The Effect of Expansion Thoracostomy on Spine Growth in Patients with Spinal Deformity and Fused Ribs Treated with Rib-Based Growing Constructs

Abstract

Study DesignRetrospective review of prospective registries. ObjectivesWe hypothesized that patients with congenitally fused ribs who underwent thoracostomy upon implantation of rib-based distraction devices would achieve improved spine growth compared with those who did not undergo thoracostomy. Summary of Background DataPatients with fused ribs may develop thoracic insufficiency syndrome. Treatment for severe early-onset spinal deformity with rib fusions often includes the placement of rib-based expansion devices with surgical division of the fused ribs (thoracostomy). The effect of thoracostomy on spinal growth has not been fully examined. MethodsTwo multicenter registries of primarily prospectively collected data were searched. Patients with fused ribs and implantation of a rib-based device were identified. A total of 151 patients with rib fusions treated with rib-based constructs and minimum two-year follow-up were included. Among those, 103 patients were treated with expansion thoracostomy at the time of implantation, whereas 48 patients received device implantation alone. We evaluated change in T1–T12 and T1–S1 height, coronal Cobb angle, kyphosis, and number of surgeries. Preoperative deformity was similar between the two groups. Only 19% of patient underwent final fusion, with similar numbers fused in each group. ResultsAt latest follow-up, the expansion thoracostomy group had a greater total improvement in T1–S1 height (7.2 cm vs. 4.8 cm, p = .004). There was no difference between the two groups for change in spinal height at each lengthening procedure. Interestingly, thoracostomy patients also underwent more total surgeries (11.5 vs. 9.6, p = .031) and more lengthening procedures (8.3 vs. 6.6, p = .017) than the comparison group despite similar length of follow-up. ConclusionsPatients who underwent expansion thoracostomy at the time of rib expansion device implantation achieved greater improvement in T1–S1 height than those who underwent implantation of rib expansion device alone. Further work is needed to evaluate whether expansion thoracostomy impacts pulmonary function.