Spine Deformity With Fused Ribs Treated With Proximal Rib- Versus Spine-Based Growing Constructs

Study Design: Retrospective review of prospectively collected data. Objective: To compare the use of spine-based versus rib-based implants for the treatment of early-onset scoliosis (EOS) in the setting of rib fusions. Summary of Background Data: Treatment for severe early-onset spinal deformity with rib fusions includes growing spine devices with proximal rib or spine anchors. The results of treatment, however, have not been compared between spine-based versus rib-based proximal anchors. Methods: 169 patients with rib fusions treated with rib-based or spine-based constructs and minimum two-year follow-up were included. Sixteen patients were treated with proximal spine-based anchors and 153 with proximal rib-based devices (VEPTRs). Overall, 104 of the patients with rib-based fixation underwent thoracoplasty at the index surgery. We evaluated change in T1–T12 and T1–S1 height, coronal Cobb angle, kyphosis, and number of lengthening/revision surgeries. Results: Kyphosis increased a mean of 7° in the rib-based group and decreased a mean of 20 degrees in the spine-based group (p =.002). Major Cobb angle decreased in both groups (p <.0001); however, the spine-based group had greater Cobb angle improvement (24 vs. 11 degrees, p =.04). From implant and lengthening of distraction devices, there was a mean 3.3-cm (22%) increase in T1–T12 height and a mean of 8.0 lengthenings in the rib-based group compared with a 5.7-cm increase and 6.3 lengthening surgeries in the spine-based group. Patients with rib-based constructs had a mean of 11 total procedures, whereas spine-based patients had a mean of 8. Conclusions: Patients underwent a mean of eight lengthening surgeries before final fusion or cessation of lengthening with a modest 2.3-cm increase in T1–T12 height. Compared with proximal rib anchors, proximal spine anchors controlled kyphosis and improved Cobb angle correction for early-onset scoliosis with rib fusions.