Periprosthetic Infection in the Setting of Periprosthetic Total Hip Fractures: Evaluation and Management.

The incidences of periprosthetic fracture and periprosthetic joint infection after total hip arthroplasty are expected to increase exponentially over the coming decades. Epidemiologic data suggest that many periprosthetic fractures after THA occur concurrently with a loose femoral implant. Recent studies suggest an approximately 8% incidence of indolent infection in cases of suspected aseptic loosening. The available data, therefore, suggest that periprosthetic fracture and infection may coexist, and this possibility should be considered, particularly in patients with a loose femoral stem and high pretest possibility. Although currently limited, the available literature provides some guidance as how to manage this complex issue.

Acetabular Retroversion: Dysplasia in Disguise that Leads to Early Arthritis of the Hip.

We aimed to assess the prevalence of acetabular retroversion (AR) in patients undergoing total hip replacement (THA) based on age. We retrospectively compared preoperative anteroposterior pelvic radiographs of patients younger than 40 years of age who underwent THA with the age- and body mass index-matched control of 40 years and older patients. Retroversion was determined based on the presence of cross-over sign, ischial spine sign, posterior wall sign, and elephant's ear sign with data stratified based on presence of dysplasia.

Commercial Synovial Antibody Testing is No Better Than Traditional Culture in Identification of Pathogen(s) Causing Periprosthetic Joint Infection.

BACKGROUND: Identification of infective organism causing periprosthetic joint infections (PJIs) is crucial to tailor the best combination of surgical and antimicrobial treatment. Traditional culture, with all its limitations, has been utilized for this purpose. A synovial fluid antibody assay against some common pathogens has been introduced by a commercial entity recently. This study aimed to determine if the antibody testing could be used as a proxy to traditional culture, and whether it provided additional information, in the setting of PJI. METHODS: A retrospective study was conducted of patients who underwent revision total hip and knee arthroplasty between January 2019 and 2020. Aspirated synovial fluid was sent for analyses including the commercial antibody testing. All patients had samples harvested for culture per standard of care. Results of the antibody testing and culture, in terms of concordance, were compared. Receiver operating characteristic curve and Youden's criterion were used to compare the 2 methods. RESULTS: A total of 419 patients were included. Using the International Consensus Meeting criteria as reference standard for PJI, antibody testing had a sensitivity and specificity of 40.5% and 93.4%, respectively. There were 59.5% false negative results with antibody testing compared with 50% for culture. Of the 12 patients who had positive results in both tests, 5 (41.7%) had discordant pathogens identified in each test. CONCLUSION: Synovial fluid antibody testing does not provide clinical benefit when compared to traditional cultures for PJI diagnosis. The antibody testing had a low sensitivity and a high rate of discordance with culture, when both tests were positive.

Interim Spacer Exchange for Treatment of Periprosthetic Joint Infection: Almost Half the Patients Subsequently Fail.

BACKGROUND: Interim spacer exchange may be performed in patients undergoing 2-stage exchange for periprosthetic joint infection. Several studies have demonstrated that interim spacer exchange is associated with poor outcomes. This study investigated the survivorship and risk factors for failure in patients with an interim spacer exchange. METHODS: Two institutional databases identified 182 patients who underwent spacer exchange from 2000 to 2017. Primary outcomes included progression to reimplantation, treatment success, and mortality. Bivariate analysis was performed to evaluate risk factors associated with failure. Kaplan-Meier curves using host and local grades were generated to evaluate for primary outcomes and differences in survivorship. RESULTS: The overall failure rate was 49% in patients with a spacer exchange. Most patients (60%) failed before 2 years. Higher comorbidity scores, elevated erythrocyte sedimentation rate, and non-White race were more prevalent in patients who failed. Negative cultures at the time of exchange were more prevalent in patients who did not fail. Failure rate was higher in immunocompromised conditions, and those who had revision prior to exchange. After considering clinically relevant variables, advanced host grade C was the single factor associated with treatment failure. Although survivorship curves were not significantly different between extremity local grades, higher host grades were associated with treatment failure. CONCLUSION: Almost 1 out of 2 patients with spacer exchange were found to fail the intended 2-stage revision arthroplasty. Benefits of delivering additional antibiotic load with a new spacer should be balanced against poor outcomes in patients with the aforementioned risk factors.

