Ossification Of The Posterior Longitudinal Ligament Research Articles

Clinical study of percutaneous endoscopic thoracic spine surgery via trench technique for thoracic spinal cord ventral decompression

To evaluate the feasibility, safety, and early effectiveness of percutaneous endoscopic thoracic spine surgery via the trench technique for ventral decompression in central calcified thoracic disc herniation (CCTDH) and thoracic ossification of the posterior longitudinal ligament (T-OPLL). Seven patients with single-segment CCTDH or T-OPLL admitted between June 2017 and May 2020 and meeting the selection criteria were retrospectively analyzed. There were 3 males and 4 females with an average age of 51.7 years ranging from 41 to 62 years. There were 2 patients with T-OPLL (T 1, 2 in 2 cases) and 5 patients with CCTDH (T 1, 2 in 1 case, T 7, 8 in 1 case, T 10, 11 in 2 cases, T 11, 12 in 1 case). Five patients with thoracic axial pain and intercostal neuralgia had a preoperative visual analogue scale (VAS) score of 6.0 (5.0, 6.5), and 7 patients had a preoperative Japanese Orthopaedic Association (JOA) score of 21 (21.0, 22.0). Transforaminal approach was used in 4 cases and transpedicular approach in 3 cases. Ventral decompression of thoracic spinal cord was performed by thoracic endoscopy combined with trench technique. The operation time, intraoperative blood loss, postoperative hospital stay, and postoperative complications were recorded. Thoracic spine CT and MRI were performed preoperatively and postoperatively to evaluate the surgical decompression, VAS score was used to evaluate the pain of thoracic back and lower limbs, and JOA score was used to evaluate the functional recovery. Modified MacNab criteria was used to evaluate the effectiveness. All surgeries were successfully completed. The operation time ranged from 60 to 100 minutes, with an average of 80.4 minutes; the intraoperative blood loss ranged from 40 to 75 mL, with an average of 57.1 mL; the postoperative hospital stay ranged from 4 to 7 days, with an average of 5.4 days. CT and MRI examinations indicated that the decompression was adequate. All 7 patients were followed up 3-22 months, with an average of 13.3 months. One case developed postoperative wound infection, and 1 case developed pneumonia; the remaining patients did not have any complications such as wound infection or cerebrospinal fluid leakage. Five patients with thoracic axial pain and intercostal neuralgia had VAS scores of 2.0 (1.5, 2.5) at 1 day after operation and 2.0 (1.0, 2.0) at last follow-up, both of which were significantly lower than the preoperative scores ( P<0.05). At 1 day after operation, the JOA scores for all 7 patients were 22.0 (21.0, 24.0), which showed no significant difference compared to the preoperative score ( P>0.05); however, at last follow-up, the score improved to 24.0 (24.0, 26.0), which was significant compared to the preoperative scores ( P<0.05). At last follow-up, the effectiveness was assessed using the modified MacNab criteria, the results were excellent in 2 cases, good in 3 cases, fair in 2 cases, and the excellent and good rate was 71.4%. Using the trench technique, percutaneous endoscopic thoracic spine surgery can achieve the ventral decompression in CCTDH and T-OPLL, providing a new approach for surgical treatment of CCTDH and T-OPLL.

Investigation of the Association Between Hyperlipidemia and Ossification of The Posterior Longitudinal Ligament Through Two-Sample Mendelian Randomization Analysis.

A Two-Sample Mendelian Randomization Analysis. This study aimed to investigate the association between genetically predicted hyperlipidemia and ossification of the posterior longitudinal ligament (OPLL) using two-sample Mendelian randomization (MR) analysis. Several observational studies suggested associations between hyperlipidemia and OPLL. Genome-wide association study (GWAS) summary statistics for hyperlipidemia and OPLL were retrieved from the public database. The MR analysis employed the Inverse Variance Weighted (IVW) method, which was supplemented by MR-Egger, weighted median, and weighted mode analyses. Sensitivity analyses, incorporating Cochran's Q test, MR-Egger regression and the MR pleiotropy residual sum and outlier test, additionally assessed the robustness of the findings. The IVW analysis revealed a significant association between total cholesterol levels and OPLL (OR: 1.44,95% CI:1.06-1.96, P=0.02). Similarly, a significant association was observed between LDL cholesterol and OPLL (OR: 1.31,95%CI:1.05-1.63, P=0.02). Supplementary analyses further supported the significant association of total cholesterol levels and LDL cholesterol on OPLL (P <0.05). In sensitivity analyses, LDL cholesterol exposure showed robust results, with no outliers detected by loo or mrpresso, despite MR-Egger hints at pleiotropy. For total cholesterol exposure, MR-Egger suggested no pleiotropy, though heterogeneity and outliers were present. Outlier removal confirmed the initial positive association, underlining study stability. However, no significant associations were found of hyperlipidemia, triglycerides, HDL cholesterol on OPLL. This study suggests a association of total cholesterol levels and LDL cholesterol levels on OPLL. Further research is warranted to validate these findings and explore potential therapeutic implications.

