Objective: To assess the survival and prognostic significance of various demographic and radiographic parameters for conversion into total hip arthroplasty after treatment with a modified porous tantalum implant technology for early and intermediate stages of osteonecrosis of the femoral head (ONFH).
Methods: This study included 45 patients (59 hips) with Steinberg Stage I-IV A ONFH undergoing progressively core decompression, impaction bone grafting of 5 mm-composite bone filling material and inserting of a porous tantalum implant. Weight-bearing was forbidden within the first 3 months after implants.
Results: A total of 57 hips (44 patients) were available during a mean follow-up period of 44.8 (11-62) months. Their mean age was 43 (21-70) years. The mean Harris hip score significantly improved from 59.93 ± 2.80 preoperative to 77.84 ± 2.95 at the last follow-up (P < 0.001). Overall, 11 hips (19.30%) were converted into total hip arthroplasty. The overall survival rate was 72.49% at 60 months postoperatively. The Cox proportional hazard model revealed that bone marrow edema was an independent prognostic factor related with a conversion into total hip arthroplasty.
Conclusion: Higher survival rates may be obtained from modified tantalum implant technology for early and intermediate stages of ONFH. And prognosis was poor for patients of ONFH with bone marrow edema.