Changes in Hip Capsule Morphology after Arthroscopic Treatment for Femoroacetabular Impingement Syndrome with Periportal Capsulotomy are Correlated With Improvements in Patient-Reported Outcomes.

PURPOSE: To assess the correlation between changes in hip capsule morphology with improvements in patient-reported outcome (PRO) scores after arthroscopic surgery for femoroacetabular impingement syndrome (FAIS) using the periportal capsulotomy technique. METHODS: Twenty-eight patients with cam morphology FAIS (without arthritis, dysplasia, or hypermobility) were prospectively enrolled before arthroscopic labral repair and femoroplasty through periportal capsulotomy (anterolateral/midanterior portals) without closure. Patients completed the Hip Disability and Osteoarthritis Outcomes Score (HOOS) and had nonarthrographic 3T magnetic resonance imaging (MRI) scans of the affected hip before and 1 year after surgery. Anterior capsule thickness, posterior capsule thickness, anterior-posterior capsule thickness ratio, and proximal-distal anterior capsule thickness ratio were measured on axial-oblique MRI sequences. Pearson correlation coefficients were calculated to determine the association between hip capsule morphology and PRO scores. RESULTS: Postoperative imaging showed that for all 28 patients (12 female), labral repairs and capsulotomies had healed within 1 year of surgery. Analysis revealed postoperative decreases in anterior hip capsule thickness (1395.4 ± 508.4 mm3 vs 1758.4 ± 487.9 mm3; P = .003) and anterior-posterior capsule thickness ratio (0.92 ± 0.33 vs 1.12 ± 0.38; P = .02). Higher preoperative anterior-posterior capsule thickness ratio correlated with lower preoperative scores for HOOS pain (R = -0.43; P = .02), activities of daily living (ADL) (R = -0.43; P = .02), and sport (R = -0.38; P = .04). Greater decrease from preoperative to postoperative anterior-posterior capsule thickness ratio correlated with greater improvement for HOOS pain (R = -0.40; P = .04), ADL (R = -0.45; P = .02), and sport (R = -0.46; P = .02). CONCLUSIONS: Periportal capsulotomy without closure demonstrates capsule healing by 1 year after arthroscopic FAIS treatment. Changes in hip capsule morphology including decreased anterior-posterior capsule thickness ratio after surgery may be correlated with improvements in patient pain, function, and ability to return to sports. LEVEL OF EVIDENCE: Level II, prospective cohort study.

Impact of fatty degeneration on the functional outcomes of 38 patients undergoing surgical repair of gluteal tendon tears.

BACKGROUND: Gluteal tendon tears (GTT) can cause pain and weakness of the hip. We analyze the impact of gluteal muscle fatty degeneration, atrophy and tear morphology on clinical outcomes of surgical repair. METHODS: All sequential patients receiving surgical repair of GTTs via anchor sutures between 1/2015 and 11/2018 were retrospectively identified. MRIs were reviewed by a radiologist for tendon retraction, muscle atrophy and tear size. The Goutallier-Fuchs Classification (GFC) was used to quantify fatty degeneration as < 2° or ≥ 2°. Demographic and clinical variables were abstracted from the electronic records. The surveys HHS Section 1 and HOOS Jr. were obtained at last follow-up. The Pearson correlation and one-way ANOVA tests served for statistical analysis of clinical variance. RESULTS: 38 patients were identified, 29 (76.3%) were female. The average age was 67. Of the 11 (28.9%) patients with a prior hip arthroplasty 87.5% of primary THAs had a direct lateral approach. 29 (76.3%) patients were treated open and 9 (23.7%) arthroscopically. At an average follow-up of 20.9 months, patients reported a significant improvement in pain (97%), analgesic use (85.7%), limp (52.6%) and abduction strength (54.2%) (all: P ≤ 0.01). GFC ≥ 2° were associated with significantly worse outcomes in terms of limp (0.19/3 vs. 1.2/3, P = 0.05), HHS-S1 (58.19 vs. 71.68, P = 0.04) and complication rates (37.5% vs. 0%, P = 0.02). There was a strong correlation between tear retraction (P = 0.005), tear size (P = 0.009) and muscle atrophy (P = 0.001) with GFC ≥ 2° but not with clinical outcomes. GFC ≥ 2° was strongly related to lateral THA exposures (P < 0.001). Surgical approach had no impact on clinical outcomes. CONCLUSION: While fatty degeneration can negatively impact functional outcomes, pain relief is reliably achieved. Tear morphology and muscle atrophy did not correlate with outcomes in this patient cohort. Patients should be counseled to expect a residual limp after surgery if they have GFC ≥ 2° on MRI.

