay attention to what’s happening to the opposite knee, to make sure you are not ignoring it and focusing your entire treatment plan on just looking at the operative knee," he said.

An unloader brace, for instance, might be appropriate for the nonoperative knee, among other possible interventions, he said. An unloader brace is designed to lessen the stress on a knee with medial compartment knee osteoarthritis. This use of the unloader brace would be to prevent development of knee OA rather than to ease the discomfort associated with established disease

During HTO, a wedge of the cancellous bone allograft is placed in the proximal end of the tibia, correcting both varus deformity and weight distribution through the knee. "Our surgeons are particularly careful to not over-correct," Mr. Boulougouris said.

Of the 38 patients, 32 were men, the average age was about 50 and average body mass index (BMI) about 27 kg/m². Varus malalignment in the operative limb was about 11 degrees and Kellgren-Lawrence grades ranged from 1 to 3. Varus malalignment was about 8 degrees in the nonoperative limb, with Kellgren-Lawrence grades ranging from 0 to 1.

Patients did well overall, reporting decreased pain and improved quality of life at 2 years. Varus malalignment was corrected in the operative limb, and unchanged in the nonoperative limb.

Knee adduction moment had also significantly decreased on the operative side (mean change, –1.99 % of body weight times height), but increased slightly on the nonoperative side. Gait changes also increased load on the nonoperative knee, including increased gait speed (mean change, 0.08 m/sec) and decreased trunk lean to the stance-phase limb (mean change, –1.43 degrees). The findings were statistically significant.

The reasons could include the operation itself, disease progression in the nonoperative knee, or the fact that patients had gained an average of about 4.5 pounds at the 2-year follow-up.

Mr. Boulougouris said that he doubts the weight gain had much to do with it. He and his colleagues hope to tease out the contributing factors in a regression analysis.

The study was funded by the Canadian Institute of Health Research. Mr. Boulougouris reported that he had no relevant financial conflicts of interest to disclose.

SAN DIEGO – It’s important to pay attention to both knees – the knee that was operated on as well as the knee that wasn’t operated on – after a unilateral, medial, opening-wedge high tibial osteotomy.

Joint load increases in the nonoperative knee following the procedure, which is used to correct varus malalignment, according to researchers at the University of Western Ontario, London.

The findings apply to a subset of opening wedge high tibial osteotomy (HTO) patients, those who present initially with significant bilateral varus, but in whom symptoms were severe enough to require surgery in only one knee.

In 38 such patients, 2 years after surgery "we noted a 0.25% [of body weight times height] increase in peak knee adduction moment in the non-operative limb," as well as a slight increase in vertical ground reaction force, said lead author and physiotherapist Angelo Boulougouris, a biomechanics doctoral candidate at the school. The external knee adduction moment measured during gait is an indicator of tibiofemoral joint osteoarthritis progression.

"The major point is to pay attention to what’s happening to the opposite knee, to make sure you are not ignoring it and focusing your entire treatment plan on just looking at the operative knee," he said.

An unloader brace, for instance, might be appropriate for the nonoperative knee, among other possible interventions, he said. An unloader brace is designed to lessen the stress on a knee with medial compartment knee osteoarthritis. This use of the unloader brace would be to prevent development of knee OA rather than to ease the discomfort associated with established disease

During HTO, a wedge of the cancellous bone allograft is placed in the proximal end of the tibia, correcting both varus deformity and weight distribution through the knee. "Our surgeons are particularly careful to not over-correct," Mr. Boulougouris said.

Of the 38 patients, 32 were men, the average age was about 50 and average body mass index (BMI) about 27 kg/m². Varus malalignment in the operative limb was about 11 degrees and Kellgren-Lawrence grades ranged from 1 to 3. Varus malalignment was about 8 degrees in the nonoperative limb, with Kellgren-Lawrence grades ranging from 0 to 1.

Patients did well overall, reporting decreased pain and improved quality of life at 2 years. Varus malalignment was corrected in the operative limb, and unchanged in the nonoperative limb.

Knee adduction moment had also significantly decreased on the operative side (mean change, –1.99 % of body weight times height), but increased slightly on the nonoperative side. Gait changes also increased load on the nonoperative knee, including increased gait speed (mean change, 0.08 m/sec) and decreased trunk lean to the stance-phase limb (mean change, –1.43 degrees). The findings were statistically significant.

The reasons could include the operation itself, disease progression in the nonoperative knee, or the fact that patients had gained an average of about 4.5 pounds at the 2-year follow-up.

Mr. Boulougouris said that he doubts the weight gain had much to do with it. He and his colleagues hope to tease out the contributing factors in a regression analysis.

The study was funded by the Canadian Institute of Health Research. Mr. Boulougouris reported that he had no relevant financial conflicts of interest to disclose.