Background: Juxta articular giant cell tumors around the knee constitute 50-60% of the total cases reported. If the disease is detected at an advanced stage, reconstruction of the joint aftertumor excision poses problems and has poor functional outcome. The aim of the study was to determine the functional outcome after resection of juxta-articular giant cell tumors around the knee and its reconstruction with mega prosthetic arthroplasty will be analyzed.

Methods: Between January 2017 and March 2021, 14 patients in the age group of 28-48 years (mean=42.85 years) with Campanacci stage three giant cell tumors around the knee were studied (12-distal femur patients, 2-proximal tibia). Patients underwent tumor excision and reconstruction with modular megaprosthesis. They were evaluated post- operatively using the Revised Musculoskeletal Tumor Society Score (MSTS) for lower limb.

Results: All the patients were followed up for 12-44 months (mean=29.5 months), the average knee flexion at 6 months being 116.4 degrees. The mean MSTS at 6, 12, 18 and 24 months are19.45, 23.23, 26.61 and 28.77 respectively. Complications observed were infection and tumor recurrence.

Conclusions: In advanced cases where tumor excision leaves large bone segment loss, reconstruction with megaprosthesis can give desirable functional outcome.