Buckling of the Ligamentum Flavum as a Rare Complication of Anterior Cervical Corpectomy and Fusion: A Case Report

Introduction and Importance Neurological deterioration due to buckling of the ligamentum flavum (LF) is an uncommon complication after anterior cervical corpectomy or discectomy with fusion. Case Presentation In this report, we present the case of a 66-year-old male who underwent anterior cervical partial corpectomy of C5 and discectomy of prolapsed C5- C6 with fusion. Postsurgery, the patient displayed signs of neurological deterioration. Upon immediate cervical magnetic resonance imaging (MRI), posterior canal stenosis and severe compression with cord signal due to LF buckling were detected. A posterior laminectomy procedure and canal decompression at the C5-C6 level with bone fusion were performed. Clinical Discussion Patient presented with walking difficulty, then walking disability, followed by bilateral upper and lower limb paresthesia with burning sensation. Examination showed ⅘ muscle strength in both handgrips. Further investigation showed brisk deep tendon reflexes, positive Hoffman sign unilaterally, equivocal Babinski sign, and progressive quadriparesis. Magnetic resonance imaging showed mild and diffuse building of some cervical discs, with spinal cord progression. We performed an anterior cervical corpectomy and fusion (ACCF) and anterior cervical discectomy and fusion (ACDF); a titanium mesh with plates and screws was used for fusion, with removal of a calcified and herniated subligamentous disc. Postoperatively, upper and lower limb strength deteriorated; immediate cervical and thoracic MRI showed LF buckling, which caused canal stenosis and severe compression. Urgent posterior laminectomy and canal decompression with bone fusion was scheduled on the same day. The patient underwent physiotherapy and regained upper and lower limb strength and his ability to walk. Conclusion This indicates the possibility of neurological deterioration as a result of LF buckling, whichmay be a result of LF thickening accompanied by hyperextension in the cervical region. In this regard, immediate imaging following signs of neurological complications after anterior cervical corpectomy or discectomy warrants early detection, which results in a better prognosis.

Espondiloartrosis cervical e hipertrofia del ligamento amarillo / Cervical Spondyloarthrosis and Hypertrophy of the Yellow Ligament

RESUMEN Introducción: La espondiloartrosis cervical es una enfermedad articular crónica degenerativa, es la afección articular más frecuentemente observada en la población madura y una de las principales causas de discapacidad en todo el mundo, por lo que es importante el diagnóstico y tratamiento en las fases tempranas. Objetivo: Informar un caso clínico representativo de espondiloartrosis cervical e hipertrofia del ligamento amarillo. Presentación del caso: Paciente femenina de 49 años que seis años atrás sufrió una caída, y se golpeó el occipucio contra la pared, lo que le provocó pérdida transitoria del conocimiento y dolor en la región cervical; tres años después comenzó con limitación a los movimientos laterales del cuello, malestar y dolor sordo, referido a la nuca y al cuello. Conclusiones: El diagnóstico de espondiloartrosis cervical e hipertrofia del ligamento amarillo representa un desafío clínico, por lo poco común de la enfermedad a esta edad. El caso presentado es una paciente con alteraciones estructuradas en el esqueleto axial y gran repercusión anatómica y funcional debido a un relativo diagnóstico tardío, con evolución insatisfactoria. Por tanto, conviene conocer la enfermedad para realizar una detección precoz y ofrecer mejor atención terapéutica(AU)

ABSTRACT Introduction: Cervical spondyloarthrosis is a chronic degenerative joint disease, it is the most frequent joint condition in the mature population and one of the main causes of disability throughout the world, so diagnosis and treatment in the early stages are important. Objective: To report a representative clinical case of cervical spondyloarthrosis and hypertrophy of the yellow ligament. Case presentation: A 49-year-old female patient suffered a fall six years ago, hitting her occiput against the wall, causing her temporary loss of consciousness and pain in the cervical region. Three years later, she began with limitation of lateral neck movements, discomfort and dull pain, referred to the nape and neck. Conclusion: The diagnosis of cervical spondyloarthrosis and hypertrophy of the yellow ligament represents a clinical challenge, due to the rare nature of the disease at this age. The case reported is a patient with structured alterations in the axial skeleton and great anatomical and functional repercussions due to a relatively late diagnosis, with unsatisfactory evolution. Therefore, it is convenient to know the disease in order to early detect it and to offer better therapeutic care(AU)

