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.
Aged ; Collagen ; Diskectomy ; Elastic Tissue ; Humans ; Hypertrophy ; Intervertebral Disc ; Laminectomy ; Leg ; Ligamentum Flavum* ; Paresis ; Pathology ; Spinal Stenosis* ; Spine ; Zygapophyseal Joint

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.
Aged ; Anti-Inflammatory Agents, Non-Steroidal ; Cell Death ; Collagen ; Cytokines ; Decompression ; Decompression, Surgical ; Fibroblasts ; Fibrosis ; Freezing ; Humans ; Hypertrophy* ; Intercellular Signaling Peptides and Proteins ; Ligaments ; Ligamentum Flavum* ; Pathology ; Relaxin ; Spinal Canal ; Spinal Stenosis ; Spine ; Zygapophyseal Joint

OBJECTIVE: To evaluate spine magnetic resonance imaging (MRI) inter-reader and intra-reader reliabilities using the thoracolumbar injury classification system and severity score (TLICS) and to analyze the effects of reader experience on reliability and the possible reasons for discordant interpretations. MATERIALS AND METHODS: Six radiologists (two senior, two junior radiologists, and two residents) independently scored 100 MRI examinations of thoracolumbar spine injuries to assess injury morphology and posterior ligamentous complex (PLC) integrity according to the TLICS. Inter-reader and intra-reader agreements were determined and analyzed according to the number of years of radiologist experience. RESULTS: Inter-reader agreement between the six readers was moderate (k = 0.538 for the first and 0.537 for the second review) for injury morphology and fair to moderate (k = 0.440 for the first and 0.389 for the second review) for PLC integrity. No significant difference in inter-reader agreement was observed according to the number of years of radiologist experience. Intra-reader agreements showed a wide range (k = 0.538-0.822 for injury morphology and 0.423-0.616 for PLC integrity). Agreement was achieved in 44 for the first and 45 for the second review about injury morphology, as well as in 41 for the first and 38 for the second review of PLC integrity. A positive correlation was detected between injury morphology score and PLC integrity. CONCLUSION: The reliability of MRI for assessing thoracolumbar spinal injuries according to the TLICS was moderate for injury morphology and fair to moderate for PLC integrity, which may not be influenced by radiologist' experience.
Adolescent ; Adult ; Aged ; Aged, 80 and over ; Child ; Female ; Humans ; *Injury Severity Score ; Ligamentum Flavum/pathology ; Lumbar Vertebrae/*injuries/pathology ; Magnetic Resonance Imaging/*methods ; Male ; Middle Aged ; Observer Variation ; Reproducibility of Results ; Retrospective Studies ; Spinal Injuries/*classification/*pathology ; Thoracic Vertebrae/*injuries/pathology ; Thoracic Wall/pathology ; Young Adult

BACKGROUNDOssification 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.

METHODSThe 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.

RESULTSSK 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%.

CONCLUSIONSSK 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.

Female ; Humans ; Ligamentum Flavum ; pathology ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Ossification, Heterotopic ; complications ; Radiography ; Spinal Cord Compression ; diagnosis ; diagnostic imaging ; surgery ; Spinal Cord Diseases ; diagnosis ; diagnostic imaging ; etiology ; surgery

BACKGROUNDSurgical treatment of thoracic myelopathy caused by ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligamentum flavum (OLF) is technically demanding, and the results tend to be unfavorable. Various operative approaches and treatment strategies have been attempted, and posterior decompression with transforaminal thoracic interbody fusion (PTTIF) may be the optimal method with which the anterior-posterior compression was removed in one step. It is comparatively less traumatic with fewer serious complications.

METHODSSixteen patients with thoracic myelopathy due to concurrent OLF and OPLL at the same level underwent PTTIF. We investigated clinical outcomes and neurological improvements. Magnetic resonance imaging (MRI) was performed on all patients preoperatively and postoperatively, and intramedullary signal changes were evaluated.

