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

Abstract

Study Design Retrospective review of prospectively collected data Objective To compare the use of spine-based vs. 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 vs. rib-based proximal anchors. Methods 169 patients with rib fusions treated with rib-based or spine-based constructs and minimum 2-year follow-up were included. 16 patients were treated with proximal spine-based anchors and 153 with proximal rib-based devices (VEPTRs). 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 degrees in the rib-based group and decreased a mean of 20 degrees in the spine-based group (p=0.002). Major Cobb angle decreased in both groups (p<0.0001); however, the spine-based group had greater Cobb angle improvement (24 vs. 11 degrees, p=0.04). 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 to 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 8 lengthening surgeries prior to final fusion or cessation of lengthening with a modest 2.3 cm increase in T1-T12 height. Compared to proximal rib anchors, proximal spine anchors controlled kyphosis and improved Cobb angle correction for early onset scoliosis with rib fusions.