Metal-on-Metal Hip Resurfacing Compares Favorably with THA at 2 Years Followup

Abstract

Metal-on-metal total hip resurfacing is a bone-conserving reconstructive option for patients with advanced articular damage. While intended to address several problems with conventional THA, the safety and efficacy is not well established. We therefore retrospectively compared the outcomes of 52 patients (57 hips) with resurfacing arthroplasty to 84 patients (93 hips) with cementless primary THAs. The patients had a minimum 2-year followup (mean 3 years). The patients with resurfacing arthroplasty had a mean age of 47 years (range, 22-64) while those with cementless primary THA had a mean age of 57 years (range, 17-92). After controlling for age, gender, and preoperative differences, the total Harris Hip Scores (HHS), function scores, and pain scores were similar between the two groups. However, the resurfacing group had higher activity scores (14 versus 13, p < 0.001) and range of motion (ROM) scores (5.0 versus 4.8, p < 0.001). The complication rates (5.3% for resurfacing versus 14.0% for THA) and reoperation rates (3.5% for resurfacing versus 4.3% for THA) were similar. The total hip arthroplasty and metal-on-metal resurfacing groups both showed improvement in HHS, pain, activity, and ROM and had similar early complication and reoperation rates.

Is Resurfacing Arthroplasty Appropriate for Posttraumatic Osteoarthritis?

“…However, resurfacing may have the potential to offer an alternative treatment that can preserve bone and allow surgeons more options when dealing with implanted hardware and deformities. According to the literature, the ideal candidates for resurfacing arthroplasty are male patients, younger than 55 years old, and having a primary diagnosis of osteoarthritis [1,2,14]. Several reports suggest patients with osteonecrosis or developmental deformities of the hip have comparable survivorship to patients with primary arthritis [8,9].…”

“…Hip resurfacing arthroplasty has achieved survivorship of 94% [1,2,14] when the appropriate patient selection criteria are used. Our observations suggest the survivorship in an expanded patient population such as those with posttraumatic osteoarthritis may be similar to these reported survivorships and could be better than those reported for standard THA in these sometimes challenging patient populations.…”

“…Early reports of patients who have received metal-on-metal (MOM) hip resurfacing arthroplasty have demonstrated survival rates from 94% to 99% between 2 and 10 years of followup [1,2,5,9,11,13,14,16]. Although these reports demonstrate an overall high survival rate, it is uncertain if hip resurfacing arthroplasty is a reasonable treatment alternative to total hip arthroplasty (THA) in patients with posttraumatic arthritis of the hip, specifically after femoral neck or acetabular fractures.…”

“…This procedure may be difficult as a result of persistent deformity, bone loss, or hardware removal [3]. Survivorships of nearly 80% for standard THA after hip trauma have been reported at various followup intervals [14,16]. Many of the resulting clinical failures occur because of difficulties that preexisting hardware and bone deficiencies add to the technical aspects of the procedure [14,15].…”

“…Survivorships of nearly 80% for standard THA after hip trauma have been reported at various followup intervals [14,16]. Many of the resulting clinical failures occur because of difficulties that preexisting hardware and bone deficiencies add to the technical aspects of the procedure [14,15]. For these patients, MOM hip resurfacing arthroplasty may offer an alternative to standard THA.…”