Review/Perspective: Incidence and treatment of CSF leaks/dural tears (DT) occurring during anterior cervical surgery

Background: The incidence of cerebrospinal fluid (CSF) leaks/dural tears (DT) occurring during anterior cervical diskectomy and fusion (ACDF) are typically relatively low. However, this frequency markedly increases when anterior corpectomy and fusion (ACF) are performed to address ossification of the posterior longitudinal ligament (OPLL). Methods: The reported frequencies of CSF leaks/DT occurring during elective ACDF (i.e. exclusive of trauma), ranges from 0.24% to 1.7%. Notably, this incidence substantially rises for multilevel ACF addressing anterior OPLL, markedly varying from 3.4 - 44.7%. Results: The classical risks of anterior cervical CSF leaks/DT with anterior cervical surgery may be minimized utilizing an operating microscope. For OPLL, careful evaluation of preoperative non-contrast CT studies is critical, especially to document whether any of the 3 signs of dural penetrance is present. Here, posterior operative choices should be strongly considered in the presence of sufficient lordosis and/or a Positive K Line (+ K Line) as this will avoid an anterior cervical CSF leak/dural fistula. Alternatively, for patients with kyphosis and a Negative K Line (- K Line), preoperative anticipation and planning to treat an intraoperative anterior CSF leak/DT (i.e. direct anterior primary dural graft repair with 7-0 Gore-Tex sutures, microdural staples, microfibrillar collagen, wound-peritoneal shunt, and lumbar drain or lumboperitneal shunt) are essential in the course of performing direct anterior OPLL resection. Conclusion: The incidence of anterior cervical CSF leaks/DT is relatively low (i.e. range 0.24 - 1.7%) where ACDF is performed for disc disease/spur/spondylosis exclusive of OPLL. However, where ACF is performed for multilevel OPLL, the risk of CSF Leaks/DT is substantially higher (i.e. range 4.3-44.7%).

Comparison of anterior vs. posterior surgery for cervical myelopathy due to OPLL: a systematic review and meta-analysis.

Systematic review and meta-analysis. To compare the effectiveness and safety between the anterior and posterior approach, and identify the more effective surgical approach for treating ossification of the posterior longitudinal ligament (OPLL) in the cervical spine. This meta-analysis searched three electronic databases (PubMed, Embase, Cochrane library), including 17 randomized and non-randomized controlled studies published since 2000-2023 that compared the effectiveness and safety of anterior and posterior surgical approaches for the treatment of ossification of the posterior longitudinal ligament. Japanese Orthopaedic Association (JOA) scores, functional recovery rates, excellent and good outcomes of the surgical approaches, Visual Analogue Scale (VAS), C2-C7 angle cobb and complication were analyzed. RevMan 5.3 was utilized for data analysis. This study suggested that there were no statistically differences between the anterior group and posterior group in terms of preoperative JOA score [WMD=0.23, 95% CI, (-0.22, 0.67), P=0.32], preoperative VAS [WMD=0.03, 95% CI, (-0.24, 0.30)], postoperative VAS [WMD=-0.16, 95% CI, (-0.47, 0.15) P=0.97] function recovery rate of patients with canal narrowing ratio less than 50-60% [WMD=-1.54, 95% CI, (-4.46, 1.38), P=0.30]. The anterior group showed higher postoperative JOA score [WMD=0.99, 95% CI, (036,1.63) P<0.05], post C2-C7 angle cobb [WMD=2.62, 95% CI, (0.36, 4.87), P=0.02] as well as function recovery rate (regardless of canal narrowing ratio) [WMD=16.05, 95% CI, (14.08, 18.03), P<0.05], especially a significant higher function recovery rate of patients with canal narrowing ratio greater than 50-60% [WMD=19.32, 95% CI, (17.25, 21.40), P<0.05]. There was a significant difference between anterior group and posterior group in complication. [OR=0.12, 95% CI, (0.01, 0.24), P<0.05]. Based on the study's finding, The study suggested that when the conservative treatment for OPLL is unsatisfied, the surgical approach of entering through the anterior approach is a better choice. Nevertheless, it is still necessary to consider the specific situation of the patient. One of the next research directions is how to reduce the complications of anterior surgery.