Diagnostic value of fluoroscopy-guided hip aspiration for periprosthetic joint infection.

PURPOSE: To assess the value of preoperative joint aspiration in detecting periprosthetic joint infection (PJI) in patients undergoing revision hip arthroplasty and to compare these with the clinical findings, serum markers, and intraoperative findings. MATERIALS AND METHODS: Fluoroscopically guided hip aspirations in patients with pain after hip arthroplasty were retrospectively reviewed from January 2014 to December 2018. All hips underwent subsequent revision hip arthroplasty. Antibiotics were discontinued at least 2 weeks before the aspiration. The 2018 Musculoskeletal Infection Society (MSIS) criteria served as a standard of reference for PJI. Clinical, serum, synovial, and intraoperative parameters were recorded in all patients. Correlations between all parameters with PJI diagnosis were analyzed using linear and logistic regression models with ROC analysis. RESULTS: In 202 hips that included 91 septic hips, hip aspiration (AUC = 0.78) and intraoperative (0.80) parameters performed better than serum-based tests (0.64) and clinical parameters (0.68) in detecting PJI. Using MSIS criteria as a standard of reference, hip aspiration had a sensitivity of 64.0% and an accuracy of 78.5% for cultures and a sensitivity of 74.2% and an accuracy of 82.1% for synovial polymorphonuclear neutrophils% (PMN%). Results substantially improved sensitivity after excluding patients that were treated with antibiotics, particularly culture results. CONCLUSIONS: Preoperative hip aspiration showed good diagnostic performance in diagnosing PJI compared with MSIS criteria as a standard of reference. But a negative result from aspirate could not rule out PJI. Based on our findings, hip aspiration is an essential test for treatment planning in patients with pain after hip arthroplasty.

Predicting outcomes in patients undergoing intra-articular corticosteroid hip injections.

OBJECTIVE: To investigate the associations between clinical, procedural, and radiographic factors and outcomes of steroid hip injections, including long-term and immediate pain reduction, time to arthroplasty, time to reinjection, and the total number of injections. MATERIALS AND METHODS: All intra-articular anesthetic and steroid injections of the hip under fluoroscopic guidance between January 2014 and March 2016 were retrospectively reviewed. Hip radiographs were scored using the Kellgren-Lawrence (KL) and Osteoarthritis Research Society International (OARSI) scores. Immediate pain relief and response were evaluated using a change in visual analog scale and OMERACT-OARSI criteria respectively. Long-term pain relief was evaluated at 2­7 months after injection by reviewing the medical records. Correlation between patient characteristics, procedural variations, and radiographic factors with injection outcomes was analyzed by using linear and logistic regression models. RESULTS: Of 361 injections, 79.8% showed an immediate pain response and 32.7% had subjective long-term pain relief (> 2 months). There was no significant correlation between immediate pain relief and response with long-term pain relief and other outcomes. Older age and higher KL score, OARSI-central joint space narrowing (JSN), and inferior acetabular osteophyte were correlated with long-term pain relief (p = 0.01­0.03). Higher KL and OARSI grades, particularly JSN, were significantly correlated with increased immediate pain relief and total number of injections but decreased time to arthroplasty. Baseline pain positively correlated with immediate pain response (p < 0.001). CONCLUSIONS: Older patients with higher grades of radiographic OA and high baseline pain were good candidates for steroid injections, particularly for those patients awaiting hip arthroplasty.

Independent Risk Factors for Transfusion in Contemporary Revision Total Hip Arthroplasty.