Ligamentum flavum in lumbar spinal stenosis, disc herniation and degenerative spondylolisthesis. An histopathological description / Ligamento amarillo en estenosis lumbar espinal, hernia de disco y espondilolistesis degenerativa. Una descripción histopatológica

Abstract: Introduction: Changes in ligamentum flavum (LF) related to degeneration are secondary to either the aging process or mechanical instability. Previous studies have indicated that LF with aging shows elastic fiber loss and increased collagen content, loss of elasticity may cause LF to fold into the spinal canal, which may further narrow of the canal. Material and methods: A total of 67 patients operated with the surgical indications of lumbar spinal stenosis (LSS), lumbar disc herniation (LDH) and lumbar degenerative spondylolisthesis (LDS) were included. LF samples were obtained from patients who had LSS (39), LDH (22) and LDS (6). Specimens were examined with regard to chondroid metaplasia, calcification, fragmentation of collagen fibers, cystic degeneration, fibrillar appearence, and hypercellularity. Results: The most frequent histopathological changes were hyalinization and fragmentation of collagen fibers occur in 34%, neovascularization in 40.3% and irregular arrangement of elastic fibers is the most prevalent change with 56.7% of the total samples. There is a difference in the presence of certain changes in the LF according to the diagnosis, being statistically significant for fragmentation of collagen fibers (p = 0.045), cystic degeneration (p = 0.001), fibrillar appearance (p = 0.007) and hypercellularity (p = 0.005) all of these, being more prevalent in LDS group. LHD group presented fragmentation of collagen fibers in 45.5% (p = 0.045) and fibrillar appearance in 4.5% (p = 0.009). Conclusions: There is not evidence of cellular hyperthophy in the histhopatological analyses, thickening of the LF can be seen by bulking of LF followed by collapse of motion segment.

Resumen: 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.

Epidural Fat-Derived Mesenchymal Stem Cell: First Report of Epidural Fat-Derived Mesenchymal Stem Cell

STUDY DESIGN: Experimental study. PURPOSE: To determine whether epidural fat (EF) tissue contains mesenchymal stem cells (MSC). OVERVIEW OF LITERATURE: Spine surgeons are unaware of the contents of EF tissue and the reason for its presence between the ligamentum flavum and the dura mater; therefore, EF tissues are routinely eliminated during surgical procedures. However, EF removal causes certain postoperative problems, such as post-laminectomy syndrome. We hypothesized that the EF tissue may play a significant supportive role for the neural structures and other nearby conditions. METHODS: EF tissues were obtained from consenting patients (n=3) during posterior decompression surgery of the lumbar spine. The primary cells were isolated and cultured as per previously described methods with some modifications, and the cell morphology and cumulation were examined. Thereafter, reverse transcription–polymerase chain reaction (RT-PCR), a fluorescence-activated cell sorting (FACS) analysis, and differentiation potency for differentiation into osteoblasts, chondroblasts, and adipocytes were investigated to identify whether the cells derived from EF are MSC. RESULTS: The cells from the EF tissue had a fibroblast or neuron-like morphology that persisted until the senescence at p18. MSC-specific genes, such as OCT4, SOX2, KLF4, MYC, and GAPDH were expressed in the RT-PCR study, while MSC-specific surface markers such as CD105, CD90, and CD73 were exhibited in the FACS analysis. The differentiation properties of EF-MSC for differentiation into the three types of cells (osteoblast, chondroblast, and adipocyte) were also confirmed. CONCLUSIONS: Based on the cell culture, FACS analysis, RT-PCR analysis, and differentiation potent outcomes, all the features of the cells corresponded to MSC. This is the first study to identify EF-MSC derived from the EF tissue.

