Dynamic Stabilization for Degenerative Spondylolisthesis and Lumbar Spinal Instability.

By London Spine

Dynamic Stabilization for Degenerative Spondylolisthesis and Lumbar Spinal Instability.

Neurol Med Chir (Tokyo). 2014 Aug 29;

Authors: Ohtonari T, Nishihara N, Suwa K, Ota T, Koyama T

Abstract
Lumbar interbody fusion is a widely accepted surgical procedure for patients with lumbar degenerative spondylolisthesis and lumbar spinal instability in the active age group. However, in elderly patients, it is often questionable whether it is truly necessary to construct rigid fixation for a short period of time. In recent years, we have been occasionally performing posterior dynamic stabilization in elderly patients with such lumbar disorders. Posterior dynamic stabilization was performed in 12 patients (6 women, 70.9 ± 5.6 years old at the time of operation) with lumbar degenerative spondylolisthesis in whom % slip was less than 20% or instability associated with lumbar disc herniation between March 2011 and March 2013. Movement occurs through the connector linked to the pedicle screw. In practice, 9 pairs of D connector system where the rod moves in the perpendicular direction alone and 8 pairs of Dynamic connector system where the connector linked to the pedicle screw rotates in the sagittal direction were installed. The observation period was 77-479 days, and the mean recovery rate of lumbar Japanese Orthopedic Association (JOA) score was 65.6 ± 20.8%. There was progression of slippage due to slight loosening in a case with lumbar degenerative spondylolisthesis, but this did not lead to exacerbation of the symptoms. Although follow-up was short, there were no symptomatic adjacent vertebral and disc disorders during this period. Posterior dynamic stabilization may diminish the development of adjacent vertebral or disc disorders due to lumbar interbody fusion, especially in elderly patients, and it may be a useful procedure that facilitates decompression and ensures a certain degree of spinal stabilization.

PMID: 25169137 [PubMed – as supplied by publisher]

IL-1ra delivered from poly(lactic-co-glycolic acid) microspheres attenuates IL-1?-mediated degradation of nucleus pulposus in vitro.

By London Spine
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IL-1ra delivered from poly(lactic-co-glycolic acid) microspheres attenuates IL-1β-mediated degradation of nucleus pulposus in vitro.

Arthritis Res Ther. 2012;14(4):R179

Authors: Gorth DJ, Mauck RL, Chiaro JA, Mohanraj B, Hebela NM, Dodge GR, Elliott DM, Smith LJ

Abstract
INTRODUCTION: Inflammation plays a key role in the progression of intervertebral disc degeneration, a condition strongly implicated as a cause of lower back pain. The objective of this study was to investigate the therapeutic potential of poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with interleukin-1 receptor antagonist (IL-1ra) for sustained attenuation of interleukin-1 beta (IL-1β) mediated degradative changes in the nucleus pulposus (NP), using an in vitro model.
METHODS: IL-1ra was encapsulated in PLGA microspheres and release kinetics were determined over 35 days. NP agarose constructs were cultured to functional maturity and treated with combinations of IL-1β and media conditioned with IL-1ra released from microspheres at intervals for up to 20 days. Construct mechanical properties, glycosaminoglycan content, nitrite production and mRNA expression of catabolic mediators were compared to properties for untreated constructs using unpaired Student’s t-tests.
RESULTS: IL-1ra release kinetics were characterized by an initial burst release reducing to a linear release over the first 10 days. IL-1ra released from microspheres attenuated the degradative effects of IL-1β as defined by mechanical properties, glycosaminoglycans (GAG) content, nitric oxide production and mRNA expression of inflammatory mediators for 7 days, and continued to limit functional degradation for up to 20 days.
CONCLUSIONS: In this study, we successfully demonstrated that IL-1ra microspheres can attenuate the degradative effects of IL-1β on the NP for extended periods. This therapeutic strategy may be appropriate for treating early-stage, cytokine-mediated disc degeneration. Ongoing studies are focusing on testing IL-1ra microspheres in an in vivo model of disc degeneration, as a prelude to clinical translation.

PMID: 22863285 [PubMed – indexed for MEDLINE]

The Torg-Pavlov ratio for the prediction of acute spinal cord injury after a minor trauma to the cervical spine.

By London Spine
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The Torg-Pavlov ratio for the prediction of acute spinal cord injury after a minor trauma to the cervical spine.

Spine J. 2013 Jan 10;

