Wearing lateral wedge insoles reduces osteoarthritis knee pain

 

LIVERPOOL, ENGLAND – Lateral wedge insoles reduced osteoarthritis knee pain to a greater extent than did wearing neutral insoles in a randomized, controlled, crossover trial.

An overall significant treatment difference of 0.7 points on a 0-10 numerical rating scale global pain score was observed when patients with painful medial osteoarthritis (OA) wore lateral wedge insoles compared with when they wore neutral insoles in their own shoes (95% confidence interval [CI], 0.1-1.2 points; P = .02).

The study’s findings are in contrast to previous research that has found no benefit of lateral wedge insoles in patients with medial compartment knee OA (JAMA. 2013;310[7]:722-30) because patients were specifically prescreened to find those who would be biomechanical responders, David T. Felson, MD, said at the World Congress on Osteoarthritis.

“There is increased medial load in medial knee OA, and that is thought to cause pain and medial joint damage,” Dr. Felson, of Boston University, said at the congress, sponsored by the Osteoarthritis Research Society International.

There is evidence, however, that by moving the center of pressure laterally during walking with the use of lateral wedge insoles, the external knee adduction movement (KAM) can be reduced by around 5%-6%, which in turn can reduce the load across the medial component.

“We asked the following question: ‘If patients were screened to remove those with painful patellofemoral OA and those who did not show a biomechanical response to lateral wedge insoles, would lateral wedge insoles actually reduce pain?’ ” Dr. Felson noted.

Sara Freeman/MDedge News

For inclusion in the trial, patients needed to be aged between 40 and 80 years and have x-rays showing Kellgren-Lawrence grade 2-4 OA with definite medial and no lateral joint space narrowing in the last 2 years. They then also needed to have experienced knee pain that was rated at least 4 or more on a 0-10 numerical rating scale in the last week. Patients then had to be examined by an experienced physiotherapist or have x-rays to exclude patellofemoral OA and inflammatory arthritis.

 

All patients then underwent biomechanical assessment which consisted of motion analysis screening. Patients who did not show at least a 2% decrease in KAM after wearing the lateral wedge insoles versus the neutral insoles were excluded.

Of 112 subjects who were screened for the study, there remained 62 with a mean age of 64 years and body mass index of 28 kg/m² who could be randomized. The subjects, 73% of whom were male, were randomized to first wear either neutral insoles or insoles with a lateral five-degree wedge for 8 weeks and then, after an 8-week washout period, to wear the other type of insole for a further 8 weeks. Participants wore the insoles for at least 4 hours a day and for a median of 7 hours per day.

Results showed that the lateral wedge insoles reduced KAM by 7.5% versus their own shoes and by 6.6% versus a neutral insole, and of the 62 patients randomized, 56 completed the trial. Two patients in each group stopped participating in the trial because of adverse events, which with lateral wedge insoles were cramps in the calf and foot and increased pain in the knee, and with the neutral insoles included a blister and increased pain in knee and foot.

At baseline, the mean global knee pain score in the last week was 5.46. After use of the lateral wedge or neutral insoles, this fell to a respective 4.2 and 4.9.

 

Patients were asked to report on the pain experience during a nominated activity. The baseline value for pain was 6.18, which decreased to 4.9 and 5.8 in the two groups, respectively, with an overall treatment difference of 0.9 (P = .001) favoring the use of the lateral wedge insoles.

There was improvement in knee pain assessed by the Knee injury and Osteoarthritis Outcomes Score from a baseline of 55 points to a score of 60.6 for lateral wedge and 58.9 for the neutral insoles, a between group difference of –1.7 (P = .45).

“Lateral wedge insoles reduce knee pain in selected subjects with painful medial OA, those without patellofemoral OA, and those who are biomechanical responders to these insoles,” Dr. Felson said.

“I think the importance of this study is that it opens the door to a treatment that we were frustrated wasn’t working,” Dr. Felson said. Insoles are inexpensive, safe, and potentially widely useful, and the research paves the way for further study of these insoles and for perhaps for shoes that could modify knee loads.

 

The findings open the door to “stratified approaches to knee OA that may also offer us an avenue toward success in developing treatments,” he added.

The National Institute for Health Research, Arthritis Research U.K., and the National Institutes of Health sponsored the study. Dr. Felson had no disclosures.

SOURCE: Felson D et al. Osteoarthritis Cartilage. 2018:26(1):S17. Abstract 14.

