Biomechanical investigation of potential prophylactic scoliosis treatments following various sizes of chest wall resection

Abstract

Background: A well-known problematic sequela of chest wall resections is development of scoliosis. Despite the seriousness and frequency of scoliosis following chest well resection, the etiology and biomechanical information needed to understand this progression aren't well-known. Methods: Range of motion of six specimen (C7–L2) was captured using a custom-built six degrees-of-freedom machine in each of three physiological rotation axes. Left posterior ribs were sequentially resected 7cm from the rib head, starting at the 5th rib and continuing until the 10th rib. Injured specimen were instrumented with unilateral anterior rod fixation and then with additional unilateral posterior fixation, each starting at T4 and then extended distally as ribs were resected. Relative motion between the constructs' proximal and distal ends was measured in all three axes for the intact, injured, unilateral anterior, and unilateral anterior with unilateral posterior constructs. Findings: Raw motion of the injured specimen increased in a stepwise manner as ribs were resected. Averaged across all injury sizes, the unilateral anterior construct significantly reduced motion by 47.0±13.4% in lateral bending (P=.001). The combined anterior-posterior construct significantly reduced motion by 57.6±15.9% in flexion/extension (P