Diagnosis Of Ossification Of The Posterior Longitudinal Ligament Research Articles

MRI-based lesion quality score assessing ossification of the posterior longitudinal ligament of the cervical spine

BACKGROUND CONTEXTNo method currently exists for MRI-based determination of ossification of the posterior longitudinal ligament (OPLL) of the cervical spine using objective criteria. PURPOSEThe purpose of this study was to develop an MRI-based score to determine whether a lesion represents a cervical OPLL lesion and to establish the objective diagnostic value. STUDY DESIGNRetrospective cohort in a single medical institution. PATIENT SAMPLEThirty-five patients undergoing surgery for OPLL (Group A) and 99 patients undergoing cervical disc arthroplasty for soft disc herniation (Group B) between 2011 and 2020 were retrospectively included. All OPLL lesions on unenhanced MRI scan were correlated with a corresponding CT scan. Demographics were comparable between the two groups. OUTCOME MEASURES (PHYSIOLOGIC MEASURES)Using unenhanced magnetic resonance imaging (MRI), the T1- and T2- lesion quality (LQ) scores were calculated. Receiver operating characteristic (ROC) analysis was performed to calculate the area-under-the-curve (AUC) of both LQ scores as a predictor of the presence of OPLL. Computed tomography (CT)-based Hounsfield unit (HU) values of OPLL lesions were obtained and compared with both LQ scores. The LQ scores for MRI scanners from different manufacturers were compared using Student's t test to confirm the validity of the LQ score by scanner type. METHODSThe regions of interest for signal intensity (SI) were defined as the darkest site of the lesion and the cerebrospinal fluid (CSF) at the cerebellomedullary cistern. The T1 and T2 LQ scores were measured as the ratio of the SI at the darkest site of the lesion divided by the SI of the CSF. RESULTSThe T1 and T2 LQ scores in Group A were significantly lower than those in Group B (p<.001). ROC analysis determined that T1 and T2 LQ scores of 0.46 and 0.07, respectively, could distinguish the presence of OPLL with an accuracy of 0.93 and 0.89, respectively (p<.001). When the T1 LQ score of the lesion is <0.46, a diagnosis of OPLL may be suspected with 100% sensitivity and 92.3% specificity. The HU of the lesion had a moderate negative correlation with the T1 LQ score (r=−0.665, p<.0001). Both LQ scores were unaffected by manufacturer type. CONCLUSIONSThis study found a correlation between the MRI-based T1 LQ scores and CT-based HU value for identifying OPLL lesions. Additional studies will be needed to validate that the T1 LQ score from the unenhanced MRI scan can identify cervical OPLL.

Surgical management of continuous and mixed type of OPLL in cervical spine: Experience in tertiary level hospital.

Background: Ossification of the posterior longitudinal ligament (OPLL) is a chronically progressive disease of ectopic enchondral and membranous ossification of posterior longitudinal ligament (PLL). Controversy still persists over the superiority of various surgical approaches for cervical OPLL management. Purpose: To see the efficacy of expansive laminoplasty for the management of continuous and mixed type of cervical OPLL retrospectively. Methods: Records of 20 male and 8 female aged 36-72 years (mean, 56.64 years), who underwent surgical treatment posteriorly for continuous and mixed type OPLL by laminoplasty were obtained from the year 2004 - 2020. Clinical features along with imaging studies, which included X -ray/CT /MRI, were done for the diagnosis of OPLL. Multiple variables were studied, including demographics, surgical parameters, complications and functional outcomes. Results: They were followed on an average of 59.86 ± 20.95 months (range, 24 -108 months). The average operative duration was 95 ± 15.52 min (range: 70 - 140), and the intraoperative blood loss was 199.29 ± 33.55 ml. The cervical curvature index reduced to 8.81 ± 1.96 from 11.00 ± 2.49 and the VAS score decreased from 4.25 ± 0.75 to 2.43 ± 1.40. mJOA score improved from 8.64 ± 1.03 to 13.96 ± 1.26 on the last follow-up after surgery (p &lt; 0.01), with average recovery rate of 65.5 %. Conclusions: The management for cervical myelopathy with multilevel stenosis due to continuous and mixed type of OPLL by Laminoplasty is safe and effective.

Detecting ossification of the posterior longitudinal ligament on plain radiographs using a deep convolutional neural network: a pilot study