 

LIVERPOOL, ENGLAND – Lateral wedge insoles reduced osteoarthritis knee pain to a greater extent than did wearing neutral insoles in a randomized, controlled, crossover trial.

An overall significant treatment difference of 0.7 points on a 0-10 numerical rating scale global pain score was observed when patients with painful medial osteoarthritis (OA) wore lateral wedge insoles compared with when they wore neutral insoles in their own shoes (95% confidence interval [CI], 0.1-1.2 points; P = .02).

The study’s findings are in contrast to previous research that has found no benefit of lateral wedge insoles in patients with medial compartment knee OA (JAMA. 2013;310[7]:722-30) because patients were specifically prescreened to find those who would be biomechanical responders, David T. Felson, MD, said at the World Congress on Osteoarthritis.

“There is increased medial load in medial knee OA, and that is thought to cause pain and medial joint damage,” Dr. Felson, of Boston University, said at the congress, sponsored by the Osteoarthritis Research Society International.

There is evidence, however, that by moving the center of pressure laterally during walking with the use of lateral wedge insoles, the external knee adduction movement (KAM) can be reduced by around 5%-6%, which in turn can reduce the load across the medial component.

“We asked the following question: ‘If patients were screened to remove those with painful patellofemoral OA and those who did not show a biomechanical response to lateral wedge insoles, would lateral wedge insoles actually reduce pain?’ ” Dr. Felson noted.

Sara Freeman/MDedge News

For inclusion in the trial, patients needed to be aged between 40 and 80 years and have x-rays showing Kellgren-Lawrence grade 2-4 OA with definite medial and no lateral joint space narrowing in the last 2 years. They then also needed to have experienced knee pain that was rated at least 4 or more on a 0-10 numerical rating scale in the last week. Patients then had to be examined by an experienced physiotherapist or have x-rays to exclude patellofemoral OA and inflammatory arthritis.

 

All patients then underwent biomechanical assessment which consisted of motion analysis screening. Patients who did not show at least a 2% decrease in KAM after wearing the lateral wedge insoles versus the neutral insoles were excluded.

Of 112 subjects who were screened for the study, there remained 62 with a mean age of 64 years and body mass index of 28 kg/m² who could be randomized. The subjects, 73% of whom were male, were randomized to first wear either neutral insoles or insoles with a lateral five-degree wedge for 8 weeks and then, after an 8-week washout period, to wear the other type of insole for a further 8 weeks. Participants wore the insoles for at least 4 hours a day and for a median of 7 hours per day.

Results showed that the lateral wedge insoles reduced KAM by 7.5% versus their own shoes and by 6.6% versus a neutral insole, and of the 62 patients randomized, 56 completed the trial. Two patients in each group stopped participating in the trial because of adverse events, which with lateral wedge insoles were cramps in the calf and foot and increased pain in the knee, and with the neutral insoles included a blister and increased pain in knee and foot.

At baseline, the mean global knee pain score in the last week was 5.46. After use of the lateral wedge or neutral insoles, this fell to a respective 4.2 and 4.9.

 

Patients were asked to report on the pain experience during a nominated activity. The baseline value for pain was 6.18, which decreased to 4.9 and 5.8 in the two groups, respectively, with an overall treatment difference of 0.9 (P = .001) favoring the use of the lateral wedge insoles.

There was improvement in knee pain assessed by the Knee injury and Osteoarthritis Outcomes Score from a baseline of 55 points to a score of 60.6 for lateral wedge and 58.9 for the neutral insoles, a between group difference of –1.7 (P = .45).

“Lateral wedge insoles reduce knee pain in selected subjects with painful medial OA, those without patellofemoral OA, and those who are biomechanical responders to these insoles,” Dr. Felson said.

“I think the importance of this study is that it opens the door to a treatment that we were frustrated wasn’t working,” Dr. Felson said. Insoles are inexpensive, safe, and potentially widely useful, and the research paves the way for further study of these insoles and for perhaps for shoes that could modify knee loads.

 

The findings open the door to “stratified approaches to knee OA that may also offer us an avenue toward success in developing treatments,” he added.

The National Institute for Health Research, Arthritis Research U.K., and the National Institutes of Health sponsored the study. Dr. Felson had no disclosures.

SOURCE: Felson D et al. Osteoarthritis Cartilage. 2018:26(1):S17. Abstract 14.

