Coleman S

The incidence of periprosthetic supracondylar fractures of the femur after total knee arthroplasty (TKA) ranges from 0.6% to 2.5%.¹ Treatment of periprosthetic fractures is often complicated by advanced patient age and osteoporosis, which frequently accompanies these fractures. Management of a periprosthetic fracture depends on the relation between the fracture site and the prosthesis, displacement of the prosthesis, integrity of the fixation of the prosthesis, extent of the bone loss caused by fracture comminution or preexisting osteolysis, general health of the patient, and surgeon expertise.^2,3 The aim is to achieve fracture union around a stable, well-aligned arthroplasty with preserved or restored bone stock and therefore to return the patient to previous level of function. Although nonoperative treatments have been shown to be successful,^4,5 in the great majority of cases surgical treatment is advised for these fractures.^6-10 In cases in which bone stock is adequate for fixation rather than replacement of the distal femur, 2 modalities are commonly used: retrograde intramedullary nailing and locking plates. Each has its drawbacks and advantages.^11,12

Although external fixation has been used in the treatment of distal femoral fractures,¹³ it is seldom considered in the treatment of periprosthetic fractures. Several authors have described cases that used external fixators, occasionally spanning the knee. The specific types of external fixators discussed in the literature have included ring fixators,^14-17 hybrid fixators,¹⁸ and uniplanar nonspanning fixators^14,19 (Table). Use of a simple anterior spanning external fixator in treating a periprosthetic femoral fracture has received little attention in the literature.

The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 54-year-old woman with previous total hip arthroplasty (THA) and ipsilateral TKA tripped on a carpet and sustained a comminuted fracture of the distal femur just above the TKA prosthesis (Figure 1). She was a Jehovah’s Witness and thus refused all blood products. She had an extensive history of osteoporosis, morbid obesity (5 feet tall, 250 pounds; body mass index, 49), diabetes, and rheumatoid arthritis. Evaluation by the internal medicine service revealed severe coronary artery disease on a stress thallium test and anemia with hematocrit of 24%. Given the patient’s medical comorbidities and religious status, and the location of the comminuted distal femur fracture, several treatment options were considered. First was nonoperative treatment with a cast or cast-brace (hinged cast). Because of her body habitus, however, we thought she would very likely experience skin complications, inadequate immobilization of the bone, and significant discomfort. Ultimately, use of a spanning external fixator was chosen as the safest course, given the significant medical risks accompanying a more extensive surgical reconstruction. With the spanning external fixator, the main risks were the inability to fully control fracture alignment and the potential introduction of infection into the functional THA. We thought that, by limiting the amount of time in the fixator and managing the pin site aggressively, we could minimize the risk for infection in this setting.

The procedure was performed with the patient under general anesthesia. During surgery, a lateral image of the femur was used to identify the distal end of the THA prosthesis. A level was marked 2 to 3 cm distal to the tip of this prosthesis, and another about 1 cm above the fracture (noted to be above the most proximal extent of the knee joint). These planned pin-entry sites were prepared from an anterior approach with incisions (using a No. 11 blade) of about 1 cm each. Blunt dissection was carried down to the femur. Each planned pin site was predrilled with a 3.5-mm drill; then, a 5-mm Shanz pin was placed. This process was repeated immediately distal to the tibial component and at the junction of the mid and distal thirds of the tibia (Figure 2). The preliminary external fixator frame was then applied. Once the reduction was satisfactory in the anteroposterior and lateral planes, the fixator clamps were tightened. A second row of bars was then incorporated.

Six weeks after surgery, radiographs showed early callus formation. Removing the external fixator and examining the knee under anesthesia confirmed there was no significant motion through the fracture site. A cast-brace (fiberglass thigh segment, fiberglass lower leg cast with hinged knee segment) was then applied. We remained concerned about skin complications but were encouraged by the early healing achieved with the fixator. The patient was started on a physical therapy program of gait training with a walker and toe-touch weight-bearing on the injured extremity. She also started a limited lower-extremity strengthening program. Three months after surgery, she was tolerating weight-bearing on the injured extremity with no pain. At 6 months, knee radiographs showed fracture consolidation with active range of motion of 10° to 120° and no pain (Figures 3A, 3B). Distal sensation, motor function, and vascular examination were normal. Two years after surgery, radiographs of the right knee showed minor malalignment in the coronal and sagittal planes (Figures 4A, 4B) and complete consolidation of the fracture.

Discussion

Periprosthetic fractures of the femur after TKA often occur in the setting of osteopenia, and some are associated with concurrent implant loosening. In most cases, these fractures require surgical stabilization. Nevertheless, the goals of treatment are to obtain and maintain anatomical alignment and stability to allow early range of motion. Nonoperative options include skeletal traction, cast, pins and plaster, and cast-brace.^3-5,20 Operative options include intramedullary fixation,^12,21 stabilization with various plates,^21-23 revision knee arthroplasty, and arthrodesis.¹ Treatment selection should be based on patient health, fracture displacement, comminution, osteopenia severity, and status of the prosthetic components.

The present case exemplifies some of the highest degrees of medical and surgical risk factors in people with a periprosthetic femoral fracture after TKA. Patients with rheumatoid arthritis, patients having corticosteroid treatment, patients of advanced age, and female patients are all at higher risk for supracondylar femoral fracture.⁹ Our patient had these risk factors on a background of anemia and extensive coronary artery disease. Given her past medical history and refusal of blood products out of religious belief, we thought she was too high risk for extensive surgical treatment for her fracture. In addition, she was not an ideal candidate for nonoperative treatment, as a periprosthetic fracture typically is treated with surgical revision or open reduction and internal fixation. Therefore, we selected an unconventional treatment modality, typically used as a temporizing measure in severe fractures around the knee—a spanning external fixator worn for 6 weeks and a cast-brace for an additional 6 weeks. This led to successful clinical and radiographic outcomes. We consider spanning external fixation a viable option for periprosthetic fractures after TKA in morbidly obese patients with relatively well-aligned fractures and extremely high risk for medical complications associated with traditional open surgery.

