In-vivo endoscopic visualization of patho-anatomy in painful degenerative conditions of the lumbar spine

The degenerative processes in an aging spine have been defined traditionally only by our knowledge of the biology of disc and facet degeneration, as well as interpretation of post-mortem cryosections by forensic anatomist Wolfgang Rauschning, M.D. In this chapter, visualization of in-vivo patho-anatomy in a degenerating disc and spinal segment is demonstrated at surgery using the Yeung Endoscopic Spine System (Y.E.S.S.), (Richard Wolf Surgical Instrument Company, Vernon Hills, IL, USA). An Institutional Review Board (IRB)-approved study of endoscopic treatment for degenerative conditions of the lumbar spine incorporated intraoperative probing under local anesthesia and endoscopic treatment of the visualized patho-anatomy. An intraoperative evocative chromo-discogram, using indigocarmine, was used to elicit discogenic pain and label the fissured and degenerative nucleus pulposus for surgical removal and thermal modulation. Painful patho-anatomy was probed in a conscious patient. The most common endoscopic finding was Inflammatory tissue in the disc and annulus. Inflammation was correlated with the presence of annular tears. Patho-physiologic changes that affect the exiting nerve, which contains the Dorsal Root Ganglion (DRG), was associated with stenotic and chemical irritation. Unavoidable postoperative dysesthesia was associated with the presence of an inflammatory membrane, and removal or thermal coagulation of "anomalous" furcal nerves in the foramen that branched off of the exiting spinal nerve. Neo-angiogenesis and neurogenesis in the inflammatory membrane present in the foraminal triangle was a new finding not reported in traditional clinical studies. Visualization and treatment of pathologic findings inside (annular tears) and outside the disc in Herniated Nucleus Pulposus (HNP), synovial cysts, foraminal stenosis, central stenosis, spondylolisthesis, is demonstrated. The endoscopic foraminal approach to the spine and disc is a technique that provides access to patho-anatomy in the lumbar spine not usually feasible with traditional surgical methods. Favorable surgical results allow for continued evolution of the endoscopic method, concomitant with the continued evolution of endoscopic spinal surgery.

Back pain and condensation of the eighth thoracic vertebra: is it always a metastatic disease?

The case of a 55-year-old female patient with discogenic sclerosis of a thoracic vertebra is illuminated by a radiologic vignette. The clinical and radiologic features, including those of conventional radiography, computed tomography scanning and magnetic resonance imaging are hallmarked in this portrait. The importance of differentiating the condition particularly from infectious spondylodiscitis and metastatic disease to the spine is underpinned.

Anatomic changes in lateral spondylolisthesis associated with adult lumbar scoliosis

STUDY DESIGN

Prospective consecutive series.

OBJECTIVE

To analyze the anatomic changes in lateral spondylolisthesis.

SUMMARY OF BACKGROUND DATA

Previous studies have focused on the correlation between lateral spondylolisthesis, and curve progression and pain. To our knowledge, there has not been any detailed report concerning anatomic changes in lateral spondylolisthesis.

METHODS

We examined 24 consecutive patients (mean age 66 years), with lateral spondylolisthesis associated with lumbar scoliosis who had computerized tomography (CT) after myelography. Coronal reconstruction CT was used to measure the vertebral translation. Vertebral rotation was measured by the Aaro method using transaxial CT.

RESULTS

The Cobb angle averaged 26 degrees (range 13 degrees-75 degrees). Lateral spondylolisthesis was found most commonly at the lower-end vertebra. The cephalad-slipped vertebra rotated toward the convex side of the main curve, whereas the caudal vertebra rotated toward the convex side of the lumbosacral hemi (or fractional) curve below. Mean lateral translation and vertebral rotation were 7 mm and 8 degrees, respectively. There was a significant correlation between lateral translation and vertebral rotation (r = 0.49; P = 0.018). The convex superior articular process of the caudal vertebra had compressed the nerve root laterally in 21 patients, of whom 10 had radicular pain. The concave, inferior articular process of the cephalad vertebra had compressed the dural sac posteriorly, and 2 patients had radicular pain.