BACKGROUND: The incidence of transfusion in contemporary revision total hip arthroplasty (THA) remains high despite recent advances in blood management, including the use of tranexamic acid. The purpose of this prospective investigation was to determine independent risk factors for transfusion in revision THA. METHODS: Six centers prospectively collected data on 175 revision THAs. A multivariable logistic analysis was performed to determine independent risk factors for transfusion. Revisions were categorized into subgroups for analysis, including femur-only, acetabulum-only, both-component, explantation with spacer, and second-stage reimplantation. Patients undergoing an isolated modular exchange were excluded. RESULTS: Twenty-nine patients required at least one unit of blood (16.6%). In the logistic model, significant risk factors for transfusion were lower preoperative hemoglobin, higher preoperative international normalized ratio (INR), and longer operative time (P < .01, P = .04, P = .05, respectively). For each preoperative 1g/dL decrease in hemoglobin, the chance of transfusion increased by 79%. For each 0.1-unit increase in the preoperative INR, transfusion chance increased by 158%. For each additional operative hour, the chance of transfusion increased by 74%. There were no differences in transfusion rates among categories of revision hip surgery (P = .23). No differences in demographic or surgical variables were found between revision types. CONCLUSION: Despite the use of tranexamic acid, transfusions are commonly required in revision THA. Preoperative hemoglobin and INR optimization are recommended when medically feasible. Efforts should also be made to decrease operative time when technically possible.

Equivalent Mid-Term Results of Open vs Endoscopic Gluteal Tendon Tear Repair Using Suture Anchors in Forty-Five Patients.

BACKGROUND: Little is known about the relative efficacy of open (OGR) vs endoscopic (EGR) gluteal tendon repair of gluteal tendon tears in minimizing pain and restoring function. Our aim is to compare these 2 surgical techniques and quantify their impact on clinical outcomes. METHODS: All patients undergoing gluteal tendon tear repair at our institution between 2015 and 2018 were retrospectively reviewed. Pain scores, limp, hip abduction strength, and the use of analgesics were recorded preoperatively and at last follow-up. The Hip disability and Osteoarthritis Outcome Score Junior and Harris Hip Score Section1 were obtained at last follow-up. Fatty degeneration was quantified using the Goutallier-Fuchs Classification (GFC). Statistical analysis was conducted using one-way analysis of variance and t-tests. RESULTS: Forty-five patients (mean age 66, 87% females) met inclusion criteria. Average follow-up was 20.3 months. None of the 10 patients (22%) undergoing EGR had prior surgery. Of 35 patients (78%) undergoing OGR, 12 (27%) had prior hip replacement (75% via lateral approach). The OGRs had more patients with GFC ≥2 (50% vs 11%, P = .02) and used more anchors (P = .03). Both groups showed statistical improvement (P ≤ .01) for all outcomes measured. GFC >2 was independently associated with a worst limp and Harris Hip Score Section 1 score (P = .05). EGR had a statistically higher opioid use reduction (P < .05) than OGR. Other comparisons between EGR and OGR did not reach statistical significance. CONCLUSION: In this series, open vs endoscopic operative approach did not impact clinical outcomes. More complex tears were treated open and with more anchors. Fatty degeneration adversely impacted outcomes. Although further evaluation of the efficacy of EGR in complex tears is indicated, both approaches can be used successfully.

Bilateral Simultaneous vs Staged Total Knee Arthroplasty: Minimal Difference in Perioperative Risks.

BACKGROUND: With the rising utilization of total joint arthroplasty, the role of simultaneous-bilateral surgery will have an expanding impact. The purpose of this study is to examine the risks of perioperative complications with this approach in total knee arthroplasty (TKA), to inform shared decision-making. METHODS: We reviewed national hospital discharge data from 2005 to 2014 to compare outcomes between simultaneous-bilateral TKAs (sim-BTKAs) and staged-bilateral TKAs (staged-BTKAs). Hierarchical logistic regression analyses were used to adjust for confounders. Outcomes analyzed included mortality, various medical complications, knee infection, and mechanical complications. RESULTS: This study analyzed 27,301 sim-BTKAs and 45,419 staged-BTKAs. Patients who underwent simultaneous surgery had a statistically significant higher adjusted odds of mortality, cardiac events, thromboembolic events, and complications involving the urinary and digestive systems, and a lower adjusted odds of deep knee infection and hematoma. Thirteen of the 14 complications had overall incidences less than 2% and 1 outcome had an incidence of 3%. The absolute between-group risk difference for any complication was 1% or less. CONCLUSION: Sim-BTKAs have a statistically significant increased odds of multiple complications compared to staged-BTKAs. However, the absolute risk differences between these options are minimal and the occurrence of any complication is low. LEVEL OF EVIDENCE: Therapeutic Level III.

Variation in the Thickness of Knee Cartilage. The Use of a Novel Machine Learning Algorithm for Cartilage Segmentation of Magnetic Resonance Images.

