A Comparison of Hip Dislocation Rates and Hip Containment Procedures After Selective Dorsal Rhizotomy Versus Intrathecal Baclofen Pump Insertion in Nonambulatory Cerebral Palsy Patients

Abstract

Spasticity is the major etiology for hip dislocation in nonambulatory cerebral palsy patients. Selective dorsal rhizotomy (SDR) was used to control lower extremity spasticity, but is now done infrequently in nonambulatory cerebral palsy. Current surgical treatment is usually intrathecal baclofen pump (ITBP) placement. A major theoretical difference between SDR and ITBP is the effect on the iliopsoas through the L1 nerve root. This study compares the rate of hip dislocation and the need for further hip surgeries in SDR and ITBP patients. All nonambulatory cerebral palsy patients who had either an SDR or ITBP and had minimum follow-up of 2 years were retrospectively reviewed for demographic data and timing, total number, and type of hip procedures (soft tissue vs. bony), and occurrence of hip dislocation. χ (2)test was used to assess for statistical significance. Sixty-nine patients who underwent SDR (40 males) and 50 patients who underwent ITBP (27 males) were included in the study. Average age at spasticity intervention was 6 years 11 months for SDR and 9 years 8 months for ITBP. In the SDR group, 25% of hips underwent reconstruction versus 32% of hips in the ITBP group. There were a total of 19 hip procedures in the SDR group and 20 in the ITBP group (P = 0.15). Seventeen soft-tissue procedures were performed in both SDR and ITBP groups (P = 0.265). Six bony procedures (0 salvage) were performed in the SDR group and 10 in the ITBP group (4 salvage; P = 0.075). At final follow-up the hip dislocation rate was 10.6% in the SDR group and 7.4% in the ITBP group. There was no significant difference in the rate of secondary hip reconstructive surgery or dislocation between nonambulatory cerebral palsy patients who underwent SDR versus ITBP. Reconstruction was required for 25% to 32% of hips despite spasticity intervention with either procedure. This suggests that the L1 nerve root alone does not play a major role in the progression of hip dislocation. Level 3--therapeutic study.