Outcomes of the Evans Calcaneal Lengthening Based on Bone Grafting Material

Primary Outcome Measures: 1. Measurement on radiographs of distance between heme clips located in calcaneous bone of the foot. Within the patient's own calcaneous bone, a heme clip will be placed on each side of the osteotomy. From radiographs, the amount of collapse will be determined by measuring the distance from one heme clip to the other. Changes in the distance between the clips indicate collapse of the graft. 2. Radiographic measurements of weight bearing feet of the bovine xenograft group and iliac crest allograft group (tricortical and bicortical), pre-operatively and post-operatively. 1. Lateral Radiographs: Talocalcaneal angle, Talo first metatarsal angle, Talo horizontal angle, and Calcaneal pitch 2. Anterior-Posterior Radiographs: Talocalcaneal angle, Talo first metatarsal angle, and Talonavicular coverage 3. Comparison of ligamentous laxity between the two grafting material groups, as measured by the Beighton measurements at patient's pre-operative orthopaedic clinical appointment. Secondary Outcome Measures: 1\. Plantar pressures values of interest are of six segments: medial heel, lateral heel, medial midfoot, lateral midfoot, first metatarsal and second metatarsal. The center of pressure index, total contact area, mean pressure, peak pressure, and pressure time intervals will also be collected and assessed to determine pressure distribution of the foot. Tertiary Outcome Measures: 1\. Health related quality of life assessments between the two groups, pre-operative and post-operative as measured by the Pediatric Orthopaedic Data Collection Instrument (PODCI) questionnaire.