Background and purpose: Growth inhibition and stimulation have both been reported after juvenile limb lengthening. Distraction of a joint usually suspends and unloads the growth plate and may stimulate growth. We investigated the influence of knee joint distraction on the speed of growth after limb lengthening. METHODS In a retrospective study, growth patterns were analyzed in 30 children mean 61 (24-109) months after limb lengthening with the Ilizarov method, each child having more than 2 years of remaining growth. In 14 patients with knee joint instability, the knee was bridged over during lengthening for joint stabilization. Whether or not joint bridging and distraction would affect patterns of growth of the lengthened limb by unloading the growth plate was evaluated with a repeated measurements analysis of variance.
Results: After lengthening procedures, the proportionate leg-length discrepancy was found to decrease in 16 children, suggesting increased growth rate in the lengthened limbs. A statistically significantly faster growth rate was seen in 8 of 14 patients with knee distraction as compared to patients with single bone frame configurations.
Interpretation: Further research is required to investigate whether growth stimulation is due to the surgical technique and whether joint distraction should be recommended during limb lengthening in growing children.