Intramuscular psoas lengthening at the pelvic brim plus proximal lengthening of the rectus femoris as a treatment for fixed knee flexion deformity in cerebral palsy.

Although the correction of knee flexion by lengthening the hamstring musculature is traditionally contemplated in cerebral palsy, literature suggests that treatment of hip flexion also improves knee extension. The aim of the study was to first show the efficacy of the sequence of intrapelvic tenotomy of the psoas followed by intramuscular lengthening of the proximal rectus anterior and, later, that of both surgical soft tissue surgeries separately. For this, a prospective study was carried out in 10 patients with a mean age of 14 years, which presented 16 fixed knee flexes with a mean of deformity of 22°. The data was analyzed through means of an ANOVA of repeated measures and to determine the effect separately of each one of the techniques, the improvements obtained with respect to the previous level were contrasted. The mean extension achieved was 12°, 7° corresponding to the intrapelvic tenotomy of the psoas and, on the remaining knee flexion, a correction of 5° after intramuscular lengthening of the anterior rectus at the proximal level. Both the sequence of proposed gestures and those that form separately, showed statistically significant differences (P <0.001) in the correction of the deformity. In conclusion, the proposed techniques applied sequentially or separately are effective in reducing knee flexion in predominantly spastic cerebral palsy, facilitating or even being able to avoid the treatment that is directly needed.