The incidence of periprosthetic supracondylar fractures of the femur after total knee arthroplasty (TKA) ranges from 0.6% to 2.5%.¹ Treatment of periprosthetic fractures is often complicated by advanced patient age and osteoporosis, which frequently accompanies these fractures. Management of a periprosthetic fracture depends on the relation between the fracture site and the prosthesis, displacement of the prosthesis, integrity of the fixation of the prosthesis, extent of the bone loss caused by fracture comminution or preexisting osteolysis, general health of the patient, and surgeon expertise.^2,3 The aim is to achieve fracture union around a stable, well-aligned arthroplasty with preserved or restored bone stock and therefore to return the patient to previous level of function. Although nonoperative treatments have been shown to be successful,^4,5 in the great majority of cases surgical treatment is advised for these fractures.^6-10 In cases in which bone stock is adequate for fixation rather than replacement of the distal femur, 2 modalities are commonly used: retrograde intramedullary nailing and locking plates. Each has its drawbacks and advantages.^11,12

Although external fixation has been used in the treatment of distal femoral fractures,¹³ it is seldom considered in the treatment of periprosthetic fractures. Several authors have described cases that used external fixators, occasionally spanning the knee. The specific types of external fixators discussed in the literature have included ring fixators,^14-17 hybrid fixators,¹⁸ and uniplanar nonspanning fixators^14,19 (Table). Use of a simple anterior spanning external fixator in treating a periprosthetic femoral fracture has received little attention in the literature.

The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 54-year-old woman with previous total hip arthroplasty (THA) and ipsilateral TKA tripped on a carpet and sustained a comminuted fracture of the distal femur just above the TKA prosthesis (Figure 1). She was a Jehovah’s Witness and thus refused all blood products. She had an extensive history of osteoporosis, morbid obesity (5 feet tall, 250 pounds; body mass index, 49), diabetes, and rheumatoid arthritis. Evaluation by the internal medicine service revealed severe coronary artery disease on a stress thallium test and anemia with hematocrit of 24%. Given the patient’s medical comorbidities and religious status, and the location of the comminuted distal femur fracture, several treatment options were considered. First was nonoperative treatment with a cast or cast-brace (hinged cast). Because of her body habitus, however, we thought she would very likely experience skin complications, inadequate immobilization of the bone, and significant discomfort. Ultimately, use of a spanning external fixator was chosen as the safest course, given the significant medical risks accompanying a more extensive surgical reconstruction. With the spanning external fixator, the main risks were the inability to fully control fracture alignment and the potential introduction of infection into the functional THA. We thought that, by limiting the amount of time in the fixator and managing the pin site aggressively, we could minimize the risk for infection in this setting.

The procedure was performed with the patient under general anesthesia. During surgery, a lateral image of the femur was used to identify the distal end of the THA prosthesis. A level was marked 2 to 3 cm distal to the tip of this prosthesis, and another about 1 cm above the fracture (noted to be above the most proximal extent of the knee joint). These planned pin-entry sites were prepared from an anterior approach with incisions (using a No. 11 blade) of about 1 cm each. Blunt dissection was carried down to the femur. Each planned pin site was predrilled with a 3.5-mm drill; then, a 5-mm Shanz pin was placed. This process was repeated immediately distal to the tibial component and at the junction of the mid and distal thirds of the tibia (Figure 2). The preliminary external fixator frame was then applied. Once the reduction was satisfactory in the anteroposterior and lateral planes, the fixator clamps were tightened. A second row of bars was then incorporated.

Six weeks after surgery, radiographs showed early callus formation. Removing the external fixator and examining the knee under anesthesia confirmed there was no significant motion through the fracture site. A cast-brace (fiberglass thigh segment, fiberglass lower leg cast with hinged knee segment) was then applied. We remained concerned about skin complications but were encouraged by the early healing achieved with the fixator. The patient was started on a physical therapy program of gait training with a walker and toe-touch weight-bearing on the injured extremity. She also started a limited lower-extremity strengthening program. Three months after surgery, she was tolerating weight-bearing on the injured extremity with no pain. At 6 months, knee radiographs showed fracture consolidation with active range of motion of 10° to 120° and no pain (Figures 3A, 3B). Distal sensation, motor function, and vascular examination were normal. Two years after surgery, radiographs of the right knee showed minor malalignment in the coronal and sagittal planes (Figures 4A, 4B) and complete consolidation of the fracture.

Discussion

Periprosthetic fractures of the femur after TKA often occur in the setting of osteopenia, and some are associated with concurrent implant loosening. In most cases, these fractures require surgical stabilization. Nevertheless, the goals of treatment are to obtain and maintain anatomical alignment and stability to allow early range of motion. Nonoperative options include skeletal traction, cast, pins and plaster, and cast-brace.^3-5,20 Operative options include intramedullary fixation,^12,21 stabilization with various plates,^21-23 revision knee arthroplasty, and arthrodesis.¹ Treatment selection should be based on patient health, fracture displacement, comminution, osteopenia severity, and status of the prosthetic components.

The present case exemplifies some of the highest degrees of medical and surgical risk factors in people with a periprosthetic femoral fracture after TKA. Patients with rheumatoid arthritis, patients having corticosteroid treatment, patients of advanced age, and female patients are all at higher risk for supracondylar femoral fracture.⁹ Our patient had these risk factors on a background of anemia and extensive coronary artery disease. Given her past medical history and refusal of blood products out of religious belief, we thought she was too high risk for extensive surgical treatment for her fracture. In addition, she was not an ideal candidate for nonoperative treatment, as a periprosthetic fracture typically is treated with surgical revision or open reduction and internal fixation. Therefore, we selected an unconventional treatment modality, typically used as a temporizing measure in severe fractures around the knee—a spanning external fixator worn for 6 weeks and a cast-brace for an additional 6 weeks. This led to successful clinical and radiographic outcomes. We consider spanning external fixation a viable option for periprosthetic fractures after TKA in morbidly obese patients with relatively well-aligned fractures and extremely high risk for medical complications associated with traditional open surgery.