Surgical Treatment of Femoroacetabular Impingement: Minimum 10-Year Outcome and Risk Factors for Failure.

BACKGROUND: Femoroacetabular impingement (FAI) is a well-known cause of hip pain and dysfunction in young adults. Surgical treatment has been widely popularized during the past decade. However, most reported results have been limited to short-term and intermediate-term follow-up. The long-term success rate and risk factors for failure are largely unknown. This study aimed to report the long-term (minimum, 10 years) clinical outcomes of surgical treatment of FAI and to describe the clinical and radiographic parameters associated with the failure of treatment involving femoroacetabular osteoplasty (FAO) and labral repair. METHODS: Using our prospective hip preservation database, 164 patients (178 hips) who had undergone FAO between January 2005 and April 2009 were identified. Patient demographic characteristics, clinical history, duration of preoperative symptoms, radiographic parameters (preoperative and postoperative alpha angles, hip dysplasia and retroversion, Tönnis grade for osteoarthritis), and intraoperative findings were reviewed and compared between the success and failure groups. At a minimum 10-year follow-up, clinical functional outcomes (modified Harris hip score [mHHS] and Short Form-36 [SF-36] at 6 weeks, 6 months, 1 year, and 10 years) and failure rates (conversion to total hip arthroplasty [THA]) were collected. RESULTS: The mean patient age (and standard deviation) was 34.3 ± 8.4 years, and 65 patients (40%) were female. After the surgical procedure, there was significant improvement in the mean mHHS (59.3 ± 7.3 points preoperatively to 88.4 ± 7.3 points postoperatively) and the mean SF-36 (61.3 ± 8.4 points preoperatively to 89.1 ± 7.2 points postoperatively). At a mean follow-up of 12.5 years, 12% (22 hips) required conversion to THA, with a mean time to THA of 5.3 ± 2.0 years. Older age, longer preoperative symptomatic period, higher preoperative and postoperative alpha angles, presence of hip dysplasia, a higher Tönnis grade, joint space narrowing, and a full-thickness acetabular chondral lesion at the time of the FAO were identified as risk factors for failure and conversion to THA. CONCLUSIONS: Patients with symptomatic FAI who undergo a surgical procedure experience pain relief and functional improvement that appear to endure over a decade in the majority of patients. This study on a relatively large cohort with a long-term follow-up has also identified patients who are at a higher risk for treatment failure. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Modular or Monolithic Tapered Fluted Prostheses for Periprosthetic Fractures: Which One Could Work for You?

Periprosthetic fracture around a femoral component is a potentially devastating complication after total hip arthroplasty. Surgical treatment is often technically demanding and requires a thorough understanding of fracture care and revision joint reconstruction. Advancements in femoral component designs for revision total hip arthroplasty have improved management of this challenging complication. It is important for surgeons to understand which femoral component design might best suit their needs. We present an overview of revision total hip arthroplasty in the setting of periprosthetic fracture, focusing on comparing the 2 most popular femoral component revision models, the modular and monolithic tapered fluted conical prostheses.

Alpha-defensin does not provide additional benefit over leukocyte esterase in the diagnosis of periprosthetic joint infection.

