Deep Learning Model for Grading and Localization of Lumbar Disc Herniation on Magnetic Resonance Imaging

BACKGROUND

Methods for grading and localization of lumbar disc herniation (LDH) on MRI are complex, time-consuming, and subjective. Utilizing deep learning (DL) models as assistance would mitigate such complexities.

PURPOSE

To develop an interpretable DL model capable of grading and localizing LDH.

STUDY TYPE

Retrospective.

SUBJECTS

1496 patients (M/F: 783/713) were evaluated, and randomly divided into training (70%), validation (10%), and test (20%) sets.

FIELD STRENGTH/SEQUENCE

1.5T MRI for axial T2-weighted sequences (spin echo).

ASSESSMENT

The training set was annotated by three spinal surgeons using the Michigan State University classification to train the DL model. The test set was annotated by a spinal surgery expert (as ground truth labels), and two spinal surgeons (comparison with the trained model). An external test set was employed to evaluate the generalizability of the DL model.

STATISTICAL TESTS

Calculated intersection over union (IoU) for detection consistency, utilized Gwet's AC1 to assess interobserver agreement, and evaluated model performance based on sensitivity and specificity, with statistical significance set at P < 0.05.

RESULTS

The DL model achieved high detection consistency in both the internal test dataset (grading: mean IoU 0.84, recall 99.6%; localization: IoU 0.82, recall 99.5%) and external test dataset (grading: 0.72, 98.0%; localization: 0.71, 97.6%). For internal testing, the DL model (grading: 0.81; localization: 0.76), Rater 1 (0.88; 0.82), and Rater 2 (0.86; 0.83) demonstrated results highly consistent with the ground truth labels. The overall sensitivity of the DL model was 87.0% for grading and 84.0% for localization, while the specificity was 95.5% and 94.4%. For external testing, the DL model showed an appreciable decrease in consistency (grading: 0.69; localization: 0.66), sensitivity (77.2%; 76.7%), and specificity (92.3%; 91.8%).

DATA CONCLUSION

The classification capabilities of the DL model closely resemble those of spinal surgeons. For future improvement, enriching the diversity of cases could enhance the model's generalization.

LEVEL OF EVIDENCE: 4

TECHNICAL EFFICACY

Stage 2.

Study on early efficacy of UBED and PEID in the treatment of L5/S1 intervertebral disc herniation

INTRODUCTION

This study aimed to compare early efficacy of UBED and PEID in the treatment of L5/S1 IDH.

MATERIAL AND METHODS

Forty-two patients who underwent surgical treatment for L5/S1 IDH were divided into two groups: UBED and PEID. Operation time, complications, VAS/ODI score were recorded. MacNab evaluation was completed one and three months postoperatively.

RESULTS

All patients were successfully operated without infection, nerve injury, or huge hematoma in the spinal canal. There were no significant differences in operation time and hospitalization days between the two groups (p > 0.05). All patients were followed up after the operation and low back/leg pain was significantly reduced. VAS for low back pain, VAS for leg pain, ODI scores in both groups one and three months after the operation were significantly lower than pre-operation (p < 0.05). There were no significant differences between one and three months after the operation in both groups (p > 0.05). There were no significant differences in VAS for low back pain, leg pain, ODI score, and overall efficacy between the two groups one and three months post-operation (p > 0.05).

CONCLUSION

UBED and PEID have very good early efficacy in treating L5/S1 IDH. Because UBED has a wider vision field and more flexible operation, it can be used as a useful complement to PEID.

Are YouTube videos claiming to describe lumbar spinal manipulation techniques adequate?

BACKGROUND AND OBJECTIVE

YouTube has become a digital visual library in almost all fields of life, including medicine. Healthcare professionals and students frequently use YouTube to gain new skills and knowledge; however, the content of these videos has not been scientifically evaluated. Therefore, this study aimed to determine the descriptive adequacy and quality of YouTube videos on lumbar spine manipulation techniques (LSMTs) prepared by different healthcare professionals.

METHODS

The first 50 most relevant videos retrieved on searching YouTube for the keyword 'lumbar spinal manipulation techniques' were included in the study. The video metrics (total duration, number of views, time since upload, number of comments, number of likes, and number of dislikes) that could be accessed from video descriptions were recorded. However the videos were scored according to manipulation definition criteria proposed by the American Academy of Orthopedic Manual Physical Therapists (AAOMPT manipulation description score - AAOMPT-MDS) and benchmark criteria for quality of digital content by the Journal of American Medical Association's (JAMA). The video metrics, AAOMPT-MDS and JAMA scores of the videos prepared by medical doctors, chiropractors, osteopaths, and physiotherapists were compared.

RESULTS

Video metrics of groups were similar. The mean AAOMPT-MDS of the videos was 2.40 ± 1.57 out of 6.00 (higher score was better), and the mean JAMA score was 2.14 ± 1.05 out of 4.00 (higher score was better). Videos created by all professional groups had statistically comparable AAOMPT-MDS and JAMA scores (p > 0.05).

CONCLUSION

Although YouTube videos on LSMTs offer valuable information for professionals and students, creators should follow the proposed recommendations when producing these videos to ensure quality content and systematic presentation.

The association between morphological characteristics of paraspinal muscle and spinal disorders

BACKGROUND

Spinal disorders affect millions of people worldwide, and can cause significant disability and pain. The paraspinal muscles, located on either side of the spinal column, play a crucial role in the movement, support, and stabilization of the spine. Many spinal disorders can affect paraspinal muscles, as evidenced by changes in their morphology, including hypertrophy, atrophy, and degeneration.

OBJECTIVES

The objectives of this review were to examine the current literature on the relationship between the paraspinal muscles and spinal disorders, summarize the methods used in previous studies, and identify areas for future research.

METHODS

We reviewed studies on the morphological characteristics of the paravertebral muscle and discussed their relationship with spinal disorders, as well as the current limitations and future research directions.

RESULTS

The paraspinal muscles play a critical role in spinal disorders and are important targets for the treatment and prevention of spinal disorders. Clinicians should consider the role of the paraspinal muscles in the development and progression of spinal disorders and incorporate assessments of the paraspinal muscle function in clinical practice.

CONCLUSION

The findings of this review highlight the need for further research to better understand the relationship between the paraspinal muscles and spinal disorders, and to develop effective interventions to improve spinal health and reduce the burden of spinal disorders.

Repairing Annulus Fibrosus Fissures Using Methacrylated Gellan Gum Combined with Novel Silk

Intervertebral disc (IVD) herniation often causes severe pain and is frequently associated with the degeneration of the IVD. As the IVD degenerates, more fissures with increasing size appear within the outer region of the IVD, the annulus fibrosus (AF), favoring the initiation and progression of IVD herniation. For this reason, we propose an AF repair approach based on methacrylated gellan gum (GG-MA) and silk fibroin. Therefore, coccygeal bovine IVDs were injured using a biopsy puncher (⌀ 2 mm) and then repaired with 2% GG-MA as a filler material and sealed with an embroidered silk yarn fabric. Then, the IVDs were cultured for 14 days either without any load, static loading, or complex dynamic loading. After 14 days of culture, no significant differences were found between the damaged and repaired IVDs, except for a significant decrease in the IVDs' relative height under dynamic loading. Based on our findings combined with the current literature that focuses on ex vivo AF repair approaches, we conclude that it is likely that the repair approach did not fail but rather insufficient harm was done to the IVD.

Perimedullary arteriovenous fistula was misdiagnosed as intervertebral disc herniation: A case report

INTRODUCTION

Spinal perimedullary arteriovenous fistula (PMAVFS) is a rare intradural vascular malformation with a high rate of misdiagnosis. In adults, most spinal PMAVFs are small and low-flow, starting with progressive spinal dysfunction.

