Effects of intramuscular psoas lengthening on pelvic and hip motion in patients with spastic diparetic cerebral palsy.

The effects of intramuscular psoas lengthening on gait in cerebral palsy patients have been the subject of debates, and the indications for such procedure are still controversial. The purpose of this study was to evaluate the effects of intramuscular psoas lengthening on sagittal plane pelvic and hip motion in patients with spastic diparetic cerebral palsy and identify the factors linked to the best possible outcome. A retrospective study was performed in 26 independent ambulatory patients. All of them had undergone an intramuscular psoas lengthening over the pelvic brim. The mean age at the time of surgery was 11.10 years, and most cases went through additional simultaneous procedures. A complete gait analysis was performed before and, on average, at 17.69 months (range, 6-39 months) after surgery. The Thomas test values, maximum hip extension in stance, and pelvic tilt were analyzed before and after surgical intervention, and the results were statistically compared. The most significant postoperative effect was the reduction of pelvic range of motion (P < 0.01). Reduction of anterior pelvic tilt was observed only in those patients with no previous need of an external aid (P < 0.01), and the studied group did not show a significant improvement of hip extension at terminal stance. According to the results, intramuscular psoas lengthening was useful in reducing pelvic range of motion at the sagittal plane, but this study also suggests that pelvic and hip disruptions of the same plane (sagittal) seem to have a multifactorial etiology. The use of external assistive devices in patients with balance problems may lead to increased anterior pelvic tilt as well as reduction of hip extension at terminal stance.