Outcomes of Hip Arthroplasty After Failed Hip Arthroscopy: A Case-Control Study.

BACKGROUND: Hip arthroscopy is increasingly being used in joint preservation surgery with clear benefits in the treatment of prearthritic conditions. A number of patients, however, will still go on to require subsequent hip arthroplasty, and at present, little evidence exists determining the impact that prior hip arthroscopy may have on the outcomes of a subsequent arthroplasty. METHODS: Using prospectively collated data, we identified 35 patients who had a hip arthroplasty (22 total hip arthroplasties and 13 hip resurfacing arthroplasties) after prior ipsilateral hip arthroscopy (cases). Cases were matched for age, gender, and prosthesis type with 70 controls (patients who received a primary arthroplasty over the same period, without prior arthroscopy). Outcome measures included range of movement, implant survival, complications, and functional outcome (Oxford Hip Score and Harris Hip Score). RESULTS: There was no demonstrable difference in improved range of motion after hip arthroplasty between the 2 groups, across any axis of movement (flexion, extension, internal/external rotation, abduction, and adduction; P = .07-.78). There was no significant difference in complication rate (P = .72). Overall 7-year implant survival was 85.9% (95% confidence interval [CI], 75-95.8). There was no difference in survival between cases (87.6%; 95% CI, 73.5-100) and controls (86.3%; 95% CI, 74.6%-98.0%; P = .2). Ten of the 11 revision arthroplasties performed were due to adverse reactions to metal debris in metal-on-metal hip resurfacing arthroplasty cases (P = .01). There was no difference in improvement of functional outcome postarthroplasty between groups (P = .48-.76). CONCLUSION: This study demonstrates that hip arthroscopy does not adversely influence outcome of a subsequent hip arthroplasty.

Does lumbar arthrodesis compromise outcome of total hip arthroplasty?

INTRODUCTION: This matched cohort study aims to determine whether the presence of a spinal arthrodesis (SA) compromises outcome of total hip arthroplasty (THA) and whether the outcome is better if THA is performed before- (THA-1st) or after- SA (THA-2nd). METHODS: This is a single centre, multi-surgeon, review of prospective data. Thirty-seven patients (47 hips) that had SA and 1° THA(s), formed the cases (26 THA-1st; 21 THA-2nd). Most cases had 1-level SA (n = 24). Controls were patients without SA that had THA, over the same period matched for age, gender and prosthesis type. Outcome measures included complication-, revision- rates, Oxford-Hip- and Harris-Hip-Scores (OHS/HHS) (Δ: difference between pre- and post-operative scores). This is a single-centre, multi-surgeon, review of prospective data. RESULTS: At a mean follow-up of 6 years, more complications were seen in cases of THA and SA compared with controls without SA (7 vs. 2) (p = 0.03). Consequently, more cases were revised (n = 4) compared with controls (n = 0) (p = 0.02). There were no differences in functional outcome between cases and controls (p = 0.1-0.6). No differences in complications- (4/26 vs. 3/21; p = 1.00) or revision- rates (2/26 vs. 2/21; p = 1.00) were seen between THA-1st and THA-2nd Groups. The THA-1st Group had higher pre- and post-operative OHS/HHS, compared to the THA-2nd Group. However, no significant difference in ΔOHS (24 vs. 17) and ΔHHS (39 vs. 26) were seen between the THA-1st and THA-2nd Groups (p = 0.1). CONCLUSIONS: Patients with THA and SA, had increased rates of revision; but no differences in patient-reported outcome measures (PROMs) were detected. Addressing the hip pathology first may be associated with improved functional outcome.

Late Nontraumatic Dissociation of the Femoral Head and Trunnion in a Total Hip Arthroplasty.

Background. Modular total hip arthroplasties are increasingly popular because customisation allows optimal restoration of patient biomechanics. However, the introduction of component interfaces provides greater opportunities for failure. We present a case of late nontraumatic dissociation of the head-neck interface, more than 10 years after insertion. Case Description. A 58-year-old woman had a left metal-on-metal total hip arthroplasty in 2002 for hip dysplasia. Following an uneventful 10-year period, she presented to hospital in severe pain after standing from a seated position, and radiographs demonstrated complete dissociation of the modular femoral head from the stem, with the femoral head remaining in its cup. There was no prior trauma or infection. Mild wear and metallosis were present on the articulating surface between the femoral head and trunnion. Soft tissues were unaffected. Discussion and Conclusions. This is the latest occurrence reported to date for nontraumatic component failure in such an implant by more than 7 years. The majority of cases occur in the context of dislocation and attempted closed reduction. We analyse and discuss possible mechanisms for failure, aiming to raise awareness of this potential complication and encouraging utmost care in component handling and insertion, as well as the long term follow-up of such patients.