What Are the Benefits of Hip Resurfacing in Appropriate Patients? A Retrospective, Propensity Score-Matched Analysis.

BACKGROUND: Hip arthritis is one of the major causes of disability worldwide. Hip resurfacing arthroplasty (HRA) has emerged in recent years as an alternative to total hip arthroplasty (THA), but complications of HRA have limited the patient population to younger male patients with primary osteoarthritis and large hip anatomy. How the functional benefits of HRA in this population compare with those of THA is not entirely clear. QUESTIONS/PURPOSES: The primary aim of this study was to determine whether there were differences in hip disability and patient satisfaction with surgery between these two groups at 2 years after surgery, using patient-reported outcome measures (PROMs) and subjective measures of patient satisfaction. Additionally, we sought to determine whether there were differences in post-operative discharge disposition, revision rates, or adverse events. METHODS: We searched an institutional database to identify patients undergoing unilateral HRA or THA between January 2007 and July 2011 who met today's recommended criteria for HRA: younger male patients with large-enough hip anatomy to make surgery viable (a femoral head of at least 48 mm in HRA patients and, in THA patients, an acetabular shell size of 54 mm, the minimum outer shell size that could accommodate a femoral head component of 48 mm; for matching purposes, acetabular shell size in THA was used as a surrogate for the femoral head size used in HRA). We used propensity score matching to control for potentially confounding pre-operative variables and administered the Hip Disability and Osteoarthritis Outcome Score (HOOS) survey, including its subdomains, at the 2-year mark. We also assessed differences between groups in Lower Extremity Activity Scale scores, 12-item Short Form Health Survey results, and answers regarding satisfaction with surgery. We calculated minimal detectable change, minimum clinically important change, and substantial clinical benefit using anchor-based techniques for multiple outcome measures. RESULTS: There were 251 patients in each group. HRA patients scored significantly higher than THA patients on the 2-year HOOS sports and recreation (92 versus 87, respectively) and on rates of overall satisfaction (94% versus 89%, respectively). The HRA group also had a greater chance of achieving minimum clinically important change (18.75 points) in the HOOS sports and recreation subdomains than the THA group (97% versus 91%). No significant difference was found in 6-month adverse event rates. HRA patients also had a significantly shorter mean hospital stay, a higher rate of discharge to home, and a lower incidence of a "significant" limp after surgery. CONCLUSION: HRA may provide a functional benefit in sports and recreation and greater satisfaction in patients who meet the current criteria for HRA. Because these benefits may be small, pre-operative counseling should focus on balancing the possible functional benefits against the longer-term risks associated with metal-on-metal bearings.

The Short Form KOOS, JR Is Valid for Revision Knee Arthroplasty.

BACKGROUND: The Knee Injury Osteoarthritis Outcome Survey, Joint Replacement (KOOS, JR) is a reliable, responsive, and validated patient-reported outcome measure (PROM) of knee health in patients with knee osteoarthritis undergoing unilateral primary total knee arthroplasty (TKA). The validity of the KOOS, JR for revision TKA remains unknown. METHODS: We identified 314 patients who underwent revision TKA and had completed preoperative and 2-year postoperative PROMs. Validation included assessment of local dependence, unidimensionality, internal consistency, external construct validity, responsiveness, and floor effects preoperatively and ceiling effects at 2 years postoperatively. RESULTS: Among patients undergoing revision TKA, the KOOS, JR demonstrated an absence of residual item correlation, adequate unidimensionality, high internal consistency (Person Separation Index: 0.897), and high external construct validity with existing validated PROMs, including KOOS Pain (Spearman's correlation coefficient 0.89) and KOOS activities of daily living (0.90) domains. The KOOS, JR was more responsive (standardized response means: 1.14) to revision TKA than other common knee PROMs. Three percent of revision TKA patients were at the floor (lowest score) preoperatively and 9% reached the ceiling (highest possible score) postoperatively. CONCLUSIONS: KOOS, JR performs well in revision TKA patients with regard to internal consistency, external validity, responsiveness, and floor and ceiling effects. Our results support extending its use to revision TKA in both clinical and research settings.

Body Mass Index Classification Is Independently Associated with Health-Related Quality of Life after Primary Total Knee Arthroplasty: An Institutional Registry-Based Study.

The purpose of this study was to compare the health-related quality of life (HRQoL) before and after successful total knee arthroplasty (TKA) across World Health Organization (WHO) body mass index (BMI) classifications. Through an institutional registry, patients with end-stage knee osteoarthritis who received elective primary unilateral TKA were identified and categorized based on WHO BMI classification. Age, gender, laterality, year of surgery, and Charlson-Deyo comorbidity index were recorded. The primary outcome was the EQ-5D-3L index and visual analog scale (VAS) at 2 years postoperatively. Inferential statistics and regression analyses were performed to determine associations between BMI classification and HRQoL. EQ-5D-3L index and VAS scores were significantly different across BMI classes, with higher scores in patients with lower BMI at baseline and at 2 years. There was no difference observed for the 2-year change in EQ-VAS scores between groups, but there was a statistically greater increase in index scores for more obese patients. In the regression analyses, there were statistically significant negative effect estimates for EQ-VAS and index scores associated with increasing BMI class, particularly for class III obesity. Higher BMI classification is independently associated with lower HRQoL scores 2 years after uncomplicated primary TKA, although obese patients experienced greater benefits in EQ-5D index scores following TKA. These results detail the relationship between BMI and HRQoL following TKA and suggest that preoperative weight loss may lead to improved outcomes following TKA, but also that obesity, alone, should not be a contraindication to TKA.