Unilateral Biportal Endoscopic Spinal Surgery Using a 30° Arthroscope for L5–S1 Foraminal Decompression

Foraminal decompression using a minimally invasive technique to preserve facet joint stability and function without fusion reportedly improves the radicular symptoms in approximately 80% of patients and is considered one of the good surgical treatment choices for lumbar foraminal or extraforaminal stenosis. However, proper decompression was not possible because of the inability to access the foramen at the L5–S1 level due to prominence of the iliac crest. To overcome this challenge, endoscopy-based minimally invasive spine surgery has recently gained attention. Here, we report the technical skills required in unilateral extraforaminal biportal endoscopic spinal surgery using a 30° arthroscope to enable foraminal decompression at the L5–S1 level. Two 0.8-cm portals were created 2 cm lateral from the lateral border of the pedicles at the L5–S1 level. After sufficient working space was made, half of the superior articular process (SAP) in the hypertrophied facet joint was removed using a high-speed burr and a 5-mm wide osteotome, whereas the remaining inside part of the SAP was removed using a Kerrison punch and pituitary punch. The foraminal ligamentum flavum should be removed to inspect the conditions of the L5 exiting root and disc. Removing of the extruded disc could decompress the L5 root. The extraforaminal approach using a 30° arthroscope is considered a minimally invasive alternative technique for decompressing foraminal stenosis at the L5–S1 level that preserves facet stability and provides symptomatic relief.

Thickening Ligamentum Flavum Mimicking Tumor in the Epidural Space of the Cervical Spine / 대한신경손상학회지

In patients with tumors and spinal cord lesions, inflammation and tissue infection can result in mass effect detection on imaging. As a result, surgical biopsy procedures are often performed on the lesions. We report a rare case in which the thickening ligamentum flavum (LF) appeared to be a tumor in the epidural space of the cervical spine based on imaging findings. A 52-year-old man visited our outpatient clinic with severe shoulder pain and radicular pain in his right arm that had developed gradually after a traffic accident two months earlier. Magnetic resonance imaging of the cervical spine revealed an extradural mass at the cervicothoracic junction level. Suspecting a tumor, spinal decompression surgery was performed and a biopsy of the mass was obtained. At the time of surgery, the LF was thick and compressed the spinal cord. After successful removal of the LF, the spinal cord appeared normal. Histopathological examination confirmed the mass as the LF. The patient was discharged without pain or weakness two weeks postoperatively. This case demonstrated that when the LF of the cervicothoracic junction is thickened, it may be misdiagnosed as a cervical spine tumor compressing the spinal cord.

Prevalence of Diffuse Idiopathic Skeletal Hyperostosis Diagnosed by Whole Spine Computed Tomography: A Preliminary Study

