Limb lengthening with submuscular plate stabilization: a case series and description of the technique.

Combining a circular fixator with a percutaneously inserted locking plate has all of the same advantages that lengthening over an intramedullary nail provides but eliminates the concern with regard to creating a deep infection in the medullary canal. It also can be applied to virtually any bone in any age group of patients without any concern with regard to causing avascular necrosis, fat embolism, or physeal injury. The design of the locking plate prevents loss of fixation and protects against bending of the regenerate bone after frame removal. This study represents a description of the surgical technique and a retrospective examination of the first 6 patients treated using this technique. The average age of the patients is 7.6 years, and the average duration of follow-up is 10 months. All 6 patients achieved solid union of the lengthening site and full, unassisted weight bearing with excellent range of motion. The mean lengthening was 3.52 cm, which represents an average of 14.6% of the overall bone length. The mean duration of external fixation was 45 days, and the mean external fixation index was 0.42 mo/cm. The mean distraction rate was 0.85 mm/d. There were 3 serious and 2 severe complications noted. The serious complications included the development of a premature consolidation and a translational deformity of the regenerate in 1 patient, requiring a revision corticotomy, and a fall of a second patient 3 months after fixator removal, causing a fracture at the superior edge of his locking plate. The 2 severe complications were an 11-degree and an 18-degree residual procurvatum deformity that developed during lengthening. In conclusion, lengthening with the assistance of a percutaneously inserted locking plate provides an alternative method to lengthening over an intramedullary nail, applicable to children with open physes.