PATIENT CONCERNS

The patient was a 58-year-old male who presented with both lower limbs numb with intermittent walking weakness, obvious at both ankles, and no obvious inducing and relieving factors. The local hospital considered the diagnosis of lumbar disc herniation after MR examination; he was treated with lumbar fixation and fusion.

DIAGNOSIS

After admission, a ce-MRA examination showed that the left spinal artery at the T10 level showed small branch blood vessels in the local area. The distal end was unclear, which seemed to be connected with the drainage vein of the spinal cord. The digital subtraction angiography (DSA) result indicated that the left intercostal artery of T10 sent the Adamkiewicz artery down to the level of L4, and an arteriovenous fistula was seen. The fistula was located at the lower edge of the L4 level and then drained to the upper premedullary vein to the level of T4 after a short descending. It was finally diagnosed as a perimedullary arteriovenous fistula.

INTERVENTIONS

It was cured by cutting the arteriovenous fistula in the spinal canal by indocyanine green-assisted angiography.

OUTCOMES

we report a case of PMAVFS misdiagnosed as lumbar disc herniation with resection and internal fixation. In our hospital, the final diagnosis was a perimedullary arteriovenous fistula, which was cured by cutting off the arteriovenous fistula within the spinal canthus.

CONCLUSION

Spinal perimedullary arteriovenous fistula (PMAVFS) is a rare intradural vascular malformation with a high rate of misdiagnosis. In adults, most spinal PMAVFs are small and low-flow, starting with progressive spinal dysfunction. It is hoped that this can provide warnings to more neurosurgeons and reduce the occurrence of misdiagnosis.

ACVIM consensus statement on diagnosis and management of acute canine thoracolumbar intervertebral disc extrusion

Background

Thoracolumbar intervertebral disc extrusion (TL‐IVDE) is the most common cause of acute paraparesis and paraplegia in dogs; however, guidelines on management of the condition are lacking.

Objectives

To summarize the current literature as it relates to diagnosis and management of acute TL‐IVDE in dogs, and to formulate clinically relevant evidence‐based recommendations.

Animals

None.

Methods

A panel of 8 experts was convened to assess and summarize evidence from the peer‐reviewed literature in order to develop consensus clinical recommendations. Level of evidence available to support each recommendation was assessed and reported.

Results

The majority of available literature described observational studies. Most recommendations made by the panel were supported by a low or moderate level of evidence, and several areas of high need for further study were identified. These include better understanding of the ideal timing for surgical decompression, expected surgical vs medical outcomes for more mildly affected dogs, impact of durotomy on locomotor outcome and development of progressive myelomalacia, and refining of postoperative care, and genetic and preventative care studies.

Conclusions and Clinical Importance

Future efforts should build on current recommendations by conducting prospective studies and randomized controlled trials, where possible, to address identified gaps in knowledge and to develop cost effectiveness and number needed to treat studies supporting various aspects of diagnosis and treatment of TL‐IVDE.

Comparison between T2-weighted two-dimensional and three-dimensional fast spin-echo MRI sequences for characterizing thoracolumbar intervertebral disc disease in small-breed dogs

Magnetic resonance imaging (MRI) is a standard test for diagnosis and treatment planning in dogs with degenerative thoracolumbar intervertebral disc disease (IVDD). However, published studies evaluating three-dimensional fast-spin echo (3D-FSE) pulse sequences for dogs with IVDD are currently limited. Aims of this retrospective, observational study were to compare findings from T2-weighted two- and three-dimensional fast spin-echo sequences (2D- and 3D-FSE, respectively) for a group of small breed dogs with thoracolumbar IVDD. Inclusion criteria were dogs with IVDD that underwent 1.5-Tesla MRI using both 2D-FSE and 3D-FSE sequences. For each dog and sequence, five pathologic indices were recorded: epidural fat discontinuation, vertebral canal compromise, spinal cord signal change, disc degeneration, and nerve root compression. Two independent investigators also scored visibility of the facet joint, intervertebral foramen, nerve roots, spinal cord grey-white matter differentiation, intervertebral discs, and epidural fat. The Wilcoxon signed-rank test was used to evaluate the between-sequence differences in pathologic indices and visibility scores. Interobserver agreement was measured using Cohen's weighted kappa along with 95% confidence intervals. A total of 21 dogs were sampled. The 3D-FSE sequences had higher pathologic indices of vertebral canal compromise (P = 0.020) and spinal cord signal change (P = 0.046) than 2D-FSE sequences. Furthermore, 3D-FSE sequences had higher visibility scores for the facet joint, intervertebral foramen, and nerve root structures (P < 0.001). Findings from the current supported the use of 3D-FSE sequences over 2D-FSE sequences for the evaluation of IVDD and visualization of spinal structures in small breed dogs.

Development of a finite element lumbar spine model to predict intervertebral disc herniation risk factors

The objective of the current study was to develop a lumbar motion segment FE model that predicts disc herniation risk. The posterolateral nucleus extrusion force and disc pressure increased as the amount of flexion and magnitude of compression was increased in all loading scenarios. The nucleus extrusion force and posterior stress in the annulus both increased when exposed to a combination of compression and flexion. Results of the current study confirmed the authors hypothesis that the model would accurately predict herniation risk when exposed to a biomechanical environment known to cause herniations.

Multi-Omics Approach to Elucidate Cerebrospinal Fluid Changes in Dogs with Intervertebral Disc Herniation

Herniation of the intervertebral disc (IVDH) is the most common cause of neurological and intervertebral disc degeneration-related diseases. Since the disc starts to degenerate before it can be observed by currently available diagnostic methods, there is an urgent need for novel diagnostic approaches. To identify molecular networks and pathways which may play important roles in intervertebral disc herniation, as well as to reveal the potential features which could be useful for monitoring disease progression and prognosis, multi-omics profiling, including high-resolution liquid chromatography-mass spectrometry (LC-MS)-based metabolomics and tandem mass tag (TMT)-based proteomics was performed. Cerebrospinal fluid of nine dogs with IVDH and six healthy controls were used for the analyses, and an additional five IVDH samples were used for proteomic data validation. Furthermore, multi-omics data were integrated to decipher a complex interaction between individual omics layers, leading to an improved prediction model. Together with metabolic pathways related to amino acids and lipid metabolism and coagulation cascades, our integromics prediction model identified the key features in IVDH, namely the proteins follistatin Like 1 (FSTL1), secretogranin V (SCG5), nucleobindin 1 (NUCB1), calcitonin re-ceptor-stimulating peptide 2 precursor (CRSP2) and the metabolites N-acetyl-D-glucosamine and adenine, involved in neuropathic pain, myelination, and neurotransmission and inflammatory response, respectively. Their clinical application is to be further investigated. The utilization of a novel integrative interdisciplinary approach may provide new opportunities to apply innovative diagnostic and monitoring methods as well as improve treatment strategies and personalized care for patients with degenerative spinal disorders.

Percutaneous Transforaminal Endoscopic Decompression for Lumbar Lateral Recess Stenosis

Objective: The aim of this study was to evaluate the treatment efficacy of lateral spinal stenosis through the decompression of the nerve root under a multiple planar endoscope.

Methods: From January 2017 to March 2019, 52 patients with lumbar spinal stenosis or lumbar spinal stenosis combined with intervertebral disc herniation had been treated via transforaminal approach spinal endoscopy. Our study retrospectively analyzed the treatment outcome. All patients experienced complications with different degrees of facet joint hyperplasia and ligamentum flavum hyperplasia and hypertrophy. Some patients suffered disc herniation. All patients were treated with percutaneous transforaminal approach multiple planar endoscopic decompression. The visual analog scale (VAS) and the Oswestry Disability Index (ODI) were compared before and after the operation, as were the horizontal foramen areas of the medial margins of the upper and lower pedicles of the vertebral arch. The treatment effectiveness was evaluated.