BACKGROUND CONTEXTIts rare prevalence and subtle radiological changes often lead to difficulties in diagnosing cervical ossification of the posterior longitudinal ligament (OPLL) on plain radiographs. However, OPLL progression may lead to trauma-induced spinal cord injury, resulting in severe paralysis. To address the difficulties in diagnosis, a deep learning approach using a convolutional neural network (CNN) was applied. PURPOSEThe aim of our research was to evaluate the performance of a CNN model for diagnosing cervical OPLL. STUDY DESIGN AND SETTINGDiagnostic image study. PATIENT SAMPLEThis study included 50 patients with cervical OPLL, and 50 control patients with plain radiographs. OUTCOME MEASURESFor the CNN model performance evaluation, we calculated the area under the receiver operating characteristic curve (AUC). We also compared the sensitivity, specificity, and accuracy of the diagnosis by the CNN with those of general orthopedic surgeons and spine specialists. METHODSComputed tomography was used as the gold standard for diagnosis. Radiographs of the cervical spine in neutral, flexion, and extension positions were used for training and validation of the CNN model. We used the deep learning PyTorch framework to construct the CNN architecture. RESULTSThe accuracy of the CNN model was 90% (18/20), with a sensitivity and specificity of 80% and 100%, respectively. In contrast, the mean accuracy of orthopedic surgeons was 70%, with a sensitivity and specificity of 73% (SD: 0.12) and 67% (SD: 0.17), respectively. The mean accuracy of the spine surgeons was 75%, with a sensitivity and specificity of 80% (SD: 0.08) and 70% (SD: 0.08), respectively. The AUC of the CNN model based on the radiographs was 0.924. CONCLUSIONSThe CNN model had successful diagnostic accuracy and sufficient specificity in the diagnosis of OPLL.

Acromegaly presenting with myelopathy due to ossification of posterior longitudinal ligament: a case report

BackgroundAcromegaly is a rare disease caused by high serum levels of growth hormone (GH) and insulin-like growth factor 1 (IGF-1), often originating from a pituitary adenoma. Spinal and peripheral joint abnormalities are caused by these hormonal hypersecretions. In particular, the response to GH is involved in the onset of ossification of the spinal ligament in vitro, especially ossification of the posterior longitudinal ligament (OPLL). However, because acromegaly and OPLL are rare diseases, we seldom encounter them in combination. To the best of our knowledge in the English-language literature, this is the first reported case of acromegaly presenting with thoracic myelopathy due to OPLL.Case presentationA 47-year-old woman presented with lower extremity weakness and paresthesia, gait disorder, and bladder disorder without any trauma. The patient’s most remarkable symptom was paraplegia, and we diagnosed myelopathy due to cervical and thoracic OPLL. Furthermore, we suspected acromegaly because of the characteristic facial features, and we found a pituitary adenoma by contrast-enhanced MRI. Cervical and thoracic decompression, posterior fixation, and pituitary adenoma resection were performed.ConclusionWe report a case of acromegaly that was detected after the diagnosis of OPLL. The main challenge in acromegaly is delayed in diagnosis. Even in this case, the facial features characteristic of acromegaly had appeared at least 9 years ago. Early diagnosis and treatment of acromegaly improve prognosis and reduce exposure to GH and IGF-1 through early intervention and seem to suppress the progression of ligament ossification. Orthopedic surgeons and neurosurgeons need to keep in mind that acromegaly is associated with bone/joint lesions and ossification of the spinal ligament and should aim to diagnose acromegaly early.

Complications following central corpectomy in 468 consecutive patients with degenerative cervical spine disease.

OBJECTIVE This study was performed to describe the incidence and predictors of perioperative complications following central corpectomy (CC) in 468 consecutive patients with cervical spondylotic myelopathy (CSM) or ossification of the posterior longitudinal ligament (OPLL). METHODS The authors performed a retrospective review of a cohort of patients who had undergone surgery for CSM (n = 338) or OPLL (n = 130) performed by a single surgeon over a 15-year period. All patients underwent uninstrumented CC with autologous iliac crest or fibular strut grafting. Preoperative clinical and imaging details were collected, and the type and incidence of complications were studied. Univariate and multivariate analyses were performed to establish risk factors for the development of perioperative complications. RESULTS Overall, 12.4% of patients suffered at least 1 complication following CC. The incidence of major complications was as follows: C-5 radiculopathy, 1.3%; recurrent laryngeal nerve injury, 0.4%; dysphagia, 0.8%; surgical-site infection, 3.4%; and dural tear, 4.3%. There was 1 postoperative death (0.2%). On multivariate analysis, patients in whom the corpectomy involved the C-4 vertebral body (alone or as part of multilevel CC) were significantly more likely to suffer complications (p = 0.004). OPLL and skip corpectomy were risk factors for dural tear (p = 0.015 and p = 0.001, respectively). No factors were found to be significantly associated with postoperative C-5 palsy, dysphagia, or acute graft extrusion on univariate or multivariate analysis. Patients who underwent multilevel CC were predisposed to surgical-site infections, with a slight trend toward statistical significance (p = 0.094). The occurrence of a complication after surgery significantly increased the mean duration of postoperative hospital stay from 5.0 ± 2.3 days to 8.9 ± 6 days (p < 0.001). CONCLUSIONS Complications following CC for CSM or OPLL are infrequent, but they significantly prolong hospital stay. The most frequent complication following CC is dural tear, for which a diagnosis of OPLL and a skip corpectomy are significant risk factors.

