Hip Resurfacing & Replacement Surgery

Ease of conversion to THA after hip resurfacing confirmed if needed…

J Bone Joint Surg Am. 2007 Apr;89(4):735-41

Ball ST,

Le Duff MJ,

Amstutz HC.

Introduction: A theoretical advantage of resurfacing arthroplasty of the hip is that a failed femoral component can be safely and successfully revised to a total hip arthroplasty, especially when there is an available unipolar ball available. This hypothesis has not been tested previously.

Methods: Twenty-one metal-on-metal resurfacing arthroplasties (MMRA) with the Conserve® Plus in 20 patients with an average age of 50.2 years were converted to a conventional stemmed total hip arthroplasty (THA) for femoral-component failures. In 18 hips, the acetabular component was retained, and in 3 hips both components were revised. The results of the resurfacing conversion group were compared to a group of primary THA’s, implanted during the same time period by the same surgeon, consisting of 58 patients (64 hips) with an average age of 50.8 years. Clinical evaluations were performed using the Harris Hip Score and the UCLA Activity Score. A Radiographic evaluation was performed in which component fixation and component positioning were assessed. The average follow-up was 46 months for the failed resurfacing group and 57 months for the patients with primary conventional THA.

Results: There was no significant difference in operative time, blood loss and complication rates between the conversion arthroplasties and the primary THA group. At final follow-up average Harris Hip Scores were 92.2 and 90.3 for the MMRA conversions and primary THA’s, respectively, a difference that was not significant (p=0.442). The UCLA activity scores were 6.8 and 6.4 in the conversion group and THA group, respectively (p=0.268). The quality of the component fixation and the alignment of the reconstruction were equivalent between the two groups. There has been no aseptic loosening of the femoral or acetabular components in either group, and there have been no dislocations after MMRA conversion.

Conclusion: Conversion of a hip resurfacing with a femoral side failure to total hip appears to be comparable to a primary THA in terms of surgical effort, safety and early clinical outcomes.