Herniated Disc Material Research Articles

A Concealed Disc Fragment under the Peridural Membrane

A herniated lumbar disc is a very common disease of the spine. However, not all of the disc fragments are located at the expected site. In particular, the ventral epidural space contains many hidden compartments with the potential to hold herniated disc material. We encountered a case of a concealed disc under the peridural membrane, which was very difficult to be identified. The peridural membrane, which is situated below the posterior longitudinal ligament, is a thin glossy membrane surrounding the entire spinal bony canal. The peridural membrane is attached loosely to the median bony septum but not to other part of vertebral body. This potential space between the peridural membrane and bare bone of the vertebral body is called the premembranous space. We report this case to introduce a potential space for disc migration and emphasize the need for a good understanding of the epidural microanatomy.

Contralateral Approach for Far Lateral Lumbar Disc Herniations

A retrospective analysis of 9 patients who underwent a modified surgical procedure for the treatment of far lateral lumbar disc herniations. To illustrate a modified technique for approaching the neural foramen from the contralateral side, minimizing muscle retraction and bone/ligament resection, and to analyze clinical results. The most commonly used surgical techniques for the removal of far lateral lumbar disc herniations are ipsilateral approaches, that require partial or complete facet resection and/or intertransverse ligament resection, which may result in vertebral instability and/or chronic back pain. Nine patients with intraforaminal or intra/extraforaminal lumbar disc herniation underwent surgery using a modified contralateral approach. There was unilateral muscle retraction and no medial facetectomy nor intertransverse/interspinous ligament resection. Preoperative and postoperative Oswestry functional status evaluation and complications were reviewed and Macnab's postoperative categories were assigned to evaluate the efficacy and safety of the surgery. No serious complications were noted. The mean preoperative and postoperative Oswestry scores were 44 and 14 respectively (P < 0.01). Overall excellent-to-good results were 100%. This modified contralateral approach offered a wide exposure of intervertebral foramen region and allowed to remove the herniated disc material with minimal resection of osseous and ligamentous structures. Successful results were achieved in all patients treated by this technique.

Computed tomographic characteristics of acute thoracolumbar intervertebral disc disease in dogs

Forty canine patients with a presumptive diagnosis of the intervertebral disc herniation at the thoracolumbar region were imaged. A neurological examination was performed and all patients were classified under four grades by the examination. The degrees of attenuation of the herniated disc material were measured in Housefield units (HU) in each image. The ratio of the area to herniated disc material and the height to disc material were measured. The clinical grade was correlated with the area ratio of the herniated disc material to the spinal cord, but not correlated with the height ratio of that. In the patients with epidural hemorrhage at surgery, HUs of the herniated disc material was lower than those with no epidural hemorrhage at surgery. Non-contrast computed tomography scans of the spine can be useful in diagnosing acute intervertebral disc disease in chondrodystrophoid breeds, evaluating patient status and identifying concurrent epidural hemorrhage.

2009 in Review

2009 in Review

Inflammatory Reaction in the Herniated Degenerative Disc Materials in Miniature Dachshunds

Histological and immunohistochemical studies were conducted using herniated intervertebral disc materials obtained surgically from 39 miniature dachshunds. Infiltration of inflammatory cells, such as macrophages, neutrophils, T or B lymphocytes, and multinucleated giant cells, were identified in intervertebral disc materials in 23 cases. Furthermore, proliferations of connective tissue, including neovascularization, were also observed in 17 cases. These results suggest that spontaneous regression of herniated intervertebral disc material could occur in affected dogs.

Conservatively treated massive prolapsed discs: a 7-year follow-up

The natural history of a lumbar hernia of the nucleus pulposus (HNP) is not fully known and clear indications for operative intervention cannot be established from the literature. Several studies have shown that the largest discs appear to have the greatest tendency to resolve. The aim of this study was to investigate whether massive prolapsed discs can be safely managed conservatively once clinical improvement has occurred. Thirty-seven patients were studied by clinical assessments and serial magnetic resonance imaging (MRI) over 2 years. Patients had severe sciatica at first, but began to show clinical improvement despite the large disc herniations. Clinical assessment included the Lasegue test and neurological appraisal. The Oswestry Disability Index was used to measure function and changes in function. Serial MRI studies allowed measurement of volume changes of the herniated disc material over a period of time. Initial follow-up at an average of 23.2 months revealed that 83% had a complete and sustained recovery at the initial follow-up. Only four patients required a discectomy. The average Oswestry disability index improved from 58% to 15%. Volumetric analysis of serial MRI scans found an average reduction of 64% in disc size. There was a poor correlation between clinical improvement and the extent of disc resolution. A massive disc herniation can pursue a favourable clinical course. If early progress is shown, the long-term prognosis is very good and even massive disc herniations can be treated conservatively.

