Ligament Flavum Research Articles

Arthroscopic-assisted uni-portal ligament flavum sparing bone anchoring annular suture technique for lumbar disc herniation: A case report and literature review.

Lumbar disc herniation (LDH) manifests in diverse forms. If the nucleus pulposus or endplate tissues protrudes, the location of annular tears also varies, which poses various challenges for the annular suture technique. Tears at the annular attachment area at the edge of the vertebral body (cephalad or caudad) are considered a prohibitively challenging area for annular suturing. A 37-year-old woman presented with a gradual onset of symptoms, experiencing leg pain and numbness over the left leg for 1 year before presentation. The pain radiated to the left S1 dermatome. Despite undergoing continuous medical therapy for more than 6 months, her symptoms showed no improvement. The strength of the left plantar flexion in the ankle and great toe was rated at 4 out of 5. The straight leg-raising and strengthening tests were positive for the left sides. Lumbar computed tomography and magnetic resonance imaging revealed left-sided disc herniation at the L5-S1 level, and nerve root compression, confirming the diagnosis of LDH. The preoperative impression was LDH, intraoperative confirmation of a tear in the annular attachment area at the vertebral body edge. This patient was treated with an arthroscopic-assisted uniportal spinal surgery (AUSS) technique focusing on ligament flavum (LF) preservation, protruding nucleus pulposus removal, nerve root decompression, and vertebral edge tear was then sutured using a bone anchoring annular suture with the Smile suture device. This technique was performed successfully in a patient with LDH. Significant improvements were observed in postoperative pain and numbness, Visual Analog Scale, and Japanese Orthopaedic Association scores. No postoperative instability or complications were observed, with computed tomography and magnetic resonance imaging confirming complete decompression. To the best of our knowledge, this is the first used AUSS with LF preservation and bone anchoring annular suture technique for LDH. This case study demonstrates the AUSS combined with LF preservation and the bone anchoring annular suture technique provides favorable clinical and imaging outcomes and is a safe and effective technique for the treatment of LDH.

Surgery on the C3-4 Level and the Presence of Ligamentum Flavum Hypertrophy Increases the Risk of 30-Day Reoperation Rate After Anterior Cervical Discectomy and Fusion

BACKGROUND AND OBJECTIVES: Cervical myelopathy caused by C3-4 level degeneration often exhibits different characteristics after anterior cervical discectomy and fusion (ACDF) than other cervical levels. This study compared the outcomes of C3-4 ACDF with surgeries at other levels and identified risk factors of 30-day reoperation after ACDF. METHODS: We retrospectively analyzed patients who underwent ACDF for degenerative cervical disease from 2018 to 2023. The patients were divided into 2 groups based on the level of surgery: C3-4 and non–C3-4 groups. Radiological outcomes, including cervical alignment and range of motion (ROM), were analyzed. Clinical outcomes were assessed with patient-reported outcomes and the rates of 30-day reoperation and complications after ACDF. Patient-reported outcomes included visual analog scale for neck pain, visual analog scale for arm pain, and modified Japanese Orthopedic Association scores. Risk factors of 30-day reoperation were assessed. RESULTS: Of 259 patients, 74 (28.6%) and 185 (71.4%) were in the C3-4 and non–C3-4 groups, respectively. The C3-4 group exhibited lower C2-7 ROM (P = .019), higher C3-4 ROM (P = .015), and greater C3-4 %ROM (P = .014). The C3-4 group demonstrated lower preoperative and 1-month postoperative modified Japanese Orthopedic Association scores (P < .001; P < .001, respectively). The rate of 30-day reoperation was significantly higher in the C3-4 group (9.5%) compared with the non–C3-4 group (2.2%) (P = .014). In addition, C3-4 surgical level (odds ratio = 4.99, P = .034) and ligament flavum hypertrophy (odds ratio = 5.84, P = .018) were identified as independent risk factors of 30-day reoperation after ACDF. CONCLUSION: Surgery on C3-4 level showed a higher risk of 30-day reoperation than other levels. It is likely due to C3-4 surgical level, and ligament flavum hypertrophy contributes to cord compression, particularly in the unstable early postoperative period.

