Identification of risk factors for reconstructive hip surgery after intrathecal baclofen therapy in children with cerebral palsy.

Abstract

This study aimed to determine the risk factors for reconstructive hip surgery after intrathecal baclofen pump application in children with cerebral palsy. Inclusion criteria were children with hypertonic (spastic or mixed spastic/dystonic motor type) cerebral palsy, intrathecal baclofen implantation <8 years of age, no reconstructive osteotomies prior to or concomitant with intrathecal baclofen implantation and at least a 5-year follow-up. Exclusion criteria included reconstructive osteotomies prior to or concurrent with intrathecal baclofen implantation, lack of at least 1 hip surveillance radiograph before intrathecal baclofen, lack of a 5-year follow-up, or having selective dorsal rhizotomy. In addition, patients with bony surgery plus last follow-up migration percentage ≥50% were labeled as required reconstruction hips. We identified 34 patients (68 hips). The mean follow-up was 9.2 ± 2.8 years. The mean age for intrathecal baclofen application was 6.4 ± 1.2 years. Seven patients were Gross Motor Function Classification System IV, and 27 were V. Eighteen patients (52.9%) with 31 hips (45.6%) were requiring reconstruction at the final follow-up. In multivariate analysis, male sex (odds ratio 12.8, P=.012), pre-intrathecal baclofen migration percentage (odds ratio 1.1, P=0.003), age at intrathecal baclofen implantation (odds ratio 0.24, P=.002), and delta migration percentage (odds ratio 1.1, P=.002) were significant risk factors for requiring reconstruction. Patients with intrathecal baclofen <6.2 years of age had a significantly higher rate of requiring reconstruction. A pre-intrathecal baclofen migration percentage >31% had a greater risk of progression to requiring reconstruction (P=.001). Delta migration percentage higher than 15% was significantly associated with progression to requiring reconstruction (P=.043). The risk of requiring reconstruction osteotomies after intrathecal baclofen was significantly increased in males, those younger (±migration percentage >31%) at the time of intrathecal baclofen implantation and those with an increased rate of migration percentage progression after intrathecal baclofen implantation. Level IV, Prognostic Study.