KLF5 promotes the ossification process of ligamentum flavum by transcriptionally activating CX43

BACKGROUND

Ossification of ligamentum flavum (OLF) is a prevalent degenerative spinal disease, typically causing severe neurological dysfunction. Kruppel-like factor 5 (KLF5) plays an essential role in the regulation of skeletal development. However, the mechanism KLF5 plays in OLF remains unclear, necessitating further investigative studies.

METHODS

qRT-PCR, immunofluorescent staining and western blot were used to measure the expression of KLF5. Alkaline Phosphatase (ALP) staining, Alizarin red staining (ARS), and the expression of Runt-related transcription factor 2 (RUNX2), osteopontin (OPN), and osteocalcin (OCN) were used to evaluate the osteogenic differentiation. Luciferase activity assay and ChIP-PCR were performed to investigate the molecular mechanisms.

RESULTS

KLF5 was significantly upregulated in OLF fibroblasts in contrast to normal ligamentum flavum (LF) fibroblasts. Silencing KLF5 diminished osteogenic markers and mineralized nodules, while its overexpression had the opposite effect, confirming KLF5's role in promoting ossification. Moreover, KLF5 promotes the ossification of LF by activating the transcription of Connexin 43 (CX43), and overexpressing CX43 could reverse the suppressive impact of KLF5 knockdown on OLF fibroblasts' osteogenesis.

CONCLUSION

KLF5 promotes the OLF by transcriptionally activating CX43. This finding contributes significantly to our understanding of OLF and may provide new therapeutic targets.

The biomechanical effect of different types of ossification of the ligamentum flavum on the spinal cord during cervical dynamic activities

Ossification of the ligamentum flavum (OLF) is thought to be an influential etiology of myelopathy, as thickened ligamentum flavum causes the stenosis of the vertebral canal, which could subsequently compress the spinal cord. Unfortunately, there was little information available on the effects of cervical OLF on spinal cord compression, such as the relationship between the progression of cervical OLF and nervous system symptoms during dynamic cervical spine activities. In this research, a finite element model of C1-C7 including the spinal cord featured by dynamic fluid-structure interaction was reconstructed and utilized to analyze how different types of cervical OLF affect principal strain and stress distribution in spinal cord during spinal activities towards six directions. For patients with cervical OLF, cervical extension induces higher stress within the spinal cord among all directions. From the perspective of biomechanics, extension leads to stress concentration in the lateral corticospinal tracts or the posterior of gray matter. Low energy damage to the spinal cord would be caused by the high and fluctuating stresses during cervical movements to the affected side for patients with unilateral OLF at lower grades.

Degeneration of the lumbar spine and its relation to the expression of collagen and elastin in facet joint capsules and ligament flavum

Objective:

The aim of the study was to assess the relationship between the expression of elastin, collagen type I, II,III and the degeneration of the facet joint capsule and the ligamentum flavum.

Methods:

10 patients (4 male, 6 female) (mean age 61 ± 14,9) undergoing surgery for degenerative lumbar spine syndrome and 5 cadavers (3 male, 2 female) (age of death 87 ± 8,6 years) were included in this study. One set of tissue samples was taken from each patient in the patient group intraoperatively and two sets of samples were taken from each cadaver in the cadaver group posthumosly from the ligamentum flavum (medial and lateral) and from the facet joint capsules (superior and inferior articular process) at the L4/5 segment.Western blot analysis was performed for collagen types I, II, III and for elastin. Disc degeneration was scored according to the Pfirmann Classification, facet joint arthrosis was scored according to the Fujiwara Classification and their relationship with protein expression was investigated.

Results:

There was a strong expression of Collagen type I in the patient group (PG) compared to the body donor group (BDG) in the facet joint capsule (FJC) and in the lateral samples of the ligamentum flavum. Samples of the FJC showed lower expression of elastin in the PG compared with the BDG, but without statistical significance. An increased expression of collagen type I compared to elastin in the PG could be shown. In contrast, elastin predominated in the samples of the BDG group compared to collagen type I (collagen type I/ elastin PG: PAsup 2,78; PAinf 2,61; LFmed 2,23; 225 LFlat 1,83; BDG: PAsup 0,15; PAinf 0,2; LFmed 0,2; LFlat 0,27). Rank correlation coefficient according to Spearman showed low to moderate correlations for collagen type I, III and elastin for the degree of disc degeneration according to Pfirrmann and the degree of facet joint osteoarthritis according to Fujiwara, all of them without statistical significance.

Conclusion:

This study has shown us that in the context of degenerative changes of the lumbar spine, there is an increased expression of collagen type I and a dominance over elastin.