Severe Rigid Scoliosis Deformity Correction Using Extended Posterior Release and Instrumentation: A Retrospective Study.

Sever rigid scoliotic deformity (magnitude of the curve >80° and <25% correction on bending film) correction is a great challenge to spine surgeons. Severe scoliosis when untreated or not treated properly, may lead to severe complications due to curve progression. The aim of operative management is to achieve significant correction of sagittal, coronal, and rotational deformity to avoid neurodeficit, maintain sagittal balance, and improve cardiopulmonary function. In this retrospective study, eight patients with severe rigid scoliosis who underwent through single-staged extended posterior release and spinal fusion between March 2022 and November 2023. The surgical procedures were the excision of the posterior ligament and spinous process, laminectomy, excision of ligament flavum, facetectomy, and posterior spinal fusion utilizing pedicle screws, rods, and sub-laminar wires. Patients were evaluated radiologically using posteroanterior and lateral X-rays of the whole spine and computed tomography scans. Demographic data, pre- and post-operative cobbs angle, osteotomized segment, instrumentation segments, blood loss, operation duration, follow-up duration, and complications were recorded. Pre-operative mean cobbs angle was 94.1° (range 83-110°) and post-operative mean cobbs angle was 33.3° (range 28-42°) with 64.6% scoliosis correction. The mean estimated blood loss was 517 mL (range 300-580 mL). The mean operation duration was 272.5 min (210-340 min). Mean spinal fixation fusion segments were 11.1 (range 8-14). No major complications were noted. Our study concluded that extended posterior-only release, facetectomy, and posterior spinal fusion by utilizing pedicle screws and pre-contoured rods significantly corrected severe and rigid scoliosis with a high correction rate and avoid complications of anterior release. Hence, we can achieve remarkable correction in rigid scoliosis using the proper choice of levels, proper implant, and extended posterior release.

Current Approaches, Significance and Prognostic Impact of Lumbar Ligament Flavum Preserving Surgeries

Objectives: The aim of this study is to evaluate the use of flavum-preserving surgeries in lumbar disc herniation surgery, compare their clinical outcomes with standard microdiscectomy techniques, and demonstrate the transflaval microdiscectomy technique.&#x0D; Material and Methods: Between 2020 and 2023, a total of 48 patients who underwent transflaval microdiscectomy and 48 patients who underwent standard microdiscectomy at a single center were included in the study. Epidemiologic characteristics of the groups were described, and preoperative and postoperative visual analoge scale scores for leg pain (LPVAS) and back pain (BPVAS) were retrospectively analyzed.&#x0D; Results: There is no significant difference between the groups in preoperative mean LPVAS scores (p=0,474) and there is no significant difference between the groups in postoperative mean LPVAS scores (p=0,598). There is no significant difference between the groups in preoperative mean BPVAS scores (p=0,608). However there is a significant difference between the groups in postoperative mean BPVAS scores (p

Biportal endoscopic spinal decompression for lumbar stenosis using the "Z" technique. Our experience in the first 50 cases of in-block flavum ligament removal (the butterfly challenge)

Biportal endoscopic spinal decompression for lumbar stenosis using the "Z" technique. Our experience in the first 50 cases of in-block flavum ligament removal (the butterfly challenge)

Unilateral Biportal Endoscopic Laminectomy-Bilateral Decompression Using a Monoportal Scope and Bipolar Coagulator for Lumbar Spinal Stenosis: A Technical Report.

