Abstract
OBJECTIVE Surgical decision-making and planning is a key factor in optimizing outcomes in adult spinal deformity (ASD). Minimally invasive spinal (MIS) strategies for ASD have been increasingly used as an option to decrease postoperative morbidity. This study analyzes factors involved in the selection of either a traditional open approach or a minimally invasive approach to treat ASD in a prospective, nonrandomized multicenter trial. All centers had at least 5 years of experience in minimally invasive techniques for ASD.
METHODS The study enrolled 268 patients, of whom 120 underwent open surgery and 148 underwent MIS surgery. Inclusion criteria included age >= 18 years, and at least one of the following criteria: coronal curve (CC) >= 20 degrees, sagittal vertical axis (SVA) > 5 cm, pelvic tilt (PT) > 25 degrees, or thoracic kyphosis (TK) > 60 degrees. Surgical approach selection was made at the discretion of the operating surgeon. Preoperative significant differences were included in a multivariate logistic regression analysis to determine odds ratios (ORs) for approach selection.
RESULTS Significant preoperative differences (p < 0.05) between open and MIS groups were noted for age (61.9 vs 66.7 years), numerical rating scale (NRS) back pain score (7.8 vs 7), CC (36 degrees vs 26.11, PT (26.4 degrees vs 23 degrees), T1 pelvic angle (TPA; 25.8 degrees vs 21.7 degrees), and pelvic incidence-lumbar lordosis (PI-LL; 19.6 degrees vs 14.9 degrees). No significant differences in BMI (29 vs 28.5 kg/m(2)), NRS leg pain score (5.2 vs 5.7), Oswestry Disability Index (48.4 vs 47.2), Scoliosis Research Society 22-item questionnaire score (2.7 vs 2.8), PI (58.3 degrees vs 57.1 degrees), LL (38.9 degrees vs 42.3 degrees), or SVA (73.8 mm vs 60.3 mm) were found. Multivariate analysis found that age (OR 1.05, p = 0.002), VAS back pain score (OR 1.21, p = 0.016), CC (OR 1.03, p < 0.001), decompression (OR 4.35, p < 0.001), and TPA (OR 1.09, p = 0.023) were significant factors in approach selection.
CONCLUSIONS Increasing age was the primary driver for selecting MIS surgery. Conversely, increasingly severe deformities and the need for open decompression were the main factors influencing the selection of traditional open surgery. As experience with MIS surgery continues to accumulate, future longitudinal evaluation will reveal if more experience, use of specialized treatment algorithms, refinement of techniques, and technology will expand surgeon adoption of MIS techniques for adult spinal deformity.