Total Hip Arthroplasty Performed for Coxarthrosis Preserves Long-Term Physical Function: A 40-Year Experience.

BACKGROUND: Measures of long-term success of total hip arthroplasty (THA) over the past 50 years have focused primarily on implant survival, with less evidence on long-term functional outcomes. QUESTIONS/PURPOSES: We aimed to study 20-to-40-year functional outcomes after primary THA. We investigated the extent to which (1) functional outcomes after THA are maintained long term; (2) patient characteristics such as age, hip disease diagnosis, and comorbidities affect recovery of function and survivorship after THA; and (3) patients' overall function after THA is affected by the need for revision, the aging process, and associated comorbidities. METHODS: We retrospectively reviewed outcomes of the senior author's patients between 1968 and 1993. Of 1207 patients, we identified 167 patients (99 female, 68 male; 276 primary THAs) who were at least 65 years old at follow-up and had at least 20 years of follow-up. Mean age at surgery was 55 years; mean follow-up time was 27 years. Bilateral THAs were performed in 109 patients (65%), and revisions in 81 patients (48.5%). Clinical outcomes including pain level, walking ability, range of motion, and overall function were determined by the Hospital for Special Surgery (HSS) hip scoring system. Contralateral and revision surgery, as well as patient age, sex, and body mass index, were included as covariates. To account for unequally spaced follow-up time points and competing causes of functional decline (e.g., age, contralateral hip disease, and need for revision THA), a latent class mixed model approach was used to identify unobserved classes of patients who had similar outcomes. Linear, quadratic, and piecewise-polynomial growth models were considered for class identification. The best fitting model was determined based on Bayesian information criterion. RESULTS: A four-class model of this patient population was identified: (1) the Elderly Class, who had a mean age of 62 years at the time of primary THA; (2) the Bilateral Class, who underwent simultaneous or staged bilateral THA; (3) the Revision Class, who required at least one revision; and (4) the Youngest Class, who had a mean age of 49 years. After an initial period of improvement in all groups, the functional trajectory diverged according to classifications. Age was the strongest determinant of long-term outcome, with HSS hip scores in the Elderly Class declining after about 20 years. The Youngest Class maintained good-to-excellent hip function for over 30 years. Revision THA and contralateral THA accounted for a temporary decline in function, after which overall good function was regained for the long term. CONCLUSIONS: All classes in the study population enjoyed good-to-excellent outcomes after THA for about 20 years. Thereafter, functional decline was attributed more to aging than to the need for revision. One or more revision THA did not negatively influence long-term clinical outcomes, suggesting that, even for younger patients, symptoms, rather than the avoidance of possible revision, should be the primary determining factor when indicating THA.

Age-Related Decline in Patient-Reported Outcomes 2 and 5 Years Following Total Hip Arthroplasty.

BACKGROUND: Patient-reported outcome measures (PROMs) help assess therapeutic effectiveness. This study assessed the effect of advanced age on the Hip Disability and Osteoarthritis Outcome Score (HOOS) and Lower Extremity Activity Scale (LEAS) after total hip arthroplasty (THA). METHODS: A prospective cohort of patients underwent primary THA at our institution between May 2007 and December 2011. Exposure was age at the time of surgery and outcomes were HOOS and LEAS scores 2 and 5 years postsurgery. We used a multivariable longitudinal generalized estimating equation to elucidate the effect of age on PROM scores. RESULTS: Our analysis of 3700 THA patients (mean age, 66 years; 56.4% female) demonstrated a decline in scores by age for the LEAS, HOOS Activities of Daily Living, and HOOS Sport and Recreation domains. There was also association between age and HOOS Symptoms and HOOS Quality of Life domains, but not between age and the HOOS Pain domain. Critical ages at which the relationship between age and outcome changed was 63 years for the HOOS Pain, Symptom, Activities of Daily Living, and Quality of Life domains, and 72 years for the HOOS Sport and Recreation domain and the LEAS. CONCLUSION: Patients undergoing THA at older ages reported lower activity and sports and recreation scores than younger patients, but similar pain, symptoms, and quality of life scores. This knowledge can help physicians guide patients' expectations before THA. Our findings also indicate that PROM scores should be age adjusted when used for quality or value comparisons between hospitals or physicians.

Patient-Reported Outcome Measures of Total Knee Arthroplasties for Post-Traumatic Arthritis versus Osteoarthritis: A Short-Term (5- to 10-year) Retrospective Matched Cohort Study.