The purpose of this study was to introduce the application of a monoportal scope and bipolar coagulator used in full-endoscopic spine surgery (FESS) for unilateral biportal endoscopy-unilateral laminectomy bilateral decompression (UBE-ULBD) in those with central stenosis. A 68-year-old man who presented with cauda equina symptoms underwent UBE-ULBD to improve his central stenosis at the L2/3 level. In this technique, a FESS scope was attached to a camera portal in place of a common arthroscope. A decompression tool was subsequently inserted through the working portal, and the lower border of the vertebral lamina and the lower border of the contralateral lamina were resected. Additionally, the superior border of the L3 level was thinned using a high-speed drill, and the ligament flavum was excised. The operation time was 70 minutes, and his symptoms improved. The patient was discharged from the hospital four days postoperatively. We found three advantages of using a FESS scope and bipolar coagulator, including the ability to 1) stabilize the camera via placement of the sleeve against the bone, 2) minimize the wounded area by irrigating saline on the side of the scope, and 3) provide bipolar tissue hemostasis in an isolated area around the nerves. Therefore, among the UBE techniques, we believe that assisted full-endoscopic spine surgery (AFESS) is a viable option to offer a more minimally invasive surgery for patients with stenosis.

Effect of graded posterior element and ligament removal on annulus stress and segmental stability in lumbar spine stenosis: a finite element analysis study.

The study aimed to investigate the impact of posterior element and ligament removal on the maximum von Mises stress, and maximum shear stress of the eight-layer annulus for treating stenosis at the L3-L4 and L4-L5 levels in the lumbar spine. Previous studies have indicated that laminectomy alone can result in segmental instability unless fusion is performed. However, no direct correlations have been established regarding the impact of posterior and ligament removal. To address this gap, four models were developed: Model 1 represented the intact L2-L5 model, while model 2 involved a unilateral laminotomy involving the removal of a section of the L4 inferior lamina and 50% of the ligament flavum between L4 and L5. Model 3 consisted of a complete laminectomy, which included the removal of the spinous process and lamina of L4, as well as the relevant connecting ligaments between L3-L4 and L4-L5 (ligament flavum, interspinous ligament, supraspinous ligament). In the fourth model, a complete laminectomy with 50% facetectomy was conducted. This involved the same removals as in model 3, along with a 50% removal of the inferior/superior facets of L4 and a 50% removal of the facet capsular ligaments between L3-L4 and L4-L5. The results indicated a significant change in the range of motion (ROM) at the L3-L4 and L4-L5 levels during flexion and torque situations, but no significant change during extension and bending simulation. The ROM increased by 10% from model 1 and 2 to model 3, and by 20% to model 4 during flexion simulation. The maximum shear stress and maximum von-Mises stress of the annulus and nucleus at the L3-L4 levels exhibited the greatest increase during flexion. In all eight layers of the annulus, there was an observed increase in both the maximum shear stress and maximum von-Mises stress from model 1&2 to model 3 and model 4, with the highest rate of increase noted in layers 7&8. These findings suggest that graded posterior element and ligament removal have a notable impact on stress distribution and range of motion in the lumbar spine, particularly during flexion.

Comparison of ligamentum flavum thickness between central and lateral lesions in a patient with central lumbar spinal canal stenosis.

Thickened ligamentum flavum has been considered as a major cause of central lumbar spinal canal stenosis (CLSCS). Previous studies have demonstrated that ligamentum flavum thickness (LFT) is correlated with aging, degenerative spinal stenosis, and disc degeneration. Thus, hypertrophy of the ligamentum flavum is a major cause of CLSCS, and measurement of LFT has been considered a morphologic parameter in the diagnosis of CLSCS. To our knowledge, comparison of LFT between central and lateral lesions has not been reported. In addition, no research has analyzed best clinical cutoff values of central ligament flavum thickness (CLFT) and lateral ligament flavum thickness (LLFT). This study aimed to compare CLFT with LLFT in patients with CLSCS and further compare the CLFT and LLFT findings between the 2 groups to analyze LFT variation. Both CLFT and LLFT samples were collected from 101 participants with CLSCS and from 103 participants in the control group who underwent lumbar magnetic resonance imaging without evidence of CLSCS. Axial T2-weighted lumbar magnetic resonance scans were acquired at the L4 to 5 facet joint level from each participant. Average CLFT value was 2.25 ± 0.51 mm in the control group and 4.02 ± 0.74 mm in the CLSCS group. Average LLFT value was 2.50 ± 0.51 mm in the control group and 3.38 ± 0.66 mm in the CLSCS group. CLSCS patients had significantly higher CLFT and LLFT (both P < .001). Regarding the validity of both CLFT and LLFT as predictors of CLSCS, a receiver operating characteristic estimation revealed that the most suitable cutoff value for CLFT was 3.10 mm, with sensitivity of 95.0%, specificity of 94.2%, and an area under the curve of 0.97. The best cut-off value of LLFT was 2.92 mm, with sensitivity of 78.2%, specificity of 77.7%, and area under the curve of 0.87. We have 4 important new findings: The mean CLFT is significantly lower than that of the mean LLFT in the normal control group; CLFT and LLFT are both significantly associated with CLSCS; Increase rate of CLFT is faster than that of LLFT in the CLSCS group; and CLFT is a more sensitive measurement parameter to predict CLSCS than LLFT.

