Adolescent idiopathic scoliosis: evaluating perioperative back pain through a simultaneous morphological and biomechanical approach

BACKGROUND: Adolescent idiopathic scoliosis (AIS) has been associated with diminished postural stability and a greater prevalence of back pain. Currently, the literature is lacking information on the effect of spinal fusion on both postural stability and its association with back pain. Our objectives were to evaluate the postsurgical effect of spinal morphological changes on static standing balance and assess the influence of these alterations on reported pain throughout the perioperative period. METHODS: Twenty consecutive AIS patients schedule to undergo spinal fusion surgery were recruited and followed prospectively at the Shriners Hospitals for Children-Canada. Data was collected at the preoperative, 6 weeks and 6 months postoperative visits. Spinal morphology data was collected through 3D reconstructed simultaneous standing biplanar radiographs using the SterEOS software. Postural balance was assessed through Moticon© sensor insoles and analyzed through their software. The data was simultaneously collected as part of the Global Biomechanical and morphological Assessment. Pain was evaluated through self-reported questionnaires. RESULTS: Morphological curve parameters were significantly reduced after surgery. Balance parameters did not change significantly throughout the perioperative period with the exception of the Center of Pressure of the left foot medial/lateral transient shift (P = 0.017) at 6 weeks. Of note, preoperative balance parameters were associated with the degree of right thoracic Cobb angles (P = 0.029 R = 0.528). Pain scores significantly improved 6 weeks and 6 months after the surgery. Pain intensity diminished in the thoracic and lumbar spine but worsen in the neck region at the 6 weeks and 6 months postoperative time points (P = 0.044). Greater residual Cobb angle difference between Mid thoracic and Thoracolumbar/Lumbar curves was associated with greater pain severity at 6 weeks postop (P < 0.005). In addition, greater residual thoracic deformity was associated with significant pain severity 6 months after surgery (P < 0.05). CONCLUSIONS: Improved spinal morphology of postsurgical AIS patients has no significant impact on their static standing balance. Suggesting that other factors apart from the spinal morphology may contribute to AIS patients’ balance during stance. Although balance did not influence pain severity, spinal morphology and its correction appear to have influenced the intensity and location of back pain.