Can VEPTR® control progression of early-onset kyphoscoliosis? A cohort study of VEPTR® patients with severe kyphoscoliosis

Background: Kyphoscoliosis is considered a relative contraindication to treatment with the Vertical Expandable Prosthetic Titanium Rib (VEPTR®; Synthes Inc, Paoli, PA). Nevertheless, patients do present with early-onset kyphoscoliosis and thoracic insufficiency syndrome, and no suitable alternative treatments are currently available. However, it is unclear whether VEPTR® is reasonable for treating patients with kyphoscoliosis. Questions/purposes: We determined whether VEPTR® controls progression in patients with kyphoscoliosis and, if so, what methods might be used to improve control of deformity progression in these patients. Patients and Methods: We retrospectively reviewed 14 patients who had VEPTR® treatment of early-onset kyphoscoliosis. Degrees of kyphosis and scoliosis before, during, and after treatment were measured, and levels of instrumentation, thoracic dimensions, and complications were recorded. Minimum followup was 1.7 years (average, 5.8 years; range, 1.7-12.8 years). Results: While scoliosis was stabilized, kyphosis increased a mean of 22° at last followup. Supple kyphosis became rigid during treatment. Proximal cradle cutout was a recurring problem. Distal anchors placed too proximally had inadequate lever arms to control kyphosis. Conclusions: Progression of kyphosis can be minimized during VEPTR® treatment by early extension of the construct to the second ribs bilaterally, distal extension of hybrid constructs to the pelvis, use of bilateral hybrid VEPTR® implants, and use of redesigned VEPTR® constructs that enhance fixation at the upper end. While our early results suggest these devices control progression of kyphosis, longer followup with more patients will be required to confirm the concept in these patients. Level of Evidence: Level IV, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.