Protocol for Ultrasound-guided Acupotomy Procedure at Ligament Flavum

Protocol for Ultrasound-guided Acupotomy Procedure at Ligament Flavum

679 Epidural Hypertension Theory in Patients With Lumbar Spinal Stenosis

INTRODUCTION: Laminectomy is the standard of treatment in Lumbar Spinal Stenosis(LSS). Multiple studies (Mariconda;Boden;Schonstrom;Matsumoto;Herno;Webber.) have not found relationship between spinal canal widening and symptoms improvement in LSS. Neurogenic compression and rootlets hypoxia theories try to explain pathophysiology of LSS. We propose Epidural Hypertension (EH) as a new paradigm that explains dynamic stress of neural structures involved in LSS. METHODS: Group A: single-segment LSS diagnosed by magnetic resonance (n = 4). Group B: Patients without LSS requiring surgery for another diagnosis (spinal cord stimulation, foraminotomy) (n = 3). Laminectomy was performed, previously, flavum ligament was meticulously dissected and a pressure microsensor was inserted in epidural space in stenotic segment. EP was measured in 0 and 50° extension in order to extrapolate EP in standing position. RESULTS: EP in LSS patients was 18,5 mmHg at 0° (IQR 16.5-37.5 mmHg) and 26 mmHg at 50° (IQR 20-34.5 mmHg). In patients without LSS, EP was 8mmHg at 0° (IQR 1-8 mmHg) and 3 mmHg at 50° (IQR 1-12 mmHg). We found differences using Wilcoxon's test. EP was greater in patients with LSS at 0° (p = 0.031) y 50° (p = 0.034). CONCLUSIONS: EH may play a foundamental role in pathophysiology of LSS. In Patients without LSS we found a drop in EP at 50° possibly secondary to caudal CSF displacement. In LSS patients we found a raise in EP at 50° possibly secondary to spinal canal narrowing impeding normal CSF flow increasing hydrostatic pressure in the stenotic segment. This results might be the first step to consider EH as a treatment target in LSS and determine its relationship with LSS symptoms.

Prevalence, Distribution, and Concomitance of Whole-Spine Ossification of the Posterior Longitudinal Ligament and Ossification of the Ligament Flavum in South Koreans: A Whole-Spine-CT-Based Cross-Sectional Study.

