Sandwich reconstruction technique for subchondral giant cell tumors around the knee

Background: Curettage followed by cementation is a commonly accepted treatment modality for giant cell tumors of bone. However, concerns regarding articular cartilage damage related to the exothermic reaction during polymerization and the change in stress distribution in the subchondral region have been reported to occur within 5 years following cementation. Methods: Twelve patients (five men, seven women) presenting with giant cell tumor of the distal femur were treated with the "sandwich technique" of subchondral bone grafting and cavity filling cementation after extensive intralesional curettage. The average age of the patients was 26.5 years. The mean duration of followup was 44.8 months. All lesions were found to extend within 3mm of the subchondral bone. Results: All patients had an uneventful recovery and regained an average range of motion of 122.9° in the knee. The average revised Musculoskeletal Tumor Society Rating Scale for the lower extremity was 26. One patient had a local recurrence within the first 2 years of the procedure and was treated with a resection arthrodesis. None of the patients developed signs of articular cartilage degeneration at final follow-up. Conclusions: The "sandwich technique" of reconstruction of the subchondral bone after extended curettage produces good functional results with a low recurrence rate. Insertion of a corticocancellous bridge between the subchondral bone and the cement layer may retard the progression of early cartilage degeneration.