Correction of Knee Flexion Contracture in Children With Cerebral Palsy by Femoral Extension Osteotomy: Evaluation of the Sagittal Profile

BACKGROUND: Knee flexion contracture is one of the most common deformities in children with cerebral palsy, significantly affecting the patients’ gait, energy expenditure, verticalization, and quality of life. Knee flexion contracture can be corrected using either soft tissue procedures (hamstring lengthening) or bony interventions (femoral extension osteotomies). Soft tissue procedures are considered less invasive and are justified based on the underlying pathology. Some studies have reported their effect on sagittal balance, specifically an increase in anterior pelvic tilt. Femoral extension osteotomies have been regarded as sagittally neutral; however, most studies included them as part of combined interventions, which precludes assessment of the isolated effect of the osteotomy itself. This emphasizes the importance of investigating the impact of femoral extension osteotomies on global sagittal alignment in children with cerebral palsy.

AIM: This study aimed to evaluate the effect of corrective femoral extension osteotomy on sagittal spinopelvic parameters in children with cerebral palsy and knee flexion contracture.

METHODS: The study included 14 patients with cerebral palsy treated at the Turner National Medical Research Center for Children’s Orthopedics between 2022 and 2025. The patients underwent corrective supracondylar femoral extension osteotomy with plate fixation with angular stability (LCP PHP 90°). Overall, 26 osteotomies were performed. In three cases, a newly developed implant designed for patients with cerebral palsy with reduced bone density was used. Clinical outcomes (i.e., active extension deficit, contracture degree, and popliteal angle) and radiological parameters (i.e., pelvic incidence, pelvic tilt, sacral slope, lumbar lordosis, thoracic kyphosis, and sagittal vertical axis) were assessed preoperatively and at 6 months postoperatively.

RESULTS: Significant correction of contracture and improvement in active knee extension were observed. Among the radiological parameters, only lumbar lordosis showed a significant change (+4.3° ± 13.5°, p = 0.049). Other parameters remained unchanged. No associations were found between the changes in clinical and radiological parameters.

CONCLUSION: Femoral extension osteotomy is an effective method for correcting knee flexion contracture in children with cerebral palsy and does not cause global sagittal alignment disruption. The increase in lumbar lordosis is adaptive in nature and is not associated with signs of decompensation. Initial experience with the newly designed implant demonstrated technical reliability of fixation and promising applicability in patients with reduced bone density.