Single-level Cervical Spondylotic Myelopathy Research Articles

Risk factors for poor neurological recovery after anterior cervical discectomy and fusion: imaging characteristics

BackgroundPoor neurological recovery in patients after anterior cervical discectomy and fusion has been frequently reported; however, no study has analyzed the preoperative imaging characteristics of patients to investigate the factors affecting surgical prognosis. The purpose of this study was to investigate the factors that affect the preoperative imaging characteristics of patients and their influence on poor neurologic recovery after anterior cervical discectomy and fusion.MethodsWe retrospectively analyzed the clinical data of 89 patients who met the criteria for anterior cervical discectomy and fusion for the treatment of single-level cervical spondylotic myelopathy and evaluated the patients’ neurological recovery based on the recovery rate of the Japanese Orthopaedic Association (JOA) scores at the time of the final follow-up visit. Patients were categorized into the “good” and “poor” groups based on the JOA recovery rates of ≥ 50% and < 50%, respectively. Clinical information (age, gender, body mass index, duration of symptoms, preoperative JOA score, and JOA score at the final follow-up) and imaging characteristics (cervical kyphosis, cervical instability, ossification of the posterior longitudinal ligament (OPLL), calcification of herniated intervertebral discs, increased signal intensity (ISI) of the spinal cord on T2-weighted imaging (T2WI), and degree of degeneration of the discs adjacent to the fused levels (cranial and caudal) were collected from the patients. Univariate and binary logistic regression analyses were performed to identify risk factors for poor neurologic recovery.ResultsThe mean age of the patients was 52.56 ± 11.18 years, and the mean follow-up was 26.89 ± 11.14 months. Twenty patients (22.5%) had poor neurological recovery. Univariate analysis showed that significant predictors of poor neurological recovery were age (p = 0.019), concomitant OPLL (p = 0.019), concomitant calcification of herniated intervertebral discs (p = 0.019), ISI of the spinal cord on T2WI (p <0.05), a high grade of degeneration of the discs of the cranial neighboring levels (p <0.05), and a high grade of discs of the caudal neighboring levels (p <0.05). Binary logistic regression analysis showed that ISI of the spinal cord on T2WI (p = 0.001 OR = 24.947) and high degree of degeneration of adjacent discs on the cranial side (p = 0.040 OR = 6.260) were independent risk factors for poor neurological prognosis.ConclusionISI of the spinal cord on T2WI and high degree of cranial adjacent disc degeneration are independent risk factors for poor neurological recovery after anterior cervical discectomy and fusion. A comprehensive analysis of the patients’ preoperative imaging characteristics can help in the development of surgical protocols and the management of patients’ surgical expectations.

Preoperative Cervical Cobb Angle Is a Risk Factor for Postoperative Axial Neck Pain after Anterior Cervical Discectomy and Fusion with Zero-Profile Interbody.

