There is concern regarding potential non-union of the fibula following distraction osteogenesis and if non-union of the fibula leads to poor outcome.

Assess the incidence of fibula non-union in patients undergoing distraction osteogenesis of the tibia and to report the effects on patient outcome. We also describe the management of this complication.

A consecutive series of patients undergoing distraction osteogenesis at a tertiary centre under a single surgeon. The amount of distraction, site of osteotomy, union of the fibula and tibia were recorded.

Fifty-eight distraction procedures. Mean age was 37.2, 36 males and 22 females. Mean follow-up 23.4 months. 49 (84.5%) achieved fibula union at frame removal, and 9 (15.5%) went on to non-union. Of the fibulas that united, the mean lengthening was 9.25mm. In fibula non-union there was significantly greater lengthening (23.66mm) (p=0.004). Fifty-four (93.1%) of the tibias united following osteotomy and distraction, whilst 4 (6.9%) went onto non-union requiring operative treatment. Of the 4 tibias that did not unite, 3 (75%) also had fibula non-union (p=0.01). Three (33.3%) of the 9 fibulas that did not unite developed symptoms. Two of these required surgery in the form of fibula plating. Both of these patient's symptoms resolved following surgery.

Fibula non-union is a relatively common complication following osteotomy in distraction osteogenesis. The length of fibula distraction and tibia non-union are significant risk factors. We recommend surgical intervention for those patients who have symptomatic fibula non-unions.

IV, case series.