Level of Evidence:

Level III, Diagnostic Study

Percutaneous Endoscopic Interlaminar Lumbar Discectomy with Local Anesthesia for L5-S1 Disc Herniation: A Feasibility Study

BACKGROUND

General anesthesia (GA), which is routinely applied in patients who undergo percutaneous endoscopic interlaminar lumbar discectomy (PEILD) of L5-S1 disc herniation, is closely associated with postoperative cognitive dysfunction (POCD) in the elderly. Local anesthesia (LA) is an alternative pain control protocol that has not yet been fully evaluated.

OBJECTIVES

To evaluate the feasibility of LA in PEILD compared with GA.

STUDY DESIGN

A retrospective study.

SETTING

This study took place at the First Affiliated Hospital of Harbin Medical University.

METHODS

A total of 120 patients (aged 60-85 years) diagnosed with L5-S1 disc herniation and with American Society of Anesthesiologists fitness grade I or II between March 2016 and August 2017 were enrolled in the current study. Patients were randomly divided into LA group and GA group. For LA, 0.25% lidocaine was injected layer-by-layer into skin, subcutaneous tissue, fasciae, lumbar facet joint, muscle, and ligamentum flavum followed by injection of 1.33% lidocaine into epidural space; for GA, propofol, sufentanil, and cisatracurium were infused intravenously at 1 to 2 mg/kg, 0.3 µg/kg, and 0.15 mg/kg, respectively. Visual Analog Scale (VAS), Oswestry Disability Index (ODI), and MacNab Criteria (MNC) evaluated the feasibility of LA as pain control protocol in comparison to GA before and after operation. The development of POCD was assessed by the Mini-Mental State Examination 1 and 7 days postsurgery. Feasibility of LA as a pain control protocol was also evaluated by patient's willingness to receive the same surgical procedure immediately and 24 hours after the surgery, and intraoperative fluoroscopy use, blood loss, surgery duration, postoperative bed confinement, and duration and cost of hospital stay were also evaluated.

RESULTS

Patients in both LA and GA groups had comparable VAS grade, ODI, and MNC pre- and post-PEILD, with significant pain reduction after operation. However, POCD developed only in GA group but not in LA group. In addition, compared with GA, LA group did not require postoperative bed confinement, had significantly shorter hospital stay, and lower hospital cost. Low intraoperative VAS grade and willingness to receive the same procedure reflected the acceptance of LA by patients.

LIMITATIONS

The development of POCD was examined only 7 days after operation. The follow-up should be extended to 3 months and 2 years postoperation.

CONCLUSIONS

LA has satisfactory pain control and low-risk of POCD in PEILD and is well accepted by patients. The benefits of LA are no postoperative bed confinement, faster recovery, shorter hospital stay, and lower hospital cost.

KEY WORDS

L5-S1 disc herniation, older patients, percutaneous endoscopic interlaminar lumbar discectomy, local anesthesia, general anesthesia, postoperative cognitive dysfunction, American Society of Anesthesiologists grade, Oswestry Disability Index, MacNab Criteria, Mini-Mental State Examination.

An histopathological description

INTRODUCCIÓN

Los cambios en el ligamento flavum (LF) relacionados con la degeneración son secundarios al proceso de envejecimiento o a la inestabilidad mecánica. Estudios anteriores han indicado que LF con envejecimiento muestra pérdida de fibras elásticas y aumento del contenido de colágeno, la pérdida de elasticidad puede hacer que el LF se pliegue en el canal espinal, disminuyendo su espacio.

MATERIAL Y MÉTODOS

Se incluyeron 67 pacientes operados de estenosis lumbar espinal (LSS), hernia de disco lumbar (LDH) y espondilolistesis degenerativa (LDS). Se obtuvieron muestras de LF de pacientes que tenían LSS (39), LDH (22) y LDS (6). Se examinaron especímenes con respecto a metaplasia condroide, calcificación, fragmentación de fibras de colágeno, degeneración quística, apariencia fibrilar e hipercelularidad.

RESULTADOS

Los cambios histopatológicos más frecuentes fueron la hialinización y la fragmentación de las fibras de colágeno (34%), neovascularización en 40.3%, y la disposición irregular de las fibras elásticas es el cambio más frecuente con 56.7% del total de muestras. Existe una diferencia en la presencia de cambios en el LF, de acuerdo con el diagnóstico, siendo estadísticamente significativo para la fragmentación de las fibras de colágeno (p = 0.045), la degeneración quística (p = 0.001), la apariencia fibrilar (p = 0.007) y la hipercelularidad (p = 0.005) todos ellos, siendo más frecuentes en el grupo LDS. El grupo LHD presentó fragmentación de las fibras de colágeno en 45.5% (p = 0.045) y la apariencia fibrilar en 4.5% (p = 0.009).