BACKGROUND: The variation in articular cartilage thickness (ACT) in healthy knees is difficult to quantify and therefore poorly documented. Our aims are to (1) define how machine learning (ML) algorithms can automate the segmentation and measurement of ACT on magnetic resonance imaging (MRI) (2) use ML to provide reference data on ACT in healthy knees, and (3) identify whether demographic variables impact these results. METHODS: Patients recruited into the Osteoarthritis Initiative with a radiographic Kellgren-Lawrence grade of 0 or 1 with 3D double-echo steady-state MRIs were included and their gender, age, and body mass index were collected. Using a validated ML algorithm, 2 orthogonal points on each femoral condyle were identified (distal and posterior) and ACT was measured on each MRI. Site-specific ACT was compared using paired t-tests, and multivariate regression was used to investigate the risk-adjusted effect of each demographic variable on ACT. RESULTS: A total of 3910 MRI were included. The average femoral ACT was 2.34 mm (standard deviation, 0.71; 95% confidence interval, 0.95-3.73). In multivariate analysis, distal-medial (-0.17 mm) and distal-lateral cartilage (-0.32 mm) were found to be thinner than posterior-lateral cartilage, while posterior-medial cartilage was found to be thicker (0.21 mm). In addition, female sex was found to negatively impact cartilage thickness (OR, -0.36; all values: P < .001). CONCLUSION: ML was effectively used to automate the segmentation and measurement of cartilage thickness on a large number of MRIs of healthy knees to provide normative data on the variation in ACT in this population. We further report patient variables that can influence ACT. Further validation will determine whether this technique represents a powerful new tool for tracking the impact of medical intervention on the progression of articular cartilage degeneration.

Editorial Commentary: Can We Achieve Personalized Risk Assessment in Hip Arthroscopy?

Gender, age, obesity, osteoarthritis, absence of labral repair, and index procedure performed by a lower volume surgeon were identified as risk factors for reoperation in a statewide study of hip arthroscopy. Although this analysis is helpful for benchmarking expectations for outcome in hip arthroscopy, unaccounted patient variables in the database could significantly complicate and confound the point of care application of the findings.

Does Intrathecal Morphine in Spinal Anesthesia Have a Role in Modern Multimodal Analgesia for Primary Total Joint Arthroplasty?

BACKGROUND: Intrathecal morphine (ITM) combined with bupivacaine spinal anesthesia can improve postoperative pain, but has potential side effects of postoperative nausea/vomiting (PONV) and pruritus. With the use of multimodal analgesia and regional anesthetic techniques, postoperative pain control has improved significantly to a point where ITM may be avoided in total joint arthroplasty (TJA). METHODS: We performed a retrospective study of primary TJA patients who underwent a standardized multimodal recovery pathway and received bupivacaine neuraxial anesthesia with ITM vs bupivacaine neuraxial anesthesia alone (control). RESULTS: In total, 598 patients were identified (131 controls, 467 ITMs) with similar demographics. On postoperative day 0 (POD 0), ITM patients had significantly lower mean visual analog scale scores (1.5 ± 1.6 vs 2.5 ± 1.9, P < .001) and consumed less oral morphine equivalents (10.5 ± 25.4 vs 16.8 ± 27.2, P = .013). ITM patients walked further compared to controls by POD 1 (133.6 ± 159.6 vs 97.3 ± 141 m, P = .028) and were less likely to develop PONV during their entire hospital stay (38.5% vs 48.6%, P = .043). No significant differences were seen for total morphine equivalents consumption, rate of discharge to care facility, length of stay, and 90-day readmission rates. CONCLUSION: ITM was associated with improved POD 0 pain scores and less initial oral/intravenous opioid consumption, which likely contributes to the subsequent improved mobilization and lower rates of PONV. In the setting of a modern regional anesthesia and multimodal analgesia recovery plan for TJA, ITM can still be considered for its benefits.

Risk Factors, Outcomes, and Timing of Manipulation Under Anesthesia After Total Knee Arthroplasty.