The incidence of periprosthetic supracondylar fractures of the femur after total knee arthroplasty (TKA) ranges from 0.6% to 2.5%.¹ Treatment of periprosthetic fractures is often complicated by advanced patient age and osteoporosis, which frequently accompanies these fractures. Management of a periprosthetic fracture depends on the relation between the fracture site and the prosthesis, displacement of the prosthesis, integrity of the fixation of the prosthesis, extent of the bone loss caused by fracture comminution or preexisting osteolysis, general health of the patient, and surgeon expertise.^2,3 The aim is to achieve fracture union around a stable, well-aligned arthroplasty with preserved or restored bone stock and therefore to return the patient to previous level of function. Although nonoperative treatments have been shown to be successful,^4,5 in the great majority of cases surgical treatment is advised for these fractures.^6-10 In cases in which bone stock is adequate for fixation rather than replacement of the distal femur, 2 modalities are commonly used: retrograde intramedullary nailing and locking plates. Each has its drawbacks and advantages.^11,12

Although external fixation has been used in the treatment of distal femoral fractures,¹³ it is seldom considered in the treatment of periprosthetic fractures. Several authors have described cases that used external fixators, occasionally spanning the knee. The specific types of external fixators discussed in the literature have included ring fixators,^14-17 hybrid fixators,¹⁸ and uniplanar nonspanning fixators^14,19 (Table). Use of a simple anterior spanning external fixator in treating a periprosthetic femoral fracture has received little attention in the literature.

The patient provided written informed consent for print and electronic publication of this case report.

Case Report

A 54-year-old woman with previous total hip arthroplasty (THA) and ipsilateral TKA tripped on a carpet and sustained a comminuted fracture of the distal femur just above the TKA prosthesis (Figure 1). She was a Jehovah’s Witness and thus refused all blood products. She had an extensive history of osteoporosis, morbid obesity (5 feet tall, 250 pounds; body mass index, 49), diabetes, and rheumatoid arthritis. Evaluation by the internal medicine service revealed severe coronary artery disease on a stress thallium test and anemia with hematocrit of 24%. Given the patient’s medical comorbidities and religious status, and the location of the comminuted distal femur fracture, several treatment options were considered. First was nonoperative treatment with a cast or cast-brace (hinged cast). Because of her body habitus, however, we thought she would very likely experience skin complications, inadequate immobilization of the bone, and significant discomfort. Ultimately, use of a spanning external fixator was chosen as the safest course, given the significant medical risks accompanying a more extensive surgical reconstruction. With the spanning external fixator, the main risks were the inability to fully control fracture alignment and the potential introduction of infection into the functional THA. We thought that, by limiting the amount of time in the fixator and managing the pin site aggressively, we could minimize the risk for infection in this setting.

The procedure was performed with the patient under general anesthesia. During surgery, a lateral image of the femur was used to identify the distal end of the THA prosthesis. A level was marked 2 to 3 cm distal to the tip of this prosthesis, and another about 1 cm above the fracture (noted to be above the most proximal extent of the knee joint). These planned pin-entry sites were prepared from an anterior approach with incisions (using a No. 11 blade) of about 1 cm each. Blunt dissection was carried down to the femur. Each planned pin site was predrilled with a 3.5-mm drill; then, a 5-mm Shanz pin was placed. This process was repeated immediately distal to the tibial component and at the junction of the mid and distal thirds of the tibia (Figure 2). The preliminary external fixator frame was then applied. Once the reduction was satisfactory in the anteroposterior and lateral planes, the fixator clamps were tightened. A second row of bars was then incorporated.

Six weeks after surgery, radiographs showed early callus formation. Removing the external fixator and examining the knee under anesthesia confirmed there was no significant motion through the fracture site. A cast-brace (fiberglass thigh segment, fiberglass lower leg cast with hinged knee segment) was then applied. We remained concerned about skin complications but were encouraged by the early healing achieved with the fixator. The patient was started on a physical therapy program of gait training with a walker and toe-touch weight-bearing on the injured extremity. She also started a limited lower-extremity strengthening program. Three months after surgery, she was tolerating weight-bearing on the injured extremity with no pain. At 6 months, knee radiographs showed fracture consolidation with active range of motion of 10° to 120° and no pain (Figures 3A, 3B). Distal sensation, motor function, and vascular examination were normal. Two years after surgery, radiographs of the right knee showed minor malalignment in the coronal and sagittal planes (Figures 4A, 4B) and complete consolidation of the fracture.

Discussion

Periprosthetic fractures of the femur after TKA often occur in the setting of osteopenia, and some are associated with concurrent implant loosening. In most cases, these fractures require surgical stabilization. Nevertheless, the goals of treatment are to obtain and maintain anatomical alignment and stability to allow early range of motion. Nonoperative options include skeletal traction, cast, pins and plaster, and cast-brace.^3-5,20 Operative options include intramedullary fixation,^12,21 stabilization with various plates,^21-23 revision knee arthroplasty, and arthrodesis.¹ Treatment selection should be based on patient health, fracture displacement, comminution, osteopenia severity, and status of the prosthetic components.

