3D Surgical Planning and Patient-Specific Instrumentation to Treat Chronic Knee Instability: A Case Report.

CASE: A 30-year-old man presented 11 months after a Gustilo type IIIA open knee fracture-dislocation, previously treated with femur fixation and posterior cruciate ligament reconstruction, with persistent painful instability and contracture. Examination showed a positive dial test at 30° and 90° and varus thrust gait. Imaging revealed anterolateral tibial plateau deficiency with external rotatory subluxation. Staged treatment involved gradual correction using a hexapod external fixator followed by patient-specific 3D guided intra-articular osteotomy and posterolateral corner reconstruction. He regained knee stability and returned to full activity.

CONCLUSION: Hexapod-assisted correction with patient-specific 3D osteotomy enabled successful joint preservation in chronic posttraumatic knee instability.