STUDY DESIGN: Retrospective review of anterior and posterior fusions for treatment of adolescent idiopathic thoracic scoliosis. OBJECTIVES: To delineate the best factors determining final lumbar curve magnitude in patients with adolescent idiopathic scoliosis undergoing a selective thoracic anterior or posterior spinal fusion at or proximal to the first lumbar vertebra. SUMMARY OF BACKGROUND DATA: Although spontaneous lumbar curve correction occurs consistently following a selective thoracic anterior or posterior spinal fusion, the degree of correction is somewhat unpredictable. METHODS: One hundred consecutive patients with major thoracic-compensatory lumbar adolescent idiopathic scoliosis treated by a single surgeon with either selective posterior spinal fusion (n = 44) or anterior spinal fusion (n = 56) of the main thoracic region with an unfused lumbar spine with a lumbar B modifier (lumbar apex touching the center sacral vertical line) or lumbar C modifier (lumbar apex completely lateral to the center sacral vertical line) were retrospectively reviewed. RESULTS: Those patients who maintained excellent postoperative coronal balance, with spontaneous lumbar curve correction, had their thoracic Cobb corrected intraoperatively to a measurement very close to but not more than that of the preoperative thoracic push-prone Cobb. Stepwise multiple linear regression analysis was used to develop a formula to help predict lumbar response in those patients undergoing selective thoracic fusion. This is represented in the following formula: Final lumbar Cobb = 14.4 + 3.06 (lumbar modifier; 0 = B, 1 = C) + 0.30 (preoperative standing lumbar Cobb) - 0.18 (preoperative supine lower Cobb) + 0.81(preoperative push/prone lumbar Cobb) - 0.15(preoperative standing thoracic Cobb) - 0.16(% thoracic Cobb change from preoperative to immediate postoperative). Final model R2 = 0.72. CONCLUSIONS: Of the preoperative measurements examined, the preoperative push-prone is the best preoperative flexibility radiograph to predict the final lumbar curve measurement and, along with other factors, can be used to formulate a model that will help the treating surgeon more confidently predict the final lumbar curve response in patients undergoing a selective thoracic fusion.
STUDY DESIGN: Retrospective review of anterior and posterior fusions for treatment of adolescent idiopathic thoracic scoliosis. OBJECTIVES: To delineate the best factors determining final lumbar curve magnitude in patients with adolescent idiopathic scoliosis undergoing a selective thoracic anterior or posterior spinal fusion at or proximal to the first lumbar vertebra. SUMMARY OF BACKGROUND DATA: Although spontaneous lumbar curve correction occurs consistently following a selective thoracic anterior or posterior spinal fusion, the degree of correction is somewhat unpredictable. METHODS: One hundred consecutive patients with major thoracic-compensatory lumbar adolescent idiopathic scoliosis treated by a single surgeon with either selective posterior spinal fusion (n = 44) or anterior spinal fusion (n = 56) of the main thoracic region with an unfused lumbar spine with a lumbar B modifier (lumbar apex touching the center sacral vertical line) or lumbar C modifier (lumbar apex completely lateral to the center sacral vertical line) were retrospectively reviewed. RESULTS: Those patients who maintained excellent postoperative coronal balance, with spontaneous lumbar curve correction, had their thoracic Cobb corrected intraoperatively to a measurement very close to but not more than that of the preoperative thoracic push-prone Cobb. Stepwise multiple linear regression analysis was used to develop a formula to help predict lumbar response in those patients undergoing selective thoracic fusion. This is represented in the following formula: Final lumbar Cobb = 14.4 + 3.06 (lumbar modifier; 0 = B, 1 = C) + 0.30 (preoperative standing lumbar Cobb) - 0.18 (preoperative supine lower Cobb) + 0.81(preoperative push/prone lumbar Cobb) - 0.15(preoperative standing thoracic Cobb) - 0.16(% thoracic Cobb change from preoperative to immediate postoperative). Final model R2 = 0.72. CONCLUSIONS: Of the preoperative measurements examined, the preoperative push-prone is the best preoperative flexibility radiograph to predict the final lumbar curve measurement and, along with other factors, can be used to formulate a model that will help the treating surgeon more confidently predict the final lumbar curve response in patients undergoing a selective thoracic fusion.
Authors: T Barrett Sullivan; Tracey P Bastrom; Carrie E Bartley; Suken A Shah; Baron S Lonner; Jahangir Asghar; Firoz Miyanji; Peter O Newton; Burt Yaszay Journal: Eur Spine J Date: 2017-06-10 Impact factor: 3.134