CONCLUSIONES

No hay evidencia de hipertrofia celular en los análisis histopatológicos, el engrosamiento del LF se puede ver por abultamiento del mismo, seguido de colapso del segmento de movimiento.

Optically Guided Epidural Needle Placement Using 405-nm Wavelength for Accurate Puncture

Several approaches of locating the epidural space have been proposed. However, loss of Resistance method (LOR) remains the most common method for epidural anesthesia. Different optical signals were received from the ligamentum flavum and the epidural space allows operator to pinpoint position of the needle and determine whether the needle tip has entered the epidural space. Optical signals throughout the penetration process was recorded and position of needle tip was confirmed with a C-arm fluoroscopy. 60 lumbar punctures were performed in 20 vivo porcine models, and success rate of locating the epidural space with the optical auxiliary is calculated statistically. The data are expressed in mean ± SD. During all the lumber puncture processes, the strength of optical signals received decreased significantly while the needle tip penetrates the ligamentum flavum and entered the epidural space. The strength of optical signal received when needle tip was in the ligamentum flavum was 1.38 ± 0.57. The signal strength at epidural space was 0.46 ± 0.35. Strength of signal decreased by 67% when entered epidural space, and there is no significant differences in decrease of strength from data obtained from thevertebrae (lumbar segments)L2-L3, L3-L4, and L4-L5. Finally, we calculated with assistance of the proposed optical auxiliary, the success rate for guiding the needle tip to the epidural space using was as high as 87%. It is evidently believed that the optical auxiliary equipped is visualized to assist operators inserting needle accurately and efficiently into epidural space during epidural anesthesia operation.

Ex vivo animal-model assessment of a non-invasive system for loss of resistance detection during epidural blockade

During recent decades epidural analgesia has gained widespread recognition in many applications. In this complex procedure, anaesthetist uses a specific needle to inject anesthetic into the epidural space. It is crucial the appropriate insertion of the needle through inhomogeneous tissues placed between the skin and the epidural space to minimize anesthetic-related complications (e.g., nausea, headache, and dural puncture). Usually, anaesthetists perform the procedure without any supporting tools, and stop pushing the syringe when they sense a loss of resistance (LOR). This phenomenon is caused by the physical properties of the epidural space: the needle breaks the ligamentum flavum and reaches the epidural space, in this stage the anaesthetist perceives a LOR because the epidural space is much softer than the ligamentum flavum. To support the clinician in this maneuver we designed a non-invasive system able to detect the LOR by measuring the pressure exerted on the syringe plunger to push the needle up to the epidural space. In a previous work we described the system and its assessment during in vitro tests. This work aims at assessing the feasibility of the system for LOR detection on a more realistic model (ex vivo pig model). The system was assessed by analyzing: its ability to hold a constant value (saturation condition) during the insertion of the needle, and its ability to detect the entrance within the epidural space by a decrease of the system's output. Lastly, the anaesthetist was asked to assess how the ex vivo procedure mimics a clinical scenario. The system reached the saturation condition during the needle insertion; this feature is critical to avoid false positive during the procedure. However, it was not easy to detect the entrance within the epidural space due to its small volume in the animal model. Lastly, the practitioner found real the model, and performed the procedures in a conventional manner because the system did not influence his actions.

Case series on variable presentation of ligamentum flavum stimulation following percutaneous cylindrical spinal cord stimulator lead implants

BACKGROUND

Stimulation-evoked discomfort secondary to ligamentum flavum stimulation (LFS) is a technological limitation of percutaneous spinal cord stimulator (SCS) lead implants. There is a paucity of literature describing the clinical presentation and time periods at which this side effect may present following insertion of cylindrical lead(s).

OBJECTIVE

To describe a series of 5 patients who presented at varying time periods after SCS lead placement with LFS.

STUDY DESIGN

Retrospective case series.

METHODS

We performed a chart review of online medical records of patients with symptoms consistent with LFS at an academic interventional pain clinic identified over 7 consecutive years (2006 - 2013).

RESULTS

LFS most frequently presented within months of implantation of cylindrical leads. One patient complained of LFS during the temporary trial while another developed LFS after lead revision. All patients were successfully treated when paddle electrodes replaced percutaneous cylindrical leads.

CONCLUSION

LFS may present as a barrier to successful SCS treatment. Clinicians placing percutaneous SCS leads should be aware of the variable time course of LFS presentation. Paddle style electrodes seem to offer an enduring solution to LFS so that patients may continue to benefit from SCS therapy.