Anterior cervical discectomy and fusion (ACDF) with zero-profile interbody has a lower incidence of complications in treating cervical spondylotic myelopathy (CSM). However, postoperative axial neck pain is still commonly occurred, and the factors affecting which is not known. Here, we retrospectively analyze the risk factors for postoperative axial pain after performing ACDF with zero-profile implant in single-level CSM. Patients who suffered from single-level CSM and who received ACDF with zero-profile implant between 2018 January to 2020 December were reviewed. Of 180 single-level CSM patients, 144 patients who passed the inclusion criteria were enrolled. Patients were divided into two groups according to the severity of postoperative axial pain as measured by postoperative neck visual analogue scale (nVAS). Clinical parameters including age, sex, smoking history, symptom duration, body mass index (BMI), the Japanese Orthopaedic Association (JOA) scores, as well as radiological parameters were obtained pre- and post-operatively, and the data were compared between two groups. Pearson's chi-square tests and Mann-Whitney U tests were implemented to identify statistically significant differences between subgroups for categorical and continuous data, respectively; otherwise, the data were tested with Student's t-test. Risk factors were identified using logistic regression. Of the patients (97.8%) achieved satisfied neurological recovery, and 88.2% of the patients achieved fusion at 1-year follow-up. 33% of the patients (48 patients out of 144) had sustained postoperative axial pain after the surgery. Comparison of different severity groups exhibited no significant differences in terms of the possible risk factors (P > 0.05) except for pre- and post-operative C2-C7 Cobb angles (6.33 ± 6.53 vs. 11.88 ± 7.41, P < 0.05; 13.49 ± 5.31 vs 16.64 ± 7.34, P < 0.05). Furthermore, correlation analysis showed that the preoperative C2-C7 Cobb angle is significantly correlated with the severity of the postoperative axial pain (R2 =0.83, P < 0.01). In addition, logistic regression analysis demonstrated that the preoperative C2-C7 Cobb angle is an independent predictor of postoperative axial pain (P < 0.01, OR=0.53). Further receiver operating characteristic (ROC) analysis displayed an area under the curve (AUC) of 0.78 (P < 0.01) for preoperative C2-C7 Cobb angle, and the optimal cutoff was 8.4° (sensitivity 0.77, specificity 0.65). The pre-operative C2-C7 Cobb angle is a risk factor for severe postoperative axial pain after anterior cervical discectomy and fusion with zero-profile interbody, and we should be cautious when poor preoperative C2-C7 Cobb angle is found in myelopathy patients planning to use zero-profile interbody to treat such patients.

Intervertebral-spreader-assisted anterior cervical discectomy and fusion prevents postoperative axial pain by alleviating facet joint pressure

ObjectiveTo evaluate the relationship of postoperative cervical axial pain with different vertebral distraction methods used during ACDF procedures in cervical spondylosis patients.MethodsNinety-four single-level cervical spondylotic myelopathy patients with significantly loss of intervertebral disc height who underwent ACDF surgery in our institute between January 2018 and January 2020 were enrolled. Cervical spine lateral radiographs were taken preoperatively, 3 days, 1-month, 2-month and 6-month after the surgery. The intervertebral disc height (IDH), interfacet distance (IFD), JOA (Japanese Orthopaedic Association) score, NDI (Neck Disability Index) score, nVAS (Neck Visual Analogue Scale) score and aVAS (Arm Visual Analogue Scale) score were measured. The correlation of clinical parameters and intervertebral disc height was evaluated. Then the correlation of clinical outcomes and different distraction method was evaluated. The patients were randomly divided into two groups, one uses Casper pin distractor system alone for distraction (Caspar alone group) and the other uses spreader assisted distraction method (Casper + spreader group). In biomechanical study, four cervical spine cadavers were selected for facet pressure measurements under different vertebral distraction methods, and the facet joint pressure was measured using force sensors.ResultsSatisfactory cervical fusion and neurological recovery were achieved in all patients. No significant correlation of IDH, IFD, JOA, NDI or aVAS with nVAS score was found. No significant difference between the change in disc height and clinical outcomes was found. However, by comparing the clinical parameters of patients in different vertebral distraction groups, we found significant changes in the early nVAS and NDI scores (P = 0.11, P = 0.48) of the Casper + spreader group (3 days postoperation), and was associated with a better nVAS score at 2 months postoperation (P < 0.05). The biomechanical study in cervical cadavers also showed significantly and continuously decreased facet joint pressure in the spreader assisted vertebral distraction group (P < 0.01).ConclusionsSpreader-assisted vertebral distraction method effectively alleviates postoperative neck pain in degenerative cervical spondylosis patients treated with ACDF. The mechanism may be related to the transient relief of facet joint pressure during the vertebral distraction procedure in ACDF.