RESULTSThe mean operating time was 275 minutes, and the mean operative bleeding amount was 1031 ml. Cerebrospinal fluid leakage occurred in three patients and healed well after repair. Neurological symptom deterioration occurred in one patient, but the patient recovered to nearly the preoperative level after methylprednisolone treatment. The follow-up period ranged from 28 to 47 months. The mean score on the Japanese Orthopedic Association scale improved from 4.3±1.2 preoperatively to 7.3±1.7 at 3 months postoperatively to 8.5±1.5 at the final follow-up (P < 0.01), with a recovery rate of (63.6±20.0)%. Postoperative images showed a significant improvement in local kyphosis (P < 0.01). Eleven patients (68.8%) showed increased signal intensity (ISI) on preoperative T2-weighted MRI. At the final follow-up, the intramedullary ISI totally recovered in five patients. Neurological improvement was worse in patients with persistent ISI than in the other patients (P < 0.05).

CONCLUSIONSPTTIF is an effective therapeutic option for combined OPLL and OLF and provides satisfactory neurological recovery and stabilized thoracic fusion through a single posterior approach. Intramedullary signal changes do not always indicate a poor prognosis; only irreversible ISI is correlated with a poor clinical result.

Adult ; Aged ; Decompression, Surgical ; Female ; Humans ; Ligamentum Flavum ; pathology ; surgery ; Longitudinal Ligaments ; pathology ; surgery ; Male ; Middle Aged ; Ossification of Posterior Longitudinal Ligament ; pathology ; surgery ; Spinal Cord Diseases ; pathology ; surgery

OBJECTIVETo investigate the prognostic factors for patients with thoracic ossification of the ligamentum flavum (OLF) and thoracic ossification of posterior longitudinal ligament (OPLL).

METHODSClinical information of 83 patients suffering from thoracic OLF and OPLL was reviewed retrospectively from January 2006 to June 2010. The related factors such as gender, age, preoperative and postoperative Japanese Orthopedic Association (JOA) score, pathological segment, type of thoracic OPLL, degree of thoracic kyphosis, anteroposterior diameter of OPLL, range of circumferential decompression, cerebrospinal fluid leakage or not and dysfunction or not and carotid lumbar disorders or not were analyzed by Chi-square and Logistic regression.

RESULTSAll cases were classified into desirable group (58 cases) and undesirable group (25 cases) based on the postoperative JOA score improvement rate. Comparison of physical characteristics between two groups of age, preoperative JOA and the course of the disease had not statistically significant (P > 0.05). Two groups in pathological segment of thoracic OPLL (χ(2) = 6.290, P = 0.043), the ossification type of OPLL (χ(2) = 5.361, P = 0.021) and dysfunction or not in preoperative (χ(2) = 27.711, P = 0.000) had significant difference. Logistic regression analysis showed that the upper thoracic segments (P = 0.044), beak type ossification (P = 0.023) and with dysfunction in preoperative (P = 0.009) were risk factors. There were 24 patients (28.9%) with cerebrospinal fluid leakage, 3 patients with early postoperative deep infection and neurological deterioration of 2 cases in postoperative.

CONCLUSIONSPatients with ossification on the upper section of thoracic have a better prognosis, but the beaked localized longitudinal ligament ossification in patients and associated with preoperative dysfunction show a poor prognosis, combined jumping segmental ossification and cervical or lumbar severe disorders are the influencing factor for poor prognosis.

Adult ; Aged ; Decompression, Surgical ; Female ; Humans ; Ligamentum Flavum ; pathology ; Logistic Models ; Male ; Middle Aged ; Ossification of Posterior Longitudinal Ligament ; diagnosis ; surgery ; Postoperative Complications ; epidemiology ; Prognosis ; Retrospective Studies

A 39-year-old man presented with recurrent lower back and leg pain for 8 months due to repeated hemorrhage into an L5 ligamentum flavum cyst. Lumbar MR imaging showed an extradural cystic mass originating from the ligamentum flavum on the right side in the L5 segment. Microsurgical laminotomy and flavectomy were performed. The symptoms resolved completely and the patient had an uneventful postoperative recovery.
Adult ; Cysts ; diagnosis ; surgery ; Humans ; Ligamentum Flavum ; pathology ; surgery ; Male

OBJECTIVETo investigate the role of platelet-derived growth factor-BB (PDGF-BB) in the degeneration of the hypertrophied ligamentum flavum (LF) in the lumbar spine.