Increased bone mineral density in patients with ossification of the ligamentum flavum: a case-control study

The present study investigated the bone mineral density (BMD) and the prevalence of osteoporosis in an ossification of the ligamentum flavum (OLF) patient group and a matched control group. We also investigated the correlation of BMD with the number of spine levels exhibiting OLF. From January 1999 to August 2012, 120 patients with spinal OLF underwent dual-energy X-ray absorptiometry at our institute, and 102 of those were included in our study. Control group members were age, sex, and body mass index (BMI) matched to OLF group members on a 1:1 basis. Age, sex, and BMI were similar in the OLF and control groups. BMDs of the OLF and control groups were significantly different in the lumbar spine (mean T-scores: -0.2 ± 1.5 and -0.7 ± 1.5, respectively; p = 0.03). The prevalences of osteopenia and osteoporosis tended to be lower in the OLF group (28.3% and 4.0%, respectively) than those in the control group (31.3% and 9.1%, respectively); however, the differences were not statistically significant (p = 0.41). A significant positive correlation was detected between the lumbar spine BMD and the number of spine levels exhibiting OLF (p = 0.03).

Thoracic myelopathy due to calcification of the ligamentum flavum with hyperproteinorachia and responsive to steroid therapy: case report

Calcification and ossification of the ligamentum flavum or of the posterior longitudinal ligament are causes of compressive myelopathy, more frequent in the lower thoracic levels, and extremely rare in Western populations. Surgical decompression is the only therapy, but the disease is usually progressive, and its recurrence after surgery is common. Inflammatory mediators might play a role in the progression of compressive myelopathy, but, to our knowledge, the therapeutic approach involving anti-inflammatory agents has never been tried before. We report a case of compressive myelopathy due to calcification of the ligamentum flavum, in which hyperproteinorachia and response to steroid therapy have been observed. Those data have not been published before and might provide new ideas for the disease understanding.

The pathophysiology and nonsurgical treatment of lumbar spinal stenosis

Lumbar spinal stenosis, which affects an ever-increasing number of patients, is best defined as a collection of clinical symptoms that includes low back pain, bilateral lower extremity pain, paresthesias, and other neurologic deficits that occur concomitantly with anatomic narrowing of the neural pathway through the spine. The narrowing may be centrally located in the spinal canal or more laterally in the lateral recesses or neuroforamina. Lumbar spinal stenosis can have a congenital or acquired etiology, and the origin of acquired lumbar stenosis is classified as degenerative, posttraumatic, or iatrogenic. In degenerative lumbar stenosis, the anatomic changes result from a cascade of events that includes intervertebral disk degeneration, facet joint arthrosis, and hypertrophy of the ligamentum flavum. The altered biomechanical characteristics of the spinal segment perpetuate a cycle of degenerative changes, and the resulting stenosis produces radicular pain through a combination of direct mechanical compression of nerve roots, restriction of microvascular circulation and axoplasmic flow, and inflammatory mediators. The initial treatment of lumbar spinal stenosis is nonsurgical. The most effective nonsurgical treatment is a comprehensive combination of oral anti-inflammatory drugs, physical therapy and conditioning, and epidural steroid injections. A significant number of patients improve after nonsurgical treatment, although most studies have found that patients treated surgically have better clinical results. Delaying surgical treatment until after a trial of nonsurgical treatment does not affect the outcome. Surgical intervention should be considered only if a comprehensive program of nonsurgical measures fails to improve the patient's quality of life.

Acute Hemorrhagic Cyst of the Ligamentum Flavum

STUDY DESIGN

A case report and clinical discussion.

OBJECTIVE

To describe a rare complication of a cyst of the ligamentum flavum, which bled spontaneously, provoking an acute lower limb monoparesis and lumbar sciatic pain. SUMMARY OF BACKGROUNDS DATA: Cysts of the ligamentum flavum have been rarely reported. Intraspinal degenerative cysts described in literature are usually juxta-articular (synovial and ganglion) cysts and have a similar radiologic appearance. They are preferentially located in the lumbar spine, while the cervical localization is unusual. Hemorrhage into the cyst is an uncommon complication and an extremely rare cause of nerve root compression.

METHODS

A 59-year-old woman presented with sudden severe radicular lumbar deficit and pain secondary to acute hemorrhage into a ligamentum flavum cyst. Magnetic resonance imaging showed at L3-L4 level a lobulated slightly hyperintense mass with a ventral area of marked hyperintensity in T1 images, hypointense on T2 images. Signal within the lesion was suggestive of intralesional hemorrhage.