BACKGROUND: The objective of the study was to compare the patient-reported outcome measures (PROM) of patients with post-traumatic arthritis (PTA) versus patients with osteoarthritis (OA) undergoing total knee arthroplasty (TKA) and compare the rates of revision among these two groups. METHODS: Using a prospectively held institutional registry, we retrospectively reviewed patients ≥60 years of age who underwent unilateral TKA between May 2007 and February 2012. Patients with previous or concomitant diagnosis of inflammatory arthropathy or an initial open fracture were excluded. PTA patients were matched 1:5 with OA patients undergoing TKA. Validated PROMs were recorded at baseline before index TKA and the last follow-up. Reason and time to revision surgery was reported, and survivorship was compared using Kaplan-Meier curves. RESULTS: Seventy-five PTA patients were matched to 375 OA patients. There was no difference between these groups with respect to age (67.7 ± 5.6 vs 67.8 ± 5.5 years; P = .876), body mass index (28.6 ± 5.4 vs 28.7 ± 5.3 kg/m2; P = .948), sex (65.3% vs 65.3% females; P = .999), Charlson Comorbidity Index (21.3% vs 21.3% Index 1-2, P = .999), and time to follow-up (93.0 ± 13.4 vs 88.2 ± 13.7 months; P = .999). No statistically significant difference was found in PROMs at baseline and the last follow-up (P > .05), the rate or time to revision surgery between the two groups (P-value = .635; log-rank test). CONCLUSION: Unlike previous studies, TKA for PTA does not pose lower PROMs or higher revision rates when compared to TKA for OA. These results could help provide surgeons with a frame of reference in terms of expectations for patients with PTA undergoing TKA.

Quality-Adjusted Life Years After Hip and Knee Arthroplasty: Health-Related Quality of Life After 12,782 Joint Replacements.

BACKGROUND: The quality-adjusted life year (QALY) is the preferred outcome measurement for cost-effectiveness analysis in health care. QALYs measure patient health-related quality of life with use of a value between 0 and 1. Few studies have provided original data delineating QALYs after hip and knee arthroplasty. In the present study, we evaluated patient utility preoperatively and 2 years after total hip arthroplasty, hip resurfacing, revision hip arthroplasty, total knee arthroplasty, unicompartmental knee arthroplasty, and revision knee arthroplasty. METHODS: A single-hospital joint registry, which enrolled patients from 2007 to 2011, was retrospectively examined for all patients who underwent primary or revision hip or knee arthroplasty and who had preoperative and 2-year postoperative Short Form-36 (SF-36), Short Form-12 (SF-12), or EuroQol 5-Dimension (EQ-5D) scores available. Patient age, body mass index (BMI), sex, American Society of Anesthesiologists (ASA) score, and Charlson Comorbidity Index were recorded. QALYs were determined from the EQ-5D index and the Short Form-6 Dimension (SF-6D) index. RESULTS: Five thousand, four hundred and sixty-three patients underwent total hip arthroplasty, with a mean annual increase (and standard deviation) of 0.25 ± 0.2 QALY; 843 patients underwent hip resurfacing, with a mean annual increase of 0.24 ± 0.17 QALY; 5,398 patients underwent primary total knee arthroplasty, with a mean annual increase of 0.17 ± 0.19 QALY; and 240 patients underwent medial unicompartmental knee arthroplasty, with a mean annual increase of 0.16 ± 0.17 QALY. Aseptic revision arthroplasty (440 hips, 323 knees) was associated with a smaller QALY gain than primary arthroplasty. Patient age, BMI, female sex, ASA category, and higher preoperative health-related quality of life were negative predictors for QALY gain after primary arthroplasty. Forty additional hip procedures and 35 additional knee procedures were also analyzed. CONCLUSIONS: Primary hip and knee arthroplasty, on average, result in substantially increased patient quality of life. Revision hip and knee replacement result in a lower, but still positive, gain in quality of life. However, there is a considerable variation in patient outcomes across all procedures. Our results may be used to improve the certainty of future cost-effectiveness analyses of hip and knee arthroplasty. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

An Analysis of the Influence of Physical Activity Level on Total Knee Arthroplasty Expectations, Satisfaction, and Outcomes: Increased Revision in Active Patients at Five to Ten Years.

