Distal Femoral Shortening Osteotomy for Severe Knee Flexion Contracture and Crouch Gait in Cerebral Palsy

Abstract

Although there have been advancements of surgical techniques to correct gait abnormalities seen in patients with cerebral palsy, the crouch gait remains one of the most difficult problems to treat. The purpose of this retrospective study was to examine our results of distal femoral shortening osteotomy (DFSO) and patellar tendon advancement (PTA), performed in patients with crouch gait associated with severe knee flexion contracture. A total of 33 patients with a mean fixed knee contracture of 38° were included in the study. The mean age at the time of surgery was 12.2 years and the mean follow-up was 26.9 months. The measurements of clinical, radiological, and gait parameters were performed before and after surgery. The mean degrees of knee flexion contracture, Koshino index of patella height, and Gait Deviation Index were found to be significantly improved at the time of final follow-up. The maximum knee extension during the stance phase improved by an average of 25°, and the range of knee motion during gait increased postoperatively. On the other hand, the mean anterior pelvic tilt increased by 9.9°. Also, the maximum knee flexion during the swing phase decreased and the timing of peak knee flexion was observed to be delayed. We conclude that combined procedure of DFSO and PTA is an effective and safe surgical method for treating severe knee flexion contracture and crouch gait. However, the surgeons should be aware of the development of increased anterior pelvic tilt and stiff knee gait after the index operation.

Keywords: cerebral palsy; crouch gait; distal femoral shortening osteotomy; patellar tendon advancement; severe knee flexion contracture.

Figure 1

Preoperative and postoperative radiographs of a patient whose preoperative knee flexion contracture measured 43°. After resection of a wedge-shaped bone via a distal femoral extension osteotomy, significant angular deformity developed at the distal femur. Difficulty in securing fixation with a plate may be encountered and the weight-bearing surface of the distal femur may shift to the posterior condyles during the mid-stance phase of the gait.

Figure 2

Preoperative and postoperative anteroposterior and lateral radiographs of the knee joints showing distal femoral shortening osteotomy fixed with a blade plate and correction of patella alta with patella tendon shortening and tension-band wiring (a) or tibial tubercle advancement (b), respectively.

Figure 3

Preoperative and final follow-up sagittal plane kinematic graphs for the whole cohort. Bold solid lines indicate average values. Bold dotted lines represent one standard deviation. Fine dotted lines indicate the normal range.

Figure 4

Preoperative and final follow-up sagittal plane kinetic graphs. Bold solid lines indicate average values. Bold dotted lines represent one standard deviation. Fine dotted lines indicate the normal range.