The present case exemplifies some of the highest degrees of medical and surgical risk factors in people with a periprosthetic femoral fracture after TKA. Patients with rheumatoid arthritis, patients having corticosteroid treatment, patients of advanced age, and female patients are all at higher risk for supracondylar femoral fracture.⁹ Our patient had these risk factors on a background of anemia and extensive coronary artery disease. Given her past medical history and refusal of blood products out of religious belief, we thought she was too high risk for extensive surgical treatment for her fracture. In addition, she was not an ideal candidate for nonoperative treatment, as a periprosthetic fracture typically is treated with surgical revision or open reduction and internal fixation. Therefore, we selected an unconventional treatment modality, typically used as a temporizing measure in severe fractures around the knee—a spanning external fixator worn for 6 weeks and a cast-brace for an additional 6 weeks. This led to successful clinical and radiographic outcomes. We consider spanning external fixation a viable option for periprosthetic fractures after TKA in morbidly obese patients with relatively well-aligned fractures and extremely high risk for medical complications associated with traditional open surgery.

With health care costs increasing and economic resources diminishing, substantial efforts have been directed toward improving the quality of care delivered in a cost-effective manner. For a total hip arthroplasty (THA) performed in the United States between 1997 and 2001, total hospital cost, including direct and indirect costs, was estimated as averaging $13,339.¹ In 2012, this cost was estimated to be between $43,000 and $100,000.² This overall cost estimate, along with the rate at which the procedure is performed, may present an opportunity for cost savings.

Length of hospital stay (LHS) is an important outcome measure that has been assessed for optimal health care delivery. Prolonged LHS implies increased resource expenditure. Therefore, it is crucial to identify factors associated with prolonged LHS in order to reduce costs. Investigations have identified factors shown to affect LHS after THA. These factors include advanced age, medical comorbidities, obesity, intraoperative time, anesthesia technique, surgical site infection, and incision length.^3-7

We conducted a study to identify the patient and clinical factors that affect LHS and to determine whether the specific day of the week when primary THA is performed affects LHS at a large tertiary-care university-based medical center. This information may prove valuable to hospital planning committees allotting operating room time and floor staffing for elective surgical cases with the goal of delivering cost-efficient care.

Materials and Methods

After obtaining institutional review board approval for this study, we retrospectively analyzed all primary unilateral THAs (273 patients) performed at our institution, a tertiary-care teaching hospital, between January 2010 and May 2011. The majority of the surgeries were performed through a posterior approach, and a majority of the implants were uncemented. All patients followed the same postoperative clinical pathway; no fast-track pathway was used.

The combined effects of day of surgery, American Society of Anesthesiologists (ASA) grade, anesthesia type, intraoperative time, estimated blood loss (EBL), incision length, presence of complications, age, sex, body mass index (BMI), disposition (skilled nursing facility vs home), transfusion, hematocrit, and hemoglobin on LHS were analyzed using a multiple quasi-Poisson regression model that included a random effect for surgeon. A Poisson regression model (typically used for count data) was deemed appropriate, as LHS was reported in whole days; a quasi-Poisson model relaxes the Poisson model assumption that the variance in the data equals the mean. The random effect for surgeon adjusts for any correlation among data from surgeries conducted by the same surgeon.

All complications were recorded. Complications included excess wound drainage,⁸ wound hematoma (a case of excess wound drainage necessitated surgical irrigation and débridement), new-onset atrial fibrillation, non-ST-elevation myocardial infarction, atrial flutter, urinary tract infection, pulmonary embolism, disseminated intravascular coagulation, hepatic decompensation as manifested by elevated liver enzymes, pneumonia, gastroesophageal reflux disease, gastric ulcer, sepsis, delirium, hypotension, and dysphagia.

The parameter estimates reported from the quasi-Poisson regression model are incident rate ratios (IRRs). IRR represents the change in expected LHS for a 1-unit change in a continuous variable (eg, age) or between categories of a categorical variable (eg, sex). IRR higher than 1 indicates higher risk as the continuous variable increases or a higher risk relative to the comparator group for a categorical variable. IRR lower than 1 indicates lower risk.

Results

Table 1 summarizes patient characteristics by surgical day. Mean LHS ranged from a minimum of 3.7 days for patients who had surgery on a Monday to a maximum of 4.2 days for patients who had surgery on a Thursday.

Table 2 summarizes results of the multivariate quasi-Poisson regression analysis of LHS by surgical day, ASA grade, anesthesia type, intraoperative time, EBL, incision length, presence of complications, age, sex, and BMI. With all other variables included in the model adjusted for, each additional point in ASA grade was associated with a 12% increase in LHS (P = .019). In addition, with all other variables included in the model adjusted for, LHS was 33% longer for patients with complications than for patients without complications (P < .001) and 12% longer for patients who received transfusions than for patients who did not (P = .046). LHS did not differ significantly by the day of the week when the surgery was performed (P = .496). Disposition status (skilled nursing facility vs home) as a variable to determine LHS did approach statistical significance (P = .061). As the effect size we were interested in detecting was an approximate 1-day increase in LHS for patients who had surgery later in the week relative to patients who had surgery earlier in the week, our sample size was adequate (range of required sample size, 200-300 patients). This study had 99% power to detect a 27% increase in LHS (equivalent to 1 day or more).

Discussion

This retrospective analysis explored how day of the week of primary THA affected LHS. Various confounders, such as surgery and patient factors, were also examined so that the multivariate analysis would be able to isolate the effects of surgical day of the week on LHS.

Effect of day of the week of primary THA on LHS was not investigated in the United States before. In Denmark, in a study similar to ours, Husted and colleagues⁴ found a 400% increase in the probability of LHS of more than 3 days when patients operated on a Thursday were compared with patients operated on a Friday. The authors reasoned that the Thursday patients most likely had a compromised physical therapy protocol owing to the inclusion of weekend days in the crucial postoperative period. LHS was consequently increased so that these patients would achieve their therapy goals before being discharged. Our investigation showed that LHS did not differ significantly by surgical day of the week. Although patients who had THA on a Thursday had 15% longer LHS than patients who had THA on a Monday, this difference was not statistically significant (P = .496), even though the study was adequately powered to detect a change in LHS of a whole day.

