Growth arrest following posterior knee release in children with arthrogryposis multiplex congenita: a previously unreported complication.

Knee flexion contractures in children with arthrogryposis multiplex congenita (AMC) significantly impair function and ambulation. Posterior knee soft tissue release is a widely used surgical intervention when conservative management fails. However, literature describing complications following this procedure remains limited. This study aims to report distal femoral and proximal tibial physeal arrest as a previously undocumented complication following posterior knee release in children with AMC. Following institutional review board approval, a retrospective case series was performed. Patients with AMC who underwent posterior soft tissue knee release and subsequently developed growth arrest of the distal femur with or without arrest of the proximal tibia were identified from an institutional database. Data collected included demographics, age at index procedure, time to diagnosis of growth arrest, adjunct procedures, clinical deformities, and subsequent interventions. Eight patients (six females and two males) were identified to have either a distal femoral or proximal tibial physeal bar following posterior knee release. Mean age at index surgery was 44 (range: 22-69) months. Growth arrest was identified at a mean of 43 months postoperatively (range: 11-104 months). Progressive deformity was seen in all patients, correlating with the location of the growth arrest. Physeal bar resection was attempted in all cases, with variable or pending outcomes. Distal femoral and proximal tibial growth arrest may occur following posterior knee release in children with AMC. Given the proximity of surgical dissection to the physis, this complication should be recognized as a potential risk. Surgeons should take care to avoid physeal injury, counsel families regarding this potential risk, and closely monitor for growth disturbance during postoperative follow-up.