Fibula-related complications during bilateral tibial lengthening

Background and purpose: Complications related to the fibula during distraction osteogenesis could cause malalignment. Most published studies have analyzed only migration of the fibula during lengthening, with few studies examining the effects of fibular complications. Patients and methods: We retrospectively reviewed 120 segments (in 60 patients) between 2002 and 2009. All patients underwent bilateral tibial lengthening of more than 5 cm. The mean follow-up time was 4.9 (2.5-6.9) years. Results: The average lengthening percentage was 34% (21-65). The ratio of mean fibular length to tibial length was 1.05 (0.91 - 1.11) preoperatively and 0.83 (0.65-0.95) postoperatively. The mean proximal fibular migration (PFM) was 15 (4-31) mm and mean distal fibular migration (DFM) was 9.7 (0-24) mm. Premature consolidation occurred in 10 segments, nonunion occurred in 12, and angulation of fibula occurred in 8 segments after lengthening. Valgus deformities of the knee occurred in 10 segments. Interpretation: PFM induced valgus deformity of the knee, and premature consolidation of the fibula was associated with the distal migration of the proximal fibula. These mechanical malalignments could sometimes be serious enough to warrant surgical correction. Thus, during lengthening repeated radiographic examinations of the fibula are necessary to avoid complications.