BACKGROUND: Knee stiffness requiring manipulation under anesthesia (MUA) is an undesirable outcome following total knee arthroplasty (TKA), but risk factors for, and optimal timing of, MUA remain unclear. METHODS: Primary TKAs performed at a single center were retrospectively reviewed. Clinical variables were compared between patients who underwent MUA and those who did not; variables that differed were utilized to identify an appropriately matched control group of non-MUA patients. The MUA group was divided into early (MUA ≤6 weeks from index) and late (>6 weeks) subgroups. Flexion values at multiple time points were compared. RESULTS: In total, 1729 TKA patients were reviewed; MUA was performed in 62 patients. Patients undergoing MUA were younger (55.2 vs 65.3 years, P < .001) and had higher rates of current smoking (21.0% vs 7.3%, P < .001) and prior procedure (59.7% vs 40.4%, P = .002), most commonly arthroscopy; a control group of patients not requiring MUA, matched on the basis of these variables, was identified. While no difference in pre-TKA flexion existed across groups, final flexion in the early MUA group (106.7°) was equivalent to that of controls (115.6°), while final flexion in the late MUA group was not (101.3°, P = .001). CONCLUSION: TKA patients undergoing MUAs were younger, more likely to be current smokers, and more likely to have undergone prior knee surgery. Even in patients with severe initial postoperative limitations in range of motion, MUA within 6 weeks may allow for final outcomes that are equivalent to those experienced by similar patients not requiring manipulation.

Hip Fractures and the Bundle: A Cost Analysis of Patients Undergoing Hip Arthroplasty for Femoral Neck Fracture vs Degenerative Joint Disease.

BACKGROUND: The purpose of this study is to determine whether episode Target Prices in the Bundled Payment for Care Improvement (BPCI) initiative sufficiently match the complexities and expenses expected for patients undergoing hip arthroplasty for femoral neck fracture (FNF) as compared to hip degenerative joint disease (DJD). METHODS: Claims data under BPCI Model 2 were collected for patients undergoing hip arthroplasty at a single institution over a 2-year period. Payments from the index hospitalization to 90 days postoperatively were aggregated by Medicare Severity Diagnosis-Related Group (469 or 470), indication (DJD vs FNF), and categorized as index procedure, postacute services, and related hospital readmissions. Actual episode costs and Target Prices were compared in both the FNF and DJD cohorts undergoing hip arthroplasty to gauge the cost discrepancy in each group. RESULTS: A total of 183 patients were analyzed (31 with FNFs, 152 with DJD). In total, the FNF cohort incurred a $415,950 loss under the current episode Target Prices, whereas the DJD cohort incurred a $172,448 gain. Episode Target Prices were significantly higher than actual episode prices for the DJD cohort ($32,573 vs $24,776, P < .001). However, Target Prices were significantly lower than actual episode prices for the FNF cohort ($32,672 vs $49,755, P = .021). CONCLUSION: Episode Target Prices in the current BPCI model fall dramatically short of the actual expenses incurred by FNF patients undergoing hip arthroplasty. Better risk-adjusting Target Prices for this fragile population should be considered to avoid disincentives and delays in care.

Perioperative Gabapentin Does Not Reduce Postoperative Delirium in Older Surgical Patients: A Randomized Clinical Trial.

BACKGROUND: Postoperative pain and opioid use are associated with postoperative delirium. We designed a single-center, randomized, placebo-controlled, parallel-arm, double-blinded trial to determine whether perioperative administration of gabapentin reduced postoperative delirium after noncardiac surgery. METHODS: Patients were randomly assigned to receive placebo (N = 347) or gabapentin 900 mg (N = 350) administered preoperatively and for the first 3 postoperative days. The primary outcome was postoperative delirium as measured by the Confusion Assessment Method. Secondary outcomes were postoperative pain, opioid use, and length of hospital stay. RESULTS: Data for 697 patients were included, with a mean ± SD age of 72 ± 6 yr. The overall incidence of postoperative delirium in any of the first 3 days was 22.4% (24.0% in the gabapentin and 20.8% in the placebo groups; the difference was 3.20%; 95% CI, 3.22% to 9.72%; P = 0.30). The incidence of delirium did not differ between the two groups when stratified by surgery type, anesthesia type, or preoperative risk status. Gabapentin was shown to be opioid sparing, with lower doses for the intervention group versus the control group. For example, the morphine equivalents for the gabapentin-treated group, median 6.7 mg (25th, 75th quartiles: 1.3, 20.0 mg), versus control group, median 6.7 mg (25th, 75th quartiles: 2.7, 24.8 mg), differed on the first postoperative day (P = 0.04). CONCLUSIONS: Although postoperative opioid use was reduced, perioperative administration of gabapentin did not result in a reduction of postoperative delirium or hospital length of stay.

Early Outcomes of Primary Total Hip Arthroplasty After Prior Lumbar Spinal Fusion.