No studies assessing the prevalence of ossification of the spinal ligament were conducted using whole-spine positron emission tomography and computed tomography (PET-CT) in healthy Koreans. We aimed to determine the prevalence of ossification of the posterior longitudinal ligament (OPLL) and ossification of the ligament flavum (OLF) in healthy Koreans using whole-body PET-CT. We reviewed whole-body PET-CT images captured during general health checkups at the General Health Promotion Center of our institution from January 2015 to 2020. OPLL and OLF were identified by the presence of heterotopic ossification in the posterior longitudinal ligament and ligament flavum on axial and sagittal PET-CT images. A total of 1,934 adults (1,645 men, 289 women) were included. The mean age was 48.05 years (range, 28-86 years). Among the 1,934 patients, 173 had OPLL (8.9%). The most commonly involved cervical vertebra levels arranged according to frequency were C4, C5, C3, and C6. OLF was observed in 125 patients (6.5%). The most commonly involved thoracic levels were T10, T11, and T5. The prevalence of OPLL and OLF was the highest in patients aged 60-69 years. Among the C-OPLL patients, 15.1% had T-OPLL, 5.0% had L-OPLL, and 25.8% had T-OLF. Our study revealed the prevalence of OPLL and OLF in healthy Korean subjects. It was consistent with that in other Asian countries. The presence of OPLL and OLF at most locations correlated with the presence or absence of spinal ossification at other locations.

Ultrasound-Guided In-Plane Interlaminar Lumbar Endoscopic Approach with Smartphone and Portable Light Source: Description of a New Surgical Technique

Abstract Introduction Endoscopic spine surgery enables the minimally invasive treatment of pathologies affecting the spinal cord and roots. Herein we describe an unprecedented technique Ultrasound-Guided in-plane interlaminar lumbar endoscopic approach with a smartphone and portable light source. Methods The interlaminar approach was performed in a cadaveric specimen at L4 to 5 and L5 to S1 bilaterally. A curvilinear 2 to 5 MHz ultrasound probe was employed, the puncture was performed with the needle, a guide wire was inserted until the flavum ligament, followed by the dilator and working cannula. A 30° spinal endoscope, with an optical adapter of the endoscope camera for smartphone and portable endoscope lighting was inserted, the flavum ligament was visualized, and an opening in this site was performed with the scissors. Open dissection of the specimen was subsequently performed by identifying the puncture site in the interlaminar window. Results The four interlaminar punctures were successfully guided by ultrasound; the opening of the ligamentum flavum was performed in the most lateral part of the interlaminar space, near the junction of the superior and inferior articular processes of the corresponding vertebrae in all the punctures. Discussion The ultrasound makes possible to identify facets, foramina, transverse processes, and the interlaminar space. It is possible to minimize the use of radioscopy and its associated risks, both for patients and health professionals. Conclusions The ultrasound-guided, in-plane, interlaminar, lumbar endoscopic approach with smartphone-adapted endoscope and portable light source is feasible and practical, minimizing radiation risks and making it possible to perform endoscopic spinal surgery.

Fibrotic and inflammatory characteristics of epidural fat adjacent to the ossification area in patients with ossification of the ligament flavum.

To observe histological and inflammatory characteristics of epidural fat (EF) adjacent to the ossification area in patients with ossification of the thoracic ligament flavum (TOLF) and provide a preliminary research basis for investigating the impact of the EF on OLF. Samples of EF and autologous subcutaneous adipose tissue (SCAT) from TOLF patients (n=26) and non-TOLF patients (n=23) were harvested during posterior thoracic spine surgery. Adipocyte size and fibrosis were measured by histology. Vascularization and inflammatory cell infiltration were evaluated by immunohistochemical staining. Adipogenesis-related genes were assessed by real-time quantitative PCR. Conditioned media from cultured EF were evaluated via enzyme-linked immunosorbent assay to detect the secretion of inflammatory cytokines, including interleukin-6 (IL-6), tumor necrosis factor (TNF-α), and leptin. The phosphorylated STAT3 protein level in ligament flavum (LF) was examined using Western blot. Adipocytes size in EF was similar between in the TOLF and non-TOLF groups, but significantly smaller than that from autologous SCAT. Adipogenesis-related mRNA expression in EF was lower than that in SCAT. More fibrosis and vascularization were found in TOLF than in non-TOLF. EF in the TOLF group exhibited more macrophages and B lymphocytes infiltrated. The levels of cytokines such as IL-6, TNF-α, and leptin secreted by EF were significantly higher in the TOLF group than non-TOLF. The level of phosphorylated STAT3 in LF was significantly upregulated in the TOLF group. Morphologically, EF adjacent to the ossification area is smaller and more uniform than autologous SCAT, exhibiting a characteristic similarity to visceral fat. EF in the TOLF group shows a more fibrotic, vascularized, and inflammatory phenotype, which secretes multiple cytokines. The phosphorylated STAT3 protein was significantly upregulated in the TOLF group. Whether these properties of EF directly affect the process of OLF needs to be further explored.