Background: Leukocyte esterase (LE) and α-defensin (AD) are two synovial biomarkers that are used for the diagnosis of periprosthetic joint infection (PJI), however, the superiority of one over the other remains unknown. We aimed to compare their diagnostic value.Methods: In this retrospective study, we evaluated patients who underwent revision total hip and knee arthroplasty at a single institution between 2013 and 2019 for whom both LE and AD were available. PJI was defined by the 2018 International Consensus Meeting criteria. The diagnostic performance of AD and LE was compared.Results: Overall, 122 patients (28 PJI and 94 aseptic revisions) were included. The area under the curve was 0.905 (95% confidence interval[CI]:0.820-0.991) and 0.913 [95%CI:0.834-0.992] for LE and AD, respectively. Positive and negative predictive values were 95.8% (95%CI:76.5%-99.4%) and 94.9% (95%CI:89.4%-97.6%) for LE and 89.0% (95%CI:72.2%-96.1%) and 96.0% (95%CI:90.5%-98.3%) for AD. While both tests were useful in 18 cases that were inconclusive based on preoperative findings, AD had no benefit over LE.Conclusion: Both LE and AD are valuable markers in patients with suspected PJI. Since LE is very inexpensive and readily available point-of-care test, we believe it offers more value in the work up of suspected PJI.

Leukocyte Esterase Versus ICM 2018 Criteria in the Diagnosis of Periprosthetic Joint Infection.

BACKGROUND: A leukocyte esterase (LE) test is inexpensive and provides real-time information about patients suspected of periprosthetic joint infections (PJIs). The 2018 International Consensus Meeting (ICM) recommends it as a diagnostic tool with a 2+ cutoff. There is still a lack of data revealing LE utility versus the ICM 2018 criteria for PJI. METHODS: This is a retrospective study of patients who underwent revision total hip and total knee arthroplasty at a single institution between March 2009 and December 2019. All patients underwent joint aspiration before the arthrotomy, and the LE strip test was performed on aspirated joint fluid. PJI was defined using the 2018 ICM criteria. RESULTS: As per the 2018 ICM criteria, 78 patients were diagnosed with chronic PJI and 181 were not infected. An LE test with a cutoff of ≥1+ had a sensitivity of 0.744, a specificity of 0.906, a positive predictive value of 0.773, an accuracy of 0.825 (95% confidence interval 0.772-0.878), and a negative predictive value of 0.891. The positive likelihood ratio (LR+) was 7.917. Using an LE cutoff of 2 + had a sensitivity of 0.513, a specificity of 1.000, and an accuracy of 0.756 (95% confidence interval-0.812). CONCLUSION: LE is a rapid and inexpensive test which can be performed at the bedside. Its performance is valuable as per ICM criteria. Based on the findings of this study and the given cohort, we suggest using the cutoff of LE1+ (result = negative or trace) as a point of care test to exclude infection, whereas LE at 2 + threshold has near absolute specificity for the diagnosis.

Prior Femoroacetabular Osteoplasty Does Not Compromise the Clinical Outcome of Subsequent Total Hip Arthroplasty.

BACKGROUND: Total hip arthroplasty (THA) is the most effective treatment option for patients with symptomatic osteoarthritis after a prior femoroacetabular osteoplasty (FAO). This study evaluated clinical outcomes of THA after a prior FAO and compared the results with a matched group of patients who underwent THA with no prior surgical procedures in the affected hip. METHODS: By reviewing our prospectively maintained database, we identified 74 hips (69 patients) that underwent THA after previous FAO between 2004 and 2017. They were matched 1:3 to a control group of primary THA with no history of any procedures on the same hip based on age, sex, body mass index, date of surgery, Charlson comorbidity index, surgical approach, and acetabular and femoral component type. At minimum 2-year follow-up, modified Harris Hip Score, 90-day readmission, and revision THA for any reason were compared between the groups. RESULTS: The median time interval between FAO and subsequent THA was 1.64 years. There was no significant difference in preoperative Harris Hip Score between patients in the case and control cohorts. At the latest follow-up, the median modified Harris Hip Score was 77.6 in the case group and 96.2 in the control, and the difference was not statistically significant. None of the patients in the case group developed infection. 7 patients in the case group required additional procedures at any point, compared with 15 in the control. CONCLUSION: THA after prior FAO has similar outcomes to primary THA in patients with no prior procedures in the affected hip. THA can be performed safely with excellent outcome in patients with a history of FAO.

