Significance of Intramedullary High Signal Intensity on Magnetic Resonance Imaging in Patients with Cervical Ossification of the Posterior Longitudinal Ligament

Does the presence of preoperative neck pain impact clinical outcomes after posterior decompression in patients with cervical ossification of the posterior longitudinal ligament?: Retrospective multicenter cohort study

STUDY DESIGN

Retrospective multicenter study.

OBJECTIVES

To evaluate how preoperative neck pain influences clinical outcomes following posterior decompression for cervical ossification of the posterior longitudinal ligament (OPLL).

SETTING

Fourteen medical institutions in Japan.

METHODS

We enrolled 90 patients with cervical OPLL who underwent posterior decompression and were followed for a minimum of two years. We collected demographic data, medical history, and imaging findings. Patients were divided into two groups based on preoperative neck pain presence (Pre-op. neck pain (-) and (+) groups), and their outcomes were compared.

RESULTS

There were no significant differences in patient demographics between the Pre-op. neck pain (-) and (+) groups. Both groups showed similar distributions of ossification types and K-line positivity. Perioperative complications were comparable between the two groups. Radiographic analysis revealed no significant differences in C2-7 angles or cervical range of motion, pre- and postoperatively. Both groups demonstrated significant improvement in postoperative Japanese orthopedic association (JOA) scores, but there were no significant differences in scores or recovery rates. In the Pre-op. neck pain (-) group, factors associated with appearance of postoperative neck pain included pre- and postoperative lower JOA scores and larger C2-7 angles in neutral and extension positions.

CONCLUSIONS

It emerges that lower pre- and postoperative JOA scores or larger C2-7 angles in neutral and extension positions predispose to postoperative neck pain even in those patients without preoperative neck pain. Therefore, this is worth discussing at the time of consenting patients for surgical decompression and fixation.

New Method for the Quantitative Assessment of Sensory Disturbances in Cervical Myelopathy: Application for Neurological Level Diagnosis

Introduction

Cervical myelopathy frequently manifests as sensory disturbances, including numbness, and their distribution pattern aids in neurological level diagnosis. However, the objective assessment of sensory disturbances is challenging. In this study, we attempted to quantitatively evaluate sensory symptoms in patients with cervical myelopathy according to lesion level using PainVision^Ⓡ.

Methods

Dermal sensations were evaluated in patients (n = 158) and healthy volunteers (n = 100) using PainVision^Ⓡ PS-2100, which measured the current perception threshold (CPT). The results were analyzed for their correlation with magnetic resonance imaging (MRI) data, visual analog scale (VAS) scores, and patient functional status assessed by the Japanese Orthopaedic Association (JOA) and JOA Cervical Myelopathy Evaluation Questionnaire (JOACMEQ) scores.

Results

Forearm and palm CPT values were significantly higher in patients with cervical myelopathy (both sites, P < 0.001) and were negatively correlated with the JOA score (forearm, r = −0.33; palm, r = −0.35; P < 0.001) and the JOACMEQ scores for upper extremity function (forearm, r = −0.37; palm, r = −0.39; P < 0.001), lower extremity function (forearm, r = −0.39; palm, r = −0.40; P < 0.001), and quality of life (forearm r = −0.27, P = 0.0025); however, no correlation was observed with the VAS score. Stratification of patients according to their lesion levels determined by MRI revealed that the C3/C4 subgroup had significantly higher forearm CPT values than the C4/C5 (P = 0.024) and C5/C6 (P = 0.0013) subgroups and higher palm CPT values than the C5/C6 subgroup (P = 0.009).

Conclusions

Quantitative measurements of sensory disturbances using the PainVision^Ⓡ device correspond to the degree of patient functional disability and the lesion level. This indicates that both the distribution and intensity of sensory abnormalities are important for neurological level diagnosis in patients with cervical myelopathy.

Clinical characteristics in patients with ossification of the posterior longitudinal ligament: A prospective multi-institutional cross-sectional study

Ossification of the posterior longitudinal ligament (OPLL) can occur throughout the entire spine and can sometimes lead to spinal disorder. Although patients with OPLL sometimes develop physical limitations because of pain, the characteristics of pain and effects on activities of daily living (ADL) have not been precisely evaluated in OPLL patients. Therefore, we conducted a multi-center prospective study to assess whether the symptoms of cervical OPLL are different from those of cervical spondylosis (CS). A total of 263 patients with a diagnosis of cervical OPLL and 50 patients with a diagnosis of CS were enrolled and provided self-reported outcomes, including responses to the Japanese Orthopaedic Association (JOA) Cervical Myelopathy Evaluation Questionnaire (JOACMEQ), JOA Back Pain Evaluation Questionnaire (JOABPEQ), visual analog scale (VAS), and SF-36 scores. The severity of myelopathy was significantly correlated with each domain of the JOACMEQ and JOABPEQ. There was a negative correlation between the VAS score for each domain and the JOA score. There were significantly positive correlations between the JOA score and the Mental Health, Bodily Pain, Physical Functioning, Role Emotional, and Role Physical domains of the SF-36. One-to-one matching resulted in 50 pairs of patients with OPLL and CS. Although there was no significant between-group difference in scores in any of the domains of the JOACMEQ or JOABPEQ, the VAS scores for pain or numbness in the buttocks or limbs were significantly higher in the CS group; however, there was no marked difference in low back pain, chest tightness, or numbness below the chest between the two study groups. The scores for the Role Physical and Body Pain domains of the SF-36 were significantly higher in the OPLL group than in the CS group, and the mean scores for the other domains was similar between the two groups. The results of this study revealed that patients with OPLL were likely to have neck and low back pain and restriction in ADL. No specific type of pain was found in patients with OPLL when compared with those who had CS.

