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Chanbour H, Waddell WH, Vickery J, LaBarge ME, Croft AJ, Longo M, Roth SG, Hills JM, Abtahi AM, Zuckerman SL, Stephens BF. L1-pelvic angle: a convenient measurement to attain optimal deformity correction. Eur Spine J 2023; 32:4003-4011. [PMID: 37736775 DOI: 10.1007/s00586-023-07920-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 05/14/2023] [Accepted: 08/26/2023] [Indexed: 09/23/2023]
Abstract
PURPOSE (1) Evaluate the associations between L1-pelvic angle (L1PA) and both sagittal vertical axis (SVA) and T1-pelvic angle (T1PA), and (2) assess the clinical impact of L1PA. METHODS A single-institution retrospective cohort study was undertaken for patients undergoing adult spinal deformity (ASD) surgery from 2013 to 2017. Ideal L1PA was defined as (0.5xPelvic Incidence)-21. Pearson correlation was performed to compare L1PA, SVA, and T1PA. Univariate/multivariate regression was performed to assess the effect of L1PA on mechanical complications, controlling for age, BMI, and postoperative pelvic incidence-lumbar lordosis mismatch (PI/LL). Due to the overlapping nature of patients with pseudarthrosis and rod fracture, these patients were analyzed together. RESULTS A total of 145 patients were included. Mean preoperative L1PA, SVA, and T1PA were 15.5 ± 8.9°, 90.7 ± 66.8 mm, and 27.1 ± 13.0°, respectively. Mean postoperative L1PA, SVA, and T1PA were 15.0 ± 8.9°, 66.7 ± 52.8 mm, and 22.3 ± 11.1°, respectively. Thirty-six (24.8%) patients achieved ideal L1PA. Though the correlation was modest, preoperative L1PA was linearly correlated with preoperative SVA (r2 = 0.16, r = 0.40, 95%CI = 0.22-0.60, p < 0.001) and T1PA (r2 = 0.41, r = 0.62, 95%CI = 0.46-0.76, p < 0.001). Postoperative L1PA was linearly correlated with postoperative SVA (r2 = 0.12, r = 0.37, 95%CI = 0.18-0.56, p < 0.001) and T1PA (r2 = 0.40, r = 0.62, 95%CI = 0.45-0.74, p < 0.001). Achieving ideal L1PA ± 5° was associated with a decreased risk of rod fracture/pseudarthrosis on univariate and multivariate regression (OR = 0.33, 95%CI = 0.12-0.86, p = 0.024). No association between achieving ideal L1PA and patient-reported outcomes was observed. CONCLUSION L1PA was modestly correlated with SVA and T1PA, and achieving ideal L1PA was associated with lower rates of rod fracture/pseudarthrosis. Future studies are warranted to better define the clinical implications of achieving a normal L1PA. LEVEL OF EVIDENCE III.
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Affiliation(s)
- Hani Chanbour
- Department of Neurological Surgery, Vanderbilt University Medical Center, South Tower, 1215 21st Ave Suite #4200, Nashville, TN, 37232, USA
| | - William Hunter Waddell
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Justin Vickery
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Matthew E LaBarge
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Andrew J Croft
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michael Longo
- Department of Neurological Surgery, Vanderbilt University Medical Center, South Tower, 1215 21st Ave Suite #4200, Nashville, TN, 37232, USA
| | - Steven G Roth
- Department of Neurological Surgery, Vanderbilt University Medical Center, South Tower, 1215 21st Ave Suite #4200, Nashville, TN, 37232, USA
| | - Jeffrey M Hills
- Department of Orthopedic Surgery, University of Texas, San Antonio, TX, USA
| | - Amir M Abtahi
- Department of Neurological Surgery, Vanderbilt University Medical Center, South Tower, 1215 21st Ave Suite #4200, Nashville, TN, 37232, USA
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Scott L Zuckerman
- Department of Neurological Surgery, Vanderbilt University Medical Center, South Tower, 1215 21st Ave Suite #4200, Nashville, TN, 37232, USA
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Byron F Stephens
- Department of Neurological Surgery, Vanderbilt University Medical Center, South Tower, 1215 21st Ave Suite #4200, Nashville, TN, 37232, USA.
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA.