Prior Pelvic Osteotomy Affects the Outcome of Subsequent Total Hip Arthroplasty.

BACKGROUND: Although pelvic osteotomy (PO) is an important surgical procedure that can alleviate symptoms and potentially slow progression of osteoarthritis in patients with development dysplasia of the hip, some patients eventually require conversion to total hip arthroplasty (THA). This study aimed to determine the outcome of conversion THA in patients with prior PO. METHODS: Forty nine patients with a history of prior PO who underwent conversion THA at a single institution were matched at a 1:3 ratio based on the date of surgery, age, gender, and body mass index with 147 developmental dysplasia of the hip patients who underwent primary THA without prior PO. A retrospective chart review was performed to compare outcomes at a minimum follow-up of 2 years. RESULTS: Patients with prior PO required more supplemental screw fixation for the acetabular component (59.2% vs 38.1%, P = .016), more autologous bone grafting (24.5% vs 11.6%, P = .048), had a longer mean operative time (106.0 vs 79.8 minutes, P < .001), and greater estimated blood loss (350.0 vs 206.8 mL, P = .015). Patients with prior PO had smaller cup version angle (26.0° vs 29.0°, P = .012) and greater discrepancy in the limb length (10.3 vs 7.26 mm, P = .041). Eight hips (16.3%) with prior PO and 6 (4.1%) without osteotomy required reoperation (P = .008). There was no difference in outcome scores at the latest follow-up. CONCLUSION: THA after prior PO is technically demanding, leading to longer operative times, greater blood loss, and variation in implant placement. Although functional outcomes are similar, THA after a prior PO is more likely to require reoperation. CONCLUSION: THA after prior PO is technically demanding, leading to longer operative times, greater blood loss, and variation in implant placement. Although functional outcomes are similar, THA after a prior PO is more likely to require reoperation.

Modern Revision Femoral Stem Designs Have No Difference in Rates of Subsidence.

BACKGROUND: Both modular and monoblock tapered fluted titanium (TFT) stems have gained popularity over fully porous-coated cylindrical (FPCC) femoral stem designs, but limited data exist comparing subsidence rates following revision total hip arthroplasty (THA). The purpose of this study is to determine differences in subsidence and clinical outcomes among 3 revision femoral stem designs. METHODS: We reviewed a consecutive series of 335 patients who underwent femoral component revision to a cementless modular TFT (n = 225), monoblock TFT (n = 63), or FPCC (n = 47) stem between 2012 and 2019. We evaluated radiographic subsidence rates, re-revision rates, and patient-reported outcomes between the 3 stems. A multivariate regression analysis was performed to determine the independent effect of stem type on the risk of subsidence >5 mm. RESULTS: At an average follow-up of 39 months (range, 12 to 96 months), there were no differences in mean subsidence rates (3.5 vs 2.4 vs 2.1 mm, P = .14), HOOS Jr scores (78 vs 74 vs 64 points, P = .15), or aseptic re-revision rates (4% vs 3% vs 0%, P = .29) between modular TFT, monoblock TFT, and FPCC stems. Although modular TFT stems were more often used in patients with extensive femoral bone loss (Paprosky III and IV), there were no differences in subsidence rates >5 mm among the 3 stems (P > .05) in multivariate analysis. CONCLUSION: Modular TFT, monoblock TFT, and FPCC femoral stem designs all perform well in revision THA with no difference in clinical outcomes or subsidence rates. Surgeons should select the stem which they feel is the most clinically appropriate.

Does a History of Slipped Capital Femoral Epiphysis in Patients Undergoing Femoroacetabular Osteoplasty for Femoroacetabular Impingement Affect Outcomes Scores or Risk of Reoperation?