Direct anterior decompression in patients with ossification of the posterior longitudinal ligament significantly relieves short-segment spinal cord high signal

BackgroundIn patients with ossification of the posterior longitudinal ligament of the cervical spine (OPLL), high spinal cord signal (HCS) is frequently observed in the spinal cord of the corresponding segment. However, studies on the differences in the improvement of high spinal cord signal due to different surgical approaches are limited. The aim of this study was to investigate the improvement of high spinal cord signal in long and short segments with different choices of surgical approaches.MethodsIn this study, we conducted a meticulous review of medical records for patients diagnosed with ossification of the posterior longitudinal ligament (OPLL). Demographic variables, including gender, age, and body mass index (BMI), were systematically recorded. We evaluated the severity of neurological impairment using the Japanese Orthopaedic Association (JOA) scores both preoperatively and at multiple postoperative follow-up points. Neurological assessments were complemented by serial magnetic resonance imaging (MRI) T2-weighted imaging (T2WI) to measure the extent of high-signal changes (HCS) in the spinal cord, and the alteration of the HCS was quantified by the SCR (the ratio between the signal intensity value of the HCS region and the signal intensity value of the normal spinal cord region at C7-T1).ResultsIn the short-segment high signal change (HCS) group, comparisons of JOA score improvement (Recovery1) and HCS improvement (CR1) at 6 months postoperatively did not demonstrate significant differences between the surgical approaches (P > 0.05; Table 1). However, at the 2-year follow-up, patients who underwent anterior surgery exhibited significantly greater improvements in both JOA scores (Recovery2) and HCS (CR2), with statistical significance achieved (P < 0.05; Table 1). In contrast, in the long-segment HCS group, there was no significant difference between the anterior and posterior surgical approaches in terms of JOA improvement and HCS improvement at 6 months and 2 years postoperatively (P > 0.05; Table 2).ConclusionsIn patients with OPLL who present with spinal cord high signal, anterior surgery by resection of the ossified posterior longitudinal ligament and direct decompression is more conducive to regression of small spinal cord high signal and improvement of clinical neurological function if the extent of spinal cord high signal is small.

Is the Ossification of the Posterior Longitudinal Ligament a Positive Factor for the Fusion after Posterior Cervical Fusion and Decompression?

Objective: Multilevel posterior cervical fusion (PCF) and decompression surgery is a viable treatment option for multilevel ossification of posterior longitudinal ligament (OPLL) and spondylotic myelopathy. Since OPLL is known to affect bone formation, this study aimed to examine the effect of OPLL on the incidence of pseudarthrosis following PCF in a cohort study. Methods: We conducted a retrospective cohort study of patients with PCF and laminectomy at our institution. This study included patients who underwent C3 to C6 posterior fusion surgery involving lateral mass screw fixation without anterior surgery for OPLL or spondylotic myelopathy. Fusion status was evaluated 1 year postoperatively with computed tomography. Bone mineral density (BMD) and sagittal parameters were also evaluated as potential contributing factors to the fusion rate.Results: Eighty patients were included. Pseudarthrosis was observed in 22.5% (n=18) of patients. Pseudarthrosis incidence was lower in patients with OPLL (spondylosis vs. OPLL, 33.3% vs. 12.2%; p=0.003), and a higher BMD T-score (pseudarthrosis vs. fusion, -1.9 ± 0.7 vs. -0.6 ± 1.3; p&lt;0.01), a larger preoperative range of motion (ROM) (26.7 ± 13.3 vs. 17.6 ± 10.9; p=0.01), and a greater preoperative-to-postoperative decrease in cervical lordosis (-8.1 ± 7.9 vs. -2.7 ± 7.9; p&lt;0.01). Pseudarthrosis was associated with worsening neck pain after surgery. Conclusion: The absence of OPLL, lower BMD, larger preoperative ROM, and a greater decrease in postoperative cervical lordosis were identified as risk factors for pseudarthrosis after multiple PCF.

