STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: To determine whether anchor density is associated with curve correction and patient-reported outcomes. SUMMARY OF BACKGROUND DATA: There is limited information as to whether anchor density affects the results of adolescent idiopathic scoliosis surgery. METHODS: A total of 952 patients with adolescent idiopathic scoliosis met inclusion criteria (Lenke 1, 2, and 5 curves) with predominantly screw constructs (no. of screws/no. of total anchors >75%). Anchor density was defined as the number of screws, hooks, and wires per level fused, with less than 1.54 considered low density. Analysis of covariance was undertaken to determine association of anchor density with percent curve correction, Scoliosis Research Society (SRS), and Spinal Appearance Questionnaire (SAQ) scores, controlling for flexibility, fusion length, demographics, and surgeon. RESULTS: High- compared with low-anchor density was associated with increased percent curve correction in Lenke 1 curves at 1 year (69% vs. 66% correction, P = 0.0022), controlling for percent preoperative curve flexibility, length of fusion, and sex (model, P < 0.0001). Similar associations held at 2-year follow-up and for Lenke 2 curves. Decreased thoracic kyphosis was found with increased anchor density for Lenke 1 and 2 curve patterns. There were no associations found between anchor density and Lenke 5 curves. For Lenke 1 curve patterns at 2 years postoperatively, in the high- versus low-anchor density cohorts, there were statistically higher SRS Activity (4.3 vs. 4.2, P = 0.019), Appearance (4.3 vs. 4.1, P = 0.0005), Satisfaction (4.5 vs. 4.3, P = 0.028), and Total scores (4.3 vs. 4.2; P = 0.024). Similarly, the SAQ Appearance score at 1 year similarly was improved in the high-anchor density group (high: 14.1 vs. low: 15.0, P = 0.03) for Lenke 1 curve patterns only. CONCLUSION: For Lenke 1 and 2 curve patterns, improved percent correction of major coronal curve was noted in the high-screw density cohort. Although statistical significance was reached, it is unclear whether screw density resulted in clinically significant differences in patient-reported outcomes.
STUDY DESIGN: Retrospective review of prospectively collected data. OBJECTIVE: To determine whether anchor density is associated with curve correction and patient-reported outcomes. SUMMARY OF BACKGROUND DATA: There is limited information as to whether anchor density affects the results of adolescent idiopathic scoliosis surgery. METHODS: A total of 952 patients with adolescent idiopathic scoliosis met inclusion criteria (Lenke 1, 2, and 5 curves) with predominantly screw constructs (no. of screws/no. of total anchors >75%). Anchor density was defined as the number of screws, hooks, and wires per level fused, with less than 1.54 considered low density. Analysis of covariance was undertaken to determine association of anchor density with percent curve correction, Scoliosis Research Society (SRS), and Spinal Appearance Questionnaire (SAQ) scores, controlling for flexibility, fusion length, demographics, and surgeon. RESULTS: High- compared with low-anchor density was associated with increased percent curve correction in Lenke 1 curves at 1 year (69% vs. 66% correction, P = 0.0022), controlling for percent preoperative curve flexibility, length of fusion, and sex (model, P < 0.0001). Similar associations held at 2-year follow-up and for Lenke 2 curves. Decreased thoracic kyphosis was found with increased anchor density for Lenke 1 and 2 curve patterns. There were no associations found between anchor density and Lenke 5 curves. For Lenke 1 curve patterns at 2 years postoperatively, in the high- versus low-anchor density cohorts, there were statistically higher SRS Activity (4.3 vs. 4.2, P = 0.019), Appearance (4.3 vs. 4.1, P = 0.0005), Satisfaction (4.5 vs. 4.3, P = 0.028), and Total scores (4.3 vs. 4.2; P = 0.024). Similarly, the SAQ Appearance score at 1 year similarly was improved in the high-anchor density group (high: 14.1 vs. low: 15.0, P = 0.03) for Lenke 1 curve patterns only. CONCLUSION: For Lenke 1 and 2 curve patterns, improved percent correction of major coronal curve was noted in the high-screw density cohort. Although statistical significance was reached, it is unclear whether screw density resulted in clinically significant differences in patient-reported outcomes.
Authors: Marinus de Kleuver; Stephen J Lewis; Niccole M Germscheid; Steven J Kamper; Ahmet Alanay; Sigurd H Berven; Kenneth M Cheung; Manabu Ito; Lawrence G Lenke; David W Polly; Yong Qiu; Maurits van Tulder; Christopher Shaffrey Journal: Eur Spine J Date: 2014-06-24 Impact factor: 3.134
Authors: Paul R P Rushton; Mahmoud Elmalky; Agnivesh Tikoo; Saumyajit Basu; Ashley A Cole; Michael P Grevitt Journal: Eur Spine J Date: 2015-12-10 Impact factor: 3.134
Authors: Pooria Hosseini; Allen Carl; Michael Grevitt; Colin Nnadi; Martin Repko; Dennis G Crandall; Ufuk Aydinli; Ľuboš Rehák; Martin Zabka; Steven Seme; Behrooz A Akbarnia Journal: Int J Spine Surg Date: 2018-08-31
Authors: Xiaoyu Wang; A Noelle Larson; Dennis G Crandall; Stefan Parent; Hubert Labelle; Charles G T Ledonio; Carl-Eric Aubin Journal: Scoliosis Spinal Disord Date: 2017-04-17