Rapidly Destructive Hip Disease Following Intra-Articular Corticosteroid Injection of the Hip.

BACKGROUND: While recent reports have suggested that hip corticosteroid injections can hasten joint degeneration, there are few published data on the topic. The purpose of the present study was to evaluate for an association between corticosteroid injection and rapidly destructive hip disease (RDHD) and to determine the rate of, and risk factors for, occurrence. METHODS: This study was conducted in 2 parts. First, to assess for a potential association between hip corticosteroid injection and RDHD, a case-control analysis was performed. Patients who developed RDHD between 2013 and 2016 served as cases, whereas those who underwent total hip arthroplasty for diagnoses other than RDHD during the same period served as controls, and the exposure of interest was prior intra-articular hip corticosteroid injection. Second, in a retrospective cohort analysis, we analyzed all patients who received a fluoroscopically guided intra-articular hip corticosteroid injection at our institution from 2013 to 2016. The rate of post-injection RDHD was determined, and logistic regression was used to identify risk factors for occurrence. RESULTS: In the case-control analysis, hip corticosteroid injection was associated with the development of RDHD (adjusted odds ratio, 8.56 [95% confidence interval, 3.29 to 22.3], p < 0.0001). There was evidence of a dose-response curve, with the risk of RDHD increasing with injection dosage as well as with the number of injections received. In the retrospective cohort analysis, the rate of post-injection RDHD was 5.4% (37 of 688). Cases of post-injection RDHD were diagnosed at an average of 5.1 months following injection and were characterized by rapidly progressive joint-space narrowing, osteolysis, and collapse of the femoral head. CONCLUSIONS: This study documents an association between hip corticosteroid injection and RDHD. While the risk of RDHD following a single low-dose (≤40 mg) triamcinolone injection is low, the risk is higher following high-dose (≥80 mg) injection and multiple injections. These findings provide information that can be used to counsel patients about the risks associated with this common procedure. In addition, caution should be taken with intra-articular hip injections utilizing ≥80 mg of corticosteroid and multiple injections. LEVEL OF EVIDENCE: Therapeutic Level III. See Instructions for Authors for a complete description of levels of evidence.

Return to Duty After Mini-Open Arthroscopic-Assisted Treatment of Femoroacetabular Impingement in an Active Military Population.

PURPOSE: To report the return-to-duty rate and surgical outcomes in a military population after mini-open arthroscopic-assisted surgery for femoroacetabular impingement (FAI) in an effort to affirm its efficacy. METHODS: A retrospective review of consecutive active-duty patients receiving mini-open arthroscopic-assisted surgery for FAI between 2007 and 2011 was performed. Patients younger than 18 years, non-active-duty patients, and patients with prior hip surgery were excluded. Demographic, radiographic, and duty-status data were collected. The primary outcome measure was a return to duty. Outcome scores were obtained in a proportion of the cohort, including the modified Harris Hip Score, Single Assessment Numeric Evaluation score, Western Ontario and McMaster Universities Osteoarthritis Index score, patient satisfaction score, and Veterans RAND 12 (VR-12) score. All patients had achieved a minimum of 1 year of follow-up at the time of assessment. All P values for significance were set at .05 or lower. RESULTS: Of 182 patients (average age, 30.4 years), 156 (86%) were available for follow-up with return-to-duty data at an average of 2.8 years (range, 1-6 years). Of the patients, 78% returned to full duty (53%) or returned to duty with restrictions (25%). Outcome scores were available for 101 of 182 patients (55%) with duty rates similar to the total cohort (81% who returned to duty: 58% with no restrictions and 23% with restrictions). Return to duty correlated with improved outcomes compared with those who were medically discharged with respect to the modified Harris Hip Score (68.2 vs 54.5, P < .03), Single Assessment Numeric Evaluation score (48.2 vs 25.3, P < .02), and VR-12 physical (39.7 vs 33.2, P < .05) and VR-12 mental (54.5 vs 43.4, P < .005) scores. CONCLUSIONS: Mini-open arthroscopic-assisted surgery for FAI is successful in returning most service members to duty at short-term follow-up. Return correlates with improved outcome scores, although previously reported minimally clinical important difference and patient acceptable symptomatic state threshold values were not uniformly achieved. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Effect of tibial component varus on wear in total knee arthroplasty.

INTRODUCTION: Malalignment can result in poor clinical outcomes and increased wear. However, component malalignment can occur even when overall limb mechanical axis is within the normal anatomic range. We studied the effect of component malalignment in the presence of acceptable knee alignment in knee arthroplasty. METHODS: Sixteen tibial inserts retrieved at revision surgery were laser-mapped to measure wear. Average implantation duration was 7.7 years (range, 1 to 13). Early (postprimary) and final (prerevision) radiographs were analyzed for overall alignment (limb, femoral and tibial components) and osteolysis. RESULTS: The tibial components were initially aligned in a mean of 1.3 ± 1.7° varus (range, -1.5 to 4.5°), which increased to 3.2 ± 2.9° (range, -2.0 to 8.0°) at the time of revision (p=0.05). Tibial components initially placed in greater than 3° varus were associated with almost twice the volumetric penetration rate. Anatomic knee angles were 5.4 ± 0.9° valgus (range, 4.0 to 7.0°) in the post-primary radiographs and decreased in prerevision radiographs to 3.8 ± 2.6° (range, -1.0 to 7.5°), (p=0.04). DISCUSSION: Tibial varus was associated with increased medial compartment wear and total wear, thus affecting osteolysis in addition to local destruction of the bearing surface. Varus malalignment as low as 3° may result in accelerated wear, even if overall limb alignment is nearly ideal. These results indicate that tibial component alignment is an important factor associated with tibial tray subsidence and polyethylene wear even when limb alignment is neutral.

Postoperative assessment of vascularity of the femoral head after surgical hip dislocation.

Treatment for femoroacetabular impingement includes surgical hip dislocation and recontouring the femoral head-neck junction. However, a potential complication of this procedure is avascular necrosis. The purpose of this study was to assess radiographically the vascularity of the femoral head after surgical hip dislocation. Ten patients underwent surgical hip dislocation and recontouring of the femoral head-neck junction for femoroacetabular impingement. Postoperatively, all 10 patients underwent magnetic resonance imaging of the hip. Magnetic resonance imaging revealed no evidence of osteonecrosis in all patients. This study provides clear radiographic evidence that surgical hip dislocation may be performed without causing avascular necrosis of the femoral head.

Hydroxyapatite-coated femoral stem survivorship at 10 years.

Ninety-six patients were implanted with the Omnifit-HA femoral stem and the Omnifit-PSL porous-coated dual-radius acetabular shell (Stryker, Mahwah, NJ) and liners that were sterilized by gamma-radiation in air. The mean age at the time of surgery was 52 years (range, 27-78 years), and male/female ratio was 54:42. The mean follow-up was 10.3 years (range, 7-12 years). The survivorship of the stem and cup was 100% and 90%, respectively. Four cups were revised for aseptic loosening, and 6 liners were exchanged. The mean polyethylene wear rate was 0.24 mm/y. Lysis was noted in 23% of the cups. No patient developed femoral lysis distally. This hydroxyapatite-coated stem continues to perform well and appears to protect against the migration of wear debris along the femoral stem.