Multicenter cross-sectional study of the clinical features and types of treatment of spinal cord-related pain syndrome

BACKGROUND

We termed chronic neuropathic pain (NeP) in patients with diseases associated with spinal cord damage as "spinal cord-related pain syndrome". We conducted a survey of patients with the syndrome to assess the type and severity of NeP and its effect on QOL, and treatment modalities.

METHODS

This cross-sectional study was conducted in 185 patients recruited from 15 medical institutions. We analyzed the questionnaires sent to clinicians (basic information, magnetic resonance imaging (MRI) findings, type and effectiveness of medications) and patients [modified Neuropathic Pain Symptom Inventory (NPSI) and short form (SF)-36 healthy survey].

RESULTS

The incidence of spinal cord-related pain syndrome was highest in patients with cervical spondylotic myelopathy, ossification of posterior longitudinal ligament (OPLL) and spinal cord injury. The number of patients with at-level pain was higher than those with below-level pain; dysesthesia/paresthesia, spontaneous and evoked pain types were mainly seen in patients with at-level pain and dysesthesia/paresthesia was common among those with below-level pain. NPSI score was higher than 10 in the majority of patients, and the subscore for dysesthesia/paresthesia was significantly the highest. The NPSI score was the highest in patients with severe hyperintense signal increase on MRI. The scores of all SF-36 sub-items were significantly lower than the national average. The majority of patients used non-steroid anti-inflammatory drugs and gabapentin/pregabalin; the latter was significantly effective for allodynia, compared with other medications, regardless of the pain level.

CONCLUSIONS

The majority of patients with spinal cord-related pain syndrome suffered from severe NeP, which affected physical activity. The pain phenotype varied according to the level of the lesion and dysesthesia/paresthesia was the most intense. Compared with other medications, gabapentin/pregabalin was significantly effective especially for dysesthesia/paresthesia and evoked pain regardless of the pain level.

Extended Laminoplasty for Ossification of Posterior Longitudinal Ligament Involving the C2 Segment

BACKGROUND

To evaluate effectiveness and safety of extended laminoplasty for the treatment of ossification of posterior longitudinal ligament (OPLL) involving the C2 segment.

METHODS

A total of 132 cases who accepted laminoplasty for treating the OPLL from 2010 to 2015 were included and divided into Group A (n = 26, with C2 OPLL and C2-C7 laminoplasty), Group B (n = 29, with C2 OPLL and C3-C7 laminoplasty), and Group C (n = 77, without C2 OPLL and had C3-C7 laminoplasty). Clinical and radiologic outcomes were compared among the 3 groups.

RESULTS

At the final visit, significant improvements in Japanese Orthopedic Association score, Neck Disability Index, Health-Related Quality-of-Life Short Form 36 Physical Component Summary, and Visual Analog Scale score in neck were observed in all 3 groups. However, all the C2-C7 Cobb angle, C2-C3 Cobb angle, sagittal vertical axis, and number of cases with cervical or segmental kyphosis in the 3 groups were not significantly changed. Although total blood loss, operation time, maximum Visual Analog Scale score in neck, incidence of axial pain, change of C2-C7, or sagittal vertical axis in Group A were all significantly larger than that in Group B or Group C, differences in neurologic recovery rate, Neck Disability Index, Health-Related Quality-of-Life Short Form 36 Physical Component Summary, change of the C2-C3 Cobb angle, and incidence of cervical or segmental malalignment among the 3 groups were not significant at the final visit.

CONCLUSIONS

If decompression indication for cases with OPLL involving the C2 segment was appropriate, extended laminoplasty up to the C2 segment could provide satisfactory neurologic recovery and would not accelerate cervical or segmental malalignment progression.

Radiological Characteristics and Clinical Outcome of Ossification of Posterior Longitudinal Ligament Involving C2 After Posterior Laminoplasty and Instrumented Fusion Surgery

STUDY DESIGN

Retrospective study.

OBJECTIVE

To analyze the radiological characteristics and surgical outcome of cervical ossification of posterior longitudinal ligament (OPLL) involving C2 level.

SUMMARY OF BACKGROUND DATA

The study and report focused on the OPLL involving C2 level are rare. Therefore, the radiological characteristics and surgical outcome remain unclear.

