Postoperative Coronal Decompensation Research Articles

Selective Posterior Thoracic Fusions for Adolescent Idiopathic Scoliosis

A retrospective review of adolescent idiopathic scoliosis (AIS) patients with major thoracic-compensatory lumbar C modifier curves treated with a selective posterior fusion using an all-hook construct versus pedicle screw construct. To compare the clinical and radiographic results of selective posterior thoracic fusion using hooks versus pedicle screws in patients with major thoracic-compensatory lumbar C modifier AIS curves. Although spontaneous lumbar curve correction often occurs following a selective thoracic spinal fusion, there are few reports that focus on selective posterior thoracic spinal fusion in the presence of a lumbar C modifier curve. Sixty-six consecutive patients with major thoracic-compensatory lumbar C modifier AIS curves underwent selective posterior thoracic fusion to T12 or L1 at a single institution (1987-2001). Hooks were used for instrumentation in 32 patients and pedicle screws were used in 34 patients. Patients were evaluated at a minimum 2-year follow-up. To test for differences between groups analysis of covariance (ANCOVA) was used. There was no statistical difference between the preoperative thoracic and lumbar Cobb values for the hook group versus the pedicle screw group. The amount of correction obtained surgically of the thoracic Cobb and the amount of spontaneous lumbar Cobb correction were significantly greater in the pedicle screw group (P < 0.001). The incidence of postoperative coronal decompensation, with a greater than 20 mm shift to the left of the C7 plumbline, was higher in the hook group (13 patients) as compared with the pedicle screw Group 4 patients (P < 0.005). There were no complications or reoperations in either group. Selective thoracic fusion of main thoracic-compensatory lumbar C modifier AIS curves with pedicle screws allowed for better thoracic correction and less postoperative coronal decompensation than seen with hooks.

Thoracic scoliosis fusion in adolescent and adult idiopathic scoliosis using posterior translational corrective techniques (Isola): is maximum correction of the thoracic curve detrimental to the unfused lumbar curve?

Background context Postoperative coronal decompensation in selective thoracic fusion was reported with derotation maneuvers when using the Cotrel-Dubousset (CD) system. Isola instrumentation is a multiple anchor system that corrects spine deformity with segmental vertebral translation to a predetermined contoured longitudinal member. Purpose To evaluate the efficacy of translational corrective techniques using Isola instrumentation in thoracic fusion for adolescent and adult idiopathic scoliosis patients. Study design/setting This is a retrospective review of adolescent and adult patients with idiopathic scoliosis who underwent posterior thoracic fusion using translational corrective techniques with Isola instrumentation. Patient sample Twenty-two patients (14 adolescents with idiopathic scoliosis, 8 adults with scoliosis) who underwent posterior thoracic fusion using translational corrective techniques were evaluated. Outcome measures The charts, radiographs and self-assessment questionnaire were reviewed. Methods Comparative analysis was done between patients who had Lenke Type A curves (Group 1) and Lenke Type B or C curves (Group 2) for both adolescent and adult scoliosis groups. Results The mean follow-up was 54 months (range, 33 to 80 months). The mean preoperative Cobb angle of thoracic and lumbar curves in all 22 patients was 48 degrees (range, 34 to 64 degrees) and 31 degrees (range, 20 to 46 degrees), respectively. Postoperative measurements were 16 degrees (range, 0 to 28 degrees) for thoracic and 13 degrees (range, 2 to 25 degrees) for lumbar (67% thoracic and 60% lumbar correction) in Group 1, and 19 degrees (range, 1 to 33 degrees) for thoracic and 12 degrees (1 to 21 degrees) for lumbar at latest follow-up (61% thoracic and 61% lumbar correction) in Group 2. There was no difference in the final correction of the lumbar curves between Groups 1 (64%) and 2 (58%), although the Cobb angle in Group 2 was larger. Radiographic coronal decompensation occurred in only one patient in Group 2, who remained asymptomatic and required no further treatment. Clinical outcome assessment showed 100% satisfaction (n = 15), 92% relief of symptoms (n = 13) and 92% improvement of activities in both groups. Conclusions Fusion of the major thoracic curve using translational corrective technique (Isola) in patients with idiopathic scoliosis is an effective procedure that achieves high patient satisfaction while providing excellent correction of both the thoracic and lumbar curves. Unlike rotational corrective techniques (CD), clinical decompensation requiring further treatment did not occur in any patient treated with this method.

Coronal Plane Imbalance in Adolescent Idiopathic Scoliosis With Left Lumbar Curves Exceeding 40°

Retrospective radiographic analysis of the potential role the lumbosacral hemicurve has on adolescent idiopathic scoliosis coronal trunk imbalance. To determine if the lumbosacral hemicurve predisposes adolescent idiopathic scoliosis to coronal decompensation preoperatively and postoperatively. Although coronal decompensation remains a clinical problem in adolescent idiopathic scoliosis, the literature regarding the role of potential intrinsic structural properties of the lumbosacral hemicurve is sparse. Fifty patients with adolescent idiopathic scoliosis were used to measure several potential parameters predisposing to coronal decompensation including lumbosacral hemicurve magnitude and flexibility, sacral and iliac obliquity. Overall, 84% (42/50) demonstrated preoperative decompensation. A more rigid lumbosacral hemicurve was significantly related to preoperative coronal decompensation in the combined and the King I groups. Preoperatively, significant correlation with decompensation was observed for sacral and iliac obliquity in the King I group and for iliac obliquity in the combined group. Postoperatively, coronal decompensation remained significantly correlated to sacral obliquity in the combined group and King I groups. Iliac obliquity was significantly related to postoperative decompensation in the combined group. The lumbosacral hemicurve represents an important structure predisposing to left coronal plane imbalance in adolescent idiopathic scoliosis that includes a large left lumbar curve as a component of the curve pattern. "At-risk" signs for persistent postoperative coronal decompensation include iliac and sacral obliquity noted on the preoperative standing full-length radiographs.