 

LIVERPOOL, ENGLAND – Lateral wedge insoles reduced osteoarthritis knee pain to a greater extent than did wearing neutral insoles in a randomized, controlled, crossover trial.

An overall significant treatment difference of 0.7 points on a 0-10 numerical rating scale global pain score was observed when patients with painful medial osteoarthritis (OA) wore lateral wedge insoles compared with when they wore neutral insoles in their own shoes (95% confidence interval [CI], 0.1-1.2 points; P = .02).

The study’s findings are in contrast to previous research that has found no benefit of lateral wedge insoles in patients with medial compartment knee OA (JAMA. 2013;310[7]:722-30) because patients were specifically prescreened to find those who would be biomechanical responders, David T. Felson, MD, said at the World Congress on Osteoarthritis.

“There is increased medial load in medial knee OA, and that is thought to cause pain and medial joint damage,” Dr. Felson, of Boston University, said at the congress, sponsored by the Osteoarthritis Research Society International.

There is evidence, however, that by moving the center of pressure laterally during walking with the use of lateral wedge insoles, the external knee adduction movement (KAM) can be reduced by around 5%-6%, which in turn can reduce the load across the medial component.

“We asked the following question: ‘If patients were screened to remove those with painful patellofemoral OA and those who did not show a biomechanical response to lateral wedge insoles, would lateral wedge insoles actually reduce pain?’ ” Dr. Felson noted.

Sara Freeman/MDedge News

For inclusion in the trial, patients needed to be aged between 40 and 80 years and have x-rays showing Kellgren-Lawrence grade 2-4 OA with definite medial and no lateral joint space narrowing in the last 2 years. They then also needed to have experienced knee pain that was rated at least 4 or more on a 0-10 numerical rating scale in the last week. Patients then had to be examined by an experienced physiotherapist or have x-rays to exclude patellofemoral OA and inflammatory arthritis.

 

All patients then underwent biomechanical assessment which consisted of motion analysis screening. Patients who did not show at least a 2% decrease in KAM after wearing the lateral wedge insoles versus the neutral insoles were excluded.

Of 112 subjects who were screened for the study, there remained 62 with a mean age of 64 years and body mass index of 28 kg/m² who could be randomized. The subjects, 73% of whom were male, were randomized to first wear either neutral insoles or insoles with a lateral five-degree wedge for 8 weeks and then, after an 8-week washout period, to wear the other type of insole for a further 8 weeks. Participants wore the insoles for at least 4 hours a day and for a median of 7 hours per day.

Results showed that the lateral wedge insoles reduced KAM by 7.5% versus their own shoes and by 6.6% versus a neutral insole, and of the 62 patients randomized, 56 completed the trial. Two patients in each group stopped participating in the trial because of adverse events, which with lateral wedge insoles were cramps in the calf and foot and increased pain in the knee, and with the neutral insoles included a blister and increased pain in knee and foot.

At baseline, the mean global knee pain score in the last week was 5.46. After use of the lateral wedge or neutral insoles, this fell to a respective 4.2 and 4.9.

 

Patients were asked to report on the pain experience during a nominated activity. The baseline value for pain was 6.18, which decreased to 4.9 and 5.8 in the two groups, respectively, with an overall treatment difference of 0.9 (P = .001) favoring the use of the lateral wedge insoles.

There was improvement in knee pain assessed by the Knee injury and Osteoarthritis Outcomes Score from a baseline of 55 points to a score of 60.6 for lateral wedge and 58.9 for the neutral insoles, a between group difference of –1.7 (P = .45).

“Lateral wedge insoles reduce knee pain in selected subjects with painful medial OA, those without patellofemoral OA, and those who are biomechanical responders to these insoles,” Dr. Felson said.

“I think the importance of this study is that it opens the door to a treatment that we were frustrated wasn’t working,” Dr. Felson said. Insoles are inexpensive, safe, and potentially widely useful, and the research paves the way for further study of these insoles and for perhaps for shoes that could modify knee loads.

 

The findings open the door to “stratified approaches to knee OA that may also offer us an avenue toward success in developing treatments,” he added.

The National Institute for Health Research, Arthritis Research U.K., and the National Institutes of Health sponsored the study. Dr. Felson had no disclosures.

SOURCE: Felson D et al. Osteoarthritis Cartilage. 2018:26(1):S17. Abstract 14.