Results: VAS and ODI scores were significantly improved at postoperative 3 days, 3 months, 6 months, and the last follow-up (P < 0.05). The area of the intervertebral foramen was 422.5 ± 159.2 mm² preoperatively and 890.8 ± 367.7 mm² postoperatively, the difference was statistically significant (P < 0.05).

Conclusion: Percutaneous transforaminal approach multiple planar endoscopic decompression could achieve an accurate and effective decompression of the lumbar lateral spinal canal. This procedure has good short-term effects, and is especially suitable for elderly patients.

Putting the Pieces in Place: Mobilizing Cellular Players to Improve Annulus Fibrosus Repair

The intervertebral disc (IVD) is an integral load-bearing tissue that derives its function from its composite structure and extracellular matrix composition. IVD herniations involve the failure of the annulus fibrosus (AF) and the extrusion of the nucleus pulposus beyond the disc boundary. Disc herniations can impinge the neural elements and cause debilitating pain and loss of function, posing a significant burden on individual patients and society as a whole. Patients with persistent symptoms may require surgery; however, surgical intervention fails to repair the ruptured AF and is associated with the risk for reherniation and further disc degeneration. Given the limitations of AF endogenous repair, many attempts have been made toward the development of effective repair approaches that reestablish IVD function. These methods, however, fail to recapitulate the composition and organization of the native AF, ultimately resulting in inferior tissue mechanics and function over time and high rates of reherniation. Harnessing the cellular function of cells (endogenous or exogenous) at the repair site through the provision of cell-instructive cues could enhance AF tissue regeneration and, ultimately, improve healing outcomes. In this study, we review the diverse approaches that have been developed for AF repair and emphasize the potential for mobilizing the appropriate cellular players at the site of injury to improve AF healing. Impact statement Conventional treatments for intervertebral disc herniation fail to repair the annulus fibrosus (AF), increasing the risk for recurrent herniation. The lack of repair devices in the market has spurred the development of regenerative approaches, yet most of these rely on a scarce endogenous cell population to repair large injuries, resulting in inadequate regeneration. This review identifies current and developing strategies for AF repair and highlights the potential for harnessing cellular function to improve AF regeneration. Ideal cell sources, differentiation strategies, and delivery methods are discussed to guide the design of repair systems that leverage specialized cells to achieve superior outcomes.

Serum C-reactive protein in dogs with paraplegia secondary to acute intervertebral disc extrusion

BACKGROUND

Apart from the absence of nociception, there is no readily available prognostic test for dogs presenting with paraplegia secondary to acute intervertebral disc extrusion (IVDE).

OBJECTIVE

To assess if serum C-reactive protein (CRP) can predict the postoperative outcome in paraplegic dogs undergoing surgery for IVDE and to assess the association between serum CRP and presence/absence of nociception on admission, and serum CRP and presence/absence of intramedullary changes seen on magnetic resonance imaging (MRI).

ANIMALS

One hundred dogs that underwent surgery at our hospital between 2018 and 2020 because of acute paraplegia secondary to IVDE and in which serum CRP was measured.

METHODS

Retrospective observational cohort study. Dogs were classified as 4 or 5 according to the modified Frankel score (MFS) depending on presence/absence of nociception, respectively. MRI images were reviewed and the T2-weighted hyperintensity: L2 vertebral body length was measured. Postoperative outcome was defined as positive if nociception, ambulation or both returned after decompressive surgery.

RESULTS

The median (95% CI) serum CRP was 4 (4-5) and 6 (4-7) mg/L in MSF4 and MSF5, respectively (P = .03). A weak linear relationship (R²  = 0.049, P = .03) was found between CRP and the T2-weighted hyperintensity: L2 vertebral length. Outcome data was available for 85 dogs: CRP was 4 (4-5) and 5 (4-10) mg/L in positive and negative outcome dogs, respectively (P = .32).

CONCLUSION AND CLINICAL IMPORTANCE

Serum CRP did not predict outcome after surgery in dogs with paraplegia secondary to IVDE.

Ozone injection therapy for intervertebral disc herniation

INTRODUCTION

Lumbar disc herniation (LDH) is a common cause of low back pain (LBP). Recently, in the setting of LBP caused by LDH, a growing interest in ozone therapies has been observed.

SOURCE OF DATA

Recent published literatures.

AREAS OF AGREEMENT

Being low back pain more common in the elderlies, exploring conservative alternatives to the surgical intervention is of especial interest.

AREAS OF CONTROVERSY

Efficacy and feasibility of ozone injections for LDH is debated. Several clinical studies showed controversial results, and the true benefit has not yet been clarified.

GROWING POINTS

Systematically summarize current evidences, analyze the quantitative available data and investigate the role of percutaneous ozone therapy for LDH.

AREAS TIMELY FOR DEVELOPING RESEARCH

Current evidence encourage the use of ozone therapy for LBP from LDH. These conclusions should be interpret in light of the limitations of the present study.

Ambulation in Dogs With Absent Pain Perception After Acute Thoracolumbar Spinal Cord Injury

Acute thoracolumbar spinal cord injury (SCI) is common in dogs frequently secondary to intervertebral disc herniation. Following severe injury, some dogs never regain sensory function to the pelvic limbs or tail and are designated chronically "deep pain negative." Despite this, a subset of these dogs develop spontaneous motor recovery over time including some that recover sufficient function in their pelvic limbs to walk independently without assistance or weight support. This type of ambulation is commonly known as "spinal walking" and can take up to a year or more to develop. This review provides a comparative overview of locomotion and explores the physiology of locomotor recovery after severe SCI in dogs. We discuss the mechanisms by which post-injury plasticity and coordination between circuitry contained within the spinal cord, peripheral sensory feedback, and residual or recovered supraspinal connections might combine to underpin spinal walking. The clinical characteristics of spinal walking are outlined including what is known about the role of patient or injury features such as lesion location, timeframe post-injury, body size, and spasticity. The relationship between the emergence of spinal walking and electrodiagnostic and magnetic resonance imaging findings are also discussed. Finally, we review possible ways to predict or facilitate recovery of walking in chronically deep pain negative dogs. Improved understanding of the mechanisms of gait generation and plasticity of the surviving tissue after injury might pave the way for further treatment options and enhanced outcomes in severely injured dogs.

Influence of Duration of Injury on Diffusion Tensor Imaging in Acute Canine Spinal Cord Injury

Diffusion tensor imaging (DTI) quantifies microstructural lesion characteristics, but impact of the interval between spinal cord injury (SCI) and examination on imaging characteristics is unclear. Our objective was to investigate the impact of duration of injury on DTI indices in dogs with acute, spontaneous SCI from thoracolumbar intervertebral disc herniation (IVDH) and explore associations with clinical severity. Twenty-six dogs with acute thoracolumbar IVDH of variable severity who underwent DTI were included. Neurological severity was graded using the modified Frankel Score (0-V). Fractional anisotropy (FA) and mean diffusivity (MD) were calculated on regions of interest within and adjacent to the lesion epicenter. Relationships between FA or MD and duration (injury to imaging interval) or neurological severity were determined using regression analysis and Wilcoxon rank sum. Median age was 6.8 years (1-13), median duration was 1.5 days (1-9), and neurological signs ranged from ambulatory paraparesis (MFS II) to paraplegia with absent pain perception (MFS V). Mean FA was 0.61 ± 0.09 cranial to the lesion, 0.57 ± 0.12 at the epicenter and 0.55 ± 0.10 caudally. Mean MD was 1.18 × 10^-3 ± 0.0002 cranially, 1.09 × 10^-3 ± 0.0002 at the epicenter, and 1.14 × 10^-3 ± 0.0002 caudally. Accounting for neurological severity and age, FA caudal to the epicenter decreased with increasing duration of injury (p = 0.02). Lower MD within the lesion epicenter was associated with worse neurological severity (p = 0.01). Duration of injury should be considered when interpreting DTI results in dogs with acute thoracolumbar IVDH. The MD might differentiate injury severity in the acute setting and be worthy of development as an imaging biomarker.

