A novel subchondral bone-grafting procedure for the treatment of giant-cell tumor around the knee: A retrospective study of 27 cases

The vast majority of giant-cell tumors occur around the knee and characteristically affect the subchondral bone. Thermal damage to the articular cartilage arising from the application of polymethylmethacrylate (PMMA) or extensive intralesional curettage presents a challenging problem to orthopedic surgeons and patients due to compliance issues. For this reason, we developed a new subchondral bone-grafting procedure to restore massive bone defects and reduce degenerative changes in the knee. The aim of this study was to describe the novel subchondral bone-grafting procedure and evaluate clinical outcomes in patients with giant-cell tumors around the knee. This retrospective single-center study included a total of 27 patients with giant-cell tumors in the distal femur and proximal tibia admitted to our department from January 2012 to December 2015 and treated with aggressive intralesional curettage. Eleven males and 16 females were included. All cases underwent subchondral autograft bone grafting followed by bone cement reconstruction and instrument internal fixation. The Musculoskeletal Tumor Society (MSTS) score and short form-36 (SF-36) were applied to assess the functional outcome of the knee joint and quality of life. Tumor recurrence, Kellgren and Lawrence (KL) grade, and the distance of the cement to the articular surface were assessed throughout the sample. All cases were followed up after surgery for an average of 32.9 ± 7.1 months (range 25–57 months). At the end of the follow-up period, all patients were alive and free from pulmonary metastasis. Complications associated with this surgery occurred only in 1 patient (3.7%), who presented with an incision infection that resolved with regular dressing and antibiotics. No fractures, instrument breakage, or joint fluid leakage occurred. Local recurrence occurred in 1 case (3.7%) at the distal femur after 23 months and was treated by wide resection followed by prosthesis reconstruction. Twenty-four patients (89%) did not develop radiographic findings of osteoarthritis: at the final follow-up 2 patients (7.4%), had progressed to KL1 and 1 patient had progressed to KL2. According to the MSTS scoring system, the functional score of the affected knee joint at the last follow-up ranged from 80% to 97%, with an average of 87.3%. The quality of life parameters assessed by the SF-36 survey at the last follow-up ranged from 47 to 96, with an average of 77. For patients with giant-cell tumor of bone near the knee, subchondral bone grafting combined with bone cement reconstruction is recommended as a feasible and effective treatment modality.