This article was updated on September 19, 2018, because of a previous error. On page 1546, in the section titled "Discussion," the sentence that had read "Although a significant improvement was found in the vast majority of the inactive group, surprisingly, a majority of the active group (72.7%) reported a decrease in their activity levels below their baseline at 5 to 10 years postoperatively." now reads "Although a significant improvement was found in the vast majority of the inactive group, surprisingly, a majority of the active group (72.7%) reported no change or a decrease in their activity levels below their baseline at 5 to 10 years postoperatively." BACKGROUND: Patients undergoing total knee arthroplasty expect pain relief, functional improvement, and a return to physical activity. The objective of this study was to determine the impact of patients' baseline physical activity level on preoperative expectations, postoperative satisfaction, and clinical outcomes in patients undergoing total knee arthroplasty. METHODS: Using an institutional registry from 2007 to 2012, we retrospectively identified patients who underwent a unilateral primary total knee arthroplasty for osteoarthritis and completed a preoperative Lower Extremity Activity Scale (LEAS), a Hospital for Special Surgery Knee Replacement Expectations Survey (HSS-KRES), and a Knee injury and Osteoarthritis Outcome Score (KOOS) evaluation in addition to 2-year KOOS and satisfaction evaluations. Active patients were defined by an LEAS level of 13 to 18. Active patients (n = 1,008) were matched to inactive patients (n = 1,008) by age, sex, body mass index, and comorbidities. The cohorts were compared with regard to the association of expectations with KOOS and satisfaction, the change in LEAS level from baseline to 2 years, complications, and revision surgical procedures. Multivariable analyses identified predictors of satisfaction, KOOS, and revision surgical procedures. RESULTS: Significantly more active patients (68.2%) expected to be back to normal with regard to the ability to exercise and participate in sports compared with inactive patients (55.5%; p < 0.0001). Although overall satisfaction was equivalent, active patients were more commonly very satisfied with regard to the ability to do recreational activities (67.2% compared with 57.7%; p = 0.001). There were no associations between expectations and satisfaction or outcomes. Only the inactive patient group improved in activity level at 2 years. At 2 years, 69.5% of the inactive patients and 27.3% of the active patients improved upon their baseline activity levels (p < 0.0001). Complications rates were similar. The revision rate was higher for active patients (3.2%) compared with inactive patients (1.6%) at 5 to 10 years postoperatively (p = 0.019). CONCLUSIONS: At 2 years following total knee arthroplasty, inactive patients improved from baseline activity levels and active patients did not. Active patients had an elevated revision risk. Therefore, active patients should be carefully counseled regarding total knee arthroplasty to give them an understanding of its limitations and the potential risk of future revision. LEVEL OF EVIDENCE: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

What Are the Minimal and Substantial Improvements in the HOOS and KOOS and JR Versions After Total Joint Replacement?

BACKGROUND: Patient-reported outcome measures (PROMs) are a gold standard for measuring therapeutic outcomes in research. Extending their use to inform clinical care decisions, determine the appropriateness of therapeutic choices, and assess healthcare quality is attractive but will require our professional community to establish valid estimates of minimal and substantial clinical improvements. QUESTIONS/PURPOSES: The purposes of this study were (1) to assess the validity of estimates for the minimal clinically important difference (MCID) calculated using distribution- and anchor-based methods by determining whether they exceed the minimal detectable change (MDC) for the Hip Disability and Osteoarthritis Outcome Score (HOOS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS) domains, the HOOS, joint replacement (JR) and the KOOS, JR among patients who underwent THA or TKA; (2) to determine substantial clinical benefit thresholds for the HOOS and KOOS domains, the HOOS, JR, and the KOOS, JR among patients who underwent THA or TKA; and (3) to assess the proportions of patients who underwent THA or TKA who achieved an MCID for the HOOS and KOOS domains, HOOS, JR, and KOOS, JR based on distribution-based and anchor-based methods as well as the percentages of patients who achieved substantial clinical benefit using the anchor-based method. METHODS: Medicare patients enrolled in our institutional joint replacement registry who subsequently underwent THA (n = 2323) or TKA (n = 2630) between 2007 and 2012 completed HOOS or KOOS preoperatively and 2 years postoperatively. Short-form joint replacement (JR) versions of each PROM were derived from the full PROMs. Of all eligible patients, 78% (3161 of 4080) of THAs and 74% of TKAs (3815 of 5156) consented to join the registry and completed a baseline survey, 88% (2796 of 3161) of THAs and 85% (3230 of 3815) of TKAs were eligible for followup survey administration, and 83% of THAs (2323 of 2796) and 81% (2630 of 3230) of TKAs returned 2-year surveys. For each HOOS domain, KOOS domain, HOOS, JR, and KOOS, JR, we calculated the calibration variation of the instrument (MDC) with confidence intervals (CIs) reflecting 80% (MDC80), 90% (MDC90), and 95% (MDC95) certainty; we calculated the smallest difference joint health patients might detect (MCID) using distribution- and anchor-based approaches and the difference that can be considered a large improvement in joint health (substantial clinical benefit) using an anchor-based approach. RESULTS: Patients undergoing THA were 57% female with a mean (± SD) age of 73 ± 6 years, whereas patients undergoing TKA were 63% female with a mean age of 74 ± 6 years. Depending on the CI chosen for the MDC, values ranged from 7 to 16 for the HOOS and KOOS domains and the JRs. The MCIDs ranged from 6 to 9 for the distribution-based approach and 7 to 36 for the anchor-based approach. All HOOS and KOOS domains and all JR scores are scores from 0 (worst joint health) to 100 (best joint health). The MCIDs calculated using the distribution-based approach were not valid, because they were lower than the MDC for all HOOS/KOOS domains and both JRs at every confidence level. The anchor-based receiver operating characteristic approach, on the other hand, resulted in MCIDs exceeding MDC80 for seven of eight HOOS/KOOS domains and MDC95 for both JR scores. For all domains and JR versions, substantial clinical benefits ranged from 15 to 36, exceeding MDC95 in all domains and JR scores. Across HOOS and KOOS domains as well as the JR, the proportion of patients undergoing THA who achieved an MCID ranged from 77% to 95% with the distribution-based method and from 67% to 96% using the anchor-based method. The proportion achieving substantial clinical benefit ranged from 67% to 85%. CONCLUSIONS: The MDC and MCID differ greatly based on assumptions and methods used. The MCID anchor-based approach had superior construct and face validity compared with the MCID distribution-based approach, which never exceeded even small MDCs. Achieving consensus about standard definitions of meaningful improvement will be necessary to maximize utility of these PROMs to inform clinical care or performance measurement. LEVEL OF EVIDENCE: Level III, diagnostic study.