BACKGROUND: Femoroacetabular impingement (FAI) can occur after slipped capital femoral epiphysis (SCFE) regardless of slip severity and even after in situ pinning. These patients represent a rare and unique demographic that is largely unreported on. It is important to further characterize the clinical presentation of these patients, associated treatment modalities, and the efficacy of these treatment modalities. QUESTIONS/PURPOSES: (1) How do patients with post-SCFE FAI typically present in terms of radiographic and surgical findings? (2) How do their hip-specific and general-health outcomes scores after mini-open femoroacetabular osteoplasty compare with those obtained in a matched group of patients with FAI caused by other etiologies? (3) How do those groups compare in terms of the proportion who undergo conversion to THA? METHODS: Between 2013 and 2017, 20 patients had femoroacetabular osteoplasty for post-SCFE FAI. During that time, general indications for this procedure were symptomatic FAI demonstrated on radiographs and physical exam. Of those, none was lost to follow-up before a minimum of 2 years, leaving all 20 available for matching, and all 20 had suitable matches in our database for patients who underwent femoroacetabular osteoplasty for other diagnoses. Matching was performed by surgeon, patient age, patient gender, and BMI. The matching group was drawn from a large database of patients who had the same procedure during the same period. We matched in a 1:3 ratio to arrive at 60 randomly selected control patients in this retrospective, comparative study. Patient demographics, medical history, clinical presentation, radiographic parameters, and intraoperative findings were compared between the two groups. At a minimum of 2 years of follow-up, the latest clinical functional outcome scores (Hip Disability and Osteoarthritis Outcome Score Jr and SF-12) and proportions of conversion to THA were compared between the groups. RESULTS: A greater percentage of patients with a history of SCFE than those without prior SCFE demonstrated full chondral lesions intraoperatively (90% [18 of 20] versus 32% [19 of 60], odds ratio 7 [95% confidence interval 1 to 178]; p < 0.01). A greater percentage of patients with a history of SCFE also demonstrated labral calcifications intraoperatively compared with those without prior SCFE (65% [13 of 20] versus 35% [21 of 60], OR 3 [95% CI 1 to 10]; p = 0.04). Radiographically, patients with SCFE had greater preoperative alpha angles than did patients without SCFE (94° ± 13° versus 72° ± 22°; p = 0.01) as well as lower lateral center-edge angles (25° ± 8° versus 31° ± 8°; p = 0.04). There was no difference in postoperative follow-up between patients with a history of SCFE and patients without a history of SCFE (4 ± 2 years versus 4 ± 2 years; p = 0.32). There was no difference in the mean postoperative outcome scores between patients with a history of SCFE and patients without (Hip Disability and Osteoarthritis Outcome Score Jr: 75 ± 28 points versus 74 ± 17 points; p = 0.95; SF-12 physical score: 40 ± 11 points versus 39 ± 8 points; p = 0.79). There was no difference with the numbers available in the percentage of patients who underwent conversion to THA (15% [3 of 20] versus 12% [7 of 60], OR 1.36 [95% CI 0 to 6]; p = 0.71). CONCLUSION: Patients with FAI after SCFE present with a greater degree of labral and chondral disease than do patients without a history of SCFE. However, at short-term follow-up, the proportion of patients who underwent conversion to THA and patients' postoperative outcome scores did not differ in this small, comparative series between patients with and without SCFE. Further evaluation with long-term follow-up is needed, especially given the more severe chondral damage we observed in patients with SCFE at the time of surgery. LEVEL OF EVIDENCE: Level III, therapeutic study.

High Risk of Conversion to THA After Femoroacetabular Osteoplasty for Femoroacetabular Impingement in Patients Older than 40 Years.

