Distal Femoral Extension Osteotomy and Patellar Tendon Advancement in Management of Fixed Knee Flexion Deformity and Crouch Gait in Cerebral Palsy

Abstract Background Cerebral palsy (CP) is generally associated with musculoskeletal deformities that occur during body growth. Fixed knee flexion deformity (FKFD) results from long standing knee flexion that is due to progressive contracture of spastic hamstrings combined with a quadriceps weakness. Fixed knee flexion compromises the passive mechanisms of joint stabilization at mid and terminal stance in children with CP. The aim of this study is to highlight the results of distal femoral extension osteotomy and patellar tendon advancement (DFEO + PTA) for management of FKFD in crouching CP patients with spastic or mixed tone diplegic ambulatory cerebral palsy children. Patients and Methods A prospective study was conducted involving twenty CP patients with fixed knee flexion deformity (14 males and 6 females). The 20 cases with fixed knee flexion deformity were GMFCS level II (4 cases), and III (16 cases). All patients were clinically and radiologically assessed according to knee flexion angle, extension lag, koshino index and the Gross motor function measure pre- and post-operative. All patients underwent DFEO ± PTA. Eighteen limbs had DFEO on the RT side, and twenty on the LT side. Results The mean age of the patients was 11.18±3.23 (6-16) years. The period of follow up ranged from 12 to 24 months (The mean follow up was 16.20 ± 2.46). At last follow up, the median knee flexion angle improved from 25 to 0. The median extension lag improved from 17.5 to 0. The mean koshino index improved from 1.59 ± 0.32 to 1.05 ± 0.10. the GMFM improved from 52.86 ± 7.36 to 68.15 ± 5. 82. Conclusion The combined procedure (DFEO + PTA) is effective in increasing knee extension in the stance phase, reducing knee pain and improving knee extension strength.