Risk factors of fracture following curettage for bone giant cell tumors of the extremities

Abstract

Background: Following curettage of giant cell tumor of bone (GCTB), it is common to fill the cavity with polymethylmethacrylate (PMMA) bone cement, bone allograft, or artificial bone to maintain bone strength; however, there is a 2-14% risk of postoperative fractures. We conducted this retrospective study to clarify the risk factors for fractures after curettage for GCTB of the extremities.

Methods: This study included 284 patients with GCTBs of the extremities who underwent curettage at our institutions between 1980 and 2018 after excluding patients whose cavities were not filled with anything or who had additional plate fixation. The tumor cavity was filled with PMMA bone cement alone (n = 124), PMMA bone cement and bone allograft (n = 81), bone allograft alone (n = 63), or hydroxyapatite graft alone (n = 16).

Results: Fractures after curettage occurred in 10 (3.5%) patients, and the median time from the curettage to fracture was 3.5 months (interquartile range [IQR], 1.8-8.3 months). The median postoperative follow-up period was 86.5 months (IQR, 50.3-118.8 months). On univariate analysis, patients who had GCTB of the proximal or distal femur (1-year fracture-free survival, 92.5%; 95% confidence interval [CI]: 85.8-96.2) presented a higher risk for postoperative fracture than those who had GCTB at another site (100%; p = 0.0005). Patients with a pathological fracture at presentation (1-year fracture-free survival, 88.2%; 95% CI: 63.2-97.0) presented a higher risk for postoperative fracture than those without a pathological fracture at presentation (97.8%; 95% CI: 95.1-99.0; p = 0.048). Patients who received bone grafting (1-year fracture-free survival, 99.4%; 95% CI: 95.7-99.9) had a lower risk of postoperative fracture than those who did not receive bone grafting (94.4%; 95% CI: 88.7-97.3; p = 0.003).

Conclusions: For GCTBs of the femur, especially those with pathological fracture at presentation, bone grafting after curettage is recommended to reduce the risk of postoperative fracture. Additional plate fixation should be considered when curettage and cement filling without bone grafting are performed in patients with GCTB of the femur. This should be specially performed for those patients with a pathological fracture at presentation.

Keywords: Bone grafting; Cement; Curettage; Denosumab; Fracture; Giant cell tumor of bone.

Fig. 1

Flow diagram of patients with giant cell tumor of bone of the extremity treated with curettage at three institutions between 1980 and 2018

Fig. 2

Radiography after PMMA bone cement filling following allograft chip bone filling in the subchondral region after curettage. The arrow indicates the allograft chip bone

Fig. 3

Radiography after cement filling following large cortical bone allograft insertion after curettage. The arrow indicates the large cortical bone allograft

Fig. 4

Radiography after filling allograft chip bone following curettage

Fig. 5

A, Radiography at the time of fracture (Case 10, Table 2). B, Radiography 3 years and 8 months after open reduction and internal fixation showed bone union

Fig. 6

A, Radiography at the time of fracture. The arrow indicates the fracture line (Case 6, Table 2). B, Radiography 2 years after cement removal, filling of allografts bone chips, and osteosynthesis with a plate

Fig. 7

Fracture-free survival rates of patients by tumor site. Shading around the curves represents the 95% confidence intervals (CI)

Fig. 8

Fracture-free survival rates of patients by pathological fracture at presentation. Shading around the curves represents the 95% confidence intervals (CI)

Fig. 9

Fracture-free survival rates of patients by use of bone grafting. Shading around the curves represents the 95% confidence intervals (CI)