Clinical significance of heterotopic ossification after metal-on-metal total hip resurfacing

Mid-term clinical and radiographic outcome of metal-on-metal hip resurfacing through an anterolateral approach

PURPOSE

The aim of this retrospective study was to evaluate the medium-term clinical and radiographic results of current generation metal-on-metal resurfacing prostheses performed through anterolateral approach.

MATERIALS AND METHODS

Fifty-seven hips in 52 patients underwent resurfacing arthroplasty. Two patients died from unrelated causes, leaving 55 hips in 35 males (3 bilateral) and 15 females (2 bilateral), with a mean age at surgery of 56.2 years (range, 27-70 years). Clinical and radiographic assessment was carried out preoperatively and at follow-up in all the survived cases. The cumulative survival rate was determined according to the method of Kaplan-Meier.

RESULTS

At a mean follow-up of 5.2 years (range, 1.8-9.1 years), 2 HRs of the same female patient were revised because of early loosening of the acetabular component. Deep venous thrombosis and transient femoral nerve palsy occurred both in 1 case. No specific complications of HR were observed. Average Harris hip score improved significantly from 59.8 points (range, 30.4-90.6) preoperatively to 93.7 points (range, 53-100) at the latest examination. Neck narrowing showed an average of 3.27%, but it never exceeded 10%. Nonprogressive acetabular radiolucencies and osteolysis were detected both in 2 hips. A high rate of patients (32, 60.4%) developed heterotopic ossifications, although low-grade in most cases (27, 84.4%). The cumulative survival rate at 9.1 years with revision for any reason as the end point was 93.0%.

CONCLUSIONS

The early clinical and radiographic results of modern metal-on-metal hip resurfacing performed through an anterolateral approach are promising, but longer-term follow-up studies are necessary.

Prophylactic Celecoxib Administration Is Associated With Decreased Incidence and Severity of Heterotopic Ossification After Hip Resurfacing by Direct Lateral Approach in Male Patients

Heterotopic ossification is a potential complication that may have a particularly higher association with hip resurfacing. The 2 current mainstays for heterotopic ossification treatment and prophylaxis are administration of nonsteroidal anti-inflammatory drugs and radiotherapy. Recent studies have determined that celecoxib is effective in heterotopic ossification prophylaxis after total hip arthroplasty. However, considering the reportedly higher incidence and severity of heterotopic ossification in these patients, relatively few studies have evaluated its role in hip resurfacing. Therefore, the authors assessed the incidence, severity, and risk factors of heterotopic ossification in patients who had hip resurfacing and did or did not receive celecoxib. Of the 198 patients, 83 received celecoxib and 115 did not. Radiographs were examined to grade heterotopic ossification using the Brooker classification system. The rate of heterotopic ossification differed between patients who did and patients who did not receive celecoxib prophylaxis (25% vs 65%, P<.001). Celecoxib was an independent predictor of decreased heterotopic ossification (odds ratio, 0.16; 95% confidence interval, 0.08-0.35). Celecoxib administration is associated with decreased incidence and severity of heterotopic ossification after hip resurfacing performed using the direct lateral approach in male patients. [Orthopedics. 2018; 41(6):e807-e812.].