Anterior or Posterior Surgery for Right Thoracic Adolescent Idiopathic Scoliosis (AIS)? A Prospective Cohorts' Comparison Using Radiologic and Functional Outcomes

Study Design: Prospective cohort study. Objective: Prospectively compare patient-reported as well as clinical and radiologic outcomes after anterior or posterior surgery for right thoracic adolescent idiopathic scoliosis (AIS) in a single center by the same surgeons. Summary of Background Data: Anterior and posterior spinal instrumentation and arthrodesis are both well-established treatments of thoracic AIS. The majority of studies comparing the 2 approaches have focused on radiographic outcomes. There remains a paucity of prospectively gathered patient-reported outcomes comparing surgical approaches. Methods: Forty-two consecutive patients with right thoracic AIS were treated in a single center by one of 2 surgeons with either anterior (n = 18) or posterior (n= 24) approaches and followed up for over 2 years. Radiographic, clinical, and patient-reported outcomes of the Modified Scoliosis Research Society Outcome Instrument were gathered and analyzed by an independent surgeon. Results: Patients reported significant improvements in all areas of the Modified Scoliosis Research Society Outcome Instrument, especially pain and self-image domains. There were no significant differences in the degree of improvement in any domains between the groups. Posterior and anterior surgery corrected rib hump by 53% and 61%, respectively (P = 0.4). The Main thoracic curve Cobb angle was corrected from 69 to 26 degrees (62%) by posterior surgery and 61 to 23 degrees (64%) by anterior surgery (P = 0.6). Posterior surgery significantly reduced kyphosis and lumbosacral lordosis. Anterior surgery had no overall affect of sagittal alignment but seemed able to correct those hypokyphotic preoperatively. Complications differed and were largely approach-related-intrathoracic in anterior and wound-related in posterior surgery. Conclusions: Patients with right thoracic AIS of differing curve types but otherwise similar preoperatively demonstrated that anterior and posterior surgery are largely equivalent. Patient-reported outcomes are improved similarly by either approach. Both offer excellent radiographic and trunk deformity correction. Differences in the effect of sagittal alignment, operative time, and complications should be considered when selecting approach.