A Systematic Review of Mechanical Lumbar Disc Decompression with Nucleoplasty

Lumbar disc prolapse, protrusion, or extrusion account for less than 5% of all low back problems, but are the most common causes of nerve root pain and surgical interventions. The primary rationale for any form of surgery for disc prolapse is to relieve nerve root irritation or compression due to herniated disc material. The primary modality of treatment continues to be either open or microdiscectomy, but several alternative techniques including nucleoplasty, automated percutaneous discectomy, and laser discectomy have been described. There is a paucity of evidence for all decompression techniques, specifically alternative techniques including nucleoplasty. A systematic review of the literature. To determine the effectiveness of mechanical lumbar disc decompression with nucleoplasty. A comprehensive evaluation of the literature relating to mechanical lumbar disc decompression with nucleoplasty was performed. The literature was evaluated according to Cochrane review criteria for randomized controlled trials (RCTs), and Agency for Healthcare Research and Quality (AHRQ) criteria was utilized for observational studies. The level of evidence was classified as Level I, II, or III with 3 subcategories in Level II based on the quality of evidence developed by the United States Preventive Services Task Force (USPSTF). A literature search was conducted using only English language literature through PubMed, EMBASE, the Cochrane library, systematic reviews, and cross-references from reviews and systematic reviews. Pain relief was the primary outcome measure. Other outcome measures were functional improvement, improvement of psychological status, opioid intake, and return to work. Short-term effectiveness was defined as one year or less, whereas, long-term effectiveness was defined as greater than one year. Based on USPSTF criteria the level of evidence for nucleoplasty is Level II-3 in managing predominantly lower extremity pain due to contained disc herniation. Paucity of literature, both observational and randomized. This systematic review illustrates Level II-3 evidence for mechanical lumbar percutaneous disc decompression with nucleoplasty in treatment of leg pain. However, there is no evidence available in managing axial low back pain.

Detection of Residual Disc Hernia Material and Confirmation of Nerve Root Decompression at Lumbar Disc Herniation Surgery by Intraoperative Ultrasound

The aim of lumbar disc herniation surgery is the removal of herniated disc material (HDM) and complete decompression of the nerve root. As some patients present with residual HDM, we examined the ability of intraoperative ultrasound (IOUS) to detect this material. Between February 2006 and June 2007, we used IOUS in 30 patients undergoing surgery for lumbar disc herniation. They were 17 men and 13 women; their ages ranged from 22 to 63 y (mean 44.0 y). The level surgically addressed was L3/4 in 1, L4/5 in 14 and L5/S1 in 15 patients; they were operated in the prone position. After placing a 3–4 cm midline skin incision, partial hemi-semilaminotomy was performed. HDM was removed through a bone window; a surgical microscope was used during the operation. After removal was judged as adequate, IOUS was performed; 17 patients also underwent IOUS before removal of the herniated disc. For the acquisition of IOUS images, we used LOGIQ 9 and 8c microconvex probes (GE Healthcare, Wauwatosa, WI, USA). The normal anatomical structures were well visualized. HDM was iso- to hyperechoic compared with normal nerve tissue. In three of 17 patients, the dural sac and nerve root could not be distinguished from HDM before removal, although in all 30, the decompressed dural sac, intradural cauda equina and nerve root were well visualized. We posit that the echogenicity of nerve tissue was raised due to compression, rendering it similar to that of the herniated disc. In two patients, IOUS detected residual disc material; the surgical procedure was resumed and sufficient removal was accomplished. IOUS monitoring is safe, convenient and inexpensive. It is also highly useful for the detection of residual HDM and the confirmation of adequate nerve root decompression. (E-mail: taoya@sirius.ocn.ne.jp)

Gas-filled intradural cysts of the lumbar spine and the possible pathogenesis

Background context There have only been four reports of gas-filled intradural cysts, and the pathogenesis is unknown. Purpose To document the radiologic and histopathologic features of gas-filled intradural cysts and to discuss the pathogenesis with a review of the literature. Study design Case report. Methods A 67-year-old woman, admitted to our institute, presented with severe right thigh pain. On admission to the institute, enhanced magnetic resonance imaging, showed a cystic lesion in the spinal canal at the L2–L3 level, with an intensity suggesting the presence of gas. An enhanced region around the cyst was noted. Computed tomography after discography also revealed a water-soluble contrast filled the subarachnoid space and area around the cyst, but not inside. Results The cyst was surgically resected. One of the nerve roots was firmly adherent to the gas-filled cyst. The cyst wall comprised fibrous tissue, including small granulations and herniated disc material. Conclusion Gas-filled intradural cysts are rare. The pathogenesis appears to involve gas in a degenerated intervertebral disc, and spontaneous absorption of herniated disc material.