Encapsulated gas accumulation in the spinal canal: Pneumorrhachis in two dogs

A 17-year-old mongrel dog and 12-year-old Shiba Inu dog presented with ataxia and paresis of the pelvic limbs, respectively. Gas accumulation within the spinal canal adjacent to the herniated disc was suspected in both cases. Since the gas remained accumulated for a prolonged period, hemilaminectomy was performed to decompress the spinal cord. The bulged external lamina of the dura matter was removed and histopathologically examined. Granulomatous inflammation and hyperplasia of fibrous connective tissues was noted, suggesting that the gas was encapsulated and the fibrous nodules made reabsorption difficult. Clinical signs resolved post-surgery. This is the first report describing histopathological features of pneumorrhachis in dogs. The accumulated gas was successfully removed by surgery. Postoperative course remained uneventful in both cases.

Comparison of Gait Assessment Scales in Dogs with Spinal Cord Injury from Intervertebral Disc Herniation

Naturally occurring thoracolumbar spinal cord injury (SCI) is common in dogs, and multi-center veterinary clinical studies can serve as translational tools to identify potentially effective therapies for human clinical trials. Assessment of gait is a key outcome, and several scales are used in dogs. The purpose of this study was to determine whether an international group of researchers could score gait reliably, to compare and contrast the performance of gait scales and to describe appropriate data analysis techniques. A training module was developed for a binary scale, modified Frankel Scale (MFS), Texas SCI Scale (TSCIS), and Open Field Scale (OFS). Raters viewed the training module, scored five training video clips to achieve proficiency, then scored 30 video clips from 10 dogs recovering from SCI. Interrater reliability was calculated, and correlation between scales was examined. Ceiling effect was described. Twenty raters with differing experience participated. The training module took 16 min to view. Raters chose identical binary outcomes in 597 of 600 observations. Intraclass correlation for MFS, TSCIS, and OFS was excellent at 0.85, 0.96, and 0.96, respectively, regardless of rater expertise. Ceiling effect occurred in all dogs that recovered ambulation, particularly using MFS and binary outcome. The TSCIS and OFS captured recovery of ambulatory dogs better, and addition of scores on hopping and proprioception mitigated ceiling effect. We conclude that gait in dogs with SCI can be scored reliably after training. A variety of different gait scales can be used in multi-center trials to capture outcome in different ways.

Morphological and biomechanical effects of annulus fibrosus injury and repair in an ovine cervical model

Tissue engineering repair of annulus fibrosus (AF) defects has the potential to prevent disability and pain from intervertebral disc (IVD) herniation and its progression to degeneration. Clinical translation of AF repair methods requires assessment in long-term large animal models. An ovine AF injury model was developed using cervical spinal levels and a biopsy-type AF defect to assess composite tissue engineering repair in 1-month and 12-month studies. The repair used a fibrin hydrogel crosslinked with genipin (FibGen) to seal defects, poly(trimethylene carbonate) (PTMC) scaffolds to replace lost AF tissue, and polyurethane membranes to prevent herniation. In the 1-month study, PTMC scaffolds sealed with FibGen herniated with polyurethane membranes. When applied alone, FibGen integrated with the surrounding AF tissue without herniation, showing promise for long-term studies. The 12-month long-term study used only FibGen which showed fibrous healing, biomaterial resorption and no obvious hydrogel-related complications. However, the 2 mm biopsy punch injury condition also exhibited fibrotic healing at 12 months. Both untreated and FibGen treated groups showed equivalency with no detectable differences in histological grades of proteoglycans, cellular morphology, IVD structure and blood vessel formation, biomechanical properties including torque range and axial range of motion, Pfirrmann grade, IVD height, and quantitative scores of vertebral body changes from clinical computed tomography. The biopsy-type injury caused endplate defects with a high prevalence of osteophytes in all groups and no nucleus herniation, indicating that the biopsy-type injury requires further refinement, such as reduction to a slit-type defect that could penetrate the full depth of the AF without damaging the endplate. Results demonstrate translational feasibility of FibGen for AF repair to seal AF defects, although future study with a more refined injury model is required to validate the efficacy of FibGen before translation.

Intradural disc herniation - report of two cases

Intradural disc herniation is a very rare condition, which occurs in up to 0.3% cases of all disc herniations. It mostly develops at L4-L5 level, which is caused by the presence of strong adhesions between the posterior longitudinal ligament and dura mater. These rare cases are included in the classifications, however, they are associated with diagnostic difficulties, both in physical examination and in the image visible in magnetic resonance.

REPORT OF 2 CASES

The presented patients were treated in the Neuroortopedic Department within the last two years. Despite previous examinations, the final diagnosis of intradural disc herniation occurred only during the surgery.

CONCLUSIONS

Rarely occurring hernias of the intervertebral disc require increased vigilance among surgeon's spine physicians. Preoperative diagnosis of intradural lesion would make it possible to develop a better surgical strategy.

Primary Versus Revision Discectomy for Adults With Herniated Nucleus Pulposus: A Propensity Score-Matched Multicenter Study

STUDY DESIGN

Retrospective propensity score matched analysis.

OBJECTIVE

To compare the incidence of any 30-day perioperative complication following primary and revision discectomy for lumbar disc herniation.

METHODS

The American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) was used to identify patients undergoing primary or revision lumbar discectomy from 2005 to 2012. Propensity score matching was performed to create matched pairs of primary and revision discectomy cases for analysis. Univariate analysis was then performed to compare 30-day morbidity and mortality between propensity score-matched pairs.

RESULTS

We identified 4730 cases of primary discectomy performed through a minimally invasive or open approach and 649 revision discectomy cases. Baseline patient characteristics and comorbidities were compared and then propensity score-matched adjustments were made to create 649 matched pairs of primary and revision cases. On univariate analysis, there were no significant differences in 30-day perioperative outcomes between the 2 groups.

CONCLUSION

While there were no significant differences in 30-day perioperative complications between patients undergoing primary lumbar discectomy and those undergoing revision lumbar discectomy, this finding should be interpreted with caution since the ACS-NSQIP database lacks functional and pain outcomes, and also does not include dural tear or durotomy as a complication. Future large-scale and long-term prospective studies including these variables are needed to better understand the outcomes and complications following primary versus revision discectomy for lumbar disc herniation.

Higher Risk of Intervertebral Disc Herniation among Neurosurgeons Than Neurologists: 15 Year-Follow-Up of a Physician Cohort

High physical activity or workload has been associated with intervertebral disc degeneration. However, there is little data on physicians' risks of disc disease. The study aimed to investigate the incidences of spinal problems among neurologists and neurosurgeons. A cohort of neurologists and neurosurgeons was derived from Taiwan's national research database. During the study period, the incidences of intervertebral disc herniation or spondylosis among these specialists were calculated. Another one-to-one by propensity score matched cohort, composed of neurologists and neurosurgeons, was also analyzed. A Cox regression hazard ratio (HR) model and Kaplan-Meier analysis were conducted to compare the risks and incidences. The entire cohort comprised 481 and 317 newly board-certified neurologists and neurosurgeons, respectively. During the 15 years of follow-up, neurosurgeons were approximately six-fold more likely to develop disc problems than neurologists (crude HR = 5.98 and adjusted HR = 6.08, both p < 0.05). In the one-to-one propensity-score matched cohort (317 neurologists versus 317 neurosurgeons), there were even higher risks among neurosurgeons than neurologists (crude HR = 8.15, and adjusted HR = 10.14, both p < 0.05). Neurosurgeons have a higher chance of intervertebral disc disorders than neurologists. This is potentially an occupational risk that warrants further investigation.