BACKGROUND: Diffuse idiopathic skeletal hyperostosis (DISH) is characterized by ossification of the enthesis. The diagnosis has been mainly based on the chest or whole spine lateral plain film. Recently, chest or thoracolumbar computed tomography (CT) has been reported to be more reliable for the diagnosis of DISH. The purposes of this study were to investigate the prevalence and location of DISH and evaluate the prevalence of comorbidities, such as ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF), using whole spine CT. METHODS: Whole spine CT scans of patients over 16 years of age who were examined at Cheju Halla General Hospital between February 2011 and December 2016 were reviewed for this study. The diagnosis of DISH was made according to the modified Resnick criteria. The prevalence of DISH in each age decade and its location were evaluated. Also, the prevalence of OPLL and OLF in DISH patients was investigated. RESULTS: The overall incidence of DISH was 24.4% (40 of 164 cases). There was no case of DISH in patients in their 40s and younger. The percentile incidences of DISH in patients in their fifth, sixth, seventh, eighth, and ninth decades were 20.0% (4 of 20 cases), 32.3% (10 of 31 cases), 40.0% (10 of 25 cases), 34.5% (10 of 29 cases), and 27.3% (6 of 22 cases), respectively. A strong positive correlation between the age decade and the incidence of DISH was noted (r = 0.853, p = 0.007). DISH patients had higher incidences of OLF (22.5%) and OPLL (37.5%). The most common location of DISH was the middle thoracic spine (90.0%) followed by the lower thoracic spine (87.5%). There was one case of DISH involving only the cervical spine. CONCLUSIONS: The incidence of DISH diagnosed by CT was higher than we expected. Whole spine CT can be a valuable modality to evaluate the location of DISH in the cervical and lumbar spine and the comorbidity rates of OLF and OPLL.

The Clinical Results after Posterior Ligaments Preserving Fenestration in Lumbar Spinal Stenosis: The Port-Hole Decompression / 대한정형외과학회잡지

PURPOSE: To describe the technical skills and to estimate the clinical outcomes of port-hole decompression preserving the posterior ligaments during lumbar spinal stenosis surgery. MATERIALS AND METHODS: Between March 2014 and March 2016, a total of 101 patients who underwent port-hole decompression were retrospectively analyzed. The mean age was 71.3 years (58–84 years) and there were 46 males and 55 females. The mean follow-up period was 18 months. Degenerative spondylolisthesis was observed in 24.8% of patients (25/101). Port-hole decompression was performed by removing the central portion of the distal part of the upper lamina with a burr. Then, the contralateral side of ligamentum flavum and hypertrophied facet joints were removed. We estimated the lumbar lordotic angle using radiographs, and measured the depth from skin to upper lamina central area using magnetic resonance imaging axial images. We estimated the mean slip angle and mean degree of slip in preoperative and postoperative radiography in standing flexion and extension. We also measured the operational time, length of skin incision, and blood loss. The clinical results were estimated by a walking distance caused by neurologic intermittent claudication, visual analogue scale, and Oswestry disability index. RESULTS: Most patients were generally older, and the mean lordotic angle was 25.3°, which is considered to be lower when compared with younger people. The mean depth from skin to lamina was mean 5.4 cm. With respect to the radiological results, there were no significant differences between the preoperative and postoperative groups. The operation time, length of skin incision, and bleeding were not increased proportionally to the operation level. The walking distance caused by neurologic intermittent claudication, visual analogue scale, and Oswestry disability index of the post-operative group were all improved compared with the pre-operative group. CONCLUSION: The port-hole decompression, which decompresses the contralateral side while preserving the posterior ligaments and facet joints may be a useful technique for elderly patients with multiple level stenosis, minimizing spinal segmental instability.

Quantitative Histological Analysis of Ligamentum Flavum

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Scoring System for Factors Affecting Aggravation of Lumbar Disc Herniation

PURPOSE: To investigate the various imaging factors associated with aggravation of lumbar disc herniation (LDH) and develop a scoring system for prediction of LDH aggravation. MATERIALS AND METHODS: From 2015 to 2017, we retrospectively reviewed the magnetic resonance imaging (MRI) findings of 60 patients (30 patients with aggravated LDH and 30 patients without any altered LDH). Imaging factors for MRI evaluation included the level of LDH, disc degeneration, back muscle atrophy, facet joint degeneration, ligamentum flavum thickness and interspinous ligament degeneration. Flexion-extension difference was measured with simple radiography. The scoring system was analyzed using receiver operating characteristic (ROC) analysis. RESULTS: The aggravated group manifested a higher grade of disc degeneration, back muscle atrophy and facet degeneration than the control group. The ligamentum flavum thickness in the aggravated group was thicker than in the group with unaltered LDH. The summation score was defined as the sum of the grade of disc degeneration, back muscle atrophy and facet joint degeneration. The area under the ROC curve showing the threshold value of the summation score for prediction of aggravation of LDH was 0.832 and the threshold value corresponded to 6.5. CONCLUSION: Disc degeneration, facet degeneration, back muscle atrophy and ligamentum flavum thickness are important factors in predicting aggravation of LDH and may facilitate the determination of treatment strategy in patients with LDH. The summation score is available as supplemental data.