Fracture-associated and idiopathic subchondral vertebral lesions: a magnetic resonance study in autopsy specimens with histologic correlation

The aim of this study was to describe and compare the magnetic resonance (MR) and histological appearance of subchondral vertebral lesions that are idiopathic or that develop with vertebral fractures. T1- and T2-weighted spin-echo images and radiographs were obtained in 81 cadaveric spine specimens. All subchondral vertebral lesions that were considered to be idiopathic or associated with vertebral end plate fractures were selected. Lesions due to growth disturbance were excluded. Radiographs and MR images were analyzed in consensus by two radiologists, and sampled specimens were analyzed by a pathologist. Eleven idiopathic and ten fracture-associated vertebral lesions were available. On T1-weighted images, all lesion signal intensity was low and homogeneous. On T2-weighted images, all idiopathic lesions showed a heterogeneous signal with a central low or intermediate signal component and a peripheral high or intermediate component. All but one fracture-related lesions showed a homogeneous intermediate to high signal intensity. Histological analysis of idiopathic lesions showed a central acellular fibrous connective tissue in all cases surrounded by loose connective tissue in nine cases. Herniated disk material and cartilage metaplasia were found in one lesion only. Fracture-associated lesions contained herniated disk material, necrotic tissue, and loose connective tissue with a peripheral component of loose fibrovascular connective tissue in four cases only. MR and histological appearance of idiopathic and fracture-associated subchondral vertebral lesions differ, suggesting that they might have a different origin.

Le ernie del disco

Disc herniation is a problem frequently found in clinical practice; its treatment involves, for various reasons, most health figures. Although this is not an issue of recent acquisitions, it is still of tremendous relevance; modern diagnostic investigations, while led to a better definition of the relations between the bony and neurologic spinal structures, in some cases have led to the tendency to rely almost exclusively on diagnostic images, ignoring or underestimating the importance of the predominant clinical findings. This has led to the development of methods of treatment which have proven ineffective over time, with no validity and then quickly abandoned. The natural history of lumbar disk herniation reveals that large herniations typically reabsorb with time, and symptoms will improve in most patients with conservative management alone. Most patients with lumbar disk herniations have symptoms improvement with conservative management during a 4–6-week period. However, imaging and invasive procedures may be considered if symptoms persist after 4–6 weeks or if neurologic function worsens. When the anatomic level of disk herniation on imaging studies correlates with physical findings of nerve root irritation at the same level, and when the result of a straight-leg raise test is positive, surgical diskectomy may lead to symptom improvement or resolution more quickly than continued conservative management. The goal of surgery is to relieve nerve root compression or irritation from herniated disk material. The success of the treatment of disc herniation is not possible without a thorough clinical evaluation and a careful selection of patients and a fair indication remain the basic elements from which — rather than a surgical technique — depend on the success of treatment.

P185. A Therapeutic Trial of Saline Injection as an Alternative Treatment for Disc Herniation

BACKGROUND CONTEXT: Since 1997 we have forcibly injected 4∼5ml of normal saline into the symptomatic disc. We believe this procedure could be done by the release of pressure within the disc, movement of herniated disc material, wash out chemical substances that caused irritation of nerve roots and acceleration of absorption of herniated mass.

Lumbar Cerebrospinal Fluid in Dogs with Type I Intervertebral Disc Herniation

Cerebrospinal fluid (CSF) in dogs with Hansen type I intervertebral disc herniation (IVDH) is classically described as normal or mildly inflammatory with a predominance of large mononuclear cells or neutrophils in severe acute herniations. However, we have observed a moderate to marked pleocytosis with a predominance of lymphocytes in some dogs with IVDH. Moderate to marked CSF pleocytosis occurs more commonly in dogs with type I IVDH than is reported in the literature. Lymphocytic predominance is more common than nonlymphocytic pleocytosis in dogs with chronic IVDH. Four hundred twenty-three client-owned dogs with type I IVDH. Retrospective study. Lumbar CSF of dogs with surgically confirmed type I IVDH was evaluated cytologically. Information obtained from medical records included signalment, prior clinical history, time from onset of signs to presentation, neurologic status, and intraoperative findings. Dogs with prior history and/or intraoperative evidence consistent with chronic IVDH before an acute herniation were termed acute-on-chronic (AOC). Pleocytosis (> 5 cells/uL) was present in 51% of dogs, including 23% with cervical IVDH and 61% with thoracolumbar IVDH. Moderate or marked inflammation (> or = 20 cells/uL) was identified in the CSF of 51% of dogs with thoracolumbar IVDH and pleocytosis. A predominance of lymphocytes was significantly more common in dogs examined > 7 days from onset of signs (P= .032) and in dogs with AOC IVDH (P= .0013). Moderate to marked CSF pleocytosis in dogs with type I IVDH is more common than previously reported. Lymphocytic pleocytosis is most common in dogs with chronic progression or AOC IVDH. Lymphocytic inflammation in the CSF of some dogs might suggest an immune-mediated response to chronically herniated disc material.

