Abstract
BackgroundEarly versions of spinal muscular atrophy (SMA) scoliosis correction surgeries often involved sublaminar devices. Recently the utilization of pedicle screw is gaining much popularity. Pedicle screw generally believed to provide additional deformity correction, but pedicle size and rotational deformity limit the application of pedicle screw in the thoracic spine, resulting in a hybrid construct of the pedicle screw and sublaminar wire. Studies of the efficacy of hybrid instrumentation in SMA scoliosis is often limited by the scarcity of the disease itself. In this study, we aimed to compare the surgical outcome of using hybrid constructs of the pedicle screw and sublaminar wire and that of sublaminar wire alone in patients with SMA scoliosis.MethodsWe retrospectively reviewed the clinical records and radiographic assessments of patients with SMA scoliosis who underwent corrective surgery between 1993 and 2015. The radiographic assessments included the deformity correction and the progressive change of major curve angle, pelvic tilt (PT) and coronal balance (CB). The correction of deformities was observed postoperatively and at the patient’s 2-year follow-up to test the efficacy of each type of constructs.ResultsThirty-three patients were included in this study. There were 14 and 19 patients in the wiring and the hybrid construct groups, respectively. The hybrid construct demonstrated a higher major curve angle correction (50.5° ± 11.2° vs. 36.4° ± 8.4°, p < 0.001), a higher apical vertebral rotation correction (10.6° ± 3.9° vs. 4.8° ± 2.6°, p < 0.001), and reduced the progression of major curve angle after the 2-year follow-up (5.1° ± 2.9° vs. 8.7° ± 4.8°, p < 0.001). A moderate correlation was observed between the magnitude of correction of apical vertebral rotation angle and major curve (r = 0.528, p = 0.002).ConclusionThis study demonstrated that hybrid instrumentation can provide a greater magnitude of correction in major curve and apical rotation, as well as less major curve progression in comparison with sublaminar wire in patients with SMA scoliosis.Level of evidence III
Hybrid versus Total Sublaminar Wires in Patients With Spinal Muscular Atrophy Undergoing Scoliosis Surgery