Variability in selective dorsal rhizotomy surgery: an analysis of the Cerebral Palsy Research Network registry

Selective dorsal rhizotomy (SDR) is a surgical procedure to reduce spasticity and improve function in children with cerebral palsy (CP). Randomized trials have shown that SDR is superior to physical therapy alone for reduction of spasticity and improvement in gait, but there is wide variation in surgical technique. The purpose of this study was to describe the scope of patient factors and surgical technique of SDR performed for the management of spasticity in children with CP.

This study is a cross-sectional analysis of data included in the Cerebral Palsy Research Network (CPRN) registry from all subjects who underwent SDR at a CPRN member site. Data from consecutive cases were collected at each site and submitted to the CPRN registry. All cases of SDR submitted to the registry were included. Descriptive statistics were used to summarize data. When possible, results were compared across CPRN centers and patients using descriptive and inferential statistics.

A total of 564 patients underwent SDR and had data in the CPRN registry. Most (n = 356, 63%) children were male and White (n = 427, 76%). The Gross Motor Function Classification System (GMFCS) level was I in 63 (14%), II in 108 (23%), III in 134 (29%), IV in 81 (17%), and V in 76 (16%) children. Dystonia was present in 25 (6.2%) children. SDR was performed at the level of the conus medullaris or upper cauda equina in 193 (50%) children. Multilevel laminotomy was performed in 194 (50%) children. Intramuscular monitoring electrodes were placed in 486 (94%) children. The median number of nerve rootlets tested on each side was 27 (IQR 31-34, range 4-139). The median proportion of rootlets cut was 0.63 (IQR 0.52-0.67, range 0.21-1.0). The proportion of rootlets cut was associated with GMFCS level; patients who had a GMFCS level of V had a greater proportion of rootlets cut compared to those with levels of I (mean difference [MD] 0.079, p < 0.01), II (MD 0.129, p < 0.01), and III (MD 0.096, p < 0.01).

There are many variations in SDR technique for the management of spasticity in CP, including differences in approach to surgical site, number of rootlets tested, and proportion cut. Detailed outcome data are needed to compare variations and determine if an optimal technique is associated with ideal treatment results.