Intravenous Versus Topical Tranexamic Acid in Total Knee Arthroplasty: Both Effective in a Randomized Clinical Trial of 640 Patients.

BACKGROUND: Tranexamic acid (TXA) reduces bleeding and the need for transfusion after total knee arthroplasty. Most literature has focused on intravenous (IV) administration of TXA, with less data available on the efficacy of topically administered TXA. This multicenter randomized clinical trial specifically assessed the efficacy of topical TXA compared with IV TXA as measured by calculated blood loss, drain output, and transfusion rates. Complications, including venous thromboembolism (VTE), were reported. METHODS: A total of 640 patients who underwent primary unilateral total knee arthroplasty for osteoarthritis at 2 large academic centers were randomized to receive 1 g of IV TXA prior to tourniquet inflation and 1 g at closure, or 3 g of TXA diluted in 45 mL of normal saline solution (total volume of 75 mL) and topically applied after cementation. Age, sex, body mass index, American Society of Anesthesiologists (ASA) score, and preoperative hemoglobin level were similar between the groups. Univariate, multiple linear regression, and multiple logistic regression analyses were performed. RESULTS: Patients who received topical TXA had significantly greater calculated blood loss compared with those who received IV TXA (mean of 324 compared with 271 mL; p = 0.005). Drain output was significantly higher in the topical TXA group compared with the IV TXA group (mean of 560 compared with 456 mL; p < 0.0001). The rate of transfusion was low in the topical and IV groups, with no significant difference on univariate analysis (1.6% compared with 0.6%, respectively; p = 0.45); however, on multiple logistic regression analysis, patients who received topical TXA were 2.2-fold more likely to receive a transfusion (p < 0.0001). The topical and IV TXA groups did not differ significantly with respect to the rate of thrombotic events (0.6% compared with 1.6%, respectively; p = 0.45). CONCLUSIONS: In this large, randomized clinical trial involving patients undergoing total knee arthroplasty, both IV and topical TXA were associated with a low rate of transfusion. While IV TXA was associated with less calculated blood loss, lower drain output, and fewer transfusions, the small differences between the groups may not be clinically important. Given the low prevalence of thrombotic complications, the relative safety of one formulation of TXA over the other cannot be definitely established. LEVEL OF EVIDENCE: Therapeutic Level I. See Instructions for Authors for a complete description of levels of evidence.

Implant Survival and Patient-Reported Outcomes After Total Hip Arthroplasty in Young Patients.

BACKGROUND: Younger patients are undergoing total hip arthroplasty (THA) for various conditions that affect the hip joint. This study evaluates the implant survival and long-term patient-reported outcomes of THA in patients aged 35 years or younger. METHODS: Data were collected through a retrospective chart review, and follow-up surveys were conducted to determine implant survival and patient-reported outcomes. Kaplan-Meier survival analysis was performed to evaluate implant survival, and the hip disability and osteoarthritis outcome score (HOOS) was used to describe patient-reported outcomes. Descriptive statistics were used to summarize baseline and follow-up data, and univariate and multivariate analyses were used to compare implant survival and patient-reported outcomes. RESULTS: This study included 400 patients (548 THAs). The average age at the time of surgery was 27 (range: 8-35) years, and the mean time to follow-up was 14 (range: 2-29.7) years. The 10- and 20-year implant survival was 87% and 61%, respectively. Implant survival differed based on primary diagnosis (P = .05), and it was significantly better in patients aged 25 years or older at the time of surgery, male patients, and patients with ceramic-on-ceramic or ceramic-on-plastic implants (P < .05). Mean HOOS scores at follow-up were 86 for pain, 84 for symptoms, 86 for ADLs, and 77 for sports. All HOOS scores were significantly worse after revision THA (P < .01). CONCLUSION: Young patients have good implant survival and favorable long-term outcomes after THA. There are several predictors of implant survival and patient-reported outcomes after THA in young patients.

Preoperative Valgus Alignment Does Not Predict Inferior Outcome of Total Knee Arthroplasty.