Table 3 summarizes the difference in quantum of workforce on weekdays and weekends at our center. The physiotherapy sessions were reduced to 1 per day. Nurse practitioners and discharge planners were not available on weekends, and some skilled nursing facilities and rehabilitation centers refused to accept patients on weekends. At our center, a teaching institute, the clinical duties of discharge planners and nurse practitioners were assumed by licensed physicians (orthopedic residents covering the arthroplasty team on weekends). This could be one of several possible reasons our study failed to detect statistically significant difference between the 2 groups. This kind of alternative arrangement may not be possible at many other centers. However, our study results provide a reasonably accurate logistical aim with regard to workforce availability on weekends to keep LHS in check.

The importance of giving patients an inpatient physical therapy regimen in timely fashion has been demonstrated in other studies. Munin and colleagues,⁹ in a randomized controlled trial, evaluated 71 patients who underwent elective hip and knee arthroplasty and received 2 different physical therapy regimens. Patients started their in-treatment physical therapy on postoperative day 3 or 7. Mean total LHS was shorter in the 3-day group (11.7 days) than in the 7-day group (14.5 days) (P < .001). Brusco and colleagues¹⁰ also showed that introducing weekend physical therapy services significantly reduced LHS in patients who underwent THA (10.6 vs 12.5 days; P < .05). Rapoport and Judd-Van Eerd¹¹ retrospectively analyzed orthopedic surgery LHS, comparing patients treated in a community hospital during a period of 5-days-a-week physical therapy coverage and patients treated during a period of 7-days-a-week physical therapy coverage. The 7-days-a-week group had significantly statistically shorter mean LHS.

Another rationale for analyzing the impact of surgical day of the week stems from the expectation that patients who undergo THA on Wednesday or Thursday and are scheduled to have physical therapy or be discharged on the weekend may be affected not only by reduced inpatient weekend physical therapy coverage but also by difficulties in being transferred to a skilled nursing facility or rehabilitation center if not discharged home. In our study, the patients who were to be discharged to a rehabilitation center were delayed by 12.5%, and this statistic trended toward significance (P = .061). Our literature search did not turn up any studies, US or European, specifically linking LHS to discharge disposition (whether patient is discharged home or to a skilled nursing facility or rehabilitation center).

Reduced medical staffing on weekends may not only affect the quality of in-hospital patient care but may also result in unnecessary delays in discharge. Chow and Szeto¹² retrospectively analyzed the medical records of all acute medical wards in a university hospital and compared weekend discharge rates before and after implementation of a work ordinance, which decreased the physician workforce by half on Saturday and Sunday. Results showed a 2.7% decrease in the weekend discharge rate after the work ordinance was established. The number of weekday discharges between the 2 time periods did not differ. Increasing the workforce availability presents a challenge in academic medical centers where graduate medical education enforces a strict cap on resident duty hours. Under these circumstances, a more feasible approach to decreasing LHS for THA patients is for surgical planning committees to provide the joint replacement services with operative block times early in the workweek.

Even though the organizational structure at our center is strong enough to provide for an adequate weekend workforce to discharge these patients, this study had a few limitations. We could not study readmission rates and whether the transition to home health and home physical therapy for the patients who went home was seamless.

We found that only 3 patient characteristics had a significant effect on LHS: higher ASA grade (a surrogate for medical comorbidities), requirement for blood transfusion, and presence of complications. In Denmark, blood transfusion increased the likelihood of longer LHS by 400%.⁴ In that study, patients who were ASA grades 1 and 2 had 60% and 20% decreased likelihood of LHS of more than 3 days compared with patients who were ASA grade 3. Similarly, in 2009, Mears and colleagues⁵ found 4 factors related to increased LHS: female sex (P < .001), older age (P < .001), higher ASA grade (3, P < .01; 4, P  < .001), and increased blood loss (P < .001).⁵

Conclusion

Over the past decade, there has been a significant reduction in LHS after THA, from a mean of 3 weeks to 4 days. Advances in implant technology, delivery of in-home physical therapy, and improved prevention and management of postoperative complications have contributed to this decline. Early identification of patients with transfusion requirements may be helpful in expediting their care. Although guidelines are in place for transfusion, further study in this regard may be needed. It is important to continue to identify surgery and patient factors that affect LHS, but the importance of organizational and planning issues in optimizing hospital health care expenditures cannot be ignored. Further study of providing a specific discharge planning service to identify patients’ discharge needs (home vs extended care facility) may help reduce LHS.

With health care costs increasing and economic resources diminishing, substantial efforts have been directed toward improving the quality of care delivered in a cost-effective manner. For a total hip arthroplasty (THA) performed in the United States between 1997 and 2001, total hospital cost, including direct and indirect costs, was estimated as averaging $13,339.¹ In 2012, this cost was estimated to be between $43,000 and $100,000.² This overall cost estimate, along with the rate at which the procedure is performed, may present an opportunity for cost savings.

Length of hospital stay (LHS) is an important outcome measure that has been assessed for optimal health care delivery. Prolonged LHS implies increased resource expenditure. Therefore, it is crucial to identify factors associated with prolonged LHS in order to reduce costs. Investigations have identified factors shown to affect LHS after THA. These factors include advanced age, medical comorbidities, obesity, intraoperative time, anesthesia technique, surgical site infection, and incision length.^3-7

We conducted a study to identify the patient and clinical factors that affect LHS and to determine whether the specific day of the week when primary THA is performed affects LHS at a large tertiary-care university-based medical center. This information may prove valuable to hospital planning committees allotting operating room time and floor staffing for elective surgical cases with the goal of delivering cost-efficient care.

Materials and Methods

After obtaining institutional review board approval for this study, we retrospectively analyzed all primary unilateral THAs (273 patients) performed at our institution, a tertiary-care teaching hospital, between January 2010 and May 2011. The majority of the surgeries were performed through a posterior approach, and a majority of the implants were uncemented. All patients followed the same postoperative clinical pathway; no fast-track pathway was used.