Compressive Myelopathy Due to Ossification of the Ligamentum Flavum: Case Report and Review of the Literature

Ossification of the ligamentum flavum (OLF) is a rare condition in which the ligamentum flavum, due to mechanical, biological and genetic factors, becomes ossified. Due to its nature and anatomic location, OLF produces symptoms characteristic of spinal cord compression. The diagnostic confirmation is based primarily on imaging tests such as computed tomography (CT) and magnetic resonance imaging (MRI). Ossification of the ligamentum flavum most often affects Asian populations, rarely occurring in black people. The authors report a case of a 61-year-old black man with progressive paraparesis due to OLF, and review the literature regarding the pathology's prevalence, pathogenesis, clinical features, diagnosis, treatment and prognosis.

A ossificação do ligamento flavo (OLF) é uma doença rara na qual o ligamento flavo se torna ossificado devido a fatores mecânicos, biológicos e genéticos. Devido à sua natureza e localização anatômica, a OLF produz sintomas característicos de compressão da medula espinhal. A confirmação diagnóstica baseia-se principalmente em exames de imagem, como tomografia computadorizada (TC) e ressonância magnética (RM). A OLF afeta mais comumente populações asiáticas, raramente sendo observada em pacientes negros. Os autores relatam o caso de um homem negro de 61 anos com paraparesia progressiva decorrente de OLF com uma revisão da literatura a respeito da prevalência, patogênese, aspectos clínicos, diagnóstico, tratamento e prognóstico desta patologia.

Prediction of midline depth from skin to cervical epidural space by lateral cervical spine X-ray

BACKGROUND: Previous studies have shown that measuring the distance from the skin to the ligamentum flavum by ultrasound preceding cervical epidural block can be beneficial in excluding false loss of resistance. However, the measurement value using ultrasound may vary depending on the degree of operator experience. Therefore, we aimed to determine the depth from skin to cervical epidural space by using lateral cervical spine X-ray, which is a more intuitive method. METHODS: We enrolled 102 adult patients who were scheduled to undergo cervical epidural anesthesia for vascular bypass surgery of upper arm. After attaching a steel rod on the needle insertion site, lateral cervical spine X-ray was taken before the epidural procedure. We measured the distance from the steel rod to the midpoint of interlaminar space on the spinolaminar line. The X-ray depth was compared with needle depth. RESULTS: Of the 102 enrolled patients, 18 patients including 13 in whom we were unable to measure X-ray depth were excluded from the analysis. In total, 84 patients were included in the analysis. Concordance correlation coefficient between the X-ray-measured depth and needle depth was 0.925. Bland-Altman analysis indicated a mean difference of ± 1.96 SD with 0.06 ± 0.56 cm. CONCLUSIONS: Lateral cervical spine X-ray can be useful for prediction of the midline depth from skin to epidural space, particularly for operators who are not skilled at spine ultrasound or the use the C-arm fluoroscopy.