BACKGROUND: Preoperative valgus deformity is present in an estimated 10-20% of patients undergoing total knee replacement (TKR). QUESTIONS/PURPOSES: The objective of this study was to compare the Western Ontario and McMaster Universities Arthritis Index (WOMAC) scores after TKR in a matched cohort of patients with preoperative valgus and varus deformities. METHODS: This is a matched cohort study of 162 patients with varus native knees and 162 patients with valgus native knees who underwent TKR and were prospectively followed in our institutional registry. Patients matched were based on age, BMI, sex, and severity of preoperative knee deformity, which was classified as mild, moderate, severe varus or valgus, or no deformity. Outcomes were evaluated using the WOMAC preoperatively and at 6 weeks, 3 months, 6 months, and 1 year postoperatively. RESULTS: No significant difference was found between the matched varus and valgus cohorts in all WOMAC subdomain scores except for a marginally worse stiffness at 1 year in patients with valgus deformity (WOMAC stiffness, 75.1 varus vs. 70.1 valgus; P = 0.049). This is below the minimal clinically important difference for WOMAC scores. There was no significant difference in postoperative varus/valgus alignment between the two groups (P = 0.092). CONCLUSION: We found no clinically significant difference in any of the WOMAC domains in patients with preoperative varus deformity versus valgus deformity within the first year after TKR. These findings may allow surgeons to more appropriately counsel patients with osteoarthritis with valgus deformity that they can expect similar outcomes compared to patients with varus deformity.

Satisfaction Rates and Quality of Life Changes Following Total Knee Arthroplasty in Age-Differentiated Cohorts.

BACKGROUND: Comparisons of satisfaction rates following total knee arthroplasty (TKA) among large, age-differentiated, rigorously matched cohorts are lacking. Therefore, we compared satisfaction rates following TKA in large, age-differentiated, propensity score-matched cohorts. METHODS: We identified primary TKAs performed for non-inflammatory arthritis in patients of ages 18-55 or 65-75, yielding 529 younger and 2001 older patients. Patient-reported outcomes were recorded pre-operatively and 2 years post-operatively. 1:1 propensity score matching between groups yielded 529 patient pairs. Matching was based on gender, body mass index, American Society of Anesthesiologists grade, Charlson Comorbidity Index, and Short Form 12 Mental Health Component score. Outcomes were compared between matched groups using t-test and Wilcoxon rank-sum test. RESULTS: Satisfaction with knee surgery was 86% among younger patients and 91% among older patients. Distribution of satisfaction responses was shifted toward greater satisfaction in older patients (P < .001). Overall quality of life (QOL) improvement was 91% among younger patients and 96% among older patients. Pre-operative and post-operative knee-related QOL was better among older patients (P < .0001). Post-operative global health-related QOL was equivalent between groups based on Short Form 12 Physical Component Score and Mental Health Component score (P = .6646 and P = .5705, respectively) and QOL improvement questionnaires (P = .181). Younger patients reported greater knee-related dysfunction and higher activity levels pre-operatively and post-operatively (P ≤ .0002). CONCLUSION: Satisfaction with knee surgery was over 85% regardless of age. Younger patients perceived more knee-related dysfunction and dissatisfaction after surgery despite higher levels of self-reported activity pre-operatively and post-operatively.

In-Hospital Morbidity and Postoperative Revisions After Direct Anterior vs Posterior Total Hip Arthroplasty.

BACKGROUND: The direct anterior approach (DAA) offers the potential for less soft tissue insult, improved early recovery, and reduced dislocation rates. However, complications are associated with the DAA, particularly during the learning curve. We compare the DAA learning curve experience with the posterior approach regarding in-hospital complications and revision rate. METHODS: We evaluated systemic and local in-hospital complications associated with primary unilateral cementless THAs from January 1, 2010 to December 31, 2012 in 4249 patients through a posterior approach and 289 patients through a DAA. All procedures were performed consecutively by high-volume surgeons who use a single approach in a nonselective manner. The DAA was performed by surgeon transitioning from the posterior approach, thus incorporating the learning curve. Demographics were comparable. Revision procedures were captured through a minimum 4-year follow-up. Analyses compared complication and revision rates. RESULTS: The DAA group demonstrated shorter length of stay, procedure time, lower blood transfusion rate, and increased discharge to home rate. Local and major systemic in-hospital complications were rare and comparable between groups. The minor systemic complication rate was significantly greater for the posterior group (10.9% posterior vs 6.2% DAA, P < .05). Revision rate was significantly greater for the posterior group (2.7% posterior vs 0.7% DAA, P < .032). The incidence of revision for dislocation was 1.5% for the posterior approach vs 0.4% for the DAA. CONCLUSION: There was an increased rate of in-hospital minor systemic complications and overall revision, predominantly due to instability, after THA by the posterior approach, in comparison with the DAA.

Bariatric Surgery Improves Outcomes After Lower Extremity Arthroplasty in the Morbidly Obese: A Propensity Score-Matched Analysis of a New York Statewide Database.