CONCLUSIONS

To our knowledge, this study has been the first attempt to analyze anatomic changes in lateral spondylolisthesis using CT. It may offer further insight into the pathogenesis of adult lumbar scoliosis.

Prognostic value of magnetic resonance imaging in dogs with paraplegia caused by thoracolumbar intervertebral disk extrusion: 77 cases (2000-2003)

OBJECTIVE

To determine whether magnetic resonance imaging findings in dogs with paraplegia caused by thoracolumbar intervertebral disk extrusion were predictive of clinical outcome.

DESIGN

Retrospective case series.

ANIMALS

77 dogs.

PROCEDURE

Medical records and magnetic resonance images were reviewed; clinical outcome was classified as successful (regained ability to walk with no more than mild neurologic deficits) or unsuccessful (severe neurologic deficits persisted). The prognostic value of magnetic resonance imaging was compared with prognostic value of deep pain perception, duration of clinical signs, and rate of onset of clinical signs.

RESULT

33 (43%) dogs had areas of hyperintensity of the spinal cord greater than or equal to the length of the L2 vertebral body on T2-weighted magnetic resonance images. All 44 dogs without areas of hyperintensity on T2-weighted images had a successful outcome, but only 18 of the 33 (55%) dogs with an area of hyperintensity did. Only 5 of 16 dogs with an area of hyperintensity that had also lost deep pain perception had a successful outcome. The odds ratio for an unsuccessful outcome for a dog with an area of hyperintensity (29.87) was higher than the odds ratio for a dog that had lost deep pain perception (5.24). Duration and rate of onset of clinical signs were not associated with clinical outcome.

CONCLUSIONS AND CLINICAL RELEVANCE

Findings suggest that results of magnetic resonance imaging can be used to predict clinical outcome in dogs with paraplegia caused by intervertebral disk extrusion.

Inclusion body myopathy and Paget disease is linked to a novel mutation in the VCP gene

Mutations in the valosin-containing protein (VCP) on chromosome 9p13-p12 were recently found to be associated with hereditary inclusion body myopathy, Paget disease of the bone, and frontotemporal dementia (IBMPFD). We identified a novel missense mutation in the VCP gene (R159H; 688G>A) segregating with this disease in an Austrian family of four affected siblings, who exhibited progressive proximal myopathy and Paget disease of the bone but without clinical signs of dementia.

[Radiological imaging in spinal pain]

Spinal pain is a very common disorder in the clinical practice and an important cause of man-power loss. Radiological investigations are commonly used to identify the underlying pathology of spinal pain. Along with the technological advancements, the radiological techniques have improved a lot during the last few decades. This review explains the use, advantages and restrictions of direct roentgenogram, myelograpy applications, computed tomography, magnetic resonance imaging, discography and spinal angiography which are commonly used radiological techniques in the diagnosis and follow-up of spinal pain conditions. Better understanding of the indications, advantages and disadvantages of such radiological techniques by the clinicians will improve the clinical output while optimizing the problems such as x-ray exposure and economical burden.

A subdural abscess and infected blood patch complicating regional analgesia for labour

We report two very unusual cases of infection complicating labour analgesia. The first case was a sub-dural abscess presenting with deep-seated backache seven days after combined spinal-epidural analgesia for labour. The second was a painful lumbar swelling and septicaemia that presented three days after a blood patch for a post dural puncture headache. Because of their complicated and unusual presentation, the diagnosis and management of both were initially delayed.

Chronic back pain is associated with decreased prefrontal and thalamic gray matter density

The role of the brain in chronic pain conditions remains speculative. We compared brain morphology of 26 chronic back pain (CBP) patients to matched control subjects, using magnetic resonance imaging brain scan data and automated analysis techniques. CBP patients were divided into neuropathic, exhibiting pain because of sciatic nerve damage, and non-neuropathic groups. Pain-related characteristics were correlated to morphometric measures. Neocortical gray matter volume was compared after skull normalization. Patients with CBP showed 5-11% less neocortical gray matter volume than control subjects. The magnitude of this decrease is equivalent to the gray matter volume lost in 10-20 years of normal aging. The decreased volume was related to pain duration, indicating a 1.3 cm3 loss of gray matter for every year of chronic pain. Regional gray matter density in 17 CBP patients was compared with matched controls using voxel-based morphometry and nonparametric statistics. Gray matter density was reduced in bilateral dorsolateral prefrontal cortex and right thalamus and was strongly related to pain characteristics in a pattern distinct for neuropathic and non-neuropathic CBP. Our results imply that CBP is accompanied by brain atrophy and suggest that the pathophysiology of chronic pain includes thalamocortical processes.