RESULTS

Complete resection of the lesion was performed, resulting in immediate recovery. The cyst was quite rounded, brownish, and contained rest of both partially fresh and coagulated hematoma. Histologic examination revealed myxoid degeneration of the ligamentum flavum with an hemorrage in the cystic cavity without a synovial layer.

CONCLUSIONS

This report identifies a rare case of radicular lumbar deficit and pain secondary to acute hemorrhage into a ligamentum flavum cyst. The pathogenesis and clinicopathologic characteristics of this lesion are described.

Surgery for thoracic myelopathy caused by ossification of the ligamentum flavum

BACKGROUND

Ossification of the ligamentum flavum overlying the lower thoracic spine frequently produces myelopathy. This study analyzed the postoperative outcomes after decompressive laminectomy for thoracic OLF.

METHODS

We retrospectively studied 13 patients (10 male, 3 female; mean age, 58 years; range, 39-69). The mean follow-up duration was 66 months (range, 21-107). All patients had undergone decompressive laminectomy and excision of the OLF. The clinical course was evaluated according to the Frankel grading system and JOA scores. The number of vertebral segments demonstrating OLF, the most frequent level of thoracic cord involvement, and spine lesions coexisting with OLF were determined by MR imaging.

RESULTS

By the Frankel system, 7 of 13 patients improved by one grade, whereas the others, classified as grade D, were unchanged after surgery. Using the JOA score, the functional improvement was excellent in 3 patients, good in 4, fair in 2, and unchanged in 4. The number of vertebral segments demonstrating OLF included 4 levels in 2 patients, 3 levels in 2 patients, 2 levels in 5 patients, and 1 level in 4 patients. Ossification of the ligamentum flavum occurred most frequently at the T10/T11 level. Tandem cervical and lumbar lesions were present in 6 patients.

CONCLUSIONS

Decompressive laminectomy for excision of OLF resulted in clinical improvement using the Frankel grading system in 7 of 13 patients. In myelopathy patients with OLF, preoperative MR imaging of the entire spine is necessary because other coexisting spinal lesions may be present.

Results of surgical treatment for thoracic myelopathy: minimum 2-year follow-up study in 132 patients

Object

Thoracic myelopathy is uncommon compared with cervical myelopathy. In this study, data obtained in patients with thoracic myelopathy caused by degenerative processes of the spine were retrospectively analyzed to clarify the surgical outcomes and to examine the various factors affecting the postoperative improvement.

Methods

Between 1988 and 2002, 132 patients with thoracic myelopathy underwent surgery and a minimum 2-year observation period. Clinical data were collected from medical and operative records, and sagittal alignment of the spine was measured on radiographs. The patients were evaluated pre- and postoperatively using the modified Japanese Orthopaedic Association (JOA) scale (maximum score 11). The relationships among various factors affecting the preoperative severity of myelopathy and postoperative improvement were also examined.

Results

The population consisted of 97 men (mean age at surgery was 58 years) and 35 women (mean age at surgery 62 years). Myelopathy was caused by ossification of the ligamentum flavum (OLF) in 73 patients, ossification of the posterior longitudinal ligament (OPLL) in 21, combined OLF–OPLL in 10, intervertebral disc herniation (IDH) in 15, posterior bone spur in 11, and OLF with IDH or posterior bone spur in one patient each. The surgical outcome was relatively good: a mean preoperative JOA score of 5.3 improved to a mean score of 7.8 at the last follow-up, 50 months on average after surgery. Thoracic myelopathy caused by OPLL, however, was associated with lower postoperative scores and recovery rates. In more than half of the patients the authors documented an increase of kyphosis of less than 2°.

Conclusions

Patients with a shorter preoperative duration of symptoms and milder myelopathy experienced significantly better postoperative neurological conditions, which indicated that those who present earlier with fewer disabilities should be recommended to undergo surgery in time, although the surgical treatment for OPLL still involves many problems.

Symptomatic hematoma of cervical ligamentum flavum: case report

STUDY DESIGN

A case of symptomatic hematoma of cervical ligamentum flavum.

OBJECTIVE

To report the first ligamentum flavum hematoma in the cervical spine and review the reported cases.

SUMMARY OF BACKGROUND DATA

A herniated nucleus pulposis, spondylosis, epidural hematoma or abscess, neoplasm, or some pathology of the ligamentum flavum, such as hypertrophy, ossification, or calcification, are the most common causes of spinal cord and nerve root compression. A ligamentum flavum hematoma has also been reported as a cause of compression of the cauda equina and lumbar nerve roots but has never been found in the cervical spine.

METHODS

A 72-year-old man presented with left upper arm pain and left hemiparesis following traditional massage therapy. Admission magnetic resonance images showed a posterior oval-shaped mass that was continuous with the ligamentum flavum at C3-C4 level.