Cell-Seeded Adhesive Biomaterial for Repair of Annulus Fibrosus Defects in Intervertebral Discs

Defects in the annulus fibrosus (AF) of intervertebral discs allow nucleus pulposus tissue to herniate causing painful disability. Microdiscectomy procedures remove herniated tissue fragments, but unrepaired defects remain allowing reherniation or progressive degeneration. Cell therapies show promise to enhance repair, but methods are undeveloped and carriers are required to prevent cell leakage. To address this challenge, this study developed and evaluated genipin-crosslinked fibrin (FibGen) as an adhesive cell carrier optimized for AF repair that can deliver cells, match AF material properties, and have low risk of extrusion during loading. Part 1 determined that feasibility of bovine AF cells encapsulated in high concentration FibGen (F140G6: 140 mg/mL fibrinogen; 6 mg/mL genipin) for 7 weeks could maintain high viability, but had little proliferation or matrix deposition. Part 2 screened tissue mechanics and in situ failure testing of nine FibGen formulations (fibrin: 35-140 mg/mL; genipin: 1-6 mg/mL). F140G6 formulation matched AF shear and compressive properties and significantly improved failure strength in situ. Formulations with reduced genipin also exhibited satisfactory material properties and failure behaviors warranting further biological screening. Part 3 screened AF cells encapsulated in four FibGen formulations for 1 week and found that reduced genipin concentrations increased cell viability and glycosaminoglycan production. F70G1 (70 mg/mL fibrinogen; 1 mg/mL genipin) demonstrated balanced biological and biomechanical performance warranting further testing. We conclude that FibGen has potential to serve as an adhesive cell carrier to repair AF defects with formulations that can be tuned to enhance biomechanical and biological performance; future studies are required to develop strategies to enhance matrix production.

Inflammatory Processes Associated with Canine Intervertebral Disc Herniation

Intervertebral disc herniation (IVDH) is an important pathology in humans and also in dogs. While the molecular disease mechanisms are well investigated in humans, little is known about the inflammatory mediators in naturally occurring canine IVDH. The objective of this study was to investigate whether the involved proinflammatory cytokines in human IVDH are also key cytokines in canine IVDH and thus to elucidate the suitability of the dog as a model for human trials. 59 samples from 25 dogs with surgically confirmed thoracolumbar IVDH were collected and classified in three subgroups: herniated (H), affected non-herniated (NH) disc, and adjacent non-affected (NA) disc. Discs from 11 healthy dogs acted as controls (C). Samples were analyzed for IL-1, IL-6, IL-8, and TNF-α expression (qPCR/ELISA) as well as cell infiltration and activation of the MAP kinase pathways (immunohistochemistry). Gene and protein expression of all key cytokines could be detected in IVDH affected dogs. Canine IVDH was significantly associated with a higher gene expression of IL-6 (H > C, NH > C) and TNF-α (H > C, NH > C, NA > C) and a significant down-regulation of IL-1β (H < C). Dogs with spontaneous pain had significantly higher IL-6 mRNA compared to those with pain arising only upon palpation. An inter-donor comparison (H and HN relative to NA) revealed a significant increase of IL-6 gene expression (H > NA, NH > NA). IL-8 (H > C, NA > C) and TNF-α (NH > C) protein levels were significantly increased in diseased dogs while inversely, IL-6 protein levels were significantly higher in patients with better clinical outcome. Aside from resident IVD cells, mostly monocytes and macrophages were found in extruded material, with concomitant activation of extracellular signal-regulated kinase p38 in the majority of samples. Dogs with spontaneous IVDH might provide a useful model for human disc diseases. Although the expression of key cytokines found in human IVDH was also demonstrated in canine tissue, the inflammatory mechanisms accompanying canine IVDH diverges partially from humans, which will require further investigations in the future. In dogs, IL-6 seems to play an important pathological role and may represent a new potential therapeutic target for canine patients.

[Percutaneous endoscopic discectomy in the treatment of patients with degenerative diseases of the lumbosacral spine]

Modern surgery uses a variety of treatments for spine pathology. Endoscopic techniques have become particularly popular across the world over the past decade. In this article, we summarize our experience and analyze the immediate and long-term results of surgical treatment of lumbar disc herniation using a percutaneous fully endoscopic technique for removing the herniated intervertebral disc, which is new for Russian medical practice.

OBJECTIVE

to evaluate the efficacy of percutaneous endoscopic discectomy in the treatment of herniated lumbar discs in patients with radicular pain syndrome.

MATERIAL AND METHODS

We conducted a cohort retrospective study that included 69 patients who underwent herniated disc removal using the percutaneous endoscopic technique. Surgery was performed through two approaches: the intralaminar approach was used in 44 patients, and the transforaminal approach was used in 25 patients. To assess the efficacy of surgery, we used a visual analogue scale (VAS) of pain: the intensity of local pain (VAS1) and the intensity of radicular pain (VAS2). Changes in the quality of life and ability to work were assessed by using the Oswestry scale; patient satisfaction with treatment was assessed by using the MacNab scale.

RESULTS

The mean follow-up period after surgery was 24 months. An analysis of changes in the pain syndrome (VAS1 and VAS2) before surgery and in the early postoperative period demonstrated a significant regression of pain regardless of the approach type (r=0.25). Patients' survey (MacNab scale) in the long-term postoperative period revealed no unsatisfactory results; excellent, good, and satisfactory results were observed in 21 (30%), 32 (46%), and 16 (24%) patients, respectively.

CONCLUSION

Percutaneous endoscopic discectomy is an effective surgical treatment for degenerative diseases of the lumbosacral spine, providing excellent and good treatment outcomes in most operated patients.

In vitro and biomechanical screening of polyethylene glycol and poly(trimethylene carbonate) block copolymers for annulus fibrosus repair

Herniated intervertebral discs (IVDs) are a common cause of back and neck pain. There is an unmet clinical need to seal annulus fibrosus (AF) defects, as discectomy surgeries address acute pain but are complicated by reherniation and recurrent pain. Copolymers of polyethylene glycol with trimethylene carbonate (TMC) and hexamethylene diisocyanate (HDI) end-groups were formulated as AF sealants as the HDI form covalent bonds with native AF tissue. TMC adhesives were evaluated and optimized using the design criteria: stable size, strong adherence to AF tissue, high cytocompatibility, restoration of IVD biomechanics to intact levels following in situ repair, and low extrusion risk. TMC adhesives had high adhesion strength as assessed with a pushout test (150 kPa), and low degradation rates over 3 weeks in vitro. Both TMC adhesives had shear moduli (220 and 490 kPa) similar to, but somewhat higher than, AF tissue. The adhesive with three TMC moieties per branch (TMC3) was selected for additional in situ testing because it best matched AF shear properties. TMC3 restored torsional stiffness, torsional hysteresis area and axial range of motion to intact states. However, in a failure test of compressive deformation under fixed 5 ° flexion, some herniation risk was observed with failure strength of 5.9 MPa compared with 13.5 MPa for intact samples; TMC3 herniated under cyclic organ culture testing. These TMC adhesives performed well during in vitro and in situ testing, but additional optimization to enhance failure strength is required to further this material to advanced screening tests, such as long-term degradation. Copyright © 2016 John Wiley & Sons, Ltd.

Quality of life in preoperative patients with sacroiliac joint dysfunction is at least as depressed as in other lumbar spinal conditions

BACKGROUND

Pain from the sacroiliac joint (SIJ) is an under-recognized cause of low back pain. The degree to which SIJ pain decreases quality of life has not been directly compared to other more familiar conditions of the lumbar spine.

