Outcomes of Core Decompression With Allograft-Bone Threaded Cage or Mineralized Collagen Threaded Scaffold for the Treatment of Early-Stage Osteonecrosis of the Femoral Head: A 10-Year Follow-Up.

Background: To delay or avoid total hip arthroplasty, joint-preserving techniques like core decompression (CD) with structural grafting are often utilized in early-stage osteonecrosis of the femoral head (ONFH) in young, active individuals. This study compared long-term (10 years) outcomes of CD combined with either an allograft-bone threaded cage (ATC) or a novel mineralized collagen threaded scaffold (MCTS).

Methods: A retrospective cohort analysis was performed on 103 consecutively enrolled patients who had unilateral ONFH classified as Steinberg stages I to IIIA and underwent CD with implantation of either ATC or MCTS between October 2010 and December 2014. Among these, 90 patients (87.4%) completed the follow-up, while 13 patients (12.6%) were lost. The primary outcome was graft survival, assessed through the Kaplan-Meier survival analysis, with total hip arthroplasty conversion as the end point. Secondary outcomes included assessments of Harris Hip Score and graft osteointegration.

Results: At an average of 10-year follow-up, graft survival rates for the ATC and MCTS groups were 75.6 and 77.6%, respectively, with no significant intergroup difference. Both groups showed significant improvements in Harris Hip Score postoperatively, though intergroup differences were nonsignificant. Radiographic evidence of osteointegration was observed in 92.7% of ATC cases after a mean follow-up of 13.2 months and in 93.9% of MCTS cases following a mean follow-up of 7.6 months. Graft failure occurred between 1.2 and 7.2 years postoperatively, with failure rates remaining below 30% for early-stage ONFH (Steinberg stages I to II) but exceeding 50% for stage IIIA in both groups.

Conclusions: In patients with precollapse ONFH, CD combined with ATC or MCTS demonstrated comparable long-term survivorship and functional outcomes, though both their efficacy diminished in advanced stages. These findings highlight the potential viability of biomaterial scaffolds in joint-preserving interventions for early-stage ONFH and underscore the importance of early intervention.