BACKGROUND: The purpose of this study was to compare risks for revision and short-term complications after total joint arthroplasty (TJA) in matched cohorts of morbidly obese patients, receiving and not receiving prior bariatric surgery. METHODS: Patients undergoing elective TJA between 1997 and 2011 were identified in a New York Statewide database, analyzing total knee arthroplasty (TKA) and total hip arthroplasty (THA) separately. Propensity scores were used to match morbidly obese patients receiving and not receiving bariatric surgery prior to TJA. Cox proportional hazard modeling assessed revision risk. Logistic regression evaluated odds for complications. RESULTS: For TKA, 2636 bariatric surgery patients were matched to 2636 morbidly obese patients. For THA, 792 bariatric surgery patients were matched to 792 morbidly obese patients. Matching balanced all covariates. Bariatric surgery reduced co-morbidities prior to TJA (TKA P < .0001; THA P < .005). Risks for in-hospital complications were lower for THA and TKA patients receiving prior bariatric surgery (odds ratio [OR] 0.25, P < .001; and OR = 0.69, P = .021, respectively). Risks for 90-day complications were lower for TKA (OR 0.61, P = .002). Revision risks were not different for either THA (P = .634) or TKA (P = .431), nor was THA dislocation risk (P = 1.000). CONCLUSION: After accounting for relevant selection biases, bariatric surgery prior to TJA was associated with reduced co-morbidity burden at the time of TJA and with reduced post-TJA complications. However, bariatric surgery did not reduce the risk for revision surgery for either TKA or THA.

Venous Hemodynamics After Total Hip Arthroplasty: A Comparison Between Portable vs Stationary Pneumatic Compression Devices and the Effect of Body Position.

BACKGROUND: Improvements in device design have allowed for portable pneumatic compression devices (PPCDs). However, portability results in smaller pumps that move less blood. Additionally, although patients often stand when wearing PPCDs, few studies have evaluated the hemodynamic effects of PCDs while standing. METHODS: A crossover study was performed to compare a PPCD (ActiveCare+S.F.T.; Medical Compression Systems, Or Akiva, Israel) to a stationary pneumatic compression device (SPCD) (VenaFlow; DJO Global, Carlsbad, CA) on hemodynamics in supine and standing positions among 2 cohorts composed of 10 controls and 10 total hip arthroplasty patients. Differences in baseline peak venous velocity (PVV), PVV with each PCD, and delta PVV with each PCD were assessed. A multivariate analysis was performed to examine differences between cohorts, devices, and position. RESULTS: In both positions, the SPCD demonstrated a larger change in PVV when compared to the PPCD (P < .001). The total hip arthroplasty group had a greater delta PVV while standing when considering both PCDs together (P < .001). When considering both cohorts, delta PVV was greater while standing, only when the SPCD was used (P < .001). There was no difference between standing and supine positions when the PPCD was used. CONCLUSION: The SPCD demonstrated a greater capacity to increase PPV in the supine and standing positions. The SPCD generated greater values of PVV and delta PVV in the standing position. Although these results demonstrate a difference between devices, it is important to establish the PVV necessary to prevent VTE before one is considered more effective.

Polished, Collarless, Tapered, Cemented Stems for Primary Hip Arthroplasty May Exhibit High Rate of Periprosthetic Fracture at Short-Term Follow-Up.

BACKGROUND: Cemented stems are designed to follow 1 of 2 principles of fixation: composite beams or slide taper. Stems in the latter category have a collarless, polished, tapered (CPT) design and subside into the cement mantle, creating hoop stresses. We compared the rate of periprosthetic fracture (PPF) of stem designed with these 2 principles of fixation. In addition, we examined radiographic factors that may predispose to the development of PPF. METHODS: We retrospectively reviewed all patients who underwent primary THA by a single surgeon using highly polished cemented stems. PPF rates were compared between CPT stems (follow-up, 21 months; standard deviation [SD], 22) and composite beam stems (follow-up, 21.7 months; SD, 26). Demographic data were compared between patients with and without a PPF. Three preoperative radiographic parameters (canal bone ratio [CBR], canal-calcar ratio, and canal flare index), stem alignment, and cement mantle were compared in match-paired patients with and without a PPF (1:34). RESULTS: Seven of 1460 THA patients developed a PPF (0.479%); 4 hips of 185 with a CPT stem (2.2%); and 3 of 1275 hips with a composite beam stem (0.23%; P = .0064). Three of the 4 PPFs in the CPT group and none in the composite beam group were classified as Vancouver B2. The CBR in patients with a PPF was 0.50 (SD, 0.07) and 0.43 (SD, 0.07) in the match cohort of hips without PPF (P = .013). CONCLUSION: CPT stems may be associated with a higher risk of PPF that often require reoperation. An increased CBR may be a risk factor for postoperative PPF.

Failure After Modern Total Knee Arthroplasty: A Prospective Study of 18,065 Knees.