BACKGROUND: The coexistence of degenerative hip disease and spinal pathology is not uncommon with the number of surgical treatments performed for each condition increasing annually. The limited research available suggests spinal pathology portends less pain relief and worse outcomes after total hip arthroplasty (THA). We hypothesize that primary THA patients with preexisting lumbar spinal fusions (LSF) experience worse early postoperative outcomes. METHODS: This study is a retrospective matched cohort study. Primary THA patients at 1 institution who had undergone prior LSF (spine arthrodesis-hip arthroplasty [SAHA]) were identified and matched to controls of primary THA without LSF. Early outcomes (<90 days) were compared. RESULTS: From 2012 to 2014, 35 SAHA patients were compared to 70 matched controls. Patients were similar in age, sex, American Society of Anesthesiologist score, body mass index, and Charlson Comorbidity Index. SAHA patients had higher rates of complications (31.4% vs 8.6%, P = .008), reoperation (14.3% vs 2.9%, P = .040), and general anesthesia (54.3% vs 5.7%, P = .0001). Bivariate analysis demonstrated SAHA to predict reoperation (odds ratio, 5.67; P = .045) and complications (odds ratio, 4.89; P = .005). With the numbers available, dislocations (0% vs 2.8%), infections (0% vs 8.6%), readmissions, postoperative walking distance, and disposition only trended to favor controls (P > .05). Comparing controls to SAHA patients with <3 or ≥3 levels fused, longer fusions had increased cumulative postoperative narcotic consumption (mean morphine equivalents, 44.3 vs 46.9 vs 169.4; P = .001). CONCLUSION: Patients with preexisting LSF experience worse early outcomes after primary THA including higher rates of complications and reoperation. Lower rates of neuraxial anesthesia and increased narcotic usage represent potential contributors. The complex interplay between the lumbar spine and hip warrants attention and further investigation.

Subchondral insufficiency fractures of the femoral head: associated imaging findings and predictors of clinical progression.

OBJECTIVES: To characterize the morphology and imaging findings of femoral head subchondral insufficiency fractures (SIF), and to investigate clinical outcomes in relation to imaging findings. METHODS: Fifty-one patients with hip/pelvis magnetic resonance (MR) images and typical SIF characteristics were identified and reviewed by two radiologists. Thirty-five patients had follow-up documentation allowing assessment of clinical outcome. Subgroup comparisons were performed using regression models adjusted for age and body mass index. RESULTS: SIF were frequently associated with cartilage loss (35/47, 74.5 %), effusion (33/42, 78.6 %), synovitis (29/44, 66 %), and bone marrow oedema pattern (BMEP) (average cross-sectional area 885.7 ± 730.2 mm(2)). Total hip arthroplasty (THA) was required in 16/35 patients, at an average of 6 months post-MRI. Compared to the THA cohort, the non-THA group had significantly (p < 0.05) smaller overlying cartilage defect size (10 mm vs. 29 mm), smaller band length ratio and fracture diameters, and greater incidence of parallel fracture morphology (p < 0.05). Male gender and increased age were significantly associated with progression, p < 0.05. CONCLUSIONS: SIF were associated with synovitis, cartilage loss, effusion, and BMEP. Male gender and increased age had a significant association with progression to THA, as did band length ratio, fracture diameter, cartilage defect size, and fracture deformity/morphology. KEY POINTS: • Femoral head subchondral insufficiency fractures (SIF) frequently require total hip arthroplasty (THA). • SIF frequently coexist with synovitis, cartilage loss, and bone marrow oedema pattern. • SIF cartilage defect size, band length ratio, and fracture diameter/morphology can predict progression risk.

Short-term Risk of Revision THA in the Medicare Population Has Not Improved With Time.

