Predictive Factors for Proximal Junctional Kyphosis in Long Fusions to the Sacrum in Adult Spinal Deformity.
ABSTRACT Study Design. A retrospective studyObjective. To assess the mechanisms and the independent risk factors associated with proximal junctional kyphosis (PJK)in patients treated surgically for adult spinal deformity with long fusions to the sacrum.Summary of Background Data. The occurrence of PJKmay be related to preoperative and postoperative sagittal parameters. The mechanisms and risk factors for PJK in adultsare not well-defined.Methods. A consecutive patients who underwent long instrumented fusionsurgery (≥6 vertebrae) to the sacrum with a minimum of 2 years follow-up were retrospectively studied.Risk factorsincluded patient factors, surgical factorsand radiographic parameters such as thoracic kyphosis (TK), lumbar lordosis (LL), sagittal vertical axis (SVA), pelvic tilt (PT), and pelvic incidence (PI).Results. Ninety consecutive patients (mean age: 64.5 years) met inclusion criteria. Radiographic PJK occurred in 37of the90 (41%) patients with a mean follow-up of 2.9 years. The most common mechanism of PJK was fracture at the upper instrumented vertebra (UIV)in 19 (51%) patients. Twelve (13%) patients with PJK were treated surgically with proximalextension of the instrumented fusion. Preoperative TK >30°, preoperative proximal junctional angle (PJA) >10°, change in LL >30°,and PI >55° were identified as predictors associated with PJK. Achievement of ideal global sagittal realignment (SVA <50mm, PT <20°,and PI-LL <±10°) protected against the development ofPJK(19% vs. 45%).Amultivariate regression analysisrevealed changesin LL >30° and preoperative TK >30° were the independent risk factors associated with PJK.Conclusion. Fracture at the UIV was the most common mechanism for PJK. Change in LL >30° and preexisting TK >30° were identified as independent risk factors. Optimal postoperative alignment of the spine protectsagainst the development of PJK. A surgical strategy to minimize PJK may include preoperative planning forreconstructions with a goal of optimal postoperative alignment.
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ABSTRACT: Severe thoracic kyphosis caused by pathologic fractures often needs to be corrected by resection of the collapsed vertebral body, reconstruction of the anterior spinal column, and correction of the kyphosis with long-segment fixation. The resection of this pathologic bone functions essentially as a vertebral column resection. With the advent of minimally invasive technology, the powerful corrective forces afforded in open cases can be applied using a less invasive approach. In this article, we describe a mini-open posterior technique for thoracic kyphosis via a vertebrectomy and cantilever technique. Two patients underwent kyphosis correction via mini-open vertebrectomy. One patient was corrected from 92 degrees to 65 degrees, and the second patient was corrected from 70 degrees to 53 degrees. Both patients underwent a mini-open approach. Cantilever correction was accomplished over an expandable cage with a minimally invasive pedicle screw system. We describe our technique of mini-open vertebral column resection and kyphosis correction in the thoracic spine.Journal of Clinical Neuroscience 10/2013; · 1.32 Impact Factor