BACKGROUND: We sought is to determine the mechanism of failure among primary total knee arthroplasties (TKAs) performed at a single high-volume institution by asking the following research questions: (1) What are the most common failure modes for modern TKA designs? and (2) What are the preoperative risk factors for failure following primary TKA? METHODS: From May 2007 to December 2012, 18,065 primary TKAs performed on 16,083 patients at a single institution were recorded in a prospective total joint arthroplasty registry with a minimum of 5-year follow-up. We retrospectively reviewed patient charts to determine a cause of failure for primary TKAs. A cox proportional hazard model was used to determine the risk of revision surgery following primary TKA. RESULTS: The most common reasons for failure within 2 years after TKA were infection and stiffness. The multivariable regression identified the following preoperative risk factors for TKA failure: history of drug abuse (hazard ratio [HR] 4.68; P = 0.03), deformity/mechanical preoperative diagnosis (HR 3.52; P < .01), having a constrained condylar knee implant over posterior-stabilized implant (HR 1.99; P < .01), post-traumatic/trauma preoperative diagnosis (HR 1.78; P = .03), and younger age (HR 0.61; P < .01) CONCLUSION: These findings add to the growing data that primary TKAs are no longer failing from polyethylene wear-related issues. This study identified preoperative risk factors for failure of primary TKAs, which may be useful information for developing strategies to improve outcomes following TKA.

Polyethylene Damage Increases With Varus Implant Alignment in Posterior-stabilized and Constrained Condylar Knee Arthroplasty.

BACKGROUND: Implant malalignment in primary TKA has been reported to increase stresses placed on the bearing surfaces of implant components. We used a longitudinally maintained registry coupled with an implant retrieval program to consider whether preoperative, postoperative, or prerevision malalignment was associated with increased risk of revision surgery after TKA. QUESTIONS/PURPOSES: (1) What is the relative polyethylene damage on medial and lateral compartments of the tibial plateaus from revised TKAs? (2) Does coronal TKA alignment affect implant performance, such that TKAs aligned in varus are predisposed to experience increased polyethylene damage? (3) Does TKA alignment differ between postoperative and prerevision radiographs, and if so, what does this difference suggest about the mechanical contact load placed on a knee with a TKA? METHODS: Between 2007 and 2012, we performed 18,065 primary TKAs at our institution. By March 2016, 178 of those TKAs (1%) were revised at our center at least 2 years after primary surgery at our institution. Eighteen of those TKAs were excluded from this analysis because the tibial insert was not explanted during revision surgery, and four more were excluded because the inserts were lost or returned to the patient before the study was initiated, leaving 156 retrieved polyethylene tibial inserts (in 153 patients) revised at greater than 2 years after the primary TKA for this retrospective study. Patients who underwent revision surgery elsewhere were not considered here, since this study depended on having retrieved components. Polyethylene damage modes of burnishing, pitting, scratching, delamination, surface deformation, abrasion, and third-body debris were subjectively graded on a scale of 0 to 3 to reflect the extent and severity of each damage mode. On preoperative, postoperative, and prerevision radiographs, overall alignment, femoral alignment, and tibial alignment in the coronal plane were measured according to the protocol recommended by the Knee Society. RESULTS: Knees with more overall varus alignment after TKA had increased total damage on the retrieved tibial inserts (Spearman's rank correlation coefficients of -0.3 [95% CI, -0.4 to -0.1; p = 0.001]). We also found revised TKAs tended to drift back into greater varus before revision surgery, with a mean (SD) of 3.6° ± 4.0° valgus for postoperative alignment compared with 1.7° ± 6.4° prerevision (p = 0.04). CONCLUSIONS: Despite surgical efforts to achieve neutral mechanical alignment, remaining varus alignment places an increased contact load on the polyethylene articular surfaces. The drift toward further varus alignment postoperatively is consistent with the knee adduction moment remaining high after surgery. CLINICAL RELEVANCE: While we found a predisposition toward recurrence of the preoperative varus deformity, we did not find increased medial as opposed to lateral polyethylene damage, which may be explained by the curve-on-curve toroidal design of the articulating surfaces of the TKA implants in this study.

Radiographic outcomes of cable-plate versus cable-grip fixation in periprosthetic fractures of the proximal femur.

BACKGROUND: Newer generation cable-plate designs are commonly used for periprosthetic proximal femur fractures; however, comparisons relative to cable-grips remain limited. The aim of this study was to compare radiographic healing rates of cable-plate versus cable-grip fixation for periprosthetic proximal femur fractures. PATIENTS AND METHODS: Consecutive patients with an acute or chronic Vancouver A, B1, or B2 periprosthetic proximal femur fracture undergoing trochanteric fixation with a cable-plate (n = 46 cases) or cable-grip (n = 24 cases) system were identified retrospectively from a single-centre hospital database (mean follow-up 28 months [range 6-89 months]). Demographics, radiographic fracture healing, and complications were compared between the 2 groups. Radiographic union rates were not different between the cable-grip versus cable-plate group (67% vs. 76% respectively; p = 0.4). Healing rates of greater trochanteric fractures alone were not different between the cable-plate versus cable-grip groups (75% vs. 71% respectively; p = 0.38). The cable-plates were used for a more diverse range of fracture patterns relative to the cable-grips. RESULTS: An increased number of cables was associated with radiographic healing (odds ratio 14 [95% confidence interval 2-64]; p = 0.01), and body mass index had a negative correlation with radiographic healing (odds ratio -0.4 [95% confidence interval 0.5-0.9]. CONCLUSIONS: Similar rates of periprosthetic fracture healing were seen using a cable-grip versus cable-plate system; however, the cable-plate system could be used for a more diverse range of fracture patterns.