Histopathological Analysis of Ligamentum Flavum in Lumbar Spinal Stenosis and Disc Herniation

STUDY DESIGN: Histopathological analyses were performed in ligamentum flavum (LF) hypertrophy patients with lumbar spinal stenosis (LSS) and lumbar disc herniation (LDH). PURPOSE: The aim of the present study was to evaluate histopathological changes in LF patients with LSS and LDH. OVERVIEW OF LITERATURE: LSS is the most common spinal disorder in elderly patients. This condition causes lower back and leg pain and paresis, and occurs as a result of degenerative changes in the lumbar spine, including bulging of the intervertebral discs, bony proliferation of the facet joints, and LF thickening; among these, LF thickening is considered a major contributor to the development of LSS. METHODS: A total of 71 patients operated with the surgical indications of LSS and LDH were included. LF samples were obtained from 31 patients who underwent decompressive laminectomy for symptomatic degenerative LSS (stenotic group) and from 40 patients who underwent lumbar discectomy for LDH (discectomy group). LF materials were examined histopathologically, and other specimens were examined for collagen content, elastic fiber number and array, and presence of calcification. RESULTS: The stenotic and discectomy groups did not differ with regard to mean collagen concentration or mean elastic fiber number (p=0.430 and p=0.457, respectively). Mean elastic fiber alignment was 2.36±0.99 in the stenotic group and 1.38±0.54 in the discectomy group (p<0.001). Mean calcification was 0.39±0.50 in the stenotic group, whereas calcification was not detected (0.00±0.00) in the discectomy group; a statistically significant difference was detected (p<0.001) between groups. CONCLUSIONS: LF hypertrophy in spinal stenosis may occur as a result of elastic fiber misalignment along with the development of calcification over time. Further studies determining the pathogenesis of LSS are needed.

Change of Lumbar Ligamentum Flavum after Indirect Decompression Using Anterior Lumbar Interbody Fusion

STUDY DESIGN: Retrospective case series. PURPOSE: The purpose of this study was to examine changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a 10-year follow-up. OVERVIEW OF LITERATURE: Extreme lateral interbody fusion provides minimally invasive treatment of the lumbar spine; this anterior fusion without direct posterior decompression, so-called indirect decompression, can achieve pain relief. Anterior fusion may restore disc height, stretch the flexure of the ligamentum flavum, and increase the spinal canal diameter. However, changes in the ligamentum flavum thickness and remodeling of the spinal canal after anterior fusion during a long follow-up have not yet been reported. METHODS: We evaluated 10 patients with L4 spondylolisthesis who underwent stand-alone anterior interbody fusion using the iliac crest bone. Magnetic resonance imaging was performed 10 years after surgery. The cross-sectional area (CSA) of the dural sac and the ligamentum flavum at L1–2 to L5–S1 was calculated using a Picture Archiving and Communication System. RESULTS: Spinal fusion with correction loss (average, 4.75 mm anterior slip) was achieved in all patients 10 years postsurgery. The average CSAs of the dural sac and the ligamentum flavum at L1–2 to L5–S1 were 150 mm² and 78 mm², respectively. The average CSA of the ligamentum flavum at L4–5 (30 mm²) (fusion level) was significantly less than that at L1–2 to L3–4 or L5–S1. Although patients had an average anterior slip of 4.75 mm, the average CSA of the dural sac at L4–5 was significantly larger than at the other levels. CONCLUSIONS: Spinal stability induced a lumbar ligamentum flavum change and a sustained remodeling of the spinal canal, which may explain the long-term pain relief after indirect decompression fusion surgery.

Analysis of the Relationship between Ligamentum Flavum Thickening and Lumbar Segmental Instability, Disc Degeneration, and Facet Joint Osteoarthritis in Lumbar Spinal Stenosis