Anterior Cervical Discectomy and Fusion Versus Laminoplasty for Multilevel Cervical Spondylotic Myelopathy: A National Administrative Database Analysis

Anterior cervical discectomy and fusion (ACDF) is effective for the treatment of single-level cervical spondylotic myelopathy (CSM). However, the data surrounding multilevel CSM have remained controversial. One alternative is laminoplasty, although evidence comparing these strategies has remained sparse. In the present report, we retrospectively reviewed the readmission and reoperation rates for patients who had undergone ACDF or laminoplasty for multilevel CSM from a national longitudinal administrative claims database. We queried the MarketScan Commercial Claims and Encounters database to identify patients who had undergone ACDF or laminoplasty for multilevel CSM from 2007 to 2016. The patients were stratified by operation type. Patients aged <18 years, patients with a history of tumor or trauma, and patients who had undergone anteroposterior approach were excluded from the present study. A total of 5445 patients were included, of whom 1521 had undergone laminoplasty. A matched cohort who had undergone ACDF was identified. The overall 90-day postoperative complication rate was greater in the laminoplasty cohort (odds ratio, 1.48; 95% confidence interval, 1.18-1.86; P < 0.0001). The mean length of stay and 90-day readmission rates were greater in the laminoplasty cohort. The hospital and total payments of the index hospitalization were greater in the ACDF cohort, as were the total payments for ≤2 years after the index hospitalization. In the present administrative claims database study, no difference was found in the reoperation rate between ACDF and laminoplasty. ACDF resulted in fewer complications and readmissions compared with laminoplasty but was associated with greater costs. Additional prospective research is required to investigate the factors driving the higher costs of ACDF in this population and the long-term clinical outcomes.

CT-Guided Posterolateral Full-Endoscopic Ventral Decompression for Single-Level Cervical Spondylotic Myelopathy

Percutaneous full-endoscopic surgery was recently developed for the treatment of cervical foraminal stenosis and posterolateral disc herniation. However, there are no studies involving endoscopic surgery to treat cervical spondylotic myelopathy (CSM). To observe the safety, feasibility, and efficacy of posterolateral full-endoscopic ventral decompression (PLEVD) via computed tomography (CT)-guided surgery in patients with single-level CSM. A prospective cohort study. The First Affiliated Hospital of Gannan Medical College. From May 2018 to August 2019, 21 patients with single-level CSM underwent CT-guided PLEVD. The posterolateral angle was measured during surgery. The neurologic condition was evaluated via the Japanese Orthopaedic Association (JOA) score and recovery rate, and a Visual Analog Scale (VAS) was used to measure pain relief. The maximum spinal canal diameter (MSCD) was measured on pre- and postoperative CT images. The mean length of follow-up was 11.3 ± 5.3 months. The average posterolateral angle was 36.0° ± 5.6°. The mean VAS score of limbs significantly decreased after surgery. The mean JOA score improved during the follow-up period. Nineteen of the 21 patients achieved good or excellent outcomes, and 2 patients had fair outcomes according to the JOA score 6 months after surgery. The average MSCD was enlarged from 0.55 ± 0.15 cm preoperatively to 1.02 ± 0.18 cm postoperatively. This study was nonrandomized and provides only preliminary clinical results for single-level CSM. Under appropriate indications, PLEVD under CT guidance is an available and safe technique for treating single-level CSM.

Evaluation of Results of Anterior Cervical Discectomy Fusion (ACDF) by Cervical Cage with Bone Graft for the Treatment of Single Level Cervical Spondylotic Myelopathy

Background: Cervical spondylotic myelopathy (CSM) is a common spinal cord disorder that develops in elderly people. Anterior cervical decompression and fusion (ACDF) is an effective and reliable procedure for the treatment of CSM.&#x0D; Objective: To find out the results of ACDF by cervical cage with bone graft for the treatment of single level cervical spondylotic myelopathy.&#x0D; Methods: This prospective observational study was conducted in the Department of Orthopedics, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, over a period of two years from March 2015 to August 2017. Forty patients with cervical spondylotic myelopathy were diagnosed on the basis of presenting complains, clinical examination and investigations and were enrolled in this study. The history of the patients was collected, clinical examination was done and relevant investigations were done for each patient. In this study, Nurick grading and VAS scale were used for evaluation of the result.&#x0D; Result: Male gender was predominant in this study; male-female ratio was 2.63:1. Mean age of the patients was 45.9 ± 9.1 years within the range of 30-65 years. Both sides were affected in 14 (35.0%) cases, only right side was affected in 15 (37.5%) cases and only left side was affected in 11 (27.5%) cases. Involved disc spaces were C3/4 (10.0%), C4/5 (22.5%), C5/6 (42.5%) and C6/7 (25.0%). Transientdysphagia was observed in 2 (5.0%), transient para paresis in 1 (2.5.0%), wound infection in 1(2.5.0%) case and damage to the dura was observed in 1 (2.5.0%) case. Signs of fusion were observed in 10 (25.0%) cases after 3 months, 30 (75.0%) cases after 6 months and in all patients after 12months. The result was found to be excellent in 35 (87.5%) and good in 5 (12.5%) cases.&#x0D; Conclusion: Anterior cervical discectomy and fusion by cervical cage with bone graft is an effective procedure for management of CSM.