Reperfusion injury case following cervical fusion with OPLL: a case report and literature review

IntroductionSpinal cord ischemic reperfusion injury is characterized by an abrupt decline in neurological function and only a few cases have been published in literature. Herein, we present a white cord syndrome following anterior decompression cervical fusion.Case ReportA 54-year-old Jewish male patient was diagnosed with disc herniation among the intervertebral discs at C2, C3, C4, C6, and C7, along with ossification of the posterior longitudinal ligament, pressuring more to the right side of the spinal canal, ruling-out cervical myelopathy. Under general anesthesia and multimodal intraoperative monitoring, he underwent laminectomy surgery from C3 to C6 and cervical fixation from C3 to C7. No blood pressure fluctuations occurred during surgery, and complete pressure release was achieved on the spinal cord and the nerve roots. In addition, neuromonitoring did not indicate any nerve damage during the surgery. A neurologic exam in the post-anesthesia care unit revealed weakness in his right hand and leg. A brain computed tomography scan ruled out cerebrovascular accident, neck computed tomography revealed optimal implant position, and magnetic resonance imaging ruled out spinal cord distress or injury. We treated him with intravenous fluids, steroids, painkillers, and anticoagulants. Following surgery, we involved the occupational therapy department. After a few days, we observed a significant improvement in motor function in the right leg; however, there was no change in the right hand.ConclusionWhite cord syndrome likely arises from reperfusion injury subsequent to surgical decompression of a compressed spinal cord segment. Although infrequent, it is imperative for spine surgeons to recognize this potential complication and apprise patients of it prior to the procedure.

Identifying Factors for Predicting Postoperative Segmental Motor Paralysis in Patients Undergoing Anterior Cervical Spine Surgery: A Multicenter Study.

Retrospective cohort study. To investigate the incidence of and risk factors for segmental motor paralysis after anterior cervical spine surgery. Segmental motor paralysis is a potential complication following both anterior and posterior cervical decompression procedures; however, previous studies investigating risk factors for segmental motor paralysis after anterior cervical spine surgery were limited by small sample sizes. Consequently, the exact pathogenesis and risk factors for this complication remain poorly understood, highlighting the need for larger-scale investigations focused exclusively on anterior cervical spine surgeries. We retrospectively reviewed the clinico-demographic and operative factors and postoperative outcomes of 1,428 patients undergoing anterior cervical spine surgery at three spine centers in Japan. Postoperative segmental motor paralysis was defined as deterioration of upper extremity muscle strength by ≥1 grade; recovery was defined as a return to preoperative muscle strength levels. Univariate and multivariate analyses were performed to identify risk factors. Ninety-nine patients (6.9%) developed segmental motor paralysis, mostly involving the C5 segment (81.8%), the incidence being highest in patients with ossification of the posterior longitudinal ligament (OPLL) and those undergoing anterior cervical corpectomy and fusion or hybrid fusion (discectomy + corpectomy). Older age, male sex, higher body mass index, OPLL, and cervical corpectomy were independent risk factors for paralysis, with these patients having significantly worse clinical outcomes at 1 year postoperatively. Most patients (74/99, 79.6%) regained preoperative muscle strength levels an final follow up. This study identified important clinico-demographic and operative risk factors for segmental motor paralysis after anterior cervical spine surgery. Patients undergoing corpectomy, with or without OPLL, were found to be at particularly high risk. While most patients recover well, worse outcomes with segmental motor paralysis highlight the importance of preventing this complication, particularly for OPLL patients and corpectomy procedures. III.

Single-cell transcriptome profiling identifies the activation of type I interferon signaling in ossified posterior longitudinal ligament.

Ossification of the posterior longitudinal ligament (OPLL) is a condition comprising ectopic bone formation from spinal ligaments. This disease is a leading cause of myelopathy in the Asian population. However, the molecular mechanism underlying OPLL and efficient preventive interventions remain unclear. Here, we performed single-cell RNA sequencing and revealed that type I interferon (IFN) signaling was activated in the ossified ligament of patients with OPLL. We also observed that IFN-β stimulation promoted the osteogenic differentiation of preosteoblasts in vitro and activated the ossification-related gene SPP1, thereby confirming the single-cell RNA sequencing findings. Further, blocking the IFN-α/β subunit 1 receptor (IFNAR1) using an anti-IFNAR1 neutralizing antibody markedly suppressed osteogenic differentiation. Together, these results demonstrated that the type I IFN signaling pathway facilitated ligament ossification, and the blockade of this signaling might provide a foundation for the prevention of OPLL.