The combined effects of day of surgery, American Society of Anesthesiologists (ASA) grade, anesthesia type, intraoperative time, estimated blood loss (EBL), incision length, presence of complications, age, sex, body mass index (BMI), disposition (skilled nursing facility vs home), transfusion, hematocrit, and hemoglobin on LHS were analyzed using a multiple quasi-Poisson regression model that included a random effect for surgeon. A Poisson regression model (typically used for count data) was deemed appropriate, as LHS was reported in whole days; a quasi-Poisson model relaxes the Poisson model assumption that the variance in the data equals the mean. The random effect for surgeon adjusts for any correlation among data from surgeries conducted by the same surgeon.

All complications were recorded. Complications included excess wound drainage,⁸ wound hematoma (a case of excess wound drainage necessitated surgical irrigation and débridement), new-onset atrial fibrillation, non-ST-elevation myocardial infarction, atrial flutter, urinary tract infection, pulmonary embolism, disseminated intravascular coagulation, hepatic decompensation as manifested by elevated liver enzymes, pneumonia, gastroesophageal reflux disease, gastric ulcer, sepsis, delirium, hypotension, and dysphagia.

The parameter estimates reported from the quasi-Poisson regression model are incident rate ratios (IRRs). IRR represents the change in expected LHS for a 1-unit change in a continuous variable (eg, age) or between categories of a categorical variable (eg, sex). IRR higher than 1 indicates higher risk as the continuous variable increases or a higher risk relative to the comparator group for a categorical variable. IRR lower than 1 indicates lower risk.

Results

Table 1 summarizes patient characteristics by surgical day. Mean LHS ranged from a minimum of 3.7 days for patients who had surgery on a Monday to a maximum of 4.2 days for patients who had surgery on a Thursday.

Table 2 summarizes results of the multivariate quasi-Poisson regression analysis of LHS by surgical day, ASA grade, anesthesia type, intraoperative time, EBL, incision length, presence of complications, age, sex, and BMI. With all other variables included in the model adjusted for, each additional point in ASA grade was associated with a 12% increase in LHS (P = .019). In addition, with all other variables included in the model adjusted for, LHS was 33% longer for patients with complications than for patients without complications (P < .001) and 12% longer for patients who received transfusions than for patients who did not (P = .046). LHS did not differ significantly by the day of the week when the surgery was performed (P = .496). Disposition status (skilled nursing facility vs home) as a variable to determine LHS did approach statistical significance (P = .061). As the effect size we were interested in detecting was an approximate 1-day increase in LHS for patients who had surgery later in the week relative to patients who had surgery earlier in the week, our sample size was adequate (range of required sample size, 200-300 patients). This study had 99% power to detect a 27% increase in LHS (equivalent to 1 day or more).

Discussion

This retrospective analysis explored how day of the week of primary THA affected LHS. Various confounders, such as surgery and patient factors, were also examined so that the multivariate analysis would be able to isolate the effects of surgical day of the week on LHS.

Effect of day of the week of primary THA on LHS was not investigated in the United States before. In Denmark, in a study similar to ours, Husted and colleagues⁴ found a 400% increase in the probability of LHS of more than 3 days when patients operated on a Thursday were compared with patients operated on a Friday. The authors reasoned that the Thursday patients most likely had a compromised physical therapy protocol owing to the inclusion of weekend days in the crucial postoperative period. LHS was consequently increased so that these patients would achieve their therapy goals before being discharged. Our investigation showed that LHS did not differ significantly by surgical day of the week. Although patients who had THA on a Thursday had 15% longer LHS than patients who had THA on a Monday, this difference was not statistically significant (P = .496), even though the study was adequately powered to detect a change in LHS of a whole day.

Table 3 summarizes the difference in quantum of workforce on weekdays and weekends at our center. The physiotherapy sessions were reduced to 1 per day. Nurse practitioners and discharge planners were not available on weekends, and some skilled nursing facilities and rehabilitation centers refused to accept patients on weekends. At our center, a teaching institute, the clinical duties of discharge planners and nurse practitioners were assumed by licensed physicians (orthopedic residents covering the arthroplasty team on weekends). This could be one of several possible reasons our study failed to detect statistically significant difference between the 2 groups. This kind of alternative arrangement may not be possible at many other centers. However, our study results provide a reasonably accurate logistical aim with regard to workforce availability on weekends to keep LHS in check.

The importance of giving patients an inpatient physical therapy regimen in timely fashion has been demonstrated in other studies. Munin and colleagues,⁹ in a randomized controlled trial, evaluated 71 patients who underwent elective hip and knee arthroplasty and received 2 different physical therapy regimens. Patients started their in-treatment physical therapy on postoperative day 3 or 7. Mean total LHS was shorter in the 3-day group (11.7 days) than in the 7-day group (14.5 days) (P < .001). Brusco and colleagues¹⁰ also showed that introducing weekend physical therapy services significantly reduced LHS in patients who underwent THA (10.6 vs 12.5 days; P < .05). Rapoport and Judd-Van Eerd¹¹ retrospectively analyzed orthopedic surgery LHS, comparing patients treated in a community hospital during a period of 5-days-a-week physical therapy coverage and patients treated during a period of 7-days-a-week physical therapy coverage. The 7-days-a-week group had significantly statistically shorter mean LHS.

Another rationale for analyzing the impact of surgical day of the week stems from the expectation that patients who undergo THA on Wednesday or Thursday and are scheduled to have physical therapy or be discharged on the weekend may be affected not only by reduced inpatient weekend physical therapy coverage but also by difficulties in being transferred to a skilled nursing facility or rehabilitation center if not discharged home. In our study, the patients who were to be discharged to a rehabilitation center were delayed by 12.5%, and this statistic trended toward significance (P = .061). Our literature search did not turn up any studies, US or European, specifically linking LHS to discharge disposition (whether patient is discharged home or to a skilled nursing facility or rehabilitation center).

