Abstract / Summary
Background: Porous tantalum implantation is a head-preserving alternative to core decompression in osteonecrosis of the femoral head. Reporting has declined in North America and Europe while continuing elsewhere; outcomes are discordant. Prior syntheses are dated and treated the two endpoints as interchangeable. Methods: MEDLINE, Embase, Web of Science, and the Cochrane Library were searched to September 2025. Eligible studies reported head-preserving implantation in ≥5 hips followed ≥12 months, retrieval analyses excepted. The two endpoints were co-primary and pooled separately by random-effects Freeman–Tukey models with Hartung–Knapp adjustment. Results: Twenty-two records (946 hips) contributed. Pooled conversion was 20.3% (95% CI 13.5–27.9; I2 = 78.8%; prediction interval 0.3–54.9). Eighteen records (729 hips) reported radiographic progression, pooled at 26.8% (95% CI 16.7–38.2), exceeding conversion within the cohort in twelve of sixteen records with matched denominators (p = 0.003). Surgical technique was the only moderator associated with either outcome: rod alone versus an adjunctive procedure gave 27.2% versus 13.9% for conversion (p = 0.028) and 37.4% versus 18.4% for progression (p = 0.041), surviving adjustment for region but not removal of the one internally controlled cohort or alternative classification of three records. Region, stage, implant generation and follow-up showed no association. It persisted within a single staging system. Retrieval analyses showed minimal ingrowth into necrotic bone. Conclusions: Roughly one hip in five proceeds to arthroplasty, and radiographic deterioration is more frequent. Dispersion may relate to whether a substrate for repair was supplied, not to geography or device, but that association is fragile and is offered as a hypothesis.