ELECTIVE dorsal rhizotomy is a surgical procedure designed to reduce spasticity and improve motor function in children with spastic CP. In the last two decades, this procedure has become accepted as a standard neurosurgical procedure for the treatment of spasticity as- sociated with CP and is currently performed at many cen- ters around the world. In SDR procedures, laminectomies or laminoplasties are performed at two to as many as six levels, involving part or all of the lumbar spinal levels; multiple dorsal rootlets are cut, and decreased tone in the lower limbs is expected. The impact of SDR on the immature spine of the child, and in particular, on the later occurrence of spinal deformities has not been well defined but should be of concern. Children with spastic CP are known to be at higher risk of spinal de- formity, particularly scoliosis, than the normal popula- tion. 5,11,22,23 Furthermore, the risk of spinal deformities de- veloping in patients may be increased after they undergo laminectomies or laminoplasties such as those performed in conjunction with SDR, although this may be less of a prob- lem in the lumbar or lumbosacral area than higher in the spinal column. 6,25,36 The effects of the decreased spasticity that typically occur after SDR, with alterations in the bal- ance of muscle tone in the trunk and hips, may also influ- ence the development of spinal deformities. The issue of spinal deformities after SDR was first ex- amined by Peter, et al., 18 who noted scoliosis in 16%, ky- phosis in 5%, and lordosis in 7% of children. This group believed that the incidence of these spinal deformities was no greater after SDR than might have been expected in a population of children with spastic CP who did not under- go laminectomy. 18 In a more recent report, Turi, et al., 35 re- ported a 32% incidence of new spinal deformity, including scoliosis, hyperlordosis, and hyperkyphosis, suggesting that this may indeed be a significant problem. Additional information on this important potential consequence of SDR is required. J. Neurosurg: Pediatrics / Volume 102 / May, 2005 J Neurosurg (Pediatrics 4) 102:363–373, 2005 Spinal deformities after selective dorsal rhizotomy for spastic cerebral palsy PAUL STEINBOK, M.B.B.S., F.R.C.S.(C), TUFAN HICDONMEZ, M.D., BONITA SAWATZKY, PH.D., RICHARD BEAUCHAMP, M.D., F.R.C.S.(C), AND DIANE WICKENHEISER, B.SC., P.T. Division of Pediatric Neurosurgery, Departments of Surgery and Orthopedic Surgery, and Physiotherapy, British Columbia’s Children’s Hospital, and University of British Columbia, Vancouver, British Columbia, Canada Object. Spinal deformities are significant problems in children with spastic cerebral palsy. The treatment of their spasticity by selective dorsal rhizotomy (SDR) may worsen or improve these problems. The purpose of this study was to determine the incidence of and change in degree of thoracolumbar scoliosis, thoracic kyphosis, and lumbar lordosis in children who have undergone SDR. Methods. A retrospective review was conducted of children younger than 18 years of age, who had undergone SDR at British Columbia’s Children’s Hospital from 1987 to 2001 and in whom preoperative and postoperative spine radiographs have been obtained. Angles for thoracolumbar scoliosis, thoracic kyphosis, and lumbar lordosis were measured. The study group comprised 105 patients. The mean age at surgery was 5.2 years (range 2.7–14.6 years), with a mean time to most recent follow-up radiographs of 4.3 years (1–13.6 years). Sixty-two children had spastic diplegia (59%), 34 spastic quadriplegia (32%), and nine quadriplegia and intellectual delay (9%). A total of 104 children underwent laminoplasty with replacement of the laminae, usually from L-1 to S-1 and 54.8% of children had scoliosis at last fol- low up, with 25% having worsening of 10˚ or more. The incidence of abnormal kyphosis at the last follow-up visit was 38.6%, with 31.8% having worsening of 15˚ or more. The incidence of hyperlordosis at last follow up was 21.3%, with 36% having worsening of 15˚ or more. The factors in this series impacting development of spinal deformities have been analyzed and are discussed. Conclusions. The relatively high incidence of spinal deformity in children who have undergone SDR via multi- level lumbosacral laminoplasties should raise some concern. KEY WORDS • spasticity • selective dorsal rhizotomy • spinal deformity • scoliosis • kyphosis • lordosis • pediatric neurosurgery S 363 Abbreviations used in this paper: BCCH = British Columbia’s Children’s Hospital; CI = confidence interval; CP = cerebral palsy; GMFCS = Gross Motor Function Classification System; OR = odds ratio; ROM = range of motion; SD = standard deviation; SDR = selective dorsal rhizotomy.