Distal femoral extension osteotomy plus patellar tendon advancement for crouch gait in children: a preliminary report

Abstract

Objective To evaluate the preliminary outcomes of distal femoral extension osteotomy plus patellar tendon advancement for crouch gait in children. Methods From April 2009 to June 2012, distal femoral extension osteotomy plus patellar tendon advancement were performed for crouch gait in cerebral children with 10-30 degree fixed knee flexion contracture. A total of 16 cases (26 lower extremities) were enrolled with a mean follow-up period of 54 (48-65) months. There were 11 males and 5 females with an average age of 8.9 years (7.5-11.6). Cast immobilization was applied for 6 weeks post-operation. After cast removal, functional exercise was enforced and long leg night splint used for maintaining correction. Degree of fixed knee flexion deformity, popliteal angle, range of motion in knee joint, improvement of crouch gait, visual analogue score (VAS) of knee pain, strength of quadriceps, hamstring and musculus triceps surae, Insall-salvati index on lateral radiographic view and Wren modified crouch gait visual score by physicians were recorded and analyzed for outcome evaluation. Results The GMFCS levels were Ⅰ (n=0), Ⅱ (n=9), Ⅲ (n=7), Ⅳ (n=0) and Ⅴ (n=0). Iliopsoas release was implemented contemporarily in 6 lower limbs and achilles tendon lengthening in 10 lower limbs simultaneously. Crouch gait improved or disappeared in all cases. Compared with preoperative VAS scores of knee pain, the postoperative scores decreased significantly (P<0.05). Degree of fixed knee flexion deformity and poplital angle diminished significantly (P<0.01). Range of motion expanded in knee joints (P<0.01). Strength of quadriceps improved significantly (P<0.05). Strength of hamstring and musculus triceps surae showed insignificant changes. Insall-salvati index on lateral radiographic view diminished with patella alta disappeared in all cases. Two cases of transient sciatic nerve injury remitted through changing cast immobilization in a 20 knee flexion position and nerve nutrition supplementation. Two cases of incision infection were cured after dressing changing. And 3 cases had a mild displacement of distal femur, but osteotmy site remolded well without treatment. There was no instance of over-correction, knee recurvatum or cast pressure sore. Conclusions Distal femoral extension osteotomy plus patellar tendon advancement can effectively improve crouch gait, correct knee flexion deformity and patella alta, boost quadriceps strength and relieve knee pain. And the preliminary outcomes are excellent. Key words: Femur; Cerebral palsy; Gait