METHODS

Multivariate regression analysis of individual patient data from two prospective multicenter clinical trials of SIJ fusion and three prospective multicenter clinical trials of surgical treatments for degenerative lumbar spine conditions.

RESULTS

Controlling for baseline demographic parameters as well as a validated disability score, quality of life scores (EuroQOL 5-D and SF-36) were, in most cases, lower in the SIJ cohorts compared to the three other spine surgery cohorts.

CONCLUSION

Patients with SIJ dysfunction considering surgery have decrements in quality of life as or more severe compared to patients with degenerative spondylolisthesis, spinal stenosis, and intervertebral disc herniation.

Lipoxin A4 attenuates radicular pain possibly by inhibiting spinal ERK, JNK and NF-κB/p65 and cytokine signals, but not p38, in a rat model of non-compressive lumbar disc herniation

Inflammatory response induced by protrused nucleus pulposus (NP) has been shown to play a crucial role in the process of radicular pain. Lipoxins represent a unique class of lipid mediators that have anti-inflammatory and pro-resolving action. The present study was undertaken to investigate if intrathecal lipoxin A4 (LXA4) could alleviate mechanical allodynia in the rat models of application of NP to the L5 dorsal root ganglion (DRG). Non-compressive models of application of NP to L5 DRG were established and intrathecal catheterization for drug administration was performed in rats. Daily intrathecal injection of vehicle or LXA4 (10ng or 100ng) was performed for three successive days post-operation. Mechanical thresholds were tested and the ipsilateral lumbar (L4-L6) segment of spinal dorsal horns were removed for the determination of tumor necrosis factor-α (TNF-α), IL-1β, transforming growth factor-β1 (TGF-β1) and IL-10 expression and NF-κB/p65, extracellular signal-regulated kinase (ERK), C-Jun N-terminal kinase (JNK) and P38 expression. Application of NP to DRG in rats induced mechanical allodynia, increased the expression of pro-inflammatory factors (TNF-α and IL-1β), NF-κB/p65, the phosphorylated-ERK (p-ERK), -JNK (p-JNK) and -P38 (p-p38) and decreased the expression of anti-inflammatory cytokines (TGF-β1 and IL-10) in the ipsilateral lumbar (L4-L6) segment of spinal dorsal horns. Intrathecal injection of LXA4 alleviated the development of neuropathic pain, inhibited the upregulation of pro-inflammatory cytokines (TNF-α and IL-1β), upregulated the expression of anti-inflammatory cytokines (TGF-β1 and IL-10) and attenuated the activation of NF-κB/p65, p-ERK, p-JNK, but not p-p38, in a dose-dependent manner. In this study, we have demonstrated that LXA4 potently alleviate radicular pain in a rat model of non-compressive lumbar disc herniation. The anti-inflammatory and pro-resolution properties of LXA4 have shown a great promise for the management of radicular pain caused by intervertebral disc herniation.

Analysis of the clinical picture in patients with osteoarthritis of the spine depending on the type and severity of lesions on magnetic resonance imaging

OBJECTIVES

Spondyloarthritis is the most common pathological change in the spine. In a significant number of cases, it leads to compression of the nervous structures of the spinal canal, causing pain and neurological symptoms. Intervertebral disc pathology is a common cause of root deficits in neurological examination of all types of degenerative changes of the spine structures. Disc herniation is pathologically divided into 4 stages of herniated nucleus pulposus: 1) bulging, 2) protrusion, 3) extrusion, 4) sequestration. The aim of this study is to analyze the correlation between the type and severity of degenerative changes in the spine and the incidence of neurological deficits.

MATERIAL AND METHODS

The study included 100 patients: 74 men and 26 women aged 50.2 ±10.43 years with pain of the spine in the cervical and/or lumbosacral segments and with degenerative changes in the plain radiographs. The mean value of body mass index (BMI) was 27.8 ±3.95 kg/m(2). Each patient underwent neurological examinations and 1.5 T magnetic resonance imaging MRI of the cervical and/or lumbar spine.

RESULTS

Every patient was diagnosed with herniated nucleus pulposus affecting on average 4 ±2 segments of the spine. The most frequently observed degree of severity of disc herniation was the second (protrusion, 71.9% of all disc disease in 89 patients). Much less frequently found was the third degree (extrusion, 45 patients, 20.1% slipped disc), the first (bulging, 14 patients, 6.3% slipped disc), and least often only a small percentage of fourth degree (sequestration, 4 patients, 1.7% slipped disc). Neurological symptoms (deficits) were observed in 34 patients. They were accompanied by disc herniations in 23.7% of patients. In remaining patients with neurological deficits there was spinal stenosis. No correlation was observed between neurological deficits and stage 1 of disc herniation.

CONCLUSIONS

The incidence rate of neurological deficits is correlated with the degree of changes in the spine, as visualized by MRI.

The effect of high obesity on outcomes of treatment for lumbar spinal conditions: subgroup analysis of the spine patient outcomes research trial

STUDY DESIGN

Spine Patient Outcomes Research Trial subgroup analysis.

OBJECTIVE

To evaluate the effect of high obesity on management of lumbar spinal stenosis, degenerative spondylolisthesis (DS), and intervertebral disc herniation (IDH).

SUMMARY OF BACKGROUND DATA

Prior Spine Patient Outcomes Research Trial analyses compared nonobese and obese patients. This study compares nonobese patients (body mass index<30 kg/m) with those with class I obesity (body mass index=30-35 kg/m) and class II/III high obesity (body mass index≥35 kg/m).

METHODS

For spinal stenosis, 250 of 634 nonobese patients, 104 of 167 obese patients, and 59 of 94 highly obese patients underwent surgery. For DS, 233 of 376 nonobese patients, 90 of 129 obese patients, and 66 of 96 highly obese patients underwent surgery. For IDH, 542 of 854 nonobese patients, 151 of 207 obese patients, and 94 of 129 highly obese patients underwent surgery. Outcomes included Short Form-36, Oswestry Disability Index, stenosis/sciatica bothersomeness index, low back pain bothersomeness index, operative events, complications, and reoperations. Operative and nonoperative outcomes were compared by change from baseline at each follow-up interval using a mixed effects longitudinal regression model. An as-treated analysis was performed because of crossover between surgical and nonoperative groups.

RESULTS

Highly obese patients had increased comorbidities. Baseline Short Form-36 physical function scores were lowest for highly obese patients. For spinal stenosis, surgical treatment effect and difference in operative events among groups were not significantly different.For DS, greatest treatment effect for the highly obese group was found in most primary outcome measures, and is attributable to the significantly poorer nonoperative outcomes. Operative times and wound infection rates were greatest for highly obese patients.For IDH, highly obese patients experienced less improvement postoperatively compared with obese and nonobese patients. However, nonoperative treatment for highly obese patients was even worse, resulting in greater treatment effect in almost all measures. Operative time was greatest for highly obese patients. Blood loss and length of stay was greater for both obese cohorts.

CONCLUSION

Highly obese patients with DS experienced longer operative times and increased infection. Operative time was greatest for highly obese patients with IDH. DS and IDH saw greater surgical treatment effect for highly obese patients due to poor outcomes of nonsurgical management.

LEVEL OF EVIDENCE

3.

Surgical treatment of thoracic disc herniations using a modified transfacet approach

BACKGROUND

Ideal surgical treatment for thoracic disc herniation (TDH) is controversial due to variations in patient presentation, pathology, and possible surgical approach. Althougth discectomy may lead to improvements in neurologic function, it can be complicated by approach related morbidity. Various posterior surgical approaches have been developed to treate TDH, but the gold standard remains transthoracic decompression. Certain patients have comorbidities and herniation that are not optimally treated with an anterior approach. A transfacet pedicle approach was first described in 1995, but outcomes and complications have not been well described. The aim of this work was to evaluate the clinical effect and complications in a consecutive series of patients with symptomatic thoracic disc herniations undergoing thoracic discectomy using a modified transfacet approach.