STUDY DESIGN: Cross-sectional study. PURPOSE: To investigate the relationship between ligamentum flavum (LF) thickening and lumbar segmental instability and disc degeneration and facet joint osteoarthritis. OVERVIEW OF LITERATURE: Posterior spinal structures, including LF thickness, play a major role in lumbar spinal canal stenosis pathogenesis. The cause of LF thickening is multifactorial and includes activity level, age, and mechanical stress. LF thickening pathogenesis is unknown. METHODS: We examined 419 patients who underwent computed tomography (CT) myelography and magnetic resonance imaging after complaints of clinical symptoms. To investigate LF hypertrophy, 57 patients whose lumbar vertebra had normal disc heights at L4–5 were selected to exclude LF buckling as a hypertrophy component. LF thickness, disc space widening angulation in flexion, segmental angulation, presence of a vacuum phenomenon, and lumbar lordosis at T12–S1 were investigated. Disc and facet degeneration were also evaluated. Facet joint orientation was measured via an axial CT scan. RESULTS: The mean LF thickness in all patients was 4.4±1.0 mm at L4–5. There was a significant correlation between LF thickness and disc degeneration; LF thickness significantly increased with severe disc degeneration and facet joint osteoarthritis. There was a tendency toward increased LF thickness in more sagittalized facet joints than in coronalized facet joints. Logistic regression analysis showed that LF thickening was influenced by segmental angulation and facet joint osteoarthritis. Patient age was associated with LF thickening. CONCLUSIONS: LF hypertrophy development was associated with segmental instability and severe disc degeneration, severe facet joint osteoarthritis, and a sagittalized facet joint orientation.

Analysis of the Relationship between Hypertrophy of the Ligamentum Flavum and Lumbar Segmental Motion with Aging Process

STUDY DESIGN: Retrospective cross-sectional study. PURPOSE: To investigate the relationship between ligamentum flavum (LF) hypertrophy and lumbar segmental motion. OVERVIEW OF LITERATURE: The pathogenesis of LF thickening is unclear and whether the thickening results from tissue hypertrophy or buckling remains controversial. METHODS: 296 consecutive patients underwent assessment of the lumbar spine by radiographic and magnetic resonance imaging (MRI). Of these patients, 39 with normal L4-L5 disc height were selected to exclude LF buckling as one component of LF hypertrophy. The study group included 27 men and 12 women, with an average age of 61.2 years (range, 23-81 years). Disc degeneration and LF thickness were quantified on MRI. Lumbar segmental spine instability and presence of a vacuum phenomenon were identified on radiographic images. RESULTS: The distribution of disc degeneration and LF thickness included grade II degeneration in 4 patients, with a mean LF thickness of 2.43±0.20 mm; grade III in 10 patients, 3.01±0.41 mm; and grade IV in 25 patients, 4.16±1.12 mm. LF thickness significantly increased with grade of disc degeneration and was significantly correlated with age (r=0.55, p<0.01). Logistic regression analysis identified predictive effects of segmental angulation (odds ratio [OR]=1.55, p=0.014) and age (OR=1.16, p=0.008). CONCLUSIONS: Age-related increases in disc degeneration, combined with continuous lumbar segmental flexion-extension motion, leads to the development of LF hypertrophy.

Spinal Cord Kinking in Thoracic Myelopathy Caused by Ossification of the Ligamentum Flavum / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Ossification of the ligamentum flavum (OLF) is being increasingly recognized as a cause of thoracic myelopathy. This study was to describe a rare clinical entity of spinal cord kinking (SK) in thoracic myelopathy secondary to OLF.</p><p><b>METHODS</b>The data of 95 patients with thoracic myelopathy secondary to OLF were analyzed retrospectively. The incidence and location of SK were determined using preoperative magnetic resonance imaging (MRI). The clinical presentation and radiological characteristics in patients with SK were analyzed. Posterior en bloc laminectomy with OLF was performed, and the surgical results were evaluated.</p><p><b>RESULTS</b>SK was found in seven patients (7.4%) based on preoperative MRI. The patients included one male and six females with an average age of 55.6 years (range, 48-64 years). Five patients presented with radiculomyelopathy and two presented with typical thoracic myelopathy of spastic paraparesis. In all cases, the kinking was located just above the end of the spinal cord where the conus medullaris (CM) was compressed by the OLF. The degree of SK varied from mild to severe. The tip of the CM was located between the upper third of T11 to the lower third of L1, above the lower edge of L1. With an average follow-up of 30.4 months, the modified Japanese Orthopedic Association score significantly improved from 5.7 ± 1.8 preoperatively to 8.9 ± 1.4 postoperatively (t = 12.05; P < 0.0001) with an improvement rate of 63.1 ± 12.3%.</p><p><b>CONCLUSIONS</b>SK is a rare radiological phenomenon. It is typically located at the thoracolumbar junction, where the CM is compressed by the OLF. Our findings indicate that these patients may benefit from a posterior decompressive procedure.</p>

