Porous Tantalum Implant in Treating Osteonecrosis of the Femoral Head: Still a Viable Option?

The purpose of this study is to evaluate the survivorship and risk factors for radiographic progression and conversion to total hip arthroplasty (THA) after porous tantalum implant surgery in the treatment of osteonecrosis of the femoral head (ONFH). The study comprised 90 ONFH patients (104 consecutive hips) who were treated with a porous tantalum implant combined with bone grafting between June 2008 and December 2013. The patients were 19–61 years of age (mean age, 38 years). The mean follow-up was 42 months. The outcome measures included Harris hip score (HHS), radiographic outcome measures, and survivorship analysis with conversion to THA as the endpoint. The mean postoperative HHS was significantly lower than the mean preoperative HHS (P < 0.001). The Cox proportional hazards model showed that age and Association Research Circulation Osseous (ARCO) stage were independent risk factors for conversion to THA, while age, China-Japan Friendship Hospital (CJFH) type, and ARCO stage were independent risk factors for radiological progression. Ultimately, only 52.9% hips survived. Porous tantalum implant surgery combined with bone grafting is not a viable option for treating ONFH, especially in patients >35 years of age with preoperative ARCO stage III and CJFH type L3.