Direct vertebral body derotation, thoracoplasty, or both: which is better with respect to inclinometer and scoliosis research society-22 scores?

Abstract

Study design: Prospective, longitudinal cohort (nonrandomized).

Objective: To compare thoracoplasty (Th), direct vertebral body derotation (DVBD), and Th and DVBD with respect to correction of the rib prominence and Scoliosis Research Society (SRS) self-image scores in patients undergoing surgery for adolescent idiopathic scoliosis (AIS).

Summary of background data: Rib prominence correction is one of the main goals of AIS surgery. Th and DVBD are powerful tools for correction of the rib prominence; however, a paucity of literature exists comparing Th, DVBD, and Th and DVBD.

Methods: A prospective longitudinal database was queried to identify patients with AIS who underwent a posterior spinal fusion with pedicle screws and 2 years of follow-up. A total of 326 patients were identified and divided into 3 groups: (1) Th alone (N = 47), (2) DVBD alone (N = 196), and (3) both Th and DVBD (N = 83). Patients were subdivided into categories on the basis of their preoperative inclinometer reading: (1) ≤9° (mild), (2) 10 to 15° (moderate), and (3) ≥ 16° (severe). Pre- and postoperative inclinometer readings and SRS self-image scores were compared using analysis of variance.

Results: Overall, the groups were similar preoperatively except for the DVBD group having higher percentage of thoracic flexibility. The preoperative rib prominence values were Th = 13.2, DVBD = 14.0, and Th and DVBD = 12.9 (P = 0.27). Taken collectively, the postoperative 2-year inclinometer readings were similar for all 3 groups (Th = 5.2, DVBD = 7.0, Th and DVBD = 5.6; P = 0.66). However, the SRS-22 self-image scores were significantly better for patients having both Th and DVBD (Th = 3.37, DVBD = 3.44, Th and DVBD = 3.76; P < 0.01). When patients were stratified by severity of preoperative rib prominence, all patients with mild prominences achieved similar corrections, although SRS self-image scores were highest in the Th and DVBD group. In patients with larger rib prominences, the addition of Th was necessary for optimal rib prominence correction, but there was no difference in SRS-22 self-image scores.

Conclusion: Our results suggest that Th alone, DVBD alone, or both Th and DVBD provide equivalent inclinometer results in patients with mild preoperative rib prominences (≤ 9°), but higher SRS-22 self-image scores are achieved using both Th and DVBD. For larger rib prominences, better inclinometer readings are achieved with Th, although SRS-22 self-image scores are comparable.