Preoperative gait pattern as predictor of gait changes following selective dorsal rhizotomy.

Abstract

Background: Selective dorsal rhizotomy (SDR) can improve gait in children with spastic paresis. However, outcomes vary, and selecting individuals who will benefit from the procedure remains challenging. How pre-SDR gait pattern predicts post-SDR gait has not previously been investigated.

Research question: This study aims to compare how different gait patterns change after SDR to gain insight into the potential relevance of gait patterns as a selection criterion for SDR.

Methods: Kinematic and kinetic data of nineteen children with bilateral spastic paresis due to cerebral palsy or hereditary spastic paraplegia, with 3D gait analysis before and two years after SDR, were extracted from an in-hospital database. A cluster analysis was performed to distinguish different gait patterns based on sagittal hip, knee and ankle angles pre-SDR. Deviations from typical gait per leg (38 legs) pre- and post-SDR were quantified with the Gait Profile Score (GPS), calculated for joint angles, moments, and powers. GPS was compared pre- and post-SDR per gait pattern, and pre-post differences were compared between gait patterns.

Results: Three distinct pre-SDR gait patterns (GPs) were identified using cluster analysis, with GP1 characterized by increased knee flexion (18 legs), GP2 by increased ankle plantarflexion (14 legs), and GP3 by increased knee flexion and increased ankle plantarflexion (6 legs). GPS-kinematics improved significantly for GP1 (-3.1°) and GP3 (-6.6°), but showed no significant change for GP2. GPS-kinematics improved significantly more in GP3 than in GP2. GPS-moments improved equally in all groups (-0.04Nm/kg--0.07Nm/kg). GPS-powers improved significantly more for GP1 and GP2 (0.07W/kg and 0.24W/kg, respectively) than for GP3 where no change occurred.

Significance: The results suggest that different pre-SDR gait patterns have distinct outcomes post-SDR in children with spastic paresis. Therefore gait patterns could guide selection and expectation management for SDR. Future studies should confirm these results in a larger cohort.