Innovative trident fixation technique for allograft knee arthrodesis for high-grade osteosarcoma around the knee.

OBJECTIVE

Reconstruction for osteosarcoma around the knee after wide resection faces the challenge of great bone defect and future limb length discrepancy in the skeletally immature patients. Modern prosthetic reconstruction may provide good results, but the longevity may be of concern and may not be affordable in certain communities. Allograft knee arthrodesis still has its role in light of bone stock preservation and cost-effectiveness.

METHODS

We developed the innovative trident fixation technique utilizing three Steinmann pins to minimize limb length inequality without jeopardizing knee fusion stability. Twelve patients were enrolled. The mean age was 11.5 (10-13) years. Two had high-grade osteosarcoma in proximal tibia and others in distal femur.

RESULTS

Two patients died of oncological disease. The median follow-up of the disease-free 10 patients was 47 (41-60) months. All allograft-host bone junctions healed uneventfully without major complications except one allograft fracture. The average limb length discrepancy was 1.45 (1.0-2.1) cm at latest follow-up.

CONCLUSIONS

This straightforward technique was successful in knee arthrodesis with minimized limb length inequality. Accordingly, in light of bone stock preservation and longevity for the young children, it may be a surgical alternative for malignant bone tumors around the knee.