A clinical return-to-work rule for patients with back pain

BACKGROUND

Tools for early identification of workers with back pain who are at high risk of adverse occupational outcome would help concentrate clinical attention on the patients who need it most, while helping reduce unnecessary interventions (and costs) among the others. This study was conducted to develop and validate clinical rules to predict the 2-year work disability status of people consulting for nonspecific back pain in primary care settings.

METHODS

This was a 2-year prospective cohort study conducted in 7 primary care settings in the Quebec City area. The study enrolled 1007 workers (participation, 68.4% of potential participants expected to be eligible) aged 18-64 years who consulted for nonspecific back pain associated with at least 1 day's absence from work. The majority (86%) completed 5 telephone interviews documenting a large array of variables. Clinical information was abstracted from the medical files. The outcome measure was "return to work in good health" at 2 years, a variable that combined patients' occupational status, functional limitations and recurrences of work absence. Predictive models of 2-year outcome were developed with a recursive partitioning approach on a 40% random sample of our study subjects, then validated on the rest.

RESULTS

The best predictive model included 7 baseline variables (patient's recovery expectations, radiating pain, previous back surgery, pain intensity, frequent change of position because of back pain, irritability and bad temper, and difficulty sleeping) and was particularly efficient at identifying patients with no adverse occupational outcome (negative predictive value 78%- 94%).

INTERPRETATION

A clinical prediction rule accurately identified a large proportion of workers with back pain consulting in a primary care setting who were at a low risk of an adverse occupational outcome.

Combination treatment of vertebral metastases using image-guided percutaneous radiofrequency ablation and vertebroplasty: a case report

BACKGROUND

We describe a case of vertebral metastases treated with a combination of percutaneous radiofrequency ablation (RFA) and vertebroplasty in a single session.

CASE DESCRIPTION

A 45-year-old female with recently diagnosed metastatic non-small cell lung cancer was referred for consideration of vertebroplasty after having several weeks of back pain. Computed tomography and magnetic resonance imaging scans of the thoracic spine revealed metastatic lesions at the T9 and T12 bodies. Radiofrequency ablation was performed using a starburst array electrode (Rita Medical Systems, Mountain View, Calif). The metastatic lesion in the T9 vertebral body measured 1.5 x 1.5 cm and was heated to 100 degrees C for 5 minutes. Vertebroplasty was then performed on this lesion as well as a lesion at T12 with no complications. The patient was discharged home the same day without complaints.

CONCLUSION

Radiofrequency ablation and vertebroplasty are minimally invasive procedures that can be used in combination to treat spinal metastases. The pain relief from these treatments is often immediate. RFA can also be used to minimize procedure-related complications during the vertebroplasty. In properly selected patients, RFA may also increase the duration of local spinal stabilization afforded by the vertebroplasty alone. Long-term studies are warranted to assess the efficacy and durability of this unique approach.

[Neuroanatomic basis for discogenic pain]

AIMS

The aim of this study is to give a short overview about the innervation of the intervertebral disc and the nerve connections between the somatosensible and autonomous nervous systems in the paravertebral region.

METHODS

A short review of the clinical and experimental literature including gross-anatomical, histochemical and immunohistochemical studies as well as functional studies after application of tracer substances has been made. We also present our own experimental immunohistochemical and molecular biological investigations on paravertebral muscle biopsies of a patient with post-discotomy syndrome.