Reduced medical staffing on weekends may not only affect the quality of in-hospital patient care but may also result in unnecessary delays in discharge. Chow and Szeto¹² retrospectively analyzed the medical records of all acute medical wards in a university hospital and compared weekend discharge rates before and after implementation of a work ordinance, which decreased the physician workforce by half on Saturday and Sunday. Results showed a 2.7% decrease in the weekend discharge rate after the work ordinance was established. The number of weekday discharges between the 2 time periods did not differ. Increasing the workforce availability presents a challenge in academic medical centers where graduate medical education enforces a strict cap on resident duty hours. Under these circumstances, a more feasible approach to decreasing LHS for THA patients is for surgical planning committees to provide the joint replacement services with operative block times early in the workweek.

Even though the organizational structure at our center is strong enough to provide for an adequate weekend workforce to discharge these patients, this study had a few limitations. We could not study readmission rates and whether the transition to home health and home physical therapy for the patients who went home was seamless.

We found that only 3 patient characteristics had a significant effect on LHS: higher ASA grade (a surrogate for medical comorbidities), requirement for blood transfusion, and presence of complications. In Denmark, blood transfusion increased the likelihood of longer LHS by 400%.⁴ In that study, patients who were ASA grades 1 and 2 had 60% and 20% decreased likelihood of LHS of more than 3 days compared with patients who were ASA grade 3. Similarly, in 2009, Mears and colleagues⁵ found 4 factors related to increased LHS: female sex (P < .001), older age (P < .001), higher ASA grade (3, P < .01; 4, P  < .001), and increased blood loss (P < .001).⁵

Conclusion

Over the past decade, there has been a significant reduction in LHS after THA, from a mean of 3 weeks to 4 days. Advances in implant technology, delivery of in-home physical therapy, and improved prevention and management of postoperative complications have contributed to this decline. Early identification of patients with transfusion requirements may be helpful in expediting their care. Although guidelines are in place for transfusion, further study in this regard may be needed. It is important to continue to identify surgery and patient factors that affect LHS, but the importance of organizational and planning issues in optimizing hospital health care expenditures cannot be ignored. Further study of providing a specific discharge planning service to identify patients’ discharge needs (home vs extended care facility) may help reduce LHS.

With health care costs increasing and economic resources diminishing, substantial efforts have been directed toward improving the quality of care delivered in a cost-effective manner. For a total hip arthroplasty (THA) performed in the United States between 1997 and 2001, total hospital cost, including direct and indirect costs, was estimated as averaging $13,339.¹ In 2012, this cost was estimated to be between $43,000 and $100,000.² This overall cost estimate, along with the rate at which the procedure is performed, may present an opportunity for cost savings.

Length of hospital stay (LHS) is an important outcome measure that has been assessed for optimal health care delivery. Prolonged LHS implies increased resource expenditure. Therefore, it is crucial to identify factors associated with prolonged LHS in order to reduce costs. Investigations have identified factors shown to affect LHS after THA. These factors include advanced age, medical comorbidities, obesity, intraoperative time, anesthesia technique, surgical site infection, and incision length.^3-7

We conducted a study to identify the patient and clinical factors that affect LHS and to determine whether the specific day of the week when primary THA is performed affects LHS at a large tertiary-care university-based medical center. This information may prove valuable to hospital planning committees allotting operating room time and floor staffing for elective surgical cases with the goal of delivering cost-efficient care.

Materials and Methods

After obtaining institutional review board approval for this study, we retrospectively analyzed all primary unilateral THAs (273 patients) performed at our institution, a tertiary-care teaching hospital, between January 2010 and May 2011. The majority of the surgeries were performed through a posterior approach, and a majority of the implants were uncemented. All patients followed the same postoperative clinical pathway; no fast-track pathway was used.

The combined effects of day of surgery, American Society of Anesthesiologists (ASA) grade, anesthesia type, intraoperative time, estimated blood loss (EBL), incision length, presence of complications, age, sex, body mass index (BMI), disposition (skilled nursing facility vs home), transfusion, hematocrit, and hemoglobin on LHS were analyzed using a multiple quasi-Poisson regression model that included a random effect for surgeon. A Poisson regression model (typically used for count data) was deemed appropriate, as LHS was reported in whole days; a quasi-Poisson model relaxes the Poisson model assumption that the variance in the data equals the mean. The random effect for surgeon adjusts for any correlation among data from surgeries conducted by the same surgeon.

All complications were recorded. Complications included excess wound drainage,⁸ wound hematoma (a case of excess wound drainage necessitated surgical irrigation and débridement), new-onset atrial fibrillation, non-ST-elevation myocardial infarction, atrial flutter, urinary tract infection, pulmonary embolism, disseminated intravascular coagulation, hepatic decompensation as manifested by elevated liver enzymes, pneumonia, gastroesophageal reflux disease, gastric ulcer, sepsis, delirium, hypotension, and dysphagia.

The parameter estimates reported from the quasi-Poisson regression model are incident rate ratios (IRRs). IRR represents the change in expected LHS for a 1-unit change in a continuous variable (eg, age) or between categories of a categorical variable (eg, sex). IRR higher than 1 indicates higher risk as the continuous variable increases or a higher risk relative to the comparator group for a categorical variable. IRR lower than 1 indicates lower risk.

Results

Table 1 summarizes patient characteristics by surgical day. Mean LHS ranged from a minimum of 3.7 days for patients who had surgery on a Monday to a maximum of 4.2 days for patients who had surgery on a Thursday.