Calcium pyrophosphate dihydrate of the ligamentum flavum in the cervical spine - A review of the literature.

Calcium pyrophosphate dihydrate (CPPD) deposition, also known as pseudogout, in the cervical ligamentum flavum (CLF), is a rare disease which can cause spinal cord signaling changes leading to rapid deterioration in function. The natural history of cervical myelopathy as a result of CPPD deposition within the CLF is not well understood. Our objective is to describe the presentation, imaging findings, and treatment options of CPPD deposition or pseudogout of the cervical spine. Using PubMed, we analyzed studies published from 1978 to 2022. Key words used were "pseudogout," "CPPD deposit disease," "cervical yellow ligament," "CLF," and "cervical spine." We excluded "crowned dense syndrome" and "ossification of ligament flavum." Using a department database, we queried for patients treated for CPPD of the cervical spine. Twenty clinical studies on CPPD of the cervical spine with 69 patients aged between 15 and 92 years (mean = 72) were identified. Neck pain and numbness of the hands were the most common symptoms. Diabetes mellitus and hypertension were the most common comorbidities. Males and females were affected at equal rates. C4-C5 and C5-C6 were the most affected segments. Earlier surgical treatment produced better outcomes. A laminectomy and fusion or laminoplasty were the most common procedures performed with most patients experiencing some return of neurologic function. Although rare, CPPD deposit disease in the CLF should be readily considered as a differential diagnosis due to the continuously aging population. CPPD's progressively worsening nature makes an early diagnosis and treatment important in improving the patient's overall quality of life.

Analysis of the surgical strategy and postoperative clinical effect of thoracic ossification of ligament flavum with dural ossification.

PurposeOur research was designed to analyse the postoperative clinical results of patients suffering from single-segment thoracic ossification of the ligamentum flavum (TOLF) combined with dural ossification (DO) who underwent posterior laminar decompression and internal fixation.MethodsThis retrospective research included thirty-two patients who underwent surgery for ossifying the ligamentum flavum in the thoracic spine between January 2016 and January 2020. Patients were fallen into one group included patients with evidence of DO during surgery, and the other group included patients without evidence of DO. We assessed and compared general clinical characteristics and health-related outcomes before surgery and during follow-up.ResultsThe DO group had a longer operation duration, more blood loss, and longer hospital stay (operation time: 94.75 ± 6.78 min vs. 80.00 ± 10.13 min, p < 0.001; blood loss: 331.67 ± 50.06 ml vs. 253.00 ± 48.24 ml, p < 0.001; length of hospital stay: 13.83 ± 2.76 days vs. 10.05 ± 2.33 days, p < 0.001).ComplicationsThere were 12 cases of cerebrospinal fluid leakage and 1 case of superficial wound infection in the DO group. However, the neurological recovery and health-associated quality of life (HRQOL) scores showed no statistically significant changes between the DO and non-DO groups (p > 0.05).ConclusionsPosterior laminectomy and internal fixation combined with intraoperative resection of the ossified ligamentum flavum and dura is an efficient and relatively safe method for treating TOLF with DO, which can provide satisfactory results. Moreover, DO had no significant effect on postoperative neurological recovery and health-related quality of life scores.

Histological difference in ligament flavum between degenerative lumbar canal stenosis and non-stenotic group: A prospective, comparative study.