Mechanism of Ligamentum Flavum Hypertrophy / 대한정형외과연구학회지

Ligamentum flavum (LF) is yellowish ligament tissue connecting the lamina of adjacent vertebra. Degenerative changes in the spine cause the hypertrophy of LF and facet joint and disc bulging and herniation. These changes results in a narrowing of the spinal canal. Neural decompression surgery by removing the hypertrophied lamina, LF and disc pathologies has been considered as successful treatment method in lumbar spinal stenosis. This surgery has showed relatively satisfactory clinical results and has increased life-expectancy in elderly patients. However, issues about post spinal surgery syndrome and re-stenosis after the surgery also have been reported. Because LF is one of the main mechanisms of spinal stenosis, accurate understanding about pathologic mechanism on the LF hypertrophy may suggest alternative treatment methods such as medical treatment or less invasive treatment than surgical decompression can be considered. Hypertrophy of the ligamentum flavum is generated from increase of collagen synthesis, fibroblast proliferation, and fibrosis caused by 1) the expression of growth factors (TGF-beta1 etc.) stimulated by the repeated mechanical tension, 2) inflammatory cytokines from spinal facet joint structure and LF 3) delayed cell death, and 4) inflammatory cytokine from hypertrophied and degenerated LF itself. After the middle ages, gradual and partial inhibition of LF hypertrophy can be expected by administration NSAIDs or selective cyclo-oxygenase-2 inhibitors because these drugs may cause reduction of the increased cytokines. Also, relaxin can be another new treatment material for spinal stenosis by the mechanism of melting hypertrophied LF and reducing synthesis of collagen.

Prevalence and Distribution of Thoracic and Lumbar Compressive Lesions in Cervical Spondylotic Myelopathy

STUDY DESIGN: Retrospective cross-sectional study. PURPOSE: This study analyzed the prevalence and distribution of horacic and lumbar compressive lesions in cervical spondylotic myelopathy as well as their relationships with cervical developmental spinal canal stenosis (DCS) by using whole-spine postmyelographic computed tomography. OVERVIEW OF LITERATURE: There are few studies on missed compressive lesions of the spinal cord or cauda equina at the thoracolumbar level in cervical spondylotic myelopathy. Furthermore, the relationships between DCS, and the prevalence and distribution of thoracic and lumbar compressive lesions are unknown. METHODS: Eighty patients with symptomatic cervical spondylotic myelopathy were evaluated. Preoperative image data were obtained. Patients were classified as DCS or non-DCS (n=40 each) if their spinal canal longitudinal diameter was or =12 mm at all levels, respectively. Compressive lesions in the anterior and anteroposterior parts, ligamentum flavum ossification, posterior longitudinal ligament ossification, and spinal cord tumors at the thoracolumbar levels were analyzed. RESULTS: Compressive lesions in the anterior and anteroposterior parts were observed in 13 (16.3%) and 45 (56.3%) patients, respectively. Ligamentum flavum and posterior longitudinal ligament ossification were observed in 19 (23.8%) and 3 (3.8%) patients, respectively. No spinal cord tumors were observed. Thoracic and lumbar compressive lesions of various causes tended to be more common in DCS patients than non-DCS patients, although the difference was statistically insignificant. CONCLUSIONS: Surveying compressive lesions and considering the thoracic and lumbar level in cervical spondylotic myelopathy in DCS patients are important for preventing unexpected neurological deterioration and predicting accurate neurological condition after cervical surgery.