Posteromedial approach to proximal tibia for corticotomy in callus distractions

Corticotomy of the tibia using Ilizarov's anterolateral approach is used routinely for callus distraction. This method is associated with impaired callus formation and delayed healing because of marginal soft tissue covering and blood supply to the proximal tibia. We presumed a newly designed posteromedial approach would result in less callus defects and improved healing. In this prospective, randomized study, 31 patients had callus distraction using an anterolateral approach or the newly designed posteromedial approach. Callus formation was assessed radiographically and histologically. Callus defects were classified using serial radiographs. Biopsy specimens were taken from high-grade defect (Grades 3-4) zones to examine the osteogenic potential. Radiographic evaluation showed 13 callus defects; 12 occurred after the anterolateral approach and only one occurred after the posteromedial method. Although low-grade defects (Grades 1-2) healed spontaneously, biopsy specimens taken from Grades 3-4 defects revealed no osteogenic potential and requiring operative revision. Because of low soft tissue covering and impaired blood supply to the anterior tibia during surgical exposure for corticotomy, less callus formation occurred after the anterolateral approach compared with the posteromedial approach. We recommend the less invasive posteromedial approach to reduce callus defects and impaired healing in callus distraction of the proximal tibia.