INTRODUCTION: Advances in surgical technique, implant design, and clinical care pathways have resulted in higher expectations for improved clinical outcomes after primary THA; however, despite these advances, it is unclear whether the risk of revision THA actually has decreased with time. Understanding trends in short- and mid-term risks of revision will be helpful in directing clinical, research, and policy efforts to improve THA outcomes. QUESTION/PURPOSES: We therefore asked (1) whether there have been changes in overall short- and mid-term risks of revision THA among patients in the Medicare population who underwent primary THA between 1998 and 2010; and (2) whether there are different demographic factors associated with short- and mid- term risks of revision THA. METHODS: Using the Medicare 5% national sample database, patients who underwent primary THA between 1998 and 2010 followed by subsequent revision through 2011 were identified by ICD-9-CM procedure codes 81.51 and 81.53/80.05/00.70-00.73, respectively. This dataset included a random sample of Medicare beneficiaries based on their social security number. Only patients with minimum 1-year followup after primary THA were included in our analysis. A total of 64,260 patients who underwent primary THA were identified from the 1998 to 2010 Medicare 5% dataset. Eighty-eight percent of the patients had 1-year followup providing a final study cohort of 56,700 patients. The risk of revision was evaluated at 1, 3, 5, and 7 years. Multivariate Cox regression was used to evaluate temporal trends in revision risk using two methods to account for time effects with periods 1998 to 2002, 2003 to 2007, and 2008 to 2010 for the index year of primary THA, and individual year of index of primary THA as independent variables. The analysis adjusted for patient age, sex, race, census region, Charlson score, and socioeconomic status. RESULTS: The 7-year crude risk of revision THA declined from 7.10% in 1998 to 2002 to 6.09% in 2008 to 2010, representing a 14.4% overall reduction in adjusted risk of revision (p = 0.0058; 95% CI, 4.4%-23%). Similarly, the 5-year crude risk of revision THA declined from 5.96% in 1998 to 2002 to 5.11% in 2008 to 2010, representing a 14.2% overall reduction in adjusted risk of revision (p = 0.0069; 95% CI, 4.1%-23%). However, the adjusted risk of revision THA at 3 years was not different from 1998 to 2002 (4.70%) and 2008 to 2010 (4.03%; p = 0.1176). Similarly, the adjusted risk of revision at 1 year did not differ from 1998 to 2002 (2.83%) and 2008 to 2010 (2.42%; p = 0.3386). Patients with more comorbidities had a greater adjusted risk of revision (p < 0.001) at all times: 94% (95% CI, 58%-138%) and 56% (95% CI, 33%-84%) at 1 year and 7 years, respectively, for Charlson score of 5+ vs 0). CONCLUSIONS: Although the mid-term (5 and 7 years) risk of revision THA has decreased during the past 14 years among Medicare beneficiaries who underwent primary THA, the short-term risk has not. These findings suggest that greater clinical, research, and policy emphasis is needed to identify potentially avoidable causes of early failure after primary THA in patients in the Medicare population, and multistakeholder solutions are needed to optimize short-term outcomes. LEVEL OF EVIDENCE: Level III, therapeutic study.

Long-Acting Opioid Use Independently Predicts Perioperative Complication in Total Joint Arthroplasty.

BACKGROUND: Opioid therapy is an increasingly used modality for treatment of musculoskeletal pain despite multiple associated risks. The purpose of this study was to evaluate how preoperative opioid use affects early outcomes after total joint arthroplasty. METHODS: A total of 174 patients undergoing total joint arthroplasty were matched by age, gender, and procedure into 3 groups stratified by preoperative opioid use (nonuser, short acting [eg, Vicodin], long acting [eg, Oxycontin]). RESULTS: Compared to nonusers, preoperative long-acting use was associated with increased postoperative mean opioid consumption (46 mg vs 366 mg mean morphine equivalents, P < .001) and independently predicted complications within 90 days (odds ratio: 6.15, confidence interval: [1.46, 25.95], P = .013). CONCLUSION: Preoperative opioid use should be disclosed as a risk factor for complication to patients and taken into consideration by physicians before initiating opioid management.

Prior Lumbar Spinal Arthrodesis Increases Risk of Prosthetic-Related Complication in Total Hip Arthroplasty.

BACKGROUND: Degenerative hip disorders often coexist with degenerative changes of the lumbar spine. Limited data on this patient population suggest inferior functional improvement and pain relief after surgical management. The purpose of this study is to compare the rates of prosthetic-related complication after primary total hip arthroplasty (THA) in patients with and without prior lumbar spine arthrodesis (SA). METHODS: Medicare patients (n = 811,601) undergoing primary THA were identified and grouped by length of prior SA (no fusion, 1-2 levels fused [S-SAHA], and ≥3 levels fused [L-SAHA]). RESULTS: Compared with controls, patients with prior SA had significantly higher rates of complications including dislocation (control: 2.36%; S-SAHA: 4.26%; and L-SAHA: 7.51%), revision (control: 3.43%, S-SAHA: 5.55%, and L-SAHA: 7.77%), loosening (control: 1.33%, S-SAHA: 2.10%, and L-SAHA: 3.04%), and any prosthetic-related complication (control: 7.33%, S-SAHA: 11.15% [relative risk: 1.52], and L-SAHA: 14.16% [relative risk: 1.93]) within 24 months (P < .001). CONCLUSION: The interplay of coexisting degenerative hip and spine disease deserves further attention of both arthroplasty and spine surgeons.