MATERIALS AND METHODS

33 patients with thoracic disc herniation were included in this study. Duration of the disease was from 12 days to 36 months, with less than 1 month in 13 patients. Of these, 15 patients were diagnosed with simple thoracic disc herniation, 6 were associated with ossified posterior longitudinal ligament, and 12 with ossified or hypertrophied yellow ligament. A total of 45 discs were involved. All the herniated discs and the ossified posterior longitudinal ligaments were excised using a modified transfacet approach. Laminectomy and replantation were performed for patients with ossified or hypertrophied yellow ligament. The screw-rod system was used on both sides in 14 patients and on one side in l9 patients.

RESULTS

29 patients were followed up for an average of 37 months (range 12-63 months) and 4 patients were lost to followup. Evaluation was based on Epstein and Schwall criteria.5 15 were classified as excellent and 10 as good, accounting for 86.21% (25/29); 2 patients were classified as improved and 2 as poor. All the patients recovered neurologically after surgery. A total of 25 patients had significantly improved motor function from 3 to 6 months after surgery and 10 patients had slow recovery 6 months after surgery.. Of the three patients with postoperative complications, two had exacerbated preexisting defects and one had implant failure. Postoperative computed tomography or magnetic resonance imaging showed that all patients had well fused replanted lamina and completely decompressed canal.

CONCLUSION

Thoracic discectomy using a modified transfacet approach can significantly improve the clinical outcomes.

Surgical versus nonoperative treatment for lumbar disc herniation: eight-year results for the spine patient outcomes research trial

STUDY DESIGN

Concurrent prospective randomized and observational cohort studies.

OBJECTIVE

To assess the 8-year outcomes of surgery versus nonoperative care.

SUMMARY OF BACKGROUND DATA

Although randomized trials have demonstrated small short-term differences in favor of surgery, long-term outcomes comparing surgical with nonoperative treatment remain controversial.

METHODS

Surgical candidates with imaging-confirmed lumbar intervertebral disc herniation meeting Spine Patient Outcomes Research Trial eligibility criteria enrolled into prospective randomized (501 participants) and observational cohorts (743 participants) at 13 spine clinics in 11 US states. Interventions were standard open discectomy versus usual nonoperative care. Main outcome measures were changes from baseline in the SF-36 Bodily Pain and Physical Function scales and the modified Oswestry Disability Index-AAOS/Modems version assessed at 6 weeks, 3 months, and 6 months, and annually thereafter.

RESULTS

Advantages were seen for surgery in intent-to-treat analyses for the randomized cohort for all primary and secondary outcomes other than work status; however, with extensive nonadherence to treatment assignment (49% patients assigned to nonoperative therapy receiving surgery versus 60% of patients assigned to surgery) these observed effects were relatively small and not statistically significant for primary outcomes (bodily pain, physical function, Oswestry Disability Index). Importantly, the overall comparison of secondary outcomes was significantly greater with surgery in the intent-to-treat analysis (sciatica bothersomeness [P > 0.005], satisfaction with symptoms [P > 0.013], and self-rated improvement [P > 0.013]) in long-term follow-up. An as-treated analysis showed significant surgical treatment effects for primary outcome measures (mean change, surgery vs. nonoperative care; treatment effect; 95% confidence interval): bodily pain (45.3 vs. 34.4; 10.9; 7.7 to 14); PF (42.2 vs. 31.5; 10.6; 7.7 to 13.5); and Oswestry Disability Index (-36.2 vs. -24.8; -11.3; -13.6 to -9.1).

CONCLUSION

Carefully selected patients who underwent surgery for a lumbar disc herniation achieved greater improvement than nonoperatively treated patients; there was little to no degradation of outcomes in either group (operative and nonoperative) from 4 to 8 years.

LEVEL OF EVIDENCE

2.

Hemilaminectomy and vertebral stabilization for thoracolumbar intervertebral disc associated dynamic compression in 11 dogs

OBJECTIVE

To describe the diagnostic findings, surgical technique and outcome in dogs with thoracolumbar intervertebral disc-associated dynamic compression.

STUDY DESIGN

Retrospective case series.

ANIMALS

Client owned dogs (n = 11).

METHODS

Medical records (2005-2010) of dogs with a stress myelographic diagnosis of spinal cord injury due to thoracolumbar intervertebral disc-associated dynamic compression with inconclusive compression in the neutral myelographic views that had hemilaminectomy and vertebral stabilization were reviewed. Data on pre- and postoperative neurologic status, diagnostic findings, surgical techniques and outcomes were retrieved. Follow-up clinical and radiographic evaluations were performed immediately, and at approximately one, two, and six months postoperatively as well as at annual follow-up examinations.

RESULTS

The stress myelography demonstrated distinct ventral dynamic compression due to bulging of the disc and additional dorsal compression due to infolding of the ligamentum flavum in some cases. The median percentage of post-stress reduction in spinal cord height on the lateral view was 18.0% (9.8-27.2%). All dogs recovered after surgery and at follow-up examinations were still ambulatory (median: 45 months, range: 7 to 94 months).

CONCLUSIONS AND CLINICAL RELEVANCE

Thoracolumbar intervertebral disc degeneration may result in disc-associated dynamic compression. Stress myelography was an effective means of diagnosing this condition and hemilaminectomy with vertebral stabilization was an effective treatment resulting in long-term neurological improvement in all dogs.

Magnetic resonance imaging predictors of surgical outcome in patients with lumbar intervertebral disc herniation

STUDY DESIGN

A retrospective cohort design.

OBJECTIVE

To determine whether baseline magnetic resonance imaging findings, including central/foraminal stenosis, Modic change, disc morphology, facet arthropathy, disc degeneration, nerve root impingement, and thecal sac compression, are associated with differential surgical treatment effect.

SUMMARY OF BACKGROUND DATA

Intervertebral disc herniation remains the most common source of lumbar radiculopathy treated either with discectomy or nonoperative intervention. Although magnetic resonance imaging remains the reliable "gold standard" for diagnosis, uncertainty surrounds the relationship between magnetic resonance imaging findings and treatment outcomes.

METHODS

Three hundred seven "complete" images from patients enrolled in a previous trial were de-identified and evaluated by 1 of 4 independent readers. Findings were compared with outcome measures including the Oswestry Disability Index. Differences in surgery and nonoperative treatment outcomes were evaluated between image characteristic subgroups and TE determined by the difference in Oswestry Disability Index scores.

RESULTS

The cohort comprised 40% females with an average age of 41.5 (±11.6) years, 61% of whom underwent discectomy for intervertebral disc herniation. Patients undergoing surgery with Modic type I endplate changes had worse outcomes (-26.4 vs. -39.7 for none and -39.2 for type 2, P = 0.002) and smaller treatment effect (-3.5 vs. -19.3 for none and -15.7 for type 2, P = 0.003). Those with compression of ≥1/3 showed the greatest improvement within the surgical group (-41.9 for ≥1/3 vs. -31.6 for none and -38.1 for <1/3, P = 0.007) and the highest TE (-23 compared with -11.7 for none and -15.2 for <1/3, P = 0.015). Furthermore, patients with minimal nerve root impingement demonstrated worse surgical outcomes (-26.5 vs. -41.1 for "displaced" and -38.9 for "compressed," P = 0.016).

CONCLUSION

Among patients with intervertebral disc herniation, those with thecal sac compression of 1/3 or more had greater surgical treatment effect than those with small disc herniations and Modic type I changes. In addition, patients with nerve root "compression" and "displacement" benefit more from surgery than those with minimal nerve root impingement.

