European spine journal : official publication of the European Spine Society, the European Spinal Deformity Society, and the European Section of the Cervical Spine Research Society
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We retrospectively studied the cases with tuberculous spondylitis of thoracolumbar region with two or more levels of involvement that underwent posterior instrumentation and fusion and anterior fusion with titanium mesh following anterior decompression using simultaneous successive posterior-anterior-posterior surgery. Among all patients with tuberculous spondylitis accompanied by medium or severe kyphosis, 20 patients who underwent simultaneous successive decompression, fusion and instrumentation with posterior-anterior-posterior surgery between 1999 and 2004 were included in the study. Patients were evaluated for fusion formation and neurological and functional status. ⋯ Regarding kyphosis angle, an average 35.1° correction (84.8%) was obtained in postoperative period (p < 0.001) and there was no significant correction loss during the follow-up period (p < 0.05). There were no grafts or instrumentation-related stabilization problems. In subjects with tuberculous spondylitis with involvements at two or more levels accompanied by medium and severe kyphosis, decompression, fusion and instrumentation by simultaneous successive posterior-anterior-posterior surgery is an effective and safe management method for effective kyphosis correction with high fusion rates.
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Progression of superior adjacent segment degeneration (PASD) could possibly be avoided by dynamic stabilization of an initially degenerated adjacent segment (AS). The current study evaluates ex vivo the biomechanics of a circumferential fixation connected to posterior dynamic stabilization at the AS. 6 human cadaver spines (L2-S1) were stabilized stepwise through the following conditions for comparison: intact spine (ISP), single-level fixation L5-S1 (SLF), SLF + dynamic AS fixation L4-L5 (DFT), and two-level fixation L4-S1 (TLF). For each condition, the moments required to reach the range of motion (ROM) of the intact whole spine segment under ±10 Nm (WSP10) were compared for all major planes of motion within L2-S1. ⋯ The moments required to reach WSP10 increase dependent on the number of fixated levels and the fixation stiffness of the implants used. Additional fixation shifts motion to the superior segment, according to fixation stiffness. Therefore, dynamic instrumentation cannot be recommended if prevention of hyper-mobility in the adjacent levels is the main target.
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Degenerative lumbar spinal stenosis is the most common reason for lumbar surgery in patients in the age of 65 years and older. The standard surgical management is decompression of the spinal canal by laminectomy and partial facetectomy. The effect of this procedure on the shear strength of the spine has not yet been investigated in vitro. ⋯ The median shear stiffness was 197.4 N/mm (range 119.2-216.7) with laminectomy and partial facetectomy which was significantly (p = 0.036) smaller than the stiffness of the control specimens (median 216.5, 188.1-250.2). It was concluded that laminectomy and partial facetectomy resulted in 22% reduction in ultimate shear force to failure and 9% reduction in shear stiffness. Although relatively small, these effects may explain why patients have an increased risk of sustaining shear force related vertebral fractures after spinal decompression surgery.
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Piriformis syndrome, sciatica caused by compression of the sciatic nerve by the piriformis muscle, has been described for over 70 years; yet, it remains controversial. The literature consists mainly of case series and narrative reviews. The objectives of the study were: first, to make the best use of existing evidence to estimate the frequencies of clinical features in patients reported to have PS; second, to identify future research questions. ⋯ A total of 55 studies were included: 51 individual and 3 aggregated data studies, and 1 combined study. The most common features found were: buttock pain, external tenderness over the greater sciatic notch, aggravation of the pain through sitting and augmentation of the pain with manoeuvres that increase piriformis muscle tension. Future research could start with comparing the frequencies of these features in sciatica patients with and without disc herniation or spinal stenosis.