Surgical outcome and prognostic factors of anterior decompression and fusion for cervical compressive myelopathy due to ossification of the posterior longitudinal ligament

Background contextAnterior decompression and fusion (ADF) for ossification of the posterior longitudinal ligament (OPLL) is technically demanding and associated with complications. Although various factors affecting clinical outcome have been investigated in posterior decompression, prognostic factors of ADF remain unclear. PurposeThe purpose of the study was to identify surgical outcome and prognostic factors of ADF for cervical myelopathy due to OPLL. Study designThis was a retrospective case study. Patient sampleBetween 2005 and 2012, 913 patients underwent decompression surgery for cervical OPLL at our institution. Among them, 131 who underwent ADF and 221 who underwent laminoplasty were enrolled. Inclusion criteria were (1) diagnosis of OPLL; (2) cervical compressive myelopathy; and (3) no trauma, infection, tumor, or previous surgery. We excluded 60 patients with ADF and 157 patients with laminoplasty owing to inadequate follow-up or absence of preoperative myelopathy. Finally, 71 patients with ADF and 64 patients with laminoplasty were enrolled in this study (mean follow-up, 48 vs 41 months). Outcome measuresNeurologic assessment was conducted using the Japanese Orthopedic Association (JOA) scoring system for cervical myelopathy. Rate of neurologic improvement was calculated by comparing preoperative and postoperative JOA scores. MethodsWe investigated the effects of such variables as age, gender, body mass index (BMI), presence of diabetes mellitus (DM), smoking history, type of OPLL, shape of the ossified lesion, occupying ratio of OPLL, presence of intramedullary increased signal intensity (ISI) on magnetic resonance imaging (MRI), and sagittal alignment of the cervical spine on surgical outcome. Severity of ISI was classified into three groups based on T2-weighted sagittal MRI as follows: Grade 0, none; Grade 1, ISI limited to one disc level; or Grade 2, ISI beyond one disc level. This work was supported by the 2013 Korea Health Technology R&D Project of the Ministry of Health and Welfare of the Republic of Korea (A120254). ResultsIn patients with an occupying ratio ≥60% or with presence of ISI on MRI, ADF yielded better surgical outcome than laminoplasty. A higher ISI grade (B=−28.5, p=.000) and a higher occupying ratio (B=0.88, p=.04) were significantly associated with a lower recovery rate (R=0.56, p=.006). Older age also was associated with a lower recovery rate. Gender, BMI, presence of DM, smoking history, type of OPLL, shape of the ossified lesion, and cervical alignment were not associated with recovery rate. ConclusionAnterior decompression and fusion has favorable outcome in patients with an occupying ratio ≥60% or with presence of ISI on MRI. Presence of higher ISI grade, higher occupying ratio, and older age were associated with a poor long-term surgical prognosis. Therefore, evaluating ISI and occupying ratio on preoperative MRI is important for selecting the appropriate surgical approach and for predicting clinical outcome after surgery for cervical compressive myelopathy due to OPLL.

Analysis of axial symptoms after indirect decompression for ossification of the posterior longitudinal ligament of the cervical spine

To study the etiology and clinical significance of axial symptoms after posterior operative procedures for ossification of the posterior longitudinal ligament (OPLL). From February 2005 to February 2010, 76 patients with OPLL treated were retrospectively experienced. There were 34 male and 42 female with average of 52.1 years (range from 37 to 74 years), the average duration of the disease was 32.1 months (range from 11 to 56 months). Nineteen patients underwent traditional laminectomy in group A, 33 patients received open-door laminoplasty in group B and 24 patients underwent lateral mass screw fixation in group C. All patients underwent X-ray examination pre- and post operative, computed tomography were used for diagnosis of OPLL, the recovery rate was calculated using pre- and postoperative Japanese Orthopedic Association (JOA) scores for each patient. Pre- and postoperative cervical curvature index and axial symptoms were measured and compared. χ(2) test and SNK test were used as statistical methods. All patients were followed up for 14 - 35 months, average (21 ± 5) months. Loss of cervical curvature index was 4.2% ± 1.7% in group A, 2.9% ± 2.2% in group B and 2.3% ± 1.9% in group C. The difference was significant in loss of cervical curvature indice between group A and B (q = 2.94, P < 0.01), group A and C (q = 4.23, P < 0.01). The average JOA recovery rate was 58.3% for group A, 64.3% for group B and 66.7% for group C. There was no significant difference in JOA recovery rate among the three groups (P > 0.05). The rate of early evident axial symptoms was 7/19 in group A, 30.3% in group B and 33.3% in group C and the difference was not statistically significant (P > 0.05). The incidence of late evident axial symptoms was 5/19 in group A, 12.1% in group B and 8.3% in group C, the difference was not significant between group B and C (χ(2) = 13.762, P < 0.01), but of statistical difference between group A and B(χ(2) = 6.368, P < 0.01), group A and C (χ(2) = 11.481, P < 0.01). No kyphotic deformity in the group A, no "Close Door" phenomenon in group B and no internal failure in group C. The incidence of early axial symptoms are of no significant difference among the three groups, but late axial symptoms are higher in the laminectomy than other groups, which may be associated with loss of cervical lordosis.