BACKGROUNDLigament flavum (LF) hypertropy is the main etiopathogenesis of lumbar canal stenosis (LCS). The purely elastic LF undergoes a morphological adaptation including a reduction in the elastic fibers and a consequent increase in the collagen content, fibrosis, cicatrization, and calcification. However, the morphometric analysis can delineate the LF in patients with LCS from those without LCS, which would help in better understanding LCS pathogenesis.AIMTo compare the histopathological changes in LF between the degenerative LCS and non-stenotic (non-LCS) group.METHODSThe present prospective study was conducted in 82 patients who were divided into two groups, namely LCS and non-LCS. Demographic details of the patients such as duration of symptoms, level of involvement, and number of segments were recorded. The LF obtained from both groups was histopathologically examined for the fibrosis score, elastic fiber degeneration, calcification, and chondroid metaplasia. Morphometrical details included a change in elastin and collagen percentages, elastin/collagen ratio, elastic fiber fragmentation, and ligamentocyte numbers. All parameters were compared between the two groups by using the independent t test, Chi-square test, and Pearson’s correlation test.RESULTSOut of 82 cases, 74 were analysed, 34 in LCS and 40 in non-LCS group. The mean ± SD age of presentation in LCS and non- LCS group was 49.2 ± 8.9 and 43.1 ± 14.3 respectively. The LCS group (n = 34) exhibited significant differences in fibrosis (P = 0.002), elastic fiber degeneration (P = 0.01), % elastic fragmentation (66.5 ± 16.3 vs 29.5 ± 16.9), % elastic, content (26.9 ± 6.7 vs 34.7 ± 8.4), % collagen content (63.6 ± 10.4 vs 54.9 ± 6.4), reduction of elastic/collagen (0.4 ± 0.1 vs 0.6 ± 0.1), and ligamentocyte number (39.1 ± 19.1 vs 53.5 ± 26.9) as compared to non-LCS group (n = 40). The calcification (P = 0.08) and Pearson’s correlation between duration and loss of elastin was not significant. The difference in LF morphology is consistent in patient’s ≥ 40 years of age among the groups as found in subgroup analysis. Similarly in the patents < 40 and > 40 in the non-LCS group.CONCLUSIONLF is vital in the pathogenesis of LCS. The purely elastic LF undergoes a morphological adaptation that includes a reduction in the elastic fibers with a consequent increase in the collagen content, fibrosis, cicatrization, and calcification. The present study provides a detailed morphometric analysis to semiquantitatively delineate the LF changes in patients with LCS from those in patients without LCS.

Which factor can predict the effect of indirect decompression using oblique lumbar interbody fusion?

The aim of this study was to investigate the association between various factors of indirect decompression. Previous studies have demonstrated the effectiveness of indirect decompression. There is no consensus regarding the predictive factors for indirect decompression. Facet joint gap (FJG) and bulging disc thickness (BDT) have never been considered as factors in other studies.We retrospectively reviewed 62 patients who underwent OLIF L4/5 between April 2018 and September 2020. The relationships between cross-sectional area (CSA) change, CSA change ratio, spinal stenosis grade, and various factors were studied. Various factors related to indirect decompression, such as ligament flavum thickness (LFT), foraminal area (FA), disc height (DH), bulging disc thickness(BDT), and facet joint gap (FJG), were measured.CSA increased from 69.72 mm2 preoperatively to 115.95 mm2 postoperatively (P < .001). BDT decreased from 4.97 mm preoperatively to 2.56 mm postoperatively (P < .001). FJG (Right) increased from 2.99 mm preoperatively to 4.38 mm postoperatively (P < .001). FJG (Left) increased from 2.95 mm preoperatively to 4.52 mm postoperatively (P < .001). The improvement of spinal stenosis grade was as follows: 1 point up group, 38 patients; 2 point up groups, 19 patients; and 3 point up groups, 3 patients. The correlation factors were prespinal stenosis grade (0.723, P < .00), CSA change (0.490, P < .00), and FJG change ratio (left, 0.336, P < .008).FJG showed statistical significance with indirect decompression. Indirect decompression principles might be utilized in patients with severe spinal canal stenosis (even grade 4).

Clinical Characteristics of Patients with Ossification of the Posterior Longitudinal Ligament and a High OP Index: A Multicenter Cross-Sectional Study (JOSL Study).