Effects of Preoperative Cervical Range of Motion on Clinical Outcomes Following Posterior Decompression: A Multicenter Study of Patients With Cervical Ossification of the Posterior Longitudinal Ligament

Study Design Retrospective multicenter study. Objectives To investigate the impact of preoperative cervical range of motion (ROM) on clinical outcomes after posterior decompression for cervical ossification of the posterior longitudinal ligament (OPLL). Methods We analyzed data from 156 patients with cervical OPLL who underwent posterior decompression and were followed for at least 2 years. Patients were divided into two groups based on preoperative gap ROM, which was a novel indicator representing the difference between flexion and extension ROM: the gROM &lt;0° and &gt;0° groups, and their outcomes were compared. Results There were no significant differences in patient demographics or surgical details between the gROM &lt;0° and &gt;0° groups. The gROM &lt;0° group exhibited less lordosis in C2-7 angles before and after surgery compared to the gROM &gt;0° group. Cervical ROM significantly decreased following posterior decompression regardless of whether preoperative gROM was &lt;0° or &gt;0°. Meanwhile, the incidence of perioperative complications was similar between the two groups. Furthermore, both groups showed significant improvement in Japanese Orthopaedic Association (JOA) scores postoperatively; however, there were no significant group differences in JOA scores, recovery rates, or visual analog scale for neck pain between the two groups at the preoperation and final follow-up. Conclusions The incidence of perioperative complications and postoperative clinical outcomes were comparable regardless of the magnitude of preoperative cervical gROM. Although cervical ROM decrease postoperatively, posterior decompression for cervical OPLL can offer favorable clinical outcomes irrespective of the preoperative cervical ROM magnitude, consequently.

Multilevel thoracic myelopathy: full-endoscopic solution. Illustrative case.

Thoracic myelopathy is relatively uncommon but, when present, causes significant disability. Early surgical intervention is often recommended for patients with myelopathy with compression at multiple levels. Surgical approaches and techniques for thoracic myelopathy have evolved from traditional open spine surgery to less invasive full-endoscopic spine surgery. This article reports an unusual presentation of a 31-year-old male with thoracic myelopathy due to thoracic disc herniation (TDH) at the T8-9 level and ossification of the ligamentum flavum at the T10-11 level that was managed using full-endoscopic spine surgery techniques in a single sitting. The presence of coexisting spinal disorders, that is, TDH and ossification of the posterior longitudinal ligament at noncontiguous spinal levels, makes surgical decision-making more complicated. Uniportal full-endoscopic spine surgery is a safe and effective surgical technique even for thoracic myelopathy. It is less invasive with minimal tissue and bone damage, better access to and visualization of the pathology, and minimal cord handling and is performed through small windows without destabilizing the spine, thus avoiding fusion. Anterior thoracic pathologies are better addressed through the transforaminal approach, whereas the interlaminar approach is preferred for posterior pathologies. Both of these approaches are complementary to each other with their own indications and advantages. https://thejns.org/doi/10.3171/CASE24413.

Distribution characteristics of stress on the vertebrae following different ranges of excision during Modified Anterior Cervical Discectomy and Fusion: A correlation study based on finite element analysis

BackgroundModified Anterior Cervical Discectomy and Fusion with specific resection ranges is an effective surgical method for the treatment of focal ossification of the posterior longitudinal ligament (OPLL). Herein, we compare and analyse the static stress area distribution by performing different cuts on an original ideal finite element model.MethodA total of 96 groups of finite element models of the C4–C6 cervical spine with different vertebral segmentation ranges (width: 1–12 mm, height: 1–8 mm) were established. The same pressure direction and size were applied to observe the size and distribution area of stress following various ranges of excision of the C5 vertebral body.ResultsDifferent cutting areas had similar stress aggregation points. As the contact area decreased, the stress and the bearing above area increased. The correlation of stress area variation was highest between the 1–2 MPa and 6 MPa–Max regions (Rho = − 0.975). In the surface visualisation model fitting, the width and height were of different ratios in different stress regions. The model with the best fitting degree was the 1–2 MPa group, and the equation fitting (Rho = 0.966) was as follows: Area = 908.80 − 25.92 × Width + 2.71 × Height.ConclusionModified Anterior Cervical Discectomy and Fusion with different resection ranges exhibited different stress areas. In a specific resection range of the cervical spine (1–12 mm, 0–8 mm), area conversion occurred at a threshold of 4 MPa. Additionally, the stress was concentrated at the contact points between the vertebral body and the rigid fixator.

