Thomas J Buell1, Ching-Jen Chen2, John C Quinn3, Avery L Buchholz4, Marcus D Mazur2, Jeffrey P Mullin2, James H Nguyen2, Davis G Taylor2, Shay Bess5, Breton G Line5, Christopher P Ames6, Frank J Schwab7, Virginie Lafage7, Christopher I Shaffrey2, Justin S Smith2. 1. Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia, USA. Electronic address: tjb4p@hscmail.mcc.virginia.edu. 2. Department of Neurological Surgery, University of Virginia Health System, Charlottesville, Virginia, USA. 3. Department of Neurological Surgery, University of Texas Health Science Center, Houston, Texas, USA. 4. Department of Neurological Surgery, Medical University of South Carolina, Charleston, South Carolina, USA. 5. Denver International Spine Center, Presbyterian St. Luke's/Rocky Mountain Hospital for Children, Denver, Colorado, USA. 6. Department of Neurological Surgery, University of California, San Francisco, California, USA. 7. Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York, USA.
Abstract
OBJECTIVE: The aims of this retrospective cohort study were to 1) identify new alignment risk factors for proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) patients with lower thoracic upper instrumented vertebra (UIV) and 2) determine the effect of junctional tethers on PJK and UIV alignment. METHODS: We analyzed consecutive ASD patients who underwent posterior instrumented fusion with lower thoracic UIV (T9-T11). Posteriorly anchored junctional tethers were used more recently for ligamentous augmentation to prevent PJK. In addition to regional and global parameters, upper segmental lumbar lordosis (ULL) versus lower segmental lumbar lordosis and UIV angle (measured from UIV inferior endplate to horizontal) were assessed. Primary outcome of PJK was defined as proximal junctional angle >10° and >10° greater than the corresponding preoperative measurement. Univariable and multivariable analyses were performed. RESULTS: The study cohort comprised 120 ASD patients (mean age, 67 years) with minimum 1-year follow-up. Preoperative ULL (P = 0.034) and UIV angle (P = 0.026) were associated with PJK. No independent preoperative alignment risk factors of PJK were identified in multivariable analysis. Tether use was protective against PJK (odds ratio, 0.063 [0.016-0.247]; P < 0.001). PJK in tethered patients was more common with greater postoperative ULL (P = 0.047) and UIV angle (P = 0.026). CONCLUSIONS: Junctional tethers significantly reduced PJK in ASD patients with lower thoracic UIV. In tethered patients, PJK was more common with greater postoperative lordosis of the upper lumbar spine and greater UIV angle. This finding suggests potential benefit of tethers to mitigate effects of segmental lumbar and focal UIV malalignment that may occur after deformity surgery.
OBJECTIVE: The aims of this retrospective cohort study were to 1) identify new alignment risk factors for proximal junctional kyphosis (PJK) in adult spinal deformity (ASD) patients with lower thoracic upper instrumented vertebra (UIV) and 2) determine the effect of junctional tethers on PJK and UIV alignment. METHODS: We analyzed consecutive ASDpatients who underwent posterior instrumented fusion with lower thoracic UIV (T9-T11). Posteriorly anchored junctional tethers were used more recently for ligamentous augmentation to prevent PJK. In addition to regional and global parameters, upper segmental lumbar lordosis (ULL) versus lower segmental lumbar lordosis and UIV angle (measured from UIV inferior endplate to horizontal) were assessed. Primary outcome of PJK was defined as proximal junctional angle >10° and >10° greater than the corresponding preoperative measurement. Univariable and multivariable analyses were performed. RESULTS: The study cohort comprised 120 ASDpatients (mean age, 67 years) with minimum 1-year follow-up. Preoperative ULL (P = 0.034) and UIV angle (P = 0.026) were associated with PJK. No independent preoperative alignment risk factors of PJK were identified in multivariable analysis. Tether use was protective against PJK (odds ratio, 0.063 [0.016-0.247]; P < 0.001). PJK in tethered patients was more common with greater postoperative ULL (P = 0.047) and UIV angle (P = 0.026). CONCLUSIONS: Junctional tethers significantly reduced PJK in ASDpatients with lower thoracic UIV. In tethered patients, PJK was more common with greater postoperative lordosis of the upper lumbar spine and greater UIV angle. This finding suggests potential benefit of tethers to mitigate effects of segmental lumbar and focal UIV malalignment that may occur after deformity surgery.
Authors: Sravisht Iyer; Francis Lovecchio; Jonathan Charles Elysée; Renaud Lafage; Michael Steinhaus; Frank J Schwab; Virginie Lafage; Han Jo Kim Journal: Global Spine J Date: 2019-08-15
Authors: Anouar Bourghli; Louis Boissiere; Thomas Chevillotte; Maxime Huneidi; Clement Silvestre; Kariman Abelin-Genevois; Pierre Grobost; Javier Pizones; Pierre Roussouly; Ibrahim Obeid Journal: Eur Spine J Date: 2021-09-29 Impact factor: 3.134