Prospective radiographic and clinical outcomes and complications of singlesolid rod instrumented anterior spinal fusion in adolescent idiopathic scoliosis

Study Design. Prospective clinical cases series. Objectives. To prospectively evaluate outcomes and critically review radiog raphic results and complications associated with single solid rod anterior spinal fusions in adolescent idiopathic scoliosis with 2-year minimum follo w-up (range, 2-6 years). Methods. Ninety consecutive patients at a single institution with thoracic (n = 43) or thoracolumbar/lumbar (n = 47) adolescent idiopathic scoliosis w ere treated by one of two surgeons with a similar anterior surgical techniq ue using rib autograft, intradiscal structural (Harms) cages placed below T 12, and anterior single solid rod convex compressive instrumentation. The p atients were evaluated prospectively with the Scoliosis Research Society ou tcome instrument and upright radiographs before surgery and minimum 2-year follow-up. Results (Radiographic). The average coronal correction of thoracic curves w as from 55 degrees to 29 degrees (47%). The average correction of thoracolu mbar/lumbar curves was from 50 degrees to 15 degrees (70%). In the sagittal plane, kyphosis was improved in thoracic fusions from 23 degrees to 30 deg rees (T5-T12) and lordosis maintained in thoracolumbar/lumbar fusions at -5 8 degrees (T12-sacrum). Five patients (5.5%) developed a pseudarthrosis, fo ur with implant failure. Three of five required a posterior fusion for a re operation rate of 3.3%. The fourth and fifth patients were asymptomatic and appeared fused at the 2-year follow-up, with minimal loss of correction. C ommon risk factors for pseudarthrosis were smoking (4 of 5), weight >70 kg (4 of 5), and for thoracic pseudarthrosis, hyperkyphosis >40 degrees T5-T12 (2 of 3). Results (Clinical Outcome). Scoliosis Research Society domain average score s were improved for function, pain, and self-image (P < 0.01). With the Sco liosis Research Society satisfaction domain, 88% responded that they were s atisfied with their results and 89% would undergo the same treatment again. Four of five patients with pseudarthrosis did not have statistically signi ficant lower final Scoliosis Research Society scores than those with solid fusions (93 vs. 97, P = 0.18). Conclusion. Anterior instrumented fusions for adolescent idiopathic scolios is using a single solid rod had good radiographic and clinical outcomes. Co nsideration should be given to alternate techniques in larger adolescents ( >70 kg) with thoracic hyperkyphosis (>40 degrees), and smoking should be av oided. Poor radiographic outcomes did not correlate with final Scoliosis Re search Society scores.