Morbidity and radiographic outcomes of severe scoliosis of 90° or more: a comparison of hybrid with total pedicle screw instrumentation

OBJECTIVES Untreated severe scoliosis is associated with increased mortality and remains a significant surgical challenge. Few studies have reported mortality after the surgical treatment of severe scoliosis beyond a 2-year follow-up. The objectives of this study were to evaluate mortality beyond standard 2-year follow-up and compare radiographic outcomes using hybrid or pedicle screw instrumentation for severe scoliosis. METHODS We evaluated 32 consecutive patients [11 males, mean age at surgery 15.3 (range 10.7-20.7) years] operated for a scoliosis of 90° or more using either hybrid (n = 15) or pedicle screw (n = 17) instrumentation. The follow-up time averaged 2.9 (2.0-6.6) years for radiographic and quality of life measurements and 5.5 years (2.0-9.0) years for mortality data. Of these patients, one had adolescent idiopathic scoliosis, three secondary scoliosis, and 28 neuromuscular scoliosis. Twelve patients in the hybrid and two patients in the pedicle screw groups underwent anteroposterior surgery (p < 0.001), and three patients in both groups had an apical vertebral column resection. RESULTS One (3.1 %) patient died during follow-up for severe pneumonia. Preoperatively, the mean magnitude of the major curve was 109° (90°-127°) in the hybrid and 100° (90°-116°) in the pedicle screw groups (p = 0.015), and was corrected to 45° (19°-69°) in the hybrid and 27° (18°-40°) in the pedicle screw groups at the 2-year follow-up (p < 0.001), with a mean correction of the major curve of 59 % (37-81 %) in the hybrid versus 73 % (60-81 %) in the pedicle screw groups, respectively (p = 0.0023). There were six postoperative complications, including one transient spinal cord deficit necessitating reoperation in the hybrid group as compared with five complications in the pedicle screw group (p = 0.53). CONCLUSIONS The mid-term mortality rate after the surgical treatment of severe scoliosis was low. Severe scoliosis can be treated safely with significantly better correction of the spinal deformity using pedicle screws than hybrid instrumentation.