Background: The purpose of this study was to clarify the clinical features of ossification of the posterior longitudinal ligament (OPLL) and extreme ossification at multiple sites. Methods: This prospective study involved patients with a diagnosis of cervical OPLL at 16 institutions in Japan. Patient-reported outcome measures, including responses on the Japanese Orthopaedic Association (JOA) Cervical Myelopathy Evaluation Questionnaire (JOA-CMEQ), JOA Back Pain Evaluation Questionnaire (JOA-BPEQ), and visual analog scale pain score, were collected to investigate clinical status. In each patient, the sum of the levels at which OPLL was located (OP index) was evaluated on whole-spine computed tomography, along with ossification of other spinal ligaments including the anterior longitudinal ligament (OALL), ligament flavum (OLF), supra- and intraspinous ligaments (SSL), and diffuse idiopathic skeletal hyperostosis (DISH). The distribution of OP index values in the study population was investigated, and the clinical and radiologic characteristics of patients in the top 10% were assessed. Results: In total, 236 patients (163 male, 73 female; mean age 63.5 years) were enrolled. Twenty-five patients with OP index ≥ 17 were categorized into a high OP index group and the remainder into a moderate/low OP index group. There were significantly more women in the high OP index group. Patients in the high OP index group also had significantly poorer scores for lower extremity function and quality of life on the JOA-CMEQ and in each domain but not for body pain on the JOA-BPEQ compared with those in the moderate/low OP index group. Patients in the high OP index group had more OALL in the cervical spine and more OLF and SSL in the thoracic spine. The prevalence of DISH was also significantly higher in the high OP index group. In the high OP index group, interestingly, OPLL was likely to be present adjacent to DISH in the cervicothoracic and thoracolumbar spine, especially in men, and often coexisted with DISH in the thoracic spine in women. Conclusion: This prospective cohort registry study is the first to demonstrate the clinical and radiologic features of patients with OPLL and a high OP index. In this study, patients with a high OP index had poorer physical function in the lumbar spine and lower extremities and were also predisposed to extreme ossification of spinal ligaments other than the OPLL.

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

The aim of the study was to assess the relationship between the expression of elastin, collagen type I, II,III and the degenera- tion of the facet joint capsule and the ligamentum flavum. 10 patients (4 male, 6 female) (mean age 61 ± 14,9) undergoing surgery for degenerative lumbar spine syndrome and 5 cadav- ers (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. 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 accord- ing to Pfirrmann and the degree of facet joint osteoarthritis according to Fujiwara, all of them without statistical significance. 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 III, Diagnostic Study.

The Change of Spinal Canal According to Oblique Lumbar Interbody Fusion in Degenerative Spondylolisthesis: A Prospective Observational Study.

ObjectiveOblique lumbar interbody fusion (OLIF) involves inserting large cages into the interbody disc space. This expands the spinal canal and neural foramen by stretching the ligament flavum and releasing the facet joint, resulting in indirect neural decompression. Our objective was to investigate the changes in the spinal canal and ligament flavum over time after OLIF. MethodsThis was a prospective observational study involving 30 patients who underwent OLIF L4–5 between 2015 and 2018. In total, 27 of the 30 patients underwent preoperative, early follow-up (< 5 days), and late follow-up (10–14 months) magnetic resonance imaging to measure the area of the spinal canal and ligament flavum. Based on the results, the patients were divided into subsidence and nonsubsidence groups for further analysis. ResultsAfter OLIF, the spinal canal area gradually increased during the preoperative, early postoperative, and late postoperative periods (p<0.001). The thickness and area of the ligament flavum decreased gradually over the same periods (p<0.001). Low-grade subsidence (2–4.4 mm) did not influence the effects on the spinal canal and ligament. ConclusionAfter OLIF, the spinal canal and ligament flavum gradually change, which is effective for indirect neural decompression. In addition, the effects of low-grade subsidence on the remodeling of the spinal canal and ligament flavum are insignificant.