LEVEL OF EVIDENCE

2.

Computed tomographic and histological findings of Hansen type I intervertebral disc herniation in dogs

OBJECTIVE

To evaluate whether non-contrast-enhanced computed tomography (CT) as a stand-alone imaging modality can be used to define the Hansen type I intervertebral disc herniation (IVDH) lesion and also whether the Hounsfield unit (HU) value of herniated disc is relevant to clinical duration and to histopathological chronicity of extruded disc material.

METHODS

Information from a series of CT studies performed on 45 dogs with a presumptive diagnosis of Hansen type I IVDH was used. Clinical duration of IVDH was estimated based on time from onset of signs per owner communication to time of surgical intervention. Hansen type I IVDH was confirmed at surgery. Retrieved herniated disc was histologically examined. The HU values were analyzed to correlate the clinical duration and histopathological chronicity of the disc lesion.

RESULTS

Non-contrast-enhanced CT provided sufficient diagnostic information to plan surgery in 42 of 45 dogs (93%). The value of the HU was significantly higher in clinically chronic cases (n = 12) compared to peracute cases (n = 11) (p <0.05). The HU values were significantly correlated with clinical duration (r = 0.482, p = 0.0008) and histopathological chronicity of the herniated disc (r = 0.408, p = 0.0056).

CONCLUSION

Consistent with the previous reports, the use of non-contrast-enhanced CT alone was sufficient for the diagnosis and surgical planning in most patients with Hansen type I IVDH in the thoracolumbar spine. In addition, the present study suggested that HU values on CT images may be useful in the evaluation of disease chronicity of IVDH.

The impact of diabetes on the outcomes of surgical and nonsurgical treatment of patients in the spine patient outcomes research trial

STUDY DESIGN

A secondary analysis comparing diabetic patients with nondiabetic patients enrolled in the Spine Patient Outcomes Research Trial (SPORT).

OBJECTIVE

To compare surgical outcomes and complications between diabetic and nondiabetic spine patients.

SUMMARY OF BACKGROUND DATA

Patients with diabetes are predisposed to comorbidities that may confound the diagnosis and treatment of patients with spinal disorders.

METHODS

Baseline characteristics and outcomes of 199 patients with diabetes were compared with those of the nondiabetic population in a total of 2405 patients enrolled in the Spine Patient Outcomes Research Trial for the diagnoses of intervertebral disc herniation (IDH), spinal stenosis (SpS), and degenerative spondylolisthesis (DS). Primary outcome measures include the 36-Item Short Form Health Survey (SF-36) Health Status questionnaire and the Oswestry Disability Index.

RESULTS

Patients with diabetes were significantly older and had a higher body mass index than nondiabetic patients. Comorbidities, including hypertension, stroke, cardiovascular disease, and joint disease, were significantly more frequent in diabetic patients than in nondiabetic patients. Patients with diabetes and IDH did not make significant gains in pain and function with surgical intervention relative to diabetic patients who underwent nonoperative treatment. Diabetic patients with SpS and DS experienced significantly greater improvements in pain and function with surgical intervention when compared with nonoperative treatment. Among those who had surgery, nondiabetic patients with SpS achieved marginally significantly greater gains in function than their diabetic counterparts (SF-36 physical function, P = 0.062). Among patients who had surgery for DS, diabetic patients did not have as much improvement in pain or function as did the nondiabetic population (SF-36 bodily pain, P = 0.003; physical function, P = 0.002). Postoperative complications were more prevalent in patients with diabetes than in nondiabetic patients with SpS (P = 0.002). There was an increase in postoperative (P = 0.028) and intraoperative (P = 0.029) blood replacement in DS patients with diabetes.

CONCLUSION

Diabetic patients with SpS and DS benefited from surgery, though older SpS patients with diabetes have more postoperative complications. IDH patients with diabetes did not benefit from surgical intervention.

Surgical versus nonoperative treatment for lumbar disc herniation: four-year results for the Spine Patient Outcomes Research Trial (SPORT)

STUDY DESIGN

Concurrent, prospective, randomized, and observational cohort study.

OBJECTIVE

To assess the 4-year outcomes of surgery versus nonoperative care.

SUMMARY OF BACKGROUND DATA

Although randomized trials have demonstrated small short-term differences in favor of surgery, long-term outcomes comparing surgical to nonoperative treatment remain controversial.

METHODS

Surgical candidates with imaging-confirmed lumbar intervertebral disc herniation meeting SPORT eligibility criteria enrolled into prospective, randomized (501 participants), and observational cohorts (743 participants) at 13 spine clinics in 11 US states. Interventions were standard open discectomy versus usual nonoperative care. Main outcome measures were changes from baseline in the SF-36 Bodily Pain (BP) and Physical Function (PF) scales and the modified Oswestry Disability Index (ODI - AAOS/Modems version) assessed at 6 weeks, 3 months, 6 months, and annually thereafter.

RESULTS

Nonadherence to treatment assignment caused the intent-to-treat analyses to underestimate the treatment effects. In the 4-year combined as-treated analysis, those receiving surgery demonstrated significantly greater improvement in all the primary outcome measures (mean change surgery vs. nonoperative; treatment effect; 95% CI): BP (45.6 vs. 30.7; 15.0; 11.8 to 18.1), PF (44.6 vs. 29.7; 14.9;12.0 to 17.8) and ODI (-38.1 vs. -24.9; -13.2; -15.6 to -10.9). The percent working was similar between the surgery and nonoperative groups, 84.4% versus 78.4% respectively.

CONCLUSION

In a combined as-treated analysis at 4 years, patients who underwent surgery for a lumbar disc herniation achieved greater improvement than nonoperatively treated patients in all primary and secondary outcomes except work status.

Racial variation in treatment preferences and willingness to randomize in the Spine Patient Outcomes Research Trial (SPORT)

STUDY DESIGN

Analysis of baseline data for patients enrolled in Spine Patient Outcomes Research Trial (SPORT), a project conducting three randomized and three observational cohort studies of surgical and nonoperative treatments for intervertebral disc herniation (IDH), spinal stenosis (SpS), and degenerative spondylolisthesis (DS).

OBJECTIVE

To explore racial variation in treatment preferences and willingness to be randomized.

SUMMARY OF BACKGROUND DATA

Increasing minority participation in research has been a priority at the NIH. Prior studies have documented lower rates of participation in research and preferences for invasive treatment among African-Americans.

METHODS

Patients enrolled in SPORT (March 2000 to February 2005) that reported data on their race (n = 2,323) were classified as White (87%), Black (8%), or Other (5%). Treatment preferences (nonoperative, unsure, surgical), and willingness to be randomized were compared among these groups while controlling for baseline differences using multivariate logistic regression. RESULTS.: There were numerous significant differences in baseline characteristics among the racial groups. Following adjustment for these differences, Blacks remained less likely to prefer surgical treatment among both IDH (White, 55%; Black, 37%; Other, 55%, P = 0.023) and SpS/DS (White, 46%; Black, 30%; Other, 43%; P = 0.017) patients. Higher randomization rates among Black IDH patients (46% vs. 30%) were no longer significant following adjustment (odds ratio [OR] = 1.45, P = 0.235). Treatment preference remained a strong independent predictor of randomization in multivariate analyses for both IDH (unsure OR = 3.88, P < 0.001 and surgical OR = 0.23, P < 0.001) and SpS/DS (unsure OR = 6.93, P < 0.001 and surgical OR = 0.45, P < 0.001) patients.

CONCLUSIONS

Similar to prior studies, Black participants were less likely than Whites or Others to prefer surgical treatment; however, they were no less likely to agree to be randomized. Treatment preferences were strongly related to both race and willingness to be randomized.