Hip Resurfacing Arthroplasty for Osteonecrosis: The Importance of Cementing the Metaphyseal Stem

Abstract

Patients diagnosed with osteonecrosis of the hip are usually young and prime candidates for conservative surgical solutions. When the femoral head has collapsed (Ficat stages III and IV), the success rate of coring and free-vascularized fibular graft drops and hip resurfacing arthroplasty is the least invasive procedure available. Cementing the metaphyseal stem to increase the area of the interface between the remaining vascularized bone and cement in hips with large femoral defects can help secure the femoral fixation. The long-term success of this particular technique in patients with ON of the hip still needs to be reported. A retrospective review of long-term survivorship, radiographic results, and clinical scores for 83 patients (101 hips) was undertaken. The patients were 83% male, 41 years of age on average, and were included regardless of the size of the osteonecrotic lesion. Forty-four hips had the metaphyseal stem left uncemented while 57 were cemented. The mean time since surgery was 14 years (range 3–20). The mean UCLA hip scores and SF-12 scores at last follow-up were not significantly different between groups. There were seven revisions, including four subsequent to aseptic loosening of the femoral component. The 15-year Kaplan–Meier survivorship of the femoral component was 93.2%. There were no femoral failures among the hips reconstructed with a cemented metaphyseal stem ( p = 0.0593). Narrowing of the femoral neck of 10% or more was observed in five hips (four patients). Four came from the uncemented stem group and one from the cemented stem group ( p = 0.1004). All were stabilized and were asymptomatic at the last follow-up visit. Cementing the metaphyseal stem improves the long-term survivorship in patients treated with HRA for ON of the hips. There is no increased risk of narrowing of the femoral neck, and the clinical scores are comparable to those of the hips with a metaphyseal stem left uncemented.