Outcome after a new porous tantalum rod implantation for treatment of early-stage femoral head osteonecrosis.

Abstract

Tantalum rods have been used in osteonecrosis of the femoral head (ONFH) for several years, while Zimmer trabecular metal implants have been proposed as the best choice. The aim of this study was to evaluate the effect of a new porous tantalum rod on the treatment of early ONFH. From July 2014 to December 2015, 19 patients (21 hips) were treated with Runze tantalum rod, and 20 patients (20 hips) received Zimmer tantalum prosthesis. All patients were followed up for at least 3 years. There was no significant difference in demographic characteristics and the Harris Hip Score (HHS) improvement between the two groups. Kaplan-Meier analysis did not show any statistically significant difference in survival rates. One case in the Runze group had persistent pain and required conversion to total hip arthroplasty (THA) 8 months post-surgery. Histological evaluations revealed the presence of abundant new bone ingrowth into pores of the tantalum. The osteonecrosis observed in other patients was almost unchanged. At final follow-up, progressive collapse of the femoral head or the apparent joint space narrowing had not occurred. Compared with the traditional implants, implantation of the Chinese tantalum rod in the treatment of Association Research Circulation Osseous (ARCO) stages I, and II ONFH demonstrated highly encouraging clinical results.