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Chanbour H, Steinle AM, Chen JW, Waddell WH, Vickery J, LaBarge ME, Longo M, Gardocki RJ, Abtahi AM, Stephens BF, Zuckerman SL. The importance of Hounsfield units in adult spinal deformity surgery: finding an optimal threshold to minimize the risk of mechanical complications. J Spine Surg 2023; 9:149-158. [PMID: 37435329 PMCID: PMC10331500 DOI: 10.21037/jss-22-102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Accepted: 04/25/2023] [Indexed: 07/13/2023]
Abstract
Background Low bone mineral density (BMD) is a well-established risk factor for mechanical complications following adult spinal deformity (ASD) surgery. Hounsfield units (HU) measured on computed tomography (CT) scans are a proxy of BMD. In ASD surgery, we sought to: (I) evaluate the association of HU with mechanical complications and reoperation, and (II) identify optimal HU threshold to predict the occurrence of mechanical complications. Methods A single-institution retrospective cohort study was undertaken for patients undergoing ASD surgery from 2013-2017. Inclusion criteria were: ≥5-level fusion, sagittal/coronal deformity, and 2-year follow-up. HU were measured on 3 axial slices of one vertebra, either at the upper instrumented vertebra (UIV) itself or UIV ±4 from CT scans. Multivariable regression controlled for age, body mass index (BMI), postoperative sagittal vertical axis (SVA), and postoperative pelvic-incidence lumbar-lordosis mismatch. Results Of 145 patients undergoing ASD surgery, 121 (83.4%) had a preoperative CT from which HU were measured. Mean age was 64.4±10.7 years, mean total instrumented levels was 9.8±2.6, and mean HU was 153.5±52.8. Mean preoperative SVA and T1PA were 95.5±71.1 mm and 28.8°±12.8°, respectively. Postoperative SVA and T1PA significantly improved to 61.2±61.6 mm (P<0.001) and 23.0°±11.0° (P<0.001). Mechanical complications occurred in 74 (61.2%) patients, including 42 (34.7%) proximal junctional kyphosis (PJK), 3 (2.5%) distal junctional kyphosis (DJK), 9 (7.4%) implant failure, 48 (39.7%) rod fracture/pseudarthrosis, and 61 (52.2%) reoperations within 2 years. Univariate logistic regression showed a significant association between low HU and PJK [odds ratio (OR) =0.99; 95% confidence interval (CI): 0.98-0.99; P=0.023], but not on multivariable analysis. No association was found regarding other mechanical complications, overall reoperations, and reoperations due to PJK. HU below 163 were associated with increased PJK on receiver operating characteristic (ROC) curve analysis [area under the curve (AUC) =0.63; 95% CI: 0.53-0.73; P<0.001]. Conclusions Though several factors contribute to PJK, it appears that 163 HU may serve as a preliminary threshold when planning ASD surgery to mitigate the risk of PJK.
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Affiliation(s)
- Hani Chanbour
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Anthony M. Steinle
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Jeffrey W. Chen
- School of Medicine, Vanderbilt University, Nashville, TN, USA
| | - William Hunter Waddell
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Justin Vickery
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Matthew E. LaBarge
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Michael Longo
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Raymond J. Gardocki
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Amir M. Abtahi
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Byron F. Stephens
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Scott L. Zuckerman
- Department of Neurological Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Orthopedic Surgery, Vanderbilt University Medical Center, Nashville, TN, USA
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Abstract
Thoracolumbar spine trauma can result in potentially life-threatening consequences and requires careful management to ensure good outcomes. The purpose of this chapter is to discuss the anatomy, diagnostic tools, non-operative, and operative treatments important when addressing thoracolumbar trauma.
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Affiliation(s)
- William Hunter Waddell
- Department of Orthopedics, Vanderbilt University Medical Center, Suite 4200, 1215 21st Avenue South, Nashville, TN 37212, USA
| | - Rishabh Gupta
- Department of Orthopedics, Vanderbilt University Medical Center, Suite 4200, 1215 21st Avenue South, Nashville, TN 37212, USA
| | - Byron Fitzgerald Stephens
- Department of Orthopedics, Vanderbilt University Medical Center, Suite 4200, 1215 21st Avenue South, Nashville, TN 37212, USA.
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Suter E, Waddell WH. AVLINE: a data base and critical review system of audiovisual materials for the education of health professionals. J Med Educ 1982; 57:139-155. [PMID: 6173483] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The AVLINE data base, operated by the National Library of Medicine, was designed to aid in the selection, use, and sharing of quality audiovisual material in the education of health professionals and to promote the quality production of such materials. AVLINE provides standardized bibliographic and critical review information in both online and printed catalog form. In this report the evolution of AVLINE is traced, and the development of its companion review system is examined.
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Suter E, Waddell WH. Attributes of quality in audiovisual materials for health professionals. J Biocommun 1981; 8:5-12. [PMID: 6168638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Utilizing a series of meetings and incorporating individual efforts of producers, evaluators, and users of audiovisual materials; an attempt has been made to define the quality of an instructional item. Attributes of quality in content, instructional design, technical production, and packaging of audiovisual materials are addressed through questions about general criteria that permit expression of individual dictates off creativity and taste. These attributes of quality are intended for use by the producers and evaluators of audiovisual instruction.
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