Published online Nov 18, 2015. doi: 10.5312/wjo.v6.i10.829
Peer-review started: May 27, 2015
First decision: June 18, 2015
Revised: July 15, 2015
Accepted: September 7, 2015
Article in press: September 8, 2015
Published online: November 18, 2015
AIM: To study a modified porous tantalum technique for the treatment of osteonecrosis of the femoral head.
METHODS: The porous tantalum rod was combined with endoscopy, curettage, autologous bone grafting and use of bone marrow aspirates from iliac crest aspiration in 49 patients (58 hips) with a mean age of 38 years. The majority of the patients had idiopathic osteonecrosis, followed by corticosteroid-induced osteonecrosis. Thirty-eight hips were of Steinberg stage II disease and 20 hips were of stage III disease. Patients were followed for 5 years and were evaluated clinically with the Merle D’Aubigne and Postel score and radiologically. The primary outcome of the study was survival based on the conversion to total hip arthroplasty (THA). Secondary outcomes included deterioration of the osteonecrosis to a higher disease stage at 5 years compared to the preoperative period and identification of factors that were associated with survival. The Kaplan-Meier survival analysis was performed to evaluate the survivorship of the prosthesis, and the Fisher exact test was performed to test associations between various parameters with survival.
RESULTS: No patient developed any serious intraoperative or postoperative complication including implant loosening or migration and donor site morbidity. During the 5-year follow up, 1 patient died, 7 patients had disease progression and 4 hips were converted to THA. The 5-year survival based on conversion to THA was 93.1% and the respective rate based on disease progression was 87.9%. Stage II disease was associated with statistically significant better survival rates compared to stage III disease (P = 0.04). The comparison between idiopathic and non-idiopathic osteonecrosis and between steroid-induced and non-steroid-induced osteonecrosis did not showed any statistically significant difference in survival rates. The clinical evaluation revealed statistically significantly improved Merle d’Aubigne scores at 12 mo postoperatively compared to the preoperative period (P < 0.001). The mean preoperative Merle d’Aubigne score was 13.0 (SD: 1.8). The respective score at 12 mo improved to 17.0 (SD: 2.0). The 12-mo mean score was retained at 5 years.
CONCLUSION: The modified porous tantalum rod technique presented here showed encouraging outcomes. The survival rates based on conversion to THA are the lowest reported in the published literature.
Core tip: In the present study, we present the results of a modified porous tantalum technique for the treatment of femoral head avascular necrosis. The porous tantalum rod was combined with endoscopy, curettage, autologous bone grafting and use of bone marrow aspirates from iliac crest aspiration in 58 hips. The 5-year survival based on conversion to total hip arthroplasty was 93.1% and the respective rate based on disease progression was 87.9%. Stage II disease was associated with statistically significantly better survival rates compared to stage III disease, while no other factor was found to be associated with outcomes.