T1 Pelvic Angle Is a Useful Parameter for Postoperative Evaluation in Adult Spinal Deformity Patients. Issue 21 (1st November 2016)

• Record Type: Journal Article
• Authors: Banno, Tomohiro; Hasegawa, Tomohiko; Yamato, Yu; Kobayashi, Sho; Togawa, Daisuke; Oe, Shin; Mihara, Yuki; Matsuyama, Yukihiro
• Is Part Of: Spine. Volume 41:Issue 21(2016)
• Page Start: 1641
• Page End: 1648
• Publication Date: 2016-11-01
• Subjects: adult spinal deformity -- C7-central sacral vertical line -- lumbar lordosis -- outcome -- pelvic incidence -- pelvic tilt -- sagittal vertical axis -- scoliosis -- spinopelvic alignment -- surgery -- T1 pelvic angle; Spine -- Abnormalities -- Periodicals; Spine -- Diseases -- Periodicals; Spine -- Surgery -- Periodicals; 616.73005
• DOI: 10.1097/BRS.0000000000001608
• Languages: English
• ISSNs: 0362-2436

Abstract

Abstract : Study Design: Retrospective review. Objective: We investigated validity of T1 pelvic angle (TPA) for postoperative assessment and determined its target value for corrective scoliosis surgery. Summary of Background Data: TPA is a novel spinopelvic parameter accounting for both pelvic retroversion and trunk anteversion. As an angle, it is less affected by posture and correlates well with health-related quality of life in adult spinal deformity patients. According to our study in elderly volunteers, the threshold TPA value for disability (Oswestry Disability Index [ODI] score >20) was approximately 20°. Methods: Seventy adult scoliosis patients (5 men and 65 women; mean age, 67.8 yr) who underwent spinal deformity surgeries and were followed up for at least 2 years postoperatively were studied. The following parameters based on whole-spine and pelvic radiography were assessed preoperatively, soon after operation, and 2 years postoperatively: C7-central sacral vertical line, TPA, sagittal vertical axis (SVA), pelvic tilt, and pelvic incidence minus lumbar lordosis. ODI and Scoliosis Research Society-22 scores were obtained preoperatively and 2 years postoperatively. Based on postoperative TPA, patients were divided into two groups: ≤20° (group G) and greater than 20° (group P). Results: TPA and SVA correlated with health-related quality of life. Two years postoperatively, TPA best correlated with ODI and Scoliosis Research Society-22 scores, although all parameters correlated with them, and TPA soon after operation best correlated with ODI scores 2 years postoperatively. Two years postoperatively, each parameter and ODI scores in group G were better than those in group P. Conclusion: The correlation results showed that TPA appropriately assessed clinical outcomes following spinal deformity surgery. TPA assessed soon after operation correlated with ODI score 2 years postoperatively, and thus predicted prognosis. Because patients whose postoperative corrected TPA was 20° or lesser had better spinopelvic parameters and ODI scores 2 years postoperatively, TPA 20° or lesser was the proper target value for corrective surgery. Level of Evidence: 4