METHODSSurgical specimens of degenerative hypertrophied LF were obtained from 11 patients with lumbar spinal stenosis (LSS, mean age 57.8 years), with those from 10 age-matched patients with lumbar disc herniation (LDH, mean age 53.5 years) as the normal controls. The thickness of the LF was measured preoperatively by axial T1-weighted magnetic resonance imaging (MRI) at the facet joint level. Immunohistochemistry was employed to determine the expression of PDGF β and PDGF-BB in the LF. The mRNA and protein expressions of PDGF-BB in the LF were detected using real-time PCR and Western blotting, respectively.

RESULTSThe thickness of the LF was 5.30±1.12 mm in the degenerative group and 2.80±1.53 mm in the control group, showing a significant difference between the two groups (P<0.001). PDGF-β and PDGF-BB were positive in the fibroblasts in hypertrophied LF. The mRNA and protein expressions of PDGF-BB were significantly higher in the degenerative group than in the control group (P=0.013 and 0.023, respectively).

CONCLUSIONThe high expression of PDGF-BB in the hypertrophied LF suggests its important role in the development of hypertrophy of LF in lumbar spinal canal stenosis.

Adult ; Aged ; Female ; Humans ; Hypertrophy ; metabolism ; Intervertebral Disc Degeneration ; metabolism ; pathology ; Ligamentum Flavum ; metabolism ; pathology ; Lumbar Vertebrae ; Male ; Middle Aged ; Proto-Oncogene Proteins c-sis ; metabolism ; Spinal Stenosis ; metabolism ; pathology

OBJECTIVETo investigate the surgical treatment of thoracic ossification of the ligamentum flavum (TOLF) and analysis of the therapeutic effects.

METHODSSix patients with thoracic ossification of the ligamentum flavum were retrospectively studied from October 2006 to October 2009. All of the patients in this group were treated by en bloc hemi-articular process laminectomy. There were 4 males and 2 females, ranging in age from 45 to 66 years, averaged 55.2 years. The evaluate factors including the preoperative and postoperative JOA scores,and the function of the urinary bladder were analyzed.

RESULTSAll the 6 patients were followed after operation. The mean followed-up duration was 10.5 months, ranging from 2 to 18 months. According to JOA evaluation criteria, 4 patients got an excellent result, 1 good and 1 bad. The one patient with bad result had spinal cord compressed for too long time, and the T2-weight MRI showed nonreversible degeneration of spinal cord and combined with schizophrenia. The clinical symptoms improved with varying degrees.

CONCLUSIONThe en bloc hemi-articular process laminectomy is an effective method for ossification of the thoracic ligamentum flavum. A thorough decompression and real-time protection of the spinal cord is the key to the success of surgery.

Aged ; Decompression, Surgical ; Female ; Humans ; Ligamentum Flavum ; pathology ; Male ; Middle Aged ; Ossification, Heterotopic ; surgery ; Postoperative Complications ; etiology ; Retrospective Studies ; Spinal Cord Injuries ; etiology ; Thoracic Vertebrae ; pathology

PURPOSE: The objective of this study was to determine the phenotypic characterization of ligamentum flavum cells from patients with ossification of the ligamentum flavum (OLF). MATERIALS AND METHODS: Ligamentum flavum tissues were harvested from OLF and non-OLF patients during surgery. OLF and non-OLF cells were isolated from explant cultures. Cultured cells were analyzed using immunofluorescence staining and reverse transcription-polymerase chain reaction. RESULTS: OLF cells exhibited various appearances compared with the typical fibroblast-like morphology of non-OLF cells. Expressions of collagen type I and collagen type III were observed in OLF and non-OLF cells. OLF cells uniquely expressed osteocalcin, which is a marker for osteoblasts, and collagen type II which is a marker for chondrocytes, whereas they were negative in non-OLF cells. CONCLUSION: These findings indicate that OLF cells have phenotypic characterization of osteoblasts and chondrocytes which could play a role in the pathophysiology of OLF.
Adolescent ; Adult ; Aged ; Cells, Cultured ; Collagen Type I/genetics/metabolism ; Collagen Type II/genetics/metabolism ; Collagen Type VI/genetics/metabolism ; Female ; Humans ; Ligamentum Flavum/metabolism/*pathology ; Male ; Microscopy, Fluorescence ; Middle Aged ; Ossification, Heterotopic/metabolism/*pathology ; Osteocalcin/genetics/metabolism ; Reverse Transcriptase Polymerase Chain Reaction ; Young Adult