BACKGROUND: Preoperative denosumab has been an essential part of the management of giant cell tumor of bone (GCTB) which enhanced subchondral bone integrity and facilitated joint preservation surgery. However, evidence suggests that denosumab-induced sclerotic changes may potentially increase the risk of postoperative recurrence. This study evaluates the efficacy of microwave ablation (MWA) as an adjuvant to intralesional curettage following denosumab treatment in advanced GCTB. METHODS: A retrospective review was conducted on 54 patients with extremity GCTB treated with preoperative denosumab between 2019 and 2024. 33 patients underwent curettage, while 21 patients underwent combined microwave ablation with curettage. The recurrence rates and joint preservation rates were analyzed. Functional outcomes were assessed by the Musculoskeletal Tumor Society (MSTS) score. RESULTS: Local recurrence occurred in 14 patients, including 3 in the MWA group and 11 in the curettage-only group. In the MWA group, all recurrences were managed with repeat curettage, whereas 6 patients in the curettage-only group required extensive resection. The joint preservation rate was significantly higher in the MWA group (100%) compared to the curettage-only group (81.8%). The local recurrence rate was lower in the MWA group (14.3%) than in the curettage-only group (33.3%), with two-year local recurrence-free survival rates of 95.2% and 68.2%, respectively
however, the difference was not statistically significant (P = 0.12). Functional outcomes were comparable, with a mean MSTS score of 24.9 ± 1.33. CONCLUSION: The preoperative denosumab combined with adjuvant MWA offers an alternative approach to enhance joint preservation in advanced GCTB, emphasizing its potential as an effective adjuvant strategy. Further large-scale studies are warranted to validate these findings and refine treatment strategies.