Calcaneocuboid joint subluxation after calcaneal lengthening for planovalgus foot deformity in children with cerebral palsy.

BACKGROUND: Calcaneal lengthening is a common procedure for the treatment of symptomatic planovalgus deformity in children with cerebral palsy. Stabilization of the calcaneocuboid joint to prevent subluxation at the time of lengthening has been described. The purpose of this study was to evaluate the magnitude of calcaneocuboid joint subluxation and associated degenerative changes in patients with cerebral palsy who underwent calcaneal lengthening for planovalgus foot deformity with and without stabilization of the calcaneocuboid joint.

METHODS: We conducted a retrospective review of children with cerebral palsy who underwent lateral column lengthening through the calcaneus. For the purposes of statistical analysis, the feet were divided into 2 groups: stabilized (those that received Steinmann pin stabilization at the time of lengthening) and nonstabilized (those feet that did not receive Steinmann pin stabilization). Initial, intraoperative, and most recent follow-up radiographs were reviewed for segmental foot analysis of planovalgus deformity, calcaneocuboid joint subluxation, and osteoarthritic changes. A minimum of 3-year follow-up was required.

RESULTS: Sixty-one feet were included in this study; 28 feet in the stabilized group and 33 in the nonstabilized group. Radiographic assessment of segmental foot analysis demonstrated significant improvement with regard to planovalgus deformity (P<0.05, 5 measurements). Calcaneocuboid joint subluxation occurred in 24 feet in the stabilized group and 29 feet in the nonstabilized group (P=0.5269). At final follow-up, the magnitude of subluxation was not significantly different between the groups (P=0.076). There was no difference in the incidence of osteoarthritic changes at the calcaneocuboid joint between the groups (P=0.2856).

CONCLUSIONS: Lateral column lengthening through the calcaneus, for planovalgus foot deformity, significantly improved the segmental alignment of the foot with respect to radiographic assessment. Stabilization of the calcaneocuboid joint at the time of lateral column lengthening through the calcaneus did not significantly reduce the incidence or magnitude of subluxation when compared with nonstabilized lengthening. In addition, stabilization did not have an effect on the development of radiographic osteoarthritic changes at the calcaneocuboid joint.

LEVEL OF EVIDENCE: Level III, retrospective comparative study.