Calcaneal shortening for talonavicular medial subluxation in pediatric equinovarus deformity.

INTRODUCTION

Medial subluxation of the talonavicular joint is a common component of equinovarus deformity. Traditional cuboid or cuneiform osteotomies may not adequately correct this deformity. This study evaluated the radiographic correction and prognostic factors of calcaneal shortening for midfoot deformity.

METHODS

We retrospectively reviewed 28 patients (32 feet) with equinovarus deformity treated by calcaneal shortening between 2011 and 2021. The shortening osteotomy was performed between the middle and posterior facets of the calcaneus to facilitate lateral translation of the navicular over the talar head. Foot alignment was assessed using anteroposterior and lateral talo-first metatarsal (TMT) and talo-calcaneal (TC) angles on standing radiographs. Satisfactory correction was defined by normalized TMT angles at two years. Factors related to unsatisfactory results were analyzed.

RESULTS

The mean age at surgery was 11.2 years, with an average follow-up of 4.0 years. Calcaneal shortening significantly improved the AP-TMT angle (33.4°→13.5°) and lateral TMT angle (12.9°→7.1°), with no change in TC angles. Satisfactory outcomes occurred in 72% of feet. Patients with paralytic neuropathies had a higher risk of poor results compared to those with congenital talipes equinovarus or spastic cerebral palsy.

CONCLUSIONS

Calcaneal shortening effectively corrects talonavicular medial subluxation in spastic cerebral palsy and relapsed clubfoot. Its limited effect on the hindfoot varus deformity led to a less reliable result in patients with myelodysplasia and Charcot-Marie-Tooth disease.

LEVEL OF EVIDENCE: Level III, retrospective case control study.