Effect of Posterior Decompression on the Spinal Cord of Thoracic Ossification of the Posterior Longitudinal Ligament: A Finite Element Analysis

Thoracic ossification of the posterior longitudinal ligament (T-OPLL) causes myelopathy. Although posterior decompression for T-OPLL has shown positive results, patients with kyphotic curvatures often endure poor outcomes. Posterior decompression with fusion (PDF) has demonstrated better results compared to posterior decompression alone. This study aims to evaluate the effects of the posterior procedures for T-OPLL. A 3-dimensional finite element model of the C2-T12 spine, created from medical images, was used to develop the following T3-T4 OPLL compression models: an intact model (no surgery), 25% canal occupancy ratio (COR) OPLL, a discontinuous 25% COR OPLL, a continuous 50% COR OPLL, and a discontinuous 50% COR OPLL. These models were analyzed to evaluate the effects of posterior decompression (laminectomy [LN]) with varied fixation lengths (LN T3-T4, PDF T3-T4, LN T2-T5, and PDF T2-T5) in neutral, flexion, and extension positions. Increased discontinuity in OPLL led to increased stress on the spinal cord. Posterior decompression reduced spinal cord stress in the neutral posture. However, in flexion and extension, spinal cord stress increased for LN T3-T4, LN T2-T5, and PDF T3-T4 compared to the neutral posture. Notably, PDF T2-T5 prevented an increase in spinal cord stress during these motions. Effective management of intervertebral mobility and the appropriate length of decompression are crucial for addressing the thickness and mobility of T-OPLL.

Cervical ossification of the posterior longitudinal ligament revealed by cervical trauma: A case report with literature review

Background: Ossification of the posterior longitudinal ligament (OPLL) refers to bone formation within the posterior longitudinal ligament of the spinal column. This disease of the cervical spine results in a reduced volume of the spinal canal and can cause spinal cord damage. The onset of cervical OPLL is insidious. OPLL may increase the risk of spinal cord injury with various neurological deficits after minor trauma. An acute event can reveal a previously unknown or paucysymptomatic cervical OLLP. The aim: To present a case of unknown cervical OLLP revealed by cervical trauma after a traffic road accident. Case report: A 47-year-old female presented intractable cervicobrachial neuralgia in the posttraumatic aftermath of a traffic road accident. Computed Tomography (CT) and Magnetic resonance imaging (MRI) demonstrated an isolated OPLL from C5 to C6, causing significant nerve compression operated via anterior approach with discectomy and intervertebral cervical cage. Conclusion: Acute cervical trauma must be considered a mode of revelation of previously unknown or paucisymptomatic cervical OLLP and must be considered in the emergency room.

Application of the "Klotski Technique" in Cervical Ossification of the Posterior Longitudinal Ligament With En Bloc Type Dura Ossification.

The anterior controllable antedisplacement and fusion (ACAF) technique is a new procedure for the treatment of cervical ossification of the posterior longitudinal ligament (OPLL) that requires management of the disc adjacent to the ossification. This study describes a novel technique to reduce the number of fixed segments, namely, the "Klotski technique." The efficacy of ACAF using the Klotski technique was compared with that of anterior cervical corpectomy and fusion (ACCF) in the treatment of OPLL with en bloc type dural ossification (DO). The clinical data of 25 patients with severe OPLL and en bloc type DO who were treated by the ACAF Klotski technique or ACCF at our hospital from January 2020 to January 2022 were retrospectively analyzed. In the Klotski technique, the number of segments fused within the OPLL is limited. The antedisplacement space was designed according to the shape of the vertebrae-OPLL-DO complex (VODC). Then, the entire VODC was antedisplaced as in Klotski. Neurological function and image examination were assessed preoperatively and postoperatively. Complications associated with surgery were recorded. Patients were followed up for 24-36 months. There were 11 patients who were treated with ACAF and 14 patients who were treated with ACCF. At 2 weeks after surgery, the incidence of neurological deterioration was 21.4% (3 of 14) in the ACCF group and 9.1% (1 of 11) in the ACAF group. The incidence of intraoperative cerebrospinal fluid leakage (CFL) was 35.7% (5 of 14) in the ACCF group and 9.1% (1 of 11) in the ACAF group. The postoperative follow-up JOA scores of the patients in both groups were significantly better than their preoperative JOA scores (p<0.05). The Klotski technique for ACAF is a good option for the treatment of patients with en bloc type OPLL-DO, as it limits the number of fused segments, has a low incidence of CFL and neurologic deficits and is associated with good neurological recovery.

