187. RETROSPECTIVE ASSESSMENT OF DISTAL FOUNDATIONS IN THE CORRECTION OF ADOLESCENT IDIOPATHIC SCOLIOSIS (AIS)

Abstract

Purpose: Determine if one or two pairs of pedicle screws were superior to multiple laminar hooks for the distal foundation segmental in spinal instrumentation (SSI) in the surgical correction of AIS.

Method: We analyzed 108 consecutive patients identi-fied from our Pediatric Orthopaedic Spine Database (1992–2005) that underwent a posterior spinal fusion (PSF) and segmental spine instrumentation (SSI). There were 3 patient groups: Group 1, one pair of pedicle screws for the distal foundation (n=12); Group 2, two or more pairs of pedicle screws (n=44) and Group 3, multiple hooks only (n=52). The mean age at surgery was 13.5 years, 14.1 years, and 13.0 years, respectively. The major curve was measured perioperatively and at one month, 6 months, 12 months, and 24 months postoperatively and the mean percentage of correction, as well as loss of correction determined. We also analyzed the length of surgery (hours), length of hospitalization and complications.

Results: The mean preoperative major curve was 52.5 degrees in Group 1, 52. degrees in Group 2, and 48.8 degrees in Group 3. The mean percent postoperative correction (POC%) at 1 month was 67.2, 65.2, and 63.4 % in the 3 groups, respectively (p=0.531). The mean percent post-operative correction (POC%) at 24 month was 55.6% for Group 1, 56.6% for Group 2 and 51.5% for Group 3 (p=0.478). The mean percent loss of correction (LOC%) at 24 months was 3.1%, 2.25%, and 2.9% respectively(p=0.648). One-way ANOVA demonstrated no significant differences in patient age, number of levels fused, length of surgery, or length of hospital stay. There were no implant related complications.

Conclusion: Hybrid constructs with one or more pairs of pedicle screws and all-hook constructs for distal foundations in SSI provided similar major curve correction, percentage postoperative correction, and are associated with a minimal loss of correction postoperatively. There was no significant difference between length of surgery, hospital stay or complications.