RESULTS

A C3-C4 laminectomy for decompression and resection of the lesion was performed. One year after surgery, the patient remained neurologically intact and symptom-free.

CONCLUSIONS

Hematoma of the ligamentum flavum occurring in the cervical spine has never been reported previously. Repeated trivial injury on a degenerative ligamentum flavum might be the leading predisposing factor. Spine surgeons should be aware of a hematoma in the ligamentum flavum as a possible cause of spinal cord or root compression, especially in the mobile cervical and lumbar spine.

Cyst of the Ligamentum Flavum-Case Report-

An 86-year-old man presented with intermittent claudication caused by a cyst of the ligamentum flavum. Lumbar magnetic resonance imaging demonstrated an extradural cystic mass at the L5-S1 intervertebral space and canal stenosis at the L4-5 space. L-5 laminectomy and flavectomy at the L4-5 and L5-S1 spaces were performed, and the cystic mass was excised. The histological features were consistent with cyst of the ligamentum flavum. The histological diagnosis was ganglion cyst of the ligamentum flavum. After surgery, claudication completely disappeared and the patient made a good recovery.

Ligamentum Flavum Hematoma in the Lumbar Spine-Case Report-

A previously healthy 45-year-old woman presented with ligamentum flavum hematoma manifesting as radicular leg pain. Neurological examination findings were consistent with L-5 root compression. An old hematoma inside the degenerated ligamentum flavum was drained. The cyst showed no connection to the facet joint. Complete resection of the mass was performed, resulting in excellent pain relief. The most common cystic lesion in the lumbar spine is synovial cyst associated with the facet joints, but ligamentum flavum hematoma should be included in the differential diagnosis. The preoperative diagnosis can be based on computed tomography and magnetic resonance imaging findings of degenerative thickening of the ligamentum flavum associated with a fluid component.

Sagittal splitting laminoplasty for spinal canal enlargement for ossification of the spinal ligaments (OPLL and OLF)

Patients have been followed up radiologically after sagittal splitting laminoplasty (SSL) for ossification of the posterior longitudinal ligament (OPLL) and ligamentum flavum. The enlarged spinal canal was maintained satisfactorily in all the cases, and the posterior spinal elements were also almost completely restored. In most cases, the range of the vertebral motion was good with more than 50% of the preoperative status. Postoperative instability of the vertebral column was not identified in any case. Mild cervical kyphosis was noted in 6% of cervical OPLL patients. There were no patients with neurological deterioration. Using SSL, reconstruction and restoration of the posterior spinal elements and retention of the enlarged spinal canal were accomplished safely and adequately.

Spinal cord and cauda equina compression in 'DISH'

Diffuse idiopathic skeletal hyperostosis (DISH) has long been regarded as a benign asymptomatic clinical entity with an innocuous clinical course. Precise information is lacking in the world literature. Authors report the results of a retrospective analysis of 74 cases of DISH. Eleven patients presented with progressive spinal cord or cauda equina compression. In nine cases ossified posterior longitudinal ligament (OPLL) and in two cases ossified ligamentum flavum (OLF) were primarily responsible. Surgically treated patients (eight) had far better outcome as compared to the patients managed conservatively, as they had refused surgery. 'DISH' is neither a benign condition, nor it always runs a innocuous clinical course. In fact, in about 15% of the cases, serious neurological manifestations occur, which may require a major neurosurgical intervention.

Cord compression secondary to cervical disc herniation associated with calcification of the ligamentum flavum: case report

OBJECTIVE AND IMPORTANCE

Calcification of the ligamentum flavum is a rare disease that occurs almost exclusively in elderly Japanese people. We report the case of a young Caucasian woman who presented with a C5-C6 disc herniation associated with a cervical calcified ligamentum flavum.

CLINICAL PRESENTATION

The patient presented with a cord compression syndrome of 76 hours' evolution. At exploration, a Brown-Sequard syndrome at the C6 level was found. Magnetic resonance imaging and computed tomography led to a correct diagnosis and planning for decompression.

INTERVENTION

We operated on the patient through a combined anterior and posterior approach. After the patient underwent anterior discectomy with intersomatic arthrodesis, we performed posterior decompression. During the operation, we observed that the dura mater could not be separated from the ligamentum, so an en bloc excision of both structures was performed. Microscopic examination indicated that the excised ligamentum had calcification, and total integration of the dura mater into the structure of the ligamentum was demonstrated. To our knowledge, this circumstance has never been described before. A posterior C3-C7 arthrodesis was performed to prevent postoperative kyphosis. Recovery was successful, with total recovery from neurological deficits 4 months later.

