Anterior distal femoral hemiepiphysiodesis with and without patellar tendon shortening for fixed knee flexion contractures in children with cerebral palsy

Abstract

Purpose Surgery is often required for fixed knee flexion contractures in patients with neuromuscular conditions. Anterior distal femoral hemiepiphysiodesis (ADFH) is an alternative to distal femoral extension osteotomy (DFEO) in skeletally immature patients. ADFH is typically not accompanied by patellar tendon shortening surgery (PTS). Our purpose was to compare ADFH alone versus ADFH with PTS for treatment of fixed knee flexion contractures and crouched gait in children with cerebral palsy (CP). Methods Retrospective review of pre- and postoperative gait analysis data for children with CP who underwent ADFH alone, or ADFH with PTS. Data were analysed using linear mixed models to control for covariates. Results In total, 25 participants (42 limbs) were included, 17 male and eight female, mean age at surgery 12.9 (sd 1.9) years. Both groups experienced significant improvement in popliteal angle, knee extension range of motion (ROM) and knee extension in stance phase. Greater improvement was seen for all variables in the ADFH/PTS group, mainly due to greater popliteal angle and knee flexion during gait preoperatively in that group (p ≤ 0.02) rather than the procedure performed (p ≥ 0.19). There was no difference between groups postoperatively. Rate of contracture resolution was 0.5° to 1.0° per month, faster in larger contractures (p = 0.02). Conclusions ADFH with and without PTS is effective in improving knee extension in skeletally immature patients with CP, correcting contractures at a rate of 0.5° to 1.0° per month. Combined ADFH and PTS surgery may be preferable in patients with larger contractures of up to 30° to 35°. Level of evidence III

Anterior distal femoral hemiepiphysiodesis in children with cerebral palsy: Establishing surgical indications and techniques using the modified Delphi method and literature review

“…Previous authors have reached similar conclusions regarding the utility of ADFH, demonstrating the ability to correct knee flexion deformity while allowing for immediate weight bearing and limited morbidity. 16,23 The optimal timing of when to perform guided growth and the degree of fixed knee flexion correction is somewhat elusive in the literature. The recorded rate of knee flexion contracture correction associated with ADFH has been reported to vary between 0.5 and 1.5 degrees/month without significant differences noted between implant types.…”

“…Previous authors have reached similar conclusions regarding the utility of ADFH, demonstrating the ability to correct knee flexion deformity while allowing for immediate weight bearing and limited morbidity. 16 , 23 …”

“…The recorded rate of knee flexion contracture correction associated with ADFH has been reported to vary between 0.5 and 1.5 degrees/month without significant differences noted between implant types. 16 , 17 Rethlefsen et al 16 have reported that greater rates of knee flexion contracture correction have been observed in scenarios where the starting knee flexion contracture is greater. Currently, no guidelines exist within the literature to indicate when ADFH is indicated in terms or age or degree of knee flexion contracture.…”

“…Recently, anterior distal femoral hemiepiphysiodesis (ADFH), or guided growth, has been described as an alternative to DFEOs in patients with FKFD and open physes. 13 , 16 – 18 This novel intervention is only designed to address the FKFD and not the additional lever arm dysfunction associated with crouch gait; however, from these recent studies, no firm conclusions can be drawn regarding timing, degree of deformity, or functional level indication. Therefore, the purpose of this study was to use a modified Delphi method and build on our previous work 6 , 7 to establish areas of consensus for surgical indications for ADFH for the management of knee flexion contracture in the setting of crouch gait in children with CP.…”

“…There is no indication for an ADFH (guided growth) unless the patient has a KFC at the time of surgery.X (88%)15. After any form of ADFH/guided growth, ongoing clinical/radiological follow-up, to skeletal maturity is essential, to monitor correction and to detect unintended coronal plane deformities.X (100%)16. Crouch gait on observation gait assessment is one indication for ADFH (guided growth).X (63%)17.…”