BACKGROUND: Femoroacetabular impingement (FAI) is a recognized cause of hip pain and decreased quality of life and has been linked to primary idiopathic hip osteoarthritis (OA). Although the operative indications for FAI have expanded to include older patients, we do not know whether there is an increased risk of conversion to THA after femoroacetabular osteoplasty (FAO) via the mini-open approach for FAI in patients older than 40 years compared with younger patients, after controlling for other confounding variables. QUESTIONS/PURPOSES: (1) After matching for gender, BMI, preoperative symptomatic period, surgeon experience, Tönnis grade, and degree of chondral lesion, are patients older than 40 years who undergo FAO for FAI more likely to be revised to THA at a minimum of 2 years' follow-up than are patients younger than 40? (2) Is there a difference in delta (postoperative minus preoperative) improvement in functional outcome scores in those patients who did not go on to THA between patients older than and younger than 40 years? METHODS: Between 2003 and 2017, one surgeon performed 281 FAOs via the mini-open approach in patients older than 40 years and 544 of the same procedure in patients younger than 40 years. During that period, the general indications for FAO were the same in both age groups: (1) history and physical exam consistent with FAI, (2) radiographic evidence of focal impingement (cam, pincer, or both), (3) evidence of labral or chondrolabral tears, and (4) minimal to no arthritic changes (all four criteria required). In general, age was not used as a contraindication for surgery. A total of 86% (241 of 281) of patients older than 40 and 91% (494 of 544) of those younger than 40 were available for minimum of 2 years' follow-up, had complete datasets (radiographs as well as preoperative and most recent patient-reported outcomes scores) at a minimum of 2 years after surgery, and were considered eligible for the match. Propensity score matching was used to match for BMI, gender, preoperative symptomatic period, surgeon experience, Tönnis grade, and degree of intraoperative chondral lesion. We matched at a 1:2 ratio 130 patients older than age 40 with 260 patients younger than age 40. The mean ± SD follow-up duration for both groups was 5 ± 2 years. The mean age of the cohort of interest was 47 ± 5 years compared with 28 ± 7 years in the control. Fifty-four percent (70 of 130) of patients older than 40 years were women and 46% (60 of 130) were men; for those younger than 40, 51% (133 of 260) of participants were women and 49% (127 of 260) were men. Tönnis grade distribution for patients older than 40 was as follows: 46% (60 of 130) had Grade 0, 42% (55 of 130) had Grade 1, and 12% (15 of 130) had Grade 2. In comparison, Tönnis grade for patients younger than 40 was as follows: 52% (136 of 260) had Grade 0, 38% (100 of 260) had Grade 1, and 9% (24 of 260) had Grade 2 (p = 0.49). Chondral lesion degree was determined intraoperatively as none, a partial-thickness tear, or a full-thickness tear. Tönnis grade was determined based on preoperative plain AP hip radiographs. We then compared the percentage of patients who converted to THA during the surveillance period (our primary study outcome). We also compared the difference in delta (preoperative minus postoperative) improvement in functional outcome scores using the modified Harris Hip Score (mHHS) between the groups, excluding those who had already been converted to THA. RESULTS: In patients older than 40 years, 16% (21 of 130) converted to THA at a mean time to conversion of 2 ± 1 years compared with 7% (17 of 260) at a mean time of 2 ± 2 years in patients younger than 40 years (p = 0.01). At a mean of 5 ± 2 years after FAO, among those patients who had not undergone conversion to THA, the mean delta mHHS score for patients older than 40 was 11 ± 17, compared with 20 ± 26 for patients younger than 40 (p = 0.04). CONCLUSION: Since approximately 1 in 6 patients older than 40 years in this series who underwent FAO for FAI opted for early conversion to THA at a mean time of 2 years after the osteoplasty procedure, and the remaining patients who did not undergo THA reported lower improvement in functional outcomes, we recommend surgeons avoid this procedure in patients in this age group until or unless we can better refine our indications. This is especially true because loss to follow-up causes us to believe that, if anything, our estimates of the risk of conversion to THA are conservative. LEVEL OF EVIDENCE: Level III, therapeutic study.