METHODS

The records of the patients with OPLL involving C2 level who underwent posterior surgery from July 2006 through October 2015 were retrospectively reviewed. The types, longitudinal and transverse extent, occupation ratio, K-line classification of OPLL, and high-intensity zone of spine cord on magnetic resonance imaging were analyzed to evaluate the radiological characteristics. All the cases received posterior open-door laminoplasty and instrumented fusion surgery. The Japanese Orthopedic Association (JOA) score and recovery rate (RR) were used to evaluate neurological function after surgery.

RESULTS

A total of 45 patients with OPLL involving C2 level were enrolled in the study. Their radiological data were carefully analyzed. The mixed (73.3%) and continuous type (24.5%) were observed. The mean number of involved segments was 5.1. The narrowest spinal canal mostly located in the level of C3-C4 and mean occupying ratio was 65.3%. Thirty-two patients were followed up for at least 2 years and the mean follow-up time was 46.2 months. The mean JOA score was 10.3 preoperatively and 15.2 at the final follow-up and the mean RR was 70.7%. The K-line (+) and (-) subgroups showed similar preoperative JOA score and RR. The high-intensity zone (+) subgroup showed lower preoperative JOA score but equal RR with (-) subgroup.

CONCLUSION

When OPLL involve C2 level, it often presented different radiological characteristics. The posterior open-door laminoplasty and instrumented fusion surgery could achieve favorable clinical outcomes. Further researches and long-term clinical follow-up are needed to better appreciate the OPLL involving C2 level.

LEVEL OF EVIDENCE

4.

Predictors for Development of Symptomatic Myelopathy in Patients with Radiculopathy Caused by Cervical Ossification of Posterior Longitudinal Ligament

OBJECTIVE

To identify clinical factors predicting the development of myelopathy in cervical ossification of the posterior longitudinal ligament (OPLL) patients with radiculopathy.

METHODS

We retrospectively reviewed 83 cervical OPLL patients who presented with radiculopathy. On the basis of the symptoms and physical findings, we divided patients into 2 groups: myelopathy group and nonmyelopathy group. Demographic, clinical, and radiologic characteristics were reviewed and analyzed among the 2 groups. Predictors for the development of myelopathy were assessed via univariate and multivariate analysis.

RESULTS

Univariate analysis demonstrated that a high occupying ratio and the presence of an intramedullary high signal were risk factors for development of myelopathy from radiculopathy in OPLL patients. Multivariate analysis further identified that a high occupying ratio was the only independent predictor (odds ratio 1.05, 95% confidence interval 1.003-1.091, P = 0.035). The cervical range of motion and minor trauma were not related to the development of myelopathy in our study.

CONCLUSIONS

Nonmyelopathic OPLL patients with radiculopathy and a high occupying ratio were at higher risk of developing myelopathy, and surgical intervention should be recommended in these cases. However, for elderly patients with significant comorbid conditions, the risks and benefits of surgery should be carefully considered.

Options of Management of the Patient with Mild Degenerative Cervical Myelopathy

Surgical management of patients with mild degenerative cervical myelopathy (DCM) is controversial. This article reviews 84 subjects with cervical spondylotic myelopathy (CSM) and ossification of the posterior longitudinal ligament (OPLL) who underwent surgical treatment. Nine had mild myelopathy: 6 CSM and 3 OPLL. Seven presented with pain or numbness of upper extremities. MRI revealed intramedullary hyperintensity in 55.6%. Five underwent anterior decompression and fusion, whereas 4 were operated posteriorly. Pain and intramedullary signal change on MRI are important. Management of patients with mild DCM should be determined individually, considering benefits and risks in long-term conservative treatment and surgery.

The cutoff value of ossification of posterior longitudinal ligament (OPLL) for early diagnosis of myelopathy using somatosensory evoked potential in cervical OPLL patients

STUDY DESIGN

Retrospective study.

OBJECTIVES

The objective of this study was to find out whether ossification of posterior longitudinal ligament (OPLL) characteristics, including size, shape and subtype, can be used to diagnose myelopathy using somatosensory evoked potential (SEP) in cervical OPLL patients.

SETTING

Yonsei University College of Medicine, Seoul, Korea.

METHODS

We retrospectively reviewed the medical records of 153 cervical OPLL patients who underwent SEP study. OPLL anterior-posterior (AP) diameter, area and involved longitudinal vertebral level were measured. OPLL was classified into subtypes according to longitudinal continuity and shape. Correlation analysis and receiver operating curve were used.

RESULTS

Tibial SEP latency was significantly correlated with OPLL AP diameter (P=0.001), diameter occupying ratio (P=0.019), area (P=0.007), area occupying ratio (P=0.008), involved longitudinal vertebral level (P=0.028) and space available for the spinal cord (P=0.019). The cutoff values that were diagnostic for SEP prolongation suggesting myelopathy were 4.91 mm for OPLL AP diameter, 6.02 mm for space available for the spinal cord, 44.5% for diameter occupying ratio, 63.4 mm² for area, 36.1% for area occupying ratio and level 2 for the involved longitudinal vertebral level.

CONCLUSIONS

Our results revealed that tibial SEP latency was significantly correlated with OPLL size and suggested cutoff values of OPLL diameter (4.91 mm, 44.5%) and area (63.4 mm², 36.1%) for early diagnosis of myelopathy. These results can help to establish treatment plans.