A review of 240 patients undergoing distraction osteogenesis for congenital post-traumatic or postinfective lower limb length discrepancy.

BACKGROUND: We reviewed 281 lower limb lengthenings in 240 patients treated at three centers for congenital, post-traumatic, or postinfective limb length discrepancy (LLD) in the period 1984 to 1992. STUDY
DESIGN: A retrospective review was done of hospital charts and radiographs of patients who had completed lengthening at least 12 months prior to the beginning of the study. The variables studied included patients' age at operation, the bone segment lengthened, whether a corticotomy or an osteotomy had been done, the amount of lengthening planned and achieved, the level(s) of corticotomy or osteotomy, the external fixator used, and the difficulties encountered.
RESULTS: Limb length discrepancy was reduced within 2 cm (1.6 percent or lower) of the normal contralateral leg in 249 (89 percent) lengthenings in 208 patients. The average time spent with the fixator in situ was 186.4 days (range, 94 to 617 days), with an average healing index of 35.3 days per cm (range, 26 to 43 days per cm). Femoral osteotomies or corticotomies healed faster than tibial osteotomies or corticotomies. The healing index in post-traumatic and postinfective LLD was significantly lower than in congenital conditions. The younger patients showed a significantly decreased time to bone healing and fewer complications.
CONCLUSIONS: A significantly greater number of difficulties were found in patients whose lengthening exceeded 18 percent of the original length of bone. Bifocal lengthenings healed significantly faster than single level ones. The three external fixators used were equally effective for lengthenings of less than 20 percent. The Ilizarov and the Monticelli-Spinelli circular fixators were associated with a significantly decreased number of complications when lengthenings above 20 percent were performed.