Soft Tissue Releases With Simultaneous Guided Growth Decrease Risk of Spastic Hip Displacement Recurrence

Background: Soft tissue release (STR) is an established treatment for spastic hip displacement, but recurrence of hip displacement is not uncommon. This study aims to (1) evaluate the recurrence of hip displacement after STR, (2) define associated factors of recurrence, and (3) elucidate the effects of guided growth on hip displacement recurrence. Methods: The study subjects included 66 individuals with spastic cerebral palsy treated by STR with or without guided growth for hip displacement. The treatment goal was the maintenance of migration percentage (MP) to <40%. Recurrence was defined by a rebound of the MP by 5% or more after the first postoperative year. Children with recurrence were compared with those without recurrence using the Mann-Whitney U test and the χ² test. The risk factors for recurrence were evaluated using multiple logistic regression analysis. Results: Nineteen individuals (29%) had a recurrence of hip displacement after the first postoperative year. They sustained a 2-fold increase in the rate of treatment failure (P < 0.001) and reoperation (P = 0.04). Age, sex, motor function, and preoperative radiographic parameters were comparable between individuals with and without recurrence. The use of guided growth was associated with less risk of recurrence than without (5% and 39%, respectively, odds ratio = 0.01 to 0.45, respectively) despite the similar risk of failure (35% and 48%, respectively, odds ratio = 0.15 to 4.82). Conclusions: Recurrence of the MP >5% after the first postoperative year is an important early indicator for failure to control MP to <40% and reoperation. Guided growth not only decreases coxa valga but also reduces the risk of recurrent hip displacement after STR.