BACKGROUND AND OBJECTIVES

Giant cell tumor of bone (GCTB) is a benign aggressive tumor primarily treated with surgery. Neoadjuvant treatment with denosumab or zoledronic acid is a common adjunct given to down-stage tumors and facilitate limb sparing surgery. This study sought to determine the characteristics, outcomes, and occurrence of complications following resection (RS) or extended curettage (EC) for GCTB of the lower extremities. Correlation of neoadjuvant therapy with the occurrence of complications was also investigated.

METHODS

This is an analytical cross-sectional study of 30 patients diagnosed with GCTB of the lower extremity treated between 2015 to 2022 in a single tertiary hospital. Functional outcomes were determined using the 1993 version of the Musculoskeletal Tumor Society (MSTS) score. Mean follow-up for all patients was 2.6 years (SD 1.8). Twenty-two patients (73%) underwent resection, while eight (27%) patients underwent extended curettage. Of the 30 patients, 26 (87%) patients received neoadjuvant therapy, with 21 (81%) given denosumab and five (19%) given zoledronic acid.

RESULTS

Functional outcomes were excellent for 23 patients (77%), with no significant difference between RS and EC groups. Nine complications occurred in the RS group, including dehiscence (n=3), superficial infection (n=2), implant failure (n=1), nonunion (n=1), palsy (n=1), and implant irritation (n=1). Five complications occurred in the EC group, four of which were noted to be recurrences, with one case of deep infection. Recurrence was noted to be significantly higher (p=0.0004) in the EC group. Separate correlation analysis showed no significant difference in incidence of complications but found that duration of surgery was significantly longer (p=0.0001), and intraoperative blood loss was significantly higher (p=0.0072) in the RS group. No significant difference (p=0.78) was noted in complication rate between patients given denosumab versus zoledronic acid.

CONCLUSION

Functional outcomes of EC and RS appear to be comparable, including the incidence of complications. However, recurrence was noted to be significantly higher in EC. There appears to be no clear advantage between denosumab or zoledronic acid for GCTB. As a neoadjuvant medication and/or to control tumor progression, zoledronic acid may be the more economic option especially for patients in developing countries.

Denosumab ; Giant Cell Tumor Of Bone ; Zoledronic Acid

Atypical cartilaginous tumor (ACT) refers to a low-grade cartilaginous neoplasm microscopically identical to grade 1 chondrosarcoma, affecting the appendicular skeleton. Treatment with intralesional curettage has been found to provide sufficient local control with less morbidity compared to wide resection. This is the first reported case of a simultaneous medial patello-femoral ligament (MPFL) reconstruction with extended curettage for ACT on the ipsilateral femur. A 45-year-old female presented with chronic recurrent patellar dislocation of the right knee. Magnetic resonance imaging revealed a tear of the MPFL, with an incidental epi-metaphyseal chondroid lesion. After biopsy confirmed an ACT, single-stage extended curettage using freezing nitrogen ethanol composite (FNEC) and MPFL reconstruction was performed, followed by augmentation with bone cement and a distal femoral plate. Currently, the patient is independently ambulatory, with full range of motion about the knee. Following histologic confirmation of an ACT in the setting of a concurrent MCL tear, a single-stage procedure to address both conditions is a viable option that can reduce complications associated with multiple surgeries. Extended curettage using FNEC has been shown to produce good short-term oncologic outcomes while maximizing function.