The Use of Spinal Instrumentation in Young Patients with Congenital Spine Deformities

Purpose: There are currently no published reports dedicated to determing if spinal instrumentation in young patients is safe and has an effect on fusion rate, curve correction, and duration of immobilization. The purpose of this study was to examine the safety and efficacy of using modern down-sized spinal instrumentation in children with congenital spine deformities.

Methods: We reviewed the cases of patients undergoing spinal instrumentation for congenital spine deformities under eight years of age between Jan.1 1996 and Dec.31 2000. Radiographs were reviewed to determine: type of anomaly, curve magnitude, and sagittal alignment. We reviewed the medical records to determine the presence of the intraoperative and postoperative complications related to the use of spinal instrumentation, and the need for postoperative immobilization. Final follow-up films were reviewed to determine fusion and coronal/sagittal measurements.

Results: We identified 40 patients treated with infant or pediatric sized spinal instrumentation. The average patient age at surgery was 3 yrs 3 mos. (8 mo-7.8yrs). The diagnosis included: 18 hemivertebra, 3 bars, 10 mixed anomalies, and 9 congenital kyphosis. 11 patients had concomitant spinal dysraphism. For patients with scoliosis the average preoperative curve was 39 degrees (range 26-54) and for patients with congenital kyphosis the average kyphotic segment was 32 degrees (range 20-45 degrees). The average sagittal profile for all patients was 30 degrees thoracic kyphosis and 30 degrees lumbar lordosis. There were 2 complications intraoperatively related to instrumentation: one lamina fracture related to hook placement and one pedicle screw cut out. One patient had a transient neurologic monitoring change related to placement of spinal implants, this resolved after spinal implant removal. No patient had a postoperative neurologic deficit. There were no infections or wound problems. 24 patients required a cast after surgery (avg.3mos.) and 12 patients required a brace after surgery (avg.3mos.).There was one postoperative complication related to spinal instrumentation: one nut disengagement from a hook requiring an operation for replacement at two months.11 patients underwent implant removal for the following reasons: two needed further imaging for dyraphism and their instrumentation was not MRI compatible, nine had prominent spinal instrumentation. At final follow-up of avg.3 yrs.3mos. (range 2-5.3 yrs) the average postoperative curve was 12 degrees (range 0- 37 degrees) for scoliosis patients and the average kyphotic segment was improved to 8 degrees (range 0-22) in congenital kyphosis patients. The average postoperative sagittal profile was 29 degrees thoracic kyphosis and 29 degrees lumbar lordosis for both groups. All patients had radiographic fusion.

Discussion: In this group of patients spinal instrumentation was safe and efficacious, even when spinal dysraphism was present. Curve correction and sagittal profile were maintained with a 100% fusion rate. There were no neurologic deficits in our series. This is the first series to show the benefits of down-sized spinal instrumentation in these patients include: diminished need for immobilization, improved curve correction, and a higher rate of fusion compared to similar patients in the literature treated without instrumentation.