[Application of Orthofix unilateral external fixator in the treatment of musculoskeletal tumors].

OBJECTIVE

To investigate the surgical characteristics and preliminary effectiveness of Orthofix unilateral external fixator in the treatment of musculoskeletal tumors.

METHODS

Twenty-two patients received Orthofix unilateral external fixator treatment for bone defect after tumor excision or complications after limb salvage surgery between June 2011 and March 2016. There were 11 males and 11 females with a median age of 23.5 years (range, 4-57 years). The bone defect or limb length discrepancy after tumor resection was at proximal femur in 6 cases, distal femur in 8 cases, diaphysis of femur in 3 cases, proximal tibia in 2 cases, and diaphysis of tibia in 3 cases. The external fixation was used for temporary fixation after reconstruction of bone defect in 10 cases [the length of bone defect was 6-19 cm (mean, 12.3 cm); using vascularized fibular graft in 2 cases, allograft bone and free fibular graft in 2 cases, allograft bone and autogenous bone graft in 5 cases, allograft bone reconstruction in 1 case]; bone distraction lengthening for limb length discrepancy in 5 cases [the length of shortening was 6.5-8.5 cm (mean, 7.5 cm)]; temporary fixation after open biopsy in 3 cases; bone transportation over locking plate in 1 case (the length of bone defect was 7.5 cm); fixation for preoperatively pathology fracture in 1 case; and joint distraction for dislocation after tumor ablation in 2 cases.

RESULTS

All the patients were followed up 12-72 months (mean, 36 months). In 10 patients with bone defect reconstruction, the wearing external fixator time was 3-8 months (mean, 4.8 months); all got bone union with the healing time of 3-16 months (mean, 6.4 months); the Musculoskeletal Tumor Society 93 (MSTS 93) score was 73.3-93.3 (mean, 87.2); and no complication occurred during wearing external fixator. In 5 patients with bone distraction lengthening for limb length discrepancy, the wearing external fixator time was 7-15 months; 2 patients had axial deviation during distraction and2 had greenstick fracture after apparatus removal; pin site infection was observed in 2 cases with grade 1 and 1 case with grade 2 according to Checketts-Otterburn classification system; the MSTS 93 score was 80.0-96.7 (mean, 89.2). The remaining patients had no complications, the knee and ankle joint movement was normal.

CONCLUSION

Orthofix unilateral external fixator can be used in fixation for complex bone defect after tumor resection and to correct limb length discrepancy after limb salvage surgery.