Free Fibula Flap for Restoration of Spinal Stability after Oncologic Vertebrectomy Is Predictive of Bony Union
Nonvascular bone grafts larger than 4 cm have a 50 percent nonunion rate in spine surgery. Vascular bone flaps are one potential solution; however, their utility in spine surgery has not been fully elucidated. The authors hypothesized that the addition of a free fibula flap after oncologic vertebrectomy would safely potentiate bone union. The authors performed a retrospective analysis, including all patients who underwent oncologic vertebrectomy for a primary bone tumor at their institution from 2002 to 2017. Patients were divided into two groups: those who underwent spinal reconstruction with nonvascularized bone graft and an alloplastic cage (control) and those whose reconstruction was augmented with a free fibula flap. Forty patients were included (free fibula flap, n = 16; control, n = 24). Adjuvant therapies and medical comorbidities were similar between the two groups. Chordoma was the most common abnormality in both groups. The median number of vertebrae resected in the free fibula flap group was two, compared to one in the cage group (p = 0.08). Despite the smaller mean resection size, there were significantly more nonunions (41.7 percent versus 6.3 percent; p = 0.02), instrumentation complications (33.3 percent versus 6.3 percent; p = 0.04), and neurologic complications (25 percent versus 0 percent; p = 0.03) in the control group. Multivariate logistic regression revealed a control reconstruction significantly predictive of nonunion (OR, 57.04; 95 percent CI, 1.17 to 2773; p = 0.04). Free fibula flap patients demonstrated evidence of bony union at a mean of 4.8 months versus 22.4 months in the control group (p < 0.001). Free fibula flap surgery in spinal reconstruction after oncologic vertebrectomy is safe and effective. Free fibula flap surgery is independently protective against nonunion and is associated with more rapid union compared with the control. Therapeutic, III.