Outcome of tantalum rod insertion in the treatment of osteonecrosis of the femoral head with minimum follow-up of 1 year: a meta-analysis and systematic review

Osteonecrosis of the femoral head (ONFH) is a debilitating disease that can cause deformity and collapse of the femoral head, thus leading to the development of degenerative joint disease that can incapacitate the patient with pain and reduction in hip mobility. This study aims to determine the safety and efficacy of tantalum rod insertion in the treatment of ONFH with a minimum follow-up period of 1 year. A multi-database search was performed according to Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. Data from studies assessing the clinical and radiological outcomes as well as complications of tantalum rod insertion in the treatment of ONFH with a minimum follow-up period of 1 year were extracted and analyzed. Ten studies were included in this meta-analysis, consisting of 550 hips. There was a statistically significant increase in HHS (MD = 30.35, 95% CI: 20.60-40.10, P < 0.001) at final follow-up versus pre-operative scores. The weighted pooled proportion (PP) of radiographic progression of ONFH was 0.221 (95% CI: 0.148-0.316), while that of progression into femoral head collapse was 0.102 (95% CI: 0.062-0.162). Conversion to total hip arthroplasty (THA) had a PP of 0.158 (95% CI: 0.107-0.227) with a mean weighted period of 32.4 months (95% CI: 24.9-39.9 months). Subgroup analysis of conversion to THA when tantalum rods were used in conjunction with bone grafting (PP = 0.150, 95% CI: 0.092-0.235) showed a marginal risk reduction than when compared with subgroup analysis of tantalum rods being used alone (PP = 0.154, 95% CI: 0.078-0.282). Tantalum rod is a safe alternative option to the current joint-preserving procedures available in the treatment of ONFH. However, more studies are needed to investigate and identify the most appropriate patients who would benefit most and the synergistic effect brought on by the use of complementary biological augmentation of bone grafting or stem cells with tantalum rods.