Cervical motion analysis using wearable inertial sensors to patients with cervical ossification of posterior longitudinal ligament.

This study aimed to clarify cervical kinematics during daily activities, including level walking and stair ascending, in patients with cervical ossification of the posterior longitudinal ligament (C-OPLL). Eighteen patients with myelopathy caused by C-OPLL and 18 healthy controls were recruited to participate in the study. The sagittal cervical kinematics during level walking and stair ascent were quantitatively assessed using a motion analysis system based on wearable inertial sensors. The Japanese Orthopaedic Association score, Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire, Neck Disability Index, and deep sensation in the lower extremities were assessed in all participants. Nine of 18 patients with C-OPLL presented with deep sensory disturbances. Patients with C-OPLL with deep sensory disturbances exhibited different sagittal plane cervical motion patterns than healthy controls during level walking and stair ascent. During the first phase of stair ascent, both patients with C-OPLL and healthy controls flexed their necks to the same degree; however, during the middle and final phases of stair ascent and all phases of level walking, the mean cervical flexion angle of patients with C-OPLL with deep sensory disturbances was significantly higher than that of patients with C-OPLL without deep sensory disturbance and healthy controls. Our data suggest that patients with C-OPLL presenting with deep sensory disturbances are likely to walk with their necks flexed and gaze downward to observe their steps throughout their daily lives. This habitual neck posture may lead to a vicious cycle of cervical kyphosis and worsening of compressive myelopathy.

Comment on, "Radiographic characterization of OPLL progression in patients receiving laminoplasty with a minimum of two-years follow-up".

The article by Liu et al. (2024) investigates the progression of ossification of the posterior longitudinal ligament (OPLL) in 29 patients post-cervical laminoplasty. The study meticulously tracks transverse and longitudinal OPLL progression, providing crucial insights into surgical planning and patient outcomes. While the research design is commendable, reliance on X-ray imaging limits precision compared to CT or MRI scans. The sample size, though adequate for initial findings, may not fully capture OPLL variability, and the follow-up period could be extended to better assess long-term outcomes. Future studies should incorporate advanced imaging techniques, larger cohorts, and patient-reported outcomes to enhance the understanding of OPLL progression, thereby refining surgical strategies and improving personalized care for OPLL patients.

Anterior decompression and posterior total laminectomy with fusion for ossification of the cervical posterior longitudinal ligament.

Surgical approaches to cervical ossification of the posterior longitudinal ligament (OPLL) remain controversial. The purpose of the present study was to analyze and compare the long-term neurological recovery following anterior decompression with fusion (ADF) and posterior laminectomy and fusion with bone graft and internal fixation (PLF) based on > ten-year follow-up outcomes in a single centre. Included in this retrospective cohort study were 48 patients (12 females; mean age 55.79 years (SD 8.94)) who were diagnosed with cervical OPLL, received treatment in our centre, and were followed up for 10.22 to 15.25 years. Of them, 24 patients (six females; mean age 52.88 years (SD 8.79)) received ADF, and the other 24 patients (five females; mean age 56.25 years (SD 9.44)) received PLF. Clinical data including age, sex, and the OPLL canal-occupying ratio were analyzed and compared. The primary outcome was Japanese Orthopaedic Association (JOA) score, and the secondary outcome was visual analogue scale neck pain. Compared with the baseline, neurological function improved significantly after surgery in all patients of both groups (p < 0.001). The JOA recovery rate in the ADF group was significantly higher than that in the PLF group (p < 0.001). There was no significant difference in postoperative cervical pain between the two groups (p = 0.387). The operating time was longer and intraoperative blood loss was greater in the PLF group than the ADF group. More complications were observed in the ADF group than in the PLF group, although the difference was not statistically significant. Long-term neurological function improved significantly after surgery in both groups, with the improvement more pronounced in the ADF group. There was no significant difference in postoperative neck pain between the two groups. The operating time was shorter and intraoperative blood loss was lower in the ADF group; however, the incidence of perioperative complications was higher.