Influence of Intervertebral Disc Fenestration at the Herniation Site in Association with Hemilaminectomy on Recurrence in Chondrodystrophic Dogs with Thoracolumbar Disc Disease: A Prospective MRI Study

To describe the influence of fenestration at the disc herniation site on recurrence in thoracolumbar disc disease of chondrodystrophoid dogs. Prospective clinical study. Chondrodystrophic dogs (n=19). Dogs were divided into 2 groups: group 1 (9 dogs) had thoracolumbar disc extrusion (Hansen type I) treated by hemilaminectomy and concomitant fenestration of the affected intervertebral disc and group 2 (10 dogs) had hemilaminectomy without fenestration. All dogs had 3 magnetic resonance imaging (MRI) examinations: preoperatively, immediately postoperatively to assess removal of herniated disc material, and again 6 weeks after surgery. There were 13 male and 6 female dogs; mean age, 7.1 years. Thoracolumbar disc herniation was confirmed with MRI. Immediate post surgical MRI revealed that the herniated disc removal was complete in all but 1 dog and that fenestration did not lead to complete removal of nucleus pulposus within the intervertebral disc space. On the 3rd MRI examination, none of the group 1 dogs had further disc material herniation at the fenestrated site. Six of the 10 group 2 dogs had a recurrence of herniation leading to clinical signs in 3 dogs (pain in 2 dogs, paresis in 1 dog). In thoracolumbar disc herniation, fenestration of the affected intervertebral disc space prevents further extrusion of disc material. Fenestration reduces the risk of early recurrence of disc herniation and associated postoperative complications.

Prospective evaluation of transabdominal percutaneous lumbar discectomy for L5–S1 disc herniation: initial clinical experience

Anterior approaches to the lumbosacral spine have become an increasingly common procedure in spine surgery, but transabdominal percutaneous lumbar discectomy (TPLD) performed anteriorly under fluoroscopic guidance is challenging. In this study the authors describe the TPLD and evaluate its safety and early clinical results in the management of L5-S1 disc herniation. Between January 2005 and June 2007, 30 consecutive patients with L5-S1 disc herniation were treated with L5-S1 TPLD. All procedures were performed with the patient in a state of local anesthesia. After bowel preparation, the hypogastrium was compressed to move the intestinal canal away from the puncture site. The TPLD was then performed with fluoroscopic guidance to remove herniated disc material. Patients were evaluated prospectively using the visual analog scale (VAS) and the Oswestry Disability Index (ODI) during <or= 30 months of follow-up. The mean hospital stay was 6.7 days. Scores on the VAS for leg pain (preoperative mean score 7.10, postoperative mean score 0.93) and the ODI (preoperative mean index 62.03, postoperative mean index 10.33) were statistically significantly (p=0.00) improved at the last follow-up examination compared with preoperative scores. All members of the study group showed favorable results. On the day after the procedure pancreatitis developed in 1 patient but was cured by fasting and intravenous nutrition with antibiotics for 7 days. No other complications occurred during the follow-up. Transabdominal percutaneous lumbar discectomy is a safe, effective, and minimally invasive procedure for the treatment of disc herniations at the L5-S1 level.

A minimally invasive technique for L5–S1 intraforaminal disc herniations: microdiscectomy with a tubular retractor via a contralateral approach

Surgical treatment of intraforaminal disc herniations at the L5-S1 level is technically demanding. The 2 most commonly used procedures involve either a medial or lateral ipsilateral approach and often require a partial or even complete facet resection, which may in turn result in vertebral instability and/or back pain, as well as, in some cases, a fusion or stabilization procedure. In this report, the authors present a new minimally invasive technique for the treatment of L5-S1 intraforaminal disc herniations. Using this technique, which involves tubular retractors and an operative microscope to approach the neural foramen from the contralateral side, the authors could easily visualize and remove the herniated disc material and perform a thorough microdiscectomy with minimal resection of osseous and ligamentous structures. To illustrate this new minimally invasive technique for the treatment of intraforaminal disc herniations at L5-S1, they describe the cases of 2 patients who underwent the procedure and in whom successful results were achieved.