RESULTS

The annulus fibrosus of the intervertebral disc is innervated by myelinated nerve fibres. Neuronal markers for pain-leading fibres were found to be positive in the dorsal region of the annulus, and especially in the posterior longitudinal ligament. Nerve ingrowth into the diseased intervertebral disc was found in chronic back pain. The main innervation of the intervertebral disc is formed by the sinuvertebral nerves. The sinuvertebral nerves are recurrent branches of the ventral rami that re-enter the intervertebral foramina to be distributed within the vertebral canal. They are mixed polysegmental nerves and nerve plexuses, each being formed by a somatic root from a ventral ramus and an autonomic root from a grey ramus communicans. The number of nerve bundles was reduced by resection of sympathetic trunks. The expression of neuronal markers in the sarcolemma of the paravertebral muscles is reduced after discotomy.

CONCLUSIONS

The neuroanatomical basis of discogenic pain can be summarised as follows: 1. The intervertebral disc receives an extensive innervation, especially the annulus fibrosus. 2. Nerve extension was found into the nucleus pulposus of the degenerated disc. 3. The sinuvertebral nerve plexuses facilitate a polysegmental signal and pain spreading. 4. The innervation of the intervertebral disc is very high connected with the paravertebral muscles. 5. A local denervation of the paravertebral muscles was found in post-discotomy syndrome.

Percutaneous vertebroplasty and kyphoplasty performed at a cancer center: refuting proposed contraindications

Object. The purpose of this study was to examine a group of patients with cancer who underwent a vertebroplasty or a kyphoplasty for a vertebral body (VB) fracture, even though the procedure may have been considered contraindicated based on previous reports in the literature.

Methods. The electronic database maintained by the Departments of Neurosurgery and Anesthesiology—Pain Management at the University of Texas M. D. Anderson Cancer Center was searched for patients who underwent vertebroplasty or kyphoplasty between January 2001 and July 2003. The criteria defining a contraindicated procedure were based on a review of the literature. Group I consisted of patients who did not undergo a contraindicated vertebroplasty or kyphoplasty, whereas Group II consisted of patients who underwent one of these procedures even though it may have been considered contraindicated.

There were 53 patients with fractures at 132 levels who met the criteria for the study. Of these, 17 patients with fractures at 18 levels (14% of total) were considered to have undergone a contraindicated vertebroplasty or kyphoplasty (Group II). There were 12 complications (11%) in the 114 levels in Group I and seven complications (39%) in the 18 levels in Group II (p = 0.03). The most common complication was cement extrusion from the anterior VB that did not involve the venous system. No patient required an open surgical procedure to remove extruded cement.

Conclusions. Vertebroplasty and kyphoplasty appear to be safe and effective in the setting of severe back pain caused by VB fracture that is unresponsive to other therapies, even in the presence of relative contraindications to the procedures.

Diagnostic Efficacy of Thin Slice CT in Osteoid Osteoma of the Thoracic Spine

We present a 24-year-old man and a 31-year-old woman who complained of persistent back pain with osteoid osteoma of the thoracic spine. Computed tomography (CT) revealed a round sclerotic lesion in the posterior element of the thoracic spine, although their plain radiographs showed no abnormalities except a slight scoliosis. The patients underwent total excision of the tumor via a posterior approach. They are currently asymptomatic with no recurrence of the lesion and have returned to full activity. The thin slice CT is one of the most important diagnostic tools for osteoid osteoma of the spine.

The Michel Benoist and Robert Mulholland yearly European Spine Journal Review. A survey of the "surgical and research" articles in the European Spine Journal, 2004

The Deputy Editor has explained in his editorial the reason for this review. I found it a challenging but very rewarding project. The overall quality of papers was so good that it was very difficult to select the necessarily few which space would allow me to review. Inevitably I am influenced by my particular interests, and hence very many excellent papers will not be discussed; failure to discuss a paper is not a reflection on its quality or importance. Criticisms of papers again reflect my own prejudices.

[Transforaminal epidural steroid injection under computed tomography guidance in relieving lumbosacral radicular pain]

OBJECTIVES

We analyzed the efficacy of transforaminal epidural steroid injections under computed tomography (CT) in relieving lumbosacral radicular pain due to spinal stenosis.