Importance of gap evaluation in the ossification of posterior longitudinal ligament lesions using 3-dimensional computed tomography

BACKGROUND CONTEXTEvaluating the gaps within the ossification of the posterior longitudinal ligament (OPLL) lesions, which may contribute to neurological symptoms, using conventional imaging techniques is challenging. OBJECTIVEThis study aimed to investigate the importance of evaluating gaps using 3-dimensional computed tomography (3D-CT) and their association with the occurrence of magnetic resonance imaging (MRI) T2 high intensity in the spinal cord. STUDY DESIGN/SETTINGRetrospective cohort study. PATIENT SAMPLERetrospective analysis of 116 patients diagnosed with cervical OPLL. OUTCOME MEASURESPresence of gaps in OPLL, presence of T2 high intensity in the cervical spinal cord, and OPLL thickness were evaluated. METHODSLateral X-ray, CT, and reconstructed 3D-CT images were reviewed to assess lesion characteristics and the presence of gaps. MRI was used to evaluate the change in spinal cord signal intensity. The relationship among gap presence, lesion morphology, and MRI T2 high intensity in the spinal cord was examined. RESULTSA significant difference in gap detection accuracy was observed between CT and 3D-CT (p=.0054). CT demonstrated false-positive results in the detection of gaps as compared with 3D-CT. The presence of gaps was significantly associated with an increased likelihood of MRI T2 high intensity in the spinal cord (p=.037). Patients with thicker lesions and smaller space available for the spinal cord (SAC) were more likely to exhibit T2 high intensity. Meanwhile, patients with gaps co-occurring with T2 high intensity exhibited significantly thinner lesions (p=.011) and larger SACs (p=.0002). Patients with gaps had a significantly lower JOA scores (p=.0035), which indicates that patient with gaps are likely to exhibit more severe clinical neurological symptoms. CONCLUSION3D-CT showed superiority in accurately identifying gaps within OPLL lesions, while CT demonstrated false-positive results in the detection of gaps. Furthermore, the gap presence was a risk factor for MRI T2 high intensity in the spinal cord, independent of lesion thickness. In addition, gaps are related to more severe clinical symptoms. This study highlighted the importance of evaluating gaps within OPLL lesions using 3D-CT to clarify neurological pathogenesis.

Impact of incidental dural tears on postoperative outcomes in patients undergoing cervical spine surgery: a multicenter retrospective cohort study

BACKGROUND CONTEXTIncidental dural tear (DT) during cervical spine surgery is a feared complication. However, its impact on patient-reported outcomes (PROs) remains unclear. PURPOSETo determine the influence of DTs on PROs 1 year after cervical spine surgery. STUDY DESIGNRetrospective cohort. PATIENT SAMPLEPatients undergoing elective cervical spine surgery for cervical spondylosis, ossification of the posterior longitudinal ligament (OPLL), and cervical disc herniation. OUTCOME MEASURESAnalysis included patients’ characteristics, perioperative complications, and PROs both preoperatively and at 1 year postoperatively. METHODSThis study enrolled consecutive patients who underwent elective cervical spine surgery at 13 high-volume spine centers. All patients were required to complete questionnaires both preoperatively and 1 year postoperatively, which included PROs such as numerical rating scales of pain or dysesthesia for each part of the body, Neck Disability Index NDI, and Core Outcome Measures Index. Patients were divided into 2 groups based on the presence (DT+) or absence (DT-) of dural injury. Comparisons were made regarding patient background, perioperative complications, and pre and postoperative PROs. Propensity score matching was also utilized to adjust for patient background, and further comparisons were made regarding complication rates and PROs. RESULTSOut of 2,704 patients, dural tears were identified in 97 (3.6%) cases. The DT+ group had a significantly higher proportion of fixation surgeries, upper cervical surgeries, OPLL, and revision surgeries. Perioperative complications were significantly higher in the DT+ group, including intraoperative nerve damage, postoperative paralysis, surgical site infections (SSI), and cerebrovascular complications. Outcomes collected from 2,163 patients (79.9%) revealed significantly more severe neck and upper limb pain in the DT+ group. After propensity score matching, significant differences persisted in postoperative paralysis and SSI in the DT+ group, but no significant differences were observed in PROs. CONCLUSIONSPatients with dural tears showed nearly equivalent postoperative outcomes at 1 year following cervical spine surgery compared to those without dural tears. However, the incidence of perioperative complications was higher, emphasizing the need for careful management.