Deep venous thrombosis after lumbar disc surgery due to compression of the vena cava caused by a retroperitoneal haematoma

The case of a 46-year-old Arabian male complaining of low back pain due to congenital lumbar spinal canal stenosis with additional disc herniation is presented. Following CT scan and MRI, bilateral enlarged partial hemilaminectomy was performed in L5/S1 with removal of herniated disc material. Intraoperatively, no complication was encountered. In the postoperative course, the patient had persistent low back pain and developed deep venous thrombosis in the left leg. Phlebography revealed thrombosis in the deep veins of the left leg extending into the pelvic region. The source of this high obstruction of the venous outflow was a retroperitoneal haematoma, visible on CT scan, compressing the vena cava at the level of L5/S1, the most probable cause of which was accidental perforation of the anterior spinal ligament. This case demonstrates that injury to the retroperitoneal vessels during lumbar disc surgery can also present as deep venous thrombosis due to obstruction of venous outflow.

Thoracic Disk Herniation With Hematoma -Case Report-

A 54-year-old man presented with an extremely rare case of intervertebral disk herniation with hematoma in the thoracic spine, manifesting as acute progressive numbness and muscle weakness in the bilateral lower extremities. He had been treated with anticoagulants. Magnetic resonance imaging of the thoracic spine showed intervertebral disk herniation and severe compression of the spinal cord at T9-10, appearing as hyperintense on T(1)- and hypointense on T(2)-weighted imaging suggestive of concomitant hematoma. His symptoms completely resolved after resection of the brownish herniated disk material. Old hemorrhage was also aspirated from the intervertebral disk space. Hemosiderin deposition was found in the cartilaginous tissue of the resected disk. Intervertebral disk herniation with hematoma is extremely rare, but may occur in patients with bleeding diathesis.

Discal Cyst Associated with Myxoid Change and Apoptosis of Herniated Disc Materials

Discal cyst is a lumbar intraspinal cyst communicating with intervertebral disc, and previously reported series described the wall of these cysts as consisting of dense fibrous connective tissue. We report a 29-year-old Japanese male with discal cyst showing unusual histological features. Clinical symptoms in the current case as well as imaging features including discography were similar to those previously reported. However, the wall of the cyst consisted of disc material with myxoid degeneration. In addition, apoptosis of chondrocytes was diffusely observed in the herniated disc material. The current case was considered a histological variant of discal cyst. Myxoid degeneration of herniated disc material with diffuse apoptotic change of chondrocytes was probably associated with the formation of discal cyst.Intraspinal cysts with a distinct connection to the corresponding intervertebral disc has been called discal cyst [1]. To clarify the location of this lesion, Coscia and Broshears in 2002 introduced the term “intracanalicular discal cyst” [2]. In the largest series of this condition, Chiba et al. reported that the wall of the discal cyst consisted of dense fibrous connective tissue [1]. We recently encountered a case showing typical clinical and imaging features of discal cyst, but its histological findings differed from those of previous reports. This study describes a case showing unusual histological features of discal cyst, and discusses its pathogenesis. All protocols were accepted by the Institutional Review Board at our institution. Informed consent was obtained from the patient.

MR Imaging Findings of a Sequestered Disc in the Lumbar Spine: A Comparison with an Extruded Disc

Purpose: To compare the MR findings of a sequestered disc with an extruded disc. Materials and Methods: MR images of 28 patients with a sequestered disc and 18 patients with an extruded disc were retrospectively reviewed. Patients with sequestered discs were divided into two groups whether definite separation from the parent disc was or was not seen. In the latter group (definite separation not seen) and the extruded disc group of patients, the signal intensities of the herniated discs were compared with the signal intensities of the parent discs and were evaluated on T1- and T2-weighted images. We also assessed the presence of a notch within the herniated disc. Results: In the sequestered disc group of patients (28 discs), only 5 discs (18%) showed obvious separation from the parent disc. Among the remaining 23 discs with indefinite separation, the notch was visible in 14 discs (61%) and 9 discs (39%) had no notch. In the extruded disc group (18 discs), the notch was visible in 2 (11%) discs and the difference between the two groups was statistically significant (p = 0.0002). The signal intensities of the herniated discs on T1-weighted images were isointense in both the sequestered and extruded discs. The difference of incidence of high signal intensities on T2-weighted images was not statistically significant (p = 0.125). Conclusion: It is necessary to consider the possibility of the presence of a sequestered disc when a herniated disc material shows a notch.