METHODS

Forty-two patients (7 males, 35 females; mean age 67 years; range 34 to 90 years) with lumbosacral radicular pain due to spinal stenosis were prospectively monitored following transforaminal epidural steroid injections under computed tomography. Injections were repeated twice in two patients (4.8%) and three times in one patient (2.4%). The severity of pain was assessed with the use of a visual analog scale (VAS) before and after injections (1st day, 1st week, 3rd week, 6th month, and the last follow-up). The mean follow-up period was 12.1 months (range 6 to 25 months).

RESULTS

The median VAS score before injections was 9 (range 6 to 10). During the first six months, the median VAS scores were always significantly lower than the preinjection score (p<0.005). The mean VAS score of 23 patients with a follow-up of at least a year was still significantly lower than that obtained at the end of six months (2.26 vs 2.52, p<0.005). No procedure-related complications occurred.

CONCLUSION

Selective transforaminal epidural steroid and analgesic injection under CT guidance is a safe and reliable conservative method to relieve lumbosacral radicular pain due to spinal stenosis.

Correlation between inter-vertebral disc morphology and the results in patients undergoing Graf ligament stabilisation

BACKGROUND

Previous studies have shown Graf ligament stabilisation procedure to give mixed results in the short to medium term. The aim of this study was to correlate the pre-operative state of the disc, multifidus muscles, age of the patient, levels operated and the clinical outcome after a mean follow-up of 47 months.

METHODS

Graf ligament stabilisation procedure was carried out in 38 patients between 1996 and 1999. Their post-operative status was assessed using MacNab criteria. The post-operative follow-up was by postal questionnaires and review of the clinical notes. Disc morphology and multifidus muscle wasting was graded blindly and independently. The intra- and interobserver reliability was measured with kappa score and classified using the kappa classification of Landis and Koch. Correlation was measured with the help of Spearman correlation coefficient.

RESULTS

Thirty-eight patients (100%) returned the questionnaires. Mean follow-up time was 47.55 months. Fifty-nine levels were operated on. Mean age was 39.68 years. The overall re-operation rate was 15.8%. The intra- and interobserver reliability was graded as good to substantial. Twenty-two patients (57.89%) were satisfied with the procedure. There was no statistically significant correlation between disc morphology, multifidus muscle wasting, sex, age, number of levels operated, the levels operated, and the satisfaction rate.

CONCLUSIONS

The indications of Graf ligament stabilisation procedure are not clear. Further work is necessary to clearly identify the indication for the procedure.

Detection of bacterial DNA in painful degenerated spinal discs in patients without signs of clinical infection

A local inflammatory and potentially painful response, of which the ultimate cause is unknown, has been described in nervous tissues in contact with degenerated disc material in patients with low back and leg pain. With the rationale that a possible cause of such inflammation could be bacterial infection, we utilized PCR (polymerase chain reaction) amplification of the 16S rRNA (ribosomal RNA) gene followed by gene sequencing, to investigate whether bacterial DNA might be detected in the degenerative discs of 10 patients operated for disc herniation or post-discectomy syndrome. One patient with disc hernia harbored DNA homologous to Bacillus cereus, and in one patient suffering from post-discectomy syndrome, Citrobacter braaki/freundii DNA was detected. The finding demonstrates that 16S rRNA PCR can be a useful tool in search of bacterial DNA in degenerated discs, which in turn may be indicative of low-grade infection, manifesting itself only as pain rather than as clinical infection.

Myelopathy due to spinal epidural abscess without cord compression: a diagnostic pitfall

Spinal epidural abscess (SEA) is a neurological emergency that requires urgent diagnosis and treatment. We report 2 patients with SEA, in whom, on neuropathological examination, the neurological signs were found to be caused by spinal cord ischemia due to thrombosis of leptomeningeal vessels and compression of spinal arteries, respectively, while evidence of spinal cord compression was absent. Clinicians and neuropathologists should be aware of the variable mechanisms underlying the neurological involvement in SEA. Absence of spinal cord compression by the abscess may hamper early diagnosis and treatment.