Authors: Aebli N, Wicki AG, Rüegg TB, Petrou N, Eisenlohr H, Krebs J

Abstract
BACKGROUND CONTEXT: Acute cervical spinal cord injury (SCI) has been observed in some patients after a minor trauma to the cervical spine. The discrepancy between the severity of the trauma and the clinical symptoms has been attributed to spinal canal stenosis. However, to date, there is no universally established radiological parameter for identifying critical spinal stenosis in these patients. The spinal canal-to-vertebral body ratio (Torg-Pavlov ratio) has been proposed for assessing developmental spinal canal stenosis. The relevance of the Torg-Pavlov ratio for predicting the occurrence and severity of acute cervical SCI after a minor trauma to the cervical spine has not yet been established. PURPOSE: To investigate the Torg-Pavlov ratio values of the cervical spine in patients suffering from acute cervical SCI after a minor trauma to the cervical spine and the use of the Torg-Pavlov ratio for identifying patients at risk of cervical SCI and predicting the severity and course of symptoms. STUDY DESIGN/SETTING: Retrospective radiological study of consecutive patients. PATIENT SAMPLE: Forty-five patients suffering from acute cervical SCI and 68 patients showing no neurologic symptoms after a minor trauma to the cervical spine. OUTCOME MEASURES: Midvertebral sagittal cervical spinal canal diameter and the sagittal vertebral body diameter. Calculation of the Torg-Pavlov ratio values. METHODS: Conventional lateral radiographs of the cervical spine (C3-C7) were analyzed to determine the Torg-Pavlov ratio values. Receiver operating characteristic curves were calculated for evaluating the classification accuracy of the Torg-Pavlov ratio for predicting SCI. RESULTS: The Torg-Pavlov ratio values in the SCI group were significantly (p<.04) smaller compared with that in the control group. A Torg-Pavlov ratio cutoff value of 0.7 yielded the greatest positive likelihood ratio for predicting the occurrence of SCI. However, there were no significant differences in the Torg-Pavlov ratio values between the different American Spinal Injury Association Impairment Score groups and between patients with complete, partial, and no recovery of symptoms. CONCLUSIONS: Developmental cervical spinal canal stenosis assessed by the Torg-Pavlov ratio was characteristic for patients suffering from acute cervical SCI after a minor trauma to the cervical spine. Patients at risk of SCI after a minor trauma to the cervical spine can be identified by applying a Torg-Pavlov ratio cutoff value of 0.7. Other factors in addition to the spinal canal-to-vertebral body ratio affect the severity and course of symptoms as a result of cervical SCI.

PMID: 23318107 [PubMed – as supplied by publisher]

Can a Thoracolumbar Injury Severity Score Be Uniformly Applied from T1 to L5 or Are Modifications Necessary?

By London Spine
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Can a Thoracolumbar Injury Severity Score Be Uniformly Applied from T1 to L5 or Are Modifications Necessary?

Global Spine J. 2015 Aug;5(4):339-45

Authors: Schroeder GD, Kepler CK, Koerner JD, Oner FC, Fehlings MG, Aarabi B, Schnake KJ, Rajasekaran S, Kandziora F, Vialle LR, Vaccaro AR

Abstract
Study Design Literature review. Objective The aim of this review is to highlight challenges in the development of a comprehensive surgical algorithm to accompany the AOSpine Thoracolumbar Spine Injury Classification System. Methods A narrative review of the relevant spine trauma literature was undertaken with input from the multidisciplinary AOSpine International Trauma Knowledge Forum. Results The transitional areas of the spine, in particular the cervicothoracic junction, pose unique challenges. The upper thoracic vertebrae have a transitional anatomy with elements similar to the subaxial cervical spine. When treating these fractures, the surgeon must be aware of the instability due to the junctional location of these fractures. Additionally, although the narrow spinal canal makes neurologic injuries common, the small pedicles and the inability to perform an anterior exposure make decompression surgery challenging. Similarly, low lumbar fractures and fractures at the lumbosacral junction cannot always be treated in the same manner as fractures in the more cephalad thoracolumbar spine. Although the unique biomechanical environment of the low lumbar spine makes a progressive kyphotic deformity less likely because of the substantial lordosis normally present in the low lumbar spine, even a fracture leading to a neutral alignment may dramatically alter the patient’s sagittal balance. Conclusion Although the new AOSpine Thoracolumbar Spine Injury Classification System was designed to be a comprehensive thoracolumbar classification, fractures at the cervicothoracic junction and the lumbosacral junction have properties unique to these junctional locations. The specific characteristics of injuries in these regions may alter the most appropriate treatment, and so surgeons must use clinical judgment to determine the optimal treatment of these complex fractures.

PMID: 26225284 [PubMed]

[Infectious spondylitis].

By London Spine
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[Infectious spondylitis].

Enferm Infecc Microbiol Clin. 2008 Oct;26(8):510-7

Authors: Pintado-García V

Abstract
Vertebral osteomyelitis or spondylodiscitis is an uncommon, mainly hematogenous, disease that usually affects adults. The incidence of this condition has steadily risen in recent years because of increases in spine surgery and nosocomial bacteremia, aging of the population, and intravenous drug addiction. Pyogenic infection due to Staphylococcus aureus is the most frequent form of the disease, but tuberculosis and brucellosis are still common causes of spondylitis in Spain. The clinical presentation is nonspecific and the diagnosis is often delayed. Magnetic resonance imaging is the most sensitive radiologic technique for this disease. Blood cultures are often positive, but computed tomography-guided needle biopsy or surgical biopsy of the affected vertebra is sometimes required to achieve a microbiological diagnosis. Prolonged antibiotic therapy and occasionally surgery are essential for cure in most patients, and both factors have contributed to a reduction in the morbidity and mortality of the disease in recent years.

PMID: 19094866 [PubMed – indexed for MEDLINE]