CONCLUSION

Calcification of the ligamentum flavum is a progressive disease that starts early in life and becomes symptomatic later in life when spinal stenosis occurs. Magnetic resonance imaging and computed tomography provide adequate diagnosis and allow proper surgical planning for decompression. The presence of hyperintense areas within the spinal cord parenchyma, in the absence of a traumatic antecedent, does not preclude a complete recovery.

Cyst of the ligamentum flavum

We report the case of a patient with sciatica resulting from a cyst of the ligamentum flavum.

Femoral neuropathy secondary to ossification of the ligamentum flavum

Radiculopathy resulting from ossification of the ligamentum flavum (OLF) is extremely rare and concerns only intercostal neuralgias. We describe a 37-year-old Caucasian woman with a lumbar radiculopathy revealing an OLF. Her symptoms were completely and definitively relieved by surgery.

[Prevalence, morphology, and pathologic implications of ossification of lumbar ligamenta flava: a large prospective CT study]

Ossifications of the ligamenta flava are described in all parts of the spine, particularly in the dorsal segment where they can produce thoracic myelopathy. Rarely reported in the cervical spine, they are only occasionally mentioned in the lumbar spine where the main reported pathology of the ligamentum flavum is the arthrosynovial cyst. To study the morphological appearances, the prevalence and the pathological implications of the lumbar ossified ligamenta flava, 1021 lower lumbar CT studies are prospectively reviewed totalizing 6080 ligamenta flava. The prevalence of clearly defined ossifications is 5.44%; it appears relatively independent from the age, sex, vertebral level and presence of spondylolysis. It significant increases with the presence and the stage of articular osteoarthritis. In more than 96% of cases, the ossifications remain confined to the lateral articular portion of the ligament and more central ossifications are very rare; therefore, the essential differential diagnosis is osteophytosis. The ossifications never cause radiculopathy except rarely, in association with more classical processes such as disk protrusions and osteophytosis. Our findings favours an essentially idiopathic and--to a lessen extent--a mechanical cause to explain ossification of the ligamenta flava.

Thoracic myelopathy in the Japanese: epidemiological and clinical observations on the cases in Miyagi Prefecture

Surgeries for thoracic myelopathy for 7 years in a northeastern prefecture (population, 2.26 million) and surrounding areas were reviewed. Eighty-one residents in the prefecture were operated on. The annual operation rate per one million people was 5.1. The rate corresponded to 9% of that reported for cervical myelopathy in the same prefecture. The mean age at operation was 55 years. Fifty-five patients (68%) were male and 26 (32%), female. Twenty-eight % of the patients had preoperative periods longer than two years, and 23% had severe disabilities. Anterior decompression was performed in 27%, posterior decompression in the others. The postoperative recovery rate averaged 48%. The lowest rate was 31% in patients with a preoperative duration of more than 2 years (p < 0.05). Sixty-four % of the patients had ossification of the ligamentum flavum; 20%, posterior spur; 19%, disc herniation; 16%, ossification of the posterior longitudinal ligament; 1%, calcification of the ligamentum flavum; 1%, degenerative spondylolisthesis. Seventy-nine % had one of the above spinal factors and 21% had two.

[Aneurysm of the celiac trunk. Etiopathogenic role of the arcuate ligament]

INTRODUCTION

Aneurysms of arteries supplying the digestive tract are uncommon and usually asymptomatic.

CLINICAL REPORT

A 58-year-old woman presented weight-loss with intestinal angina and a painful abdomen. Explorations induced an arteriogram of the aorta and the digestive arteries which showed an aneurysm of the celiac trunk located immediately below a stenosis facing the arcuate ligament.

DISCUSSION

The discovery of an aneurysm of the celiac trunk in a patient without any history of hypertension or artheromatous disease led us to implicate the arcuate ligament as the causal agent. Radiography and histology findings favored this hypothesis.

Spinal intermittent claudication due to cervical and thoracic degenerative spine disease

STUDY DESIGN

Neurogenic intermittent claudication can be caused by spinal cord compression. In this study, 20 patients with spinal intermittent claudication due to degenerative spine diseases were evaluated.

OBJECTIVES

This study clarified the clinical features and pathomechanism of spinal intermittent claudication due to degenerative spine diseases.

SUMMARY OF BACKGROUND DATA

Spinal intermittent claudication may either be produced by intrinsic or extrinsic lesions. Little is known about spinal intermittent claudication due to extrinsic lesions such as spinal cord compression. Twenty patients with spinal intermittent claudication, caused by cervical or thoracic lesions, who were given surgical treatment except for one, were studied. Their main subjective symptoms were tightness, weakness, and numbness in the lower limbs and a strangulated sensation in the trunk to lower limbs. The objective findings were occurrence and/or aggravation of spinothalamic signs.