Functional Outcomes are Comparable Between Posterior Stabilized and Cruciate-Substituting Total Knee Arthroplasty Designs at Short-Term Follow-up.

BACKGROUND: Posterior stabilized (PS) polyethylene inserts have been shown to have excellent long-term functional results following total knee arthroplasty (TKA). A cruciate-substituting (CS) design has been introduced to minimize bony resection and eliminate concerns regarding wear on the PS post. The purpose of this study is to compare the outcomes of patients who underwent TKA using either a PS or CS insert. METHODS: We reviewed a consecutive series of 5970 patients who underwent a cruciate-sacrificing TKA and received either a PS (3,314) or CS (2,656) polyethylene liner. We compared demographics, Knee Injury and Osteoarthritis Outcome Score Jr (KOOS Jr), Short-Form 12 (SF-12) scores, and revision rates between the groups at a minimum 2 years followup. A multivariate regression was performed to identify the independent effect of design on functional outcomes. RESULTS: Revision rates between the groups were comparably low (0.35% for PS vs 0.51% for CS, P = .466) at an overall mean follow-up of 43 months. Patients in the PS cohort had statistically higher KOOS Jr scores at 2 years (69.8 vs 72.9, P < .001). Multivariate regression analysis found CS patients to have lower postoperative KOOS Jr scores (estimate -2.26, P = .003), and less overall improvement in KOOS Jr scores (estimate -2.42, P = .024) than PS patients, but neither was a clinically significant difference. CONCLUSION: Patients who undergo TKA with a CS polyethylene insert have comparable functional outcomes and revision rates to those with a PS design at short-term follow-up. Longer follow-up is needed to determine whether CS can match the outstanding track record of PS TKA.

Return to Sports After Joint Preservation Hip Surgery.

Femoroacetabular impingement results from a mismatch of congruency between the femoral head and the acetabulum. This condition is most common among young, active patients and may lead to pain, decreased quality of life, and inability to participate in athletics. Hip preservation surgery is widely performed is used as a definitive treatment option in athletes at all levels of competition. Athletes have reported high rates of return to play and satisfaction and expect rehabilitation to require approximately 4 to 6 months. This article provides an overview of femoroacetabular impingement, including diagnosis and treatment, with focus on athletes and return to play.

Web-Based Self-Directed Exercise Program Is Cost-Effective Compared to Formal Physical Therapy After Primary Total Knee Arthroplasty.

BACKGROUND: Web-based physical therapy (WBPT) is a potential means to reduce costs following total knee arthroplasty (TKA). Although outcomes data support the use of self-directed therapy after TKA, there is a paucity of literature evaluating its cost-effectiveness. This study aimed to determine utilization trends of either outpatient physical therapy (OPPT) or WBPT after TKA, assess the outcomes of patients based on their use of WBPT, OPPT, or both, and evaluate OPPT costs based on the amount of WBPT used. METHODS: A retrospective review of 701 patients (731 TKAs) was performed. Patients were given a prescription for OPPT and access to a self-directed WBPT program. Functional scores were obtained preoperatively and 6 months postoperatively, and the rate of manipulation under anesthesia (MUA), range of motion, and PT costs were recorded. RESULTS: About 49.8% of patients utilized WBPT, 34.7% of patients utilized WBPT and OPPT, and 23% of patients utilized neither source of therapy. Patients that utilized both WBPT and OPPT demonstrated the lowest rates of MUA. There were no differences in postoperative outcomes based on the number of WBPT logins. Overall, PT cost was 3.4× higher for those that underwent MUA. Subgroup analysis of patients that utilized WBPT revealed that the cost and number of PT visits decreased as the number of logins increased. Patients younger than 65 utilized more WBPT and OPPT while demonstrating worse outcomes (lower Knee Injury and Osteoarthritis Outcome Score for Joint Replacement postoperative scores and more MUAs). CONCLUSION: WBPT can be an effective option to offset costs associated with OPPT, without compromising outcomes.