Reconstruction of the Proximal Tibia and Extensor Mechanism After Tumor Resection: A Systematic Review and Meta-Analysis.

BACKGROUND

Proximal tibia reconstruction after tumor resection is technically challenging due to the dual requirement of skeletal stability and extensor mechanism restoration. Multiple reconstruction methods exist, but comparative data on complications, survival, and functional outcomes remain limited. This study aimed to compare complication rates and implant survival across different proximal tibia reconstruction methods (megaprostheses, osteoarticular allografts [OAs], intercalary allografts [ICAs], and allograft-prosthetic composites [APCs]) and to evaluate how extensor mechanism reconstruction technique influences functional outcomes.

METHODS

A systematic review and meta-analysis was performed following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. PubMed and Embase databases were searched through September 2025. Studies reporting outcomes of proximal tibia and/or extensor mechanism reconstruction for oncologic indications were included. Complications were classified using the Henderson system. Random-effects meta-analysis was performed for complication rates, implant survival, and extension lag. Subgroup analyses were performed by reconstruction type.

RESULTS

Seventy-eight studies including 2,825 patients were analyzed (mean age 25.9 years, mean follow-up 84.7 months). Prosthetic reconstruction demonstrated the lowest overall complication rate (39.2%, 95% confidence interval [CI] 32%-45%) compared with OAs (69.6%, 95% CI 55%-82%), APCs (52.7%, 95% CI 32%-73%), and ICAs (53.4%, 95% CI 34%-70%) (p = 0.004). Biological reconstructions had significantly higher structural failure rates (OA 31.0%, ICA 24.5% vs. prosthesis 5.5%, p < 0.001). Five-year implant survival showed no significant differences between prosthesis (75.3%), OA (67.4%), and APC (74.3%). At 10 years, survival rates converged across all methods (63%-71%). Extensor mechanism reconstruction technique significantly influenced extension lag: direct tendon-to-metal reattachment (11.0°) resulted in worse outcomes than synthetic augmentation (5.7°), allograft reattachment (4.6°), or autograft reconstruction (2.3°) (p < 0.001).

CONCLUSION

While prosthetic reconstruction offers lower short-term complication rates, long-term implant survival is comparable across reconstruction methods. Extensor mechanism reconstruction technique is a critical determinant of functional outcome. Surgeons should consider techniques beyond simple direct reattachment, particularly synthetic augmentation or biological reconstruction, when feasible to optimize extension function. Individual patient factors should guide selection between prosthetic and biological reconstruction.

LEVEL OF EVIDENCE: Level IV. See Instructions for Authors for a complete description of levels of evidence.