The sensory and sympathetic nerve supply within the cervical spine: review of recent observations

The purpose of this review is to identify recently observed features of the sympathetic and sensory systems and their pathways which characterize cervical spine innervation and their potential relevance to the clinical pain syndromes. The results of studies examining the innervation patterns of the zygoapophysial joints serve to demonstrate that structures in the cervical spine, as in other spinal regions, are partly innervated by sensory nerves traveling along sympathetic pathways. These studies also demonstrate that the neuropeptide levels in the cell bodies located within the dorsal root ganglion of these sensory nerves fluctuate according to the physiological state of the zygoapophysial joint. Additional to the sympathetic nerves accompanying the vertebral artery, the innervation patterns of dura and posterior longitudinal ligament in the upper cervical spine are distinctive features of cervical spine innervation. The possible clinical implications of cervical innervation patterns are considered with reference to referred pain, the pain patterns associated with a dissecting vertebral artery and cervicogenic headaches.

Synovial excrescences and cysts of the spine: clinicopathological features and contributions to spinal stenosis

Synovial cysts occur throughout the body and are generally benign lesions with limited clinical consequences. Juxtafacet cysts of the spine, in contrast, often press on a nerve root as it exits in the foramen, causing radiculopathy. Synovial tissue that emanates from the facet joint but extends medially, is an additional important cause of spinal stenosis. Over the past 5 years, neurosurgeons at our institution have operated on a large number of patients with back pain, with removal of abnormal synovial tissues. Histological examination of these tissues distinguishes the different types of pathologic processes responsible for producing symptoms. Juxtafacet cysts may be either mucin-filled ganglion cysts devoid of cyst lining or true synovial cysts with watery content and lined by synovial cells. Ganglion cysts arise in degenerated ligament at the facet joint, and occasionally within synovial stroma. Synovial cysts arise within synovium and, unlike synovial cysts in the extremities, have a thick wall containing granulation tissue, numerous histiocytes and giant cells. This hyperplastic, irritated synovium of the spine, which we term "synovial excrescences", is voluminous and this reactive part overshadows the cystic portion of the lesion in most instances. Iron pigment deposition and inflammation are mild to absent, making synovial excrescences different from pigmented villonodular synovitis. Synovial excrescences of the spine are an important cause of spinal stenosis, predominantly in elderly patients. Surgical removal of excrescences protruding into the spinal canal provides prompt and durable relief of symptoms, usually without the need for extensive bony laminectomy or spinal fusion. Several patients in our study had both spinal ganglion cysts and synovial excrescences, suggesting common risk factors for both lesions.

Mitomycin C in preventing spinal epidural fibrosis in a laminectomy model in rats

Object. Extensive epidural fibrosis after lumbar surgery may be the underlying cause in most cases of failed—back surgery syndrome. Various materials have been used to prevent epidural fibrosis, but only moderate success has been shown.

Mitomycin C, an alkylosing antibiotic substance isolated from Streptomyces caespitosus, potentially supresses fibroblast proliferation after surgery. In this study, the authors investigated the effect of mitomycin C by local application on spinal epidural fibrosis in a rat laminectomy model.

Methods. Five Wistar rats underwent laminectomy at cervical, thoracic, and lumbar levels. Based on data obtained from ophthalmological studies, mitomycin C was applied to the laminectomy sites in various concentrations (0.01, 0.05, and 0.1 mg/ml). One laminectomy site in each rat was left untreated and thus served as a control. Evoked potentials were measured pre- and postoperatively, and all rats underwent clinical evaluation. Mobility status and evidence of neurological deficit were recorded. Twelve weeks later, the rats were killed, and the spinal column, including surrounding muscle tissue, was removed en bloc, decalcified, and fixed in formaldehyde. Epidural fibrosis was evaluated histologically.

In all mitomycin C—treated laminectomy sites, epidural scarring was significantly reduced compared with control sites. Remarkably, dural adhesions were absent in laminectomy defects treated with mitomycin C concentrations of 0.05 and 0.1 mg/ml. Moderate to marked epidural fibrosis with adhesion to the dura mater was noted at sites receiving 0.01 mg/ml of mitomycin C. All control sites showed dense epidural fibrosis with marked dura adherence.

Conclusions. In this experimental model, mitomycin C applied locally at a concentration of 0.1 mg/ml effectively reduced epidural fibrosis, completely avoided dural adherence, and induced no side effects.