METHODS

The gait loading test was performed on these 20 patients. Selective spinal angiography was performed on the patients with thoracic myelopathy and its therapeutic effects were evaluated. A radiographic assessment was made in all patients.

RESULTS

The subjective symptoms and objective findings were reproduced by the gait loading test. Selective spinal angiography temporarily relieved or improved the spinal intermittent claudication due to the thoracic myelopathy. Spinal intermittent claudication disappeared immediately after surgical treatment.

CONCLUSIONS

Circulatory impairment of the spinal cord seems to be closely related to the etiology of spinal intermittent claudication. Besides providing diagnostic information, selective spinal angiography may also have a temporary therapeutic effect.

Cyst of the ligamentum flavum

STUDY DESIGN

A patient with sciatica resulting from a hemorrhagic cyst of the ligamentum flavum is reported. Surgical removal of the cyst relieved the patient of her sciatic symptoms.

SUMMARY OF BACKGROUND DATA

Cyst of ligamentum flavum is an uncommon cause of radiculopathy. There are 13 cases in the literature.

CONCLUSIONS

The differential diagnosis of benign interspinal extradural mass lesions includes spinal synovial cysts, ligamentum flavum cysts, perineural cysts, dermoid cysts, and parasitic cysts.

Calcification of ligamentum flavum causing spinal cord compression in a stroke patient

Hypertrophy or calcification of the ligamentum flavum may be a cause of spinal cord compression. Most cases have been reported to occur in either the cervical or thoracolumbar region. We report an unusual case of a 59-year-old man admitted to the rehabilitation service with a recent diagnosis of right cerebrovascular accident with left hemiparesis. The patient had a history of gait disturbance, motor weakness, and bowel/bladder changes. Admission FIM scores were approximately 62 with complete dependence in mobility (ie, transfers) and locomotion. Fluctuating changes in his neurological status were observed; further testing led to an uncommon diagnoses of thoracic radiculomyelopathy caused by calcification of the ligamentum flavum. This diagnosis, although rare, should be considered in the diagnosis of patients suspected to have spinal cord compression.

Ligamentum flavum and apophyseal cysts as an unusual cause of root compression

Patients with symptoms and signs of radicular compression often present to neurosurgeons and orthopaedic surgeons. In an elderly population metastatic disease is often the cause, but degenerative disc disease also occurs. This case shows an alternative benign condition that may be overlooked, and the clinical implications are discussed.

[Ossification and calcification of the cervical ligamentum flavum--case reports]

Ossification of ligamentum flavum was reported usually lower thoracic and lumbar region, and rarely seen in the cervical region. Calcification of cervical ligamentum flavum is also relatively rare. We report a case of ossification and another of calcification of cervical ligamentum flavum, and discussed the difference of the clinical and radiological features in these conditions. Case 1: A 55-year-old man presented with numbness of the left shoulder and urinary dysfunction. Neurological examination revealed weakness, muscle atrophy and elevated deep tendon reflexes of the left extremities. CT showed ossified mass protruding into the right side of the canal and compressing the spinal cord at C 3/4 and C 4/5. MRI showed low intensity mass both on T1- and T2-weighted images and severe compression of the spinal cord. Left side partial hemilaminectomy with foraminotomy, so called "key hole" foraminotomy, satisfactorily decompressed the cord with clinical improvement. Case 2: A 70-year-old woman complained numbness of both hands for two years. She had sensory disturbance of both hands and spastic gait disturbance. Cervical X-ray films showed calcified nodules on the inner surface of lamina at C4/5. Axial CT demonstrated calcification in the ligamentum flavum at the C4/5 and C5/6 levels. MRI showed posterior spinal cord compression at the C4/5 and C5/6 levels. Osteoplastic laminotomy and removal of the affected ligamentum flavum were performed with successful result. Only 8 cases ossification of cervical ligamentum flavum above C6/7 have been so far reported. All are Japanese; four male and four female cases.(ABSTRACT TRUNCATED AT 250 WORDS)

[Radicular compression syndrome due to protrusion of the ligamentum flavum]

O autor apresenta um caso de protrusão de ligamento amarelo, ao nível de L4, que se mostrava espessado. O paciente exibia sintomatologia clínica idêntica à da hérnia discal, com déficit motor e perturbações sensitivas localizadas. A hemilaminectomia curou o doente de suas manifestações dolorosas e sensitivas; hipotonia muscular muito diminuída quatro meses após a operação.