The Use of Hyaluronic Acid and Corticosteroid Injections Among Medicare Patients With Knee Osteoarthritis.

INTRODUCTION: Hyaluronic acid (HA) and corticosteroid (CS) injections are frequently used in the management of osteoarthritis (OA) of the knee, despite a lack of strong evidence supporting their efficacy in the literature. The purpose of this study is to evaluate trends in HA and CS usage in Medicare patients over the past 15 years. METHODS: The Medicare 5% national sample database was used to identify 581,022 patients (representing an estimated 11.6 million) with a diagnosis of knee OA between 1999 and 2013. RESULTS: The percentage of newly diagnosed knee OA patients who received any injection trended from 39% in 1999 to 47% in 2006 and then declined to 37.5% in 2013. However, the mean number of injections per newly diagnosed OA patient nearly doubled from 0.27 to 0.45 for CS and from 0.18 to 0.36 for HA. Among those having both HA and CS injections, 69% had CS as first-line treatment, whereas 31% had HA first. CONCLUSION: The percentage of newly diagnosed knee OA patients receiving injections peaked in 2007 and then decreased steadily through 2013, as did the proportion of patients receiving HA injections as first-line therapy. However, the number of injections per patient has increased significantly over the past 15 years in both groups.

Comparative Epidemiology of Revision Arthroplasty: Failed THA Poses Greater Clinical and Economic Burdens Than Failed TKA.

BACKGROUND: Revision THA and TKA are growing and important clinical and economic challenges. Healthcare systems tend to combine revision joint replacement procedures into a single service line, and differences between revision THA and revision TKA remain incompletely characterized. These differences carry implications for guiding care and resource allocation. We therefore evaluated epidemiologic trends associated with revision THAs and TKAs. QUESTIONS/PURPOSES: We sought to determine differences in (1) the number of patients undergoing revision TKA and THA and respective demographic trends; (2) differences in the indications for and types of revision TKA and THA; (3) differences in patient severity of illness scoring between THA and TKA; and (4) differences in resource utilization (including cost and length of stay [LOS]) between revision THA and TKA. METHODS: The Nationwide Inpatient Sample (NIS) was used to evaluate 235,857 revision THAs and 301,718 revision TKAs between October 1, 2005 and December 31, 2010. Patient characteristics, procedure information, and resource utilization were compared across revision THAs and TKAs. A revision burden (ratio of number of revisions to total number of revision and primary surgeries) was calculated for hip and knee procedures. Severity of illness scoring and cost calculations were derived from the NIS. As our study was principally descriptive, statistical analyses generally were not performed; however, owing to the large sample size available to us through this NIS analysis, even small observed differences presented are likely to be highly statistically significant. RESULTS: Revision TKAs increased by 39% (revision burden, 9.1%-9.6%) and THAs increased by 23% (revision burden, 15.4%-14.6%). Revision THAs were performed more often in older patients compared with revision TKAs. Periprosthetic joint infection (25%) and mechanical loosening (19%) were the most common reasons for revision TKA compared with dislocation (22%) and mechanical loosening (20%) for revision THA. Full (all-component) revision was more common in revision THAs (43%) than in TKAs (37%). Patients who underwent revision THA generally were sicker (> 50% major severity of illness score) than patients who underwent revision TKA (65% moderate severity of illness score). Mean LOS was longer for revision THAs than for TKAs. Mean hospitalization costs were slightly higher for revision THA (USD 24,697 +/- USD 40,489 [SD]) than revision TKA (USD 23,130 +/- USD 36,643 [SD]). Periprosthetic joint infection and periprosthetic fracture were associated with the greatest LOS and costs for revision THAs and TKAs. CONCLUSIONS: These data could prove important for healthcare systems to appropriately allocate resources to hip and knee procedures: the revision burden for THA is 52% greater than for TKA, but revision TKAs are increasing at a faster rate. Likewise, the treating clinician should understand that while both revision THAs and TKAs bear significant clinical and economic costs, patients undergoing revision THA tend to be older, sicker, and have greater costs of care.