Table 2 summarizes results of the multivariate quasi-Poisson regression analysis of LHS by surgical day, ASA grade, anesthesia type, intraoperative time, EBL, incision length, presence of complications, age, sex, and BMI. With all other variables included in the model adjusted for, each additional point in ASA grade was associated with a 12% increase in LHS (P = .019). In addition, with all other variables included in the model adjusted for, LHS was 33% longer for patients with complications than for patients without complications (P < .001) and 12% longer for patients who received transfusions than for patients who did not (P = .046). LHS did not differ significantly by the day of the week when the surgery was performed (P = .496). Disposition status (skilled nursing facility vs home) as a variable to determine LHS did approach statistical significance (P = .061). As the effect size we were interested in detecting was an approximate 1-day increase in LHS for patients who had surgery later in the week relative to patients who had surgery earlier in the week, our sample size was adequate (range of required sample size, 200-300 patients). This study had 99% power to detect a 27% increase in LHS (equivalent to 1 day or more).

Discussion

This retrospective analysis explored how day of the week of primary THA affected LHS. Various confounders, such as surgery and patient factors, were also examined so that the multivariate analysis would be able to isolate the effects of surgical day of the week on LHS.

Effect of day of the week of primary THA on LHS was not investigated in the United States before. In Denmark, in a study similar to ours, Husted and colleagues⁴ found a 400% increase in the probability of LHS of more than 3 days when patients operated on a Thursday were compared with patients operated on a Friday. The authors reasoned that the Thursday patients most likely had a compromised physical therapy protocol owing to the inclusion of weekend days in the crucial postoperative period. LHS was consequently increased so that these patients would achieve their therapy goals before being discharged. Our investigation showed that LHS did not differ significantly by surgical day of the week. Although patients who had THA on a Thursday had 15% longer LHS than patients who had THA on a Monday, this difference was not statistically significant (P = .496), even though the study was adequately powered to detect a change in LHS of a whole day.

Table 3 summarizes the difference in quantum of workforce on weekdays and weekends at our center. The physiotherapy sessions were reduced to 1 per day. Nurse practitioners and discharge planners were not available on weekends, and some skilled nursing facilities and rehabilitation centers refused to accept patients on weekends. At our center, a teaching institute, the clinical duties of discharge planners and nurse practitioners were assumed by licensed physicians (orthopedic residents covering the arthroplasty team on weekends). This could be one of several possible reasons our study failed to detect statistically significant difference between the 2 groups. This kind of alternative arrangement may not be possible at many other centers. However, our study results provide a reasonably accurate logistical aim with regard to workforce availability on weekends to keep LHS in check.

The importance of giving patients an inpatient physical therapy regimen in timely fashion has been demonstrated in other studies. Munin and colleagues,⁹ in a randomized controlled trial, evaluated 71 patients who underwent elective hip and knee arthroplasty and received 2 different physical therapy regimens. Patients started their in-treatment physical therapy on postoperative day 3 or 7. Mean total LHS was shorter in the 3-day group (11.7 days) than in the 7-day group (14.5 days) (P < .001). Brusco and colleagues¹⁰ also showed that introducing weekend physical therapy services significantly reduced LHS in patients who underwent THA (10.6 vs 12.5 days; P < .05). Rapoport and Judd-Van Eerd¹¹ retrospectively analyzed orthopedic surgery LHS, comparing patients treated in a community hospital during a period of 5-days-a-week physical therapy coverage and patients treated during a period of 7-days-a-week physical therapy coverage. The 7-days-a-week group had significantly statistically shorter mean LHS.

Another rationale for analyzing the impact of surgical day of the week stems from the expectation that patients who undergo THA on Wednesday or Thursday and are scheduled to have physical therapy or be discharged on the weekend may be affected not only by reduced inpatient weekend physical therapy coverage but also by difficulties in being transferred to a skilled nursing facility or rehabilitation center if not discharged home. In our study, the patients who were to be discharged to a rehabilitation center were delayed by 12.5%, and this statistic trended toward significance (P = .061). Our literature search did not turn up any studies, US or European, specifically linking LHS to discharge disposition (whether patient is discharged home or to a skilled nursing facility or rehabilitation center).

Reduced medical staffing on weekends may not only affect the quality of in-hospital patient care but may also result in unnecessary delays in discharge. Chow and Szeto¹² retrospectively analyzed the medical records of all acute medical wards in a university hospital and compared weekend discharge rates before and after implementation of a work ordinance, which decreased the physician workforce by half on Saturday and Sunday. Results showed a 2.7% decrease in the weekend discharge rate after the work ordinance was established. The number of weekday discharges between the 2 time periods did not differ. Increasing the workforce availability presents a challenge in academic medical centers where graduate medical education enforces a strict cap on resident duty hours. Under these circumstances, a more feasible approach to decreasing LHS for THA patients is for surgical planning committees to provide the joint replacement services with operative block times early in the workweek.

Even though the organizational structure at our center is strong enough to provide for an adequate weekend workforce to discharge these patients, this study had a few limitations. We could not study readmission rates and whether the transition to home health and home physical therapy for the patients who went home was seamless.

We found that only 3 patient characteristics had a significant effect on LHS: higher ASA grade (a surrogate for medical comorbidities), requirement for blood transfusion, and presence of complications. In Denmark, blood transfusion increased the likelihood of longer LHS by 400%.⁴ In that study, patients who were ASA grades 1 and 2 had 60% and 20% decreased likelihood of LHS of more than 3 days compared with patients who were ASA grade 3. Similarly, in 2009, Mears and colleagues⁵ found 4 factors related to increased LHS: female sex (P < .001), older age (P < .001), higher ASA grade (3, P < .01; 4, P  < .001), and increased blood loss (P < .001).⁵

Conclusion

Over the past decade, there has been a significant reduction in LHS after THA, from a mean of 3 weeks to 4 days. Advances in implant technology, delivery of in-home physical therapy, and improved prevention and management of postoperative complications have contributed to this decline. Early identification of patients with transfusion requirements may be helpful in expediting their care. Although guidelines are in place for transfusion, further study in this regard may be needed. It is important to continue to identify surgery and patient factors that affect LHS, but the importance of organizational and planning issues in optimizing hospital health care expenditures cannot be ignored. Further study of providing a specific discharge planning service to identify patients’ discharge needs (home vs extended care facility) may help reduce LHS.