Morphologic Characteristics of the Deep Cervical Paraspinal Muscles in Patients with Single-Level Cervical Spondylotic Myelopathy

This study aimed to compare morphologic changes of deep paraspinal muscles at C4-7 in patients with C5-6 single-level cervical spondylotic myelopathy (CSM), and to evaluate the relationship between morphologic changes and the level of spinal cord compression. The study included 15 patients with C5-6 single-level CSM and 15 age- and sex-matched healthy subjects. Cross-sectional area (CSA) and functional CSA of the bilateral longus capitis (LCap), longus colli (LC), multifidus (MF), semispinalis cervicis (SSC), semispinalis capitis, splenius capitis, and splenius cervicis were measured on preoperative magnetic resonance images at C4-7, and calculated as ratios with respect to the corresponding vertebral body CSA. The mean maximum spinal cord compression was 22.30% in the CSM group. At the cranial level (C4-5), the CSM group had more fat infiltration in the MF and SSC (P < 0.05). At the spinal cord compression segment and caudal adjacent segment (C5-6 and C6-7), the degree of fat infiltration of all paravertebral muscles was aggravated, accompanied by atrophy of LCap, LC, and MF (P < 0.05). Compared between different levels, fat infiltration in the MF at C5-6 was greater than adjacent levels. In patients with C5-6 single-level CSM, fat infiltration and atrophy of deep paraspinal muscles, especially the Lcap, LC, and MF, mainly occurred in the level of spinal cord compression and caudal adjacent level. In the cranial adjacent segment, the degree of MF and SSC fat infiltration in patients with CSM was also aggravated. This may suggest that multiple mechanisms are involved in paraspinal muscles degeneration in CSM.

Anterior Cervical Corpectomy and Fusion Versus Anterior Cervical Discectomy and Fusion for Treatment of Multilevel Cervical Spondylotic Myelopathy: Insights from a National Registry

Anterior cervical discectomy and fusion (ACDF) is the most common procedure for single-level cervical spondylotic myelopathy (CSM); however, for multilevel CSM, some patients may also undergo anterior cervical corpectomy and fusion (ACCF). We sought to assess differences in clinical outcomes between patients undergoing ACDF and those undergoing ACCF for multilevel CSM. The National Surgical Quality Improvement Program (NSQIP) database was queried from 2007 to 2017 to identify patients diagnosed with CSM undergoing 1- or 2-level ACCF and 2- or 3-level ACDF. Three-to-one propensity scoring was used to match patients undergoing 1-level ACCF to those undergoing 2-level ACDF. Multivariable regression was performed to compare 30-day clinical outcomes between ACCF and ACDF recipients. A total of 3708 patients undergoing 1-level ACCF (n= 729; 18.7%) or 2-level ACDF (n= 3179; 81.3%) were identified. On multivariable regression, 1-level ACCF was associated with significantly longer length of stay (coefficient, 0.79; 95% confidence interval [CI], 0.46-1.11; P < 0.001), longer operative time (coefficient, 19.01; 95% CI, 11.94-26.08; P < 0.001), decreased odds of readmissions (odds ratio [OR], 0.95; 95% CI, 0.91-0.99; P= 0.018), and increased odds of complications (OR, 1.02; 95% CI, 1.00-1.04; P= 0.028) compared with those undergoing 2-level ACDF. A total of 939 patients undergoing either 2-level ACCF (n= 348; 37.1%) or 3-level ACDF (n= 591; 62.9%) were identified. On multivariable regression, 2-level ACCF was associated with significantly longer length of stay (coefficient, 1.17; 95% CI, 0.55-1.79; P < 0.001) and increased risk of complications (OR, 1.05; 95% CI, 1.01-1.08; P= 0.004) compared with 3-level ACDF. Our analyses indicate that ACCF may be associated with worse clinical outcomes than ACDF following multilevel treatment for CSM.

Disc associating axial pain were indicated by PLL resection in ACDF surgery

The generation and tissue origination of disc-associated axial pain is still under exploration. This study was performed to evaluate disc-associated axial pain and to explore whether it originates in the disc or its surrounding components. A 6-year series of 88 single-level Smith-Robinson disc and posterior longitudinal ligament (PLL) resections performed to treat single-level cervical spondylotic myelopathy was retrospectively examined. All single-level anterior disc decompressions were performed under local infiltration anesthesia; the PLL was not anesthetized to avoid cervical cord block. The patients were grouped by disc level. The centered foci of the pain localization were subjectively recorded before, during, and after the operation. Radiological examinations (plain X-ray, computed tomography, and magnetic resonance imaging) were performed before and after the operation to diagnose the compression and evaluate the decompression. All 88 patients who underwent single-level PLL resection had no intraoperative pain responses except during resection of the PLL. Their provoked pain responses were similar to their familiar pain responses. The axial pain disappeared postoperatively. Complications developed in six patients (6.8%). All patients recovered well, and the absence of the axial pain was maintained at the 12-month follow-up. Preoperative axial pain due to single-level disc protrusion was triggered and aggravated only during PLL resection and disappeared postoperatively. This implies that the intervertebral PLL could be the site of origination of axial pain. Axial pain from the PLL at different disc levels had different distributions.

Comparison of 2 Zero-Profile Implants in the Treatment of Single-Level Cervical Spondylotic Myelopathy: A Preliminary Clinical Study of Cervical Disc Arthroplasty versus Fusion

ObjectivesCervical disc arthroplasty (CDA) with Discover prosthesis or anterior cervical discectomy and fusion (ACDF) with Zero-P cage has been widely used in the treatment of cervical spondylotic myelopathy (CSM). However, little is known about the comparison of the 2 zero-profile implants in the treatment of single-level CSM. The aim was to compare the clinical outcomes and radiographic parameters of CDA with Discover prosthesis and ACDF with Zero-P cage for the treatment of single-level CSM.MethodsA total of 128 consecutive patients who underwent 1-level CDA with Discover prosthesis or ACDF with Zero-P cage for single-level CSM between September 2009 and December 2012 were included in this study. Clinical outcomes were evaluated using the Japanese Orthopaedic Association (JOA) score and Neck Disability Index (NDI). For radiographic assessment, the overall sagittal alignment (OSA), functional spinal unit (FSU) angle, and range of motion (ROM) at the index and adjacent levels were measured before and after surgery. Additionally, the complications were also recorded.ResultsBoth treatments significantly improved all clinical parameters (P < 0.05), without statistically relevant differences between the 2 groups. The OSA and FSU angle increased significantly in both groups (P <0.05). Compared with Zero-P group, ROMs at the index levels were well maintained in the Discover group (P < 0.05). However, there were no statistical differences in the ROMs of adjacent levels between the 2 groups (P > 0.05). Besides, no significant differences existed in dysphagia, subsidence, or adjacent disc degeneration between the 2 groups (P > 0.05). However, significant differences occurred in prosthesis migration in CDA group.ConclusionsThe results of this study showed that clinical outcomes and radiographic parameters were satisfactory and comparable with the 2 techniques. However, more attention to prosthesis migration of artificial cervical disc should be paid in the postoperative early-term follow-up.

Comparison of Anterior Surgical Options for the Treatment of Multilevel Cervical Spondylotic Myelopathy

Systematic review. The primary objectives of this review were to compare the effectiveness and safety of various anterior cervical decompressive and reconstructive procedures for diffuse or multifocal cervical spondylotic myelopathy (CSM). An additional objective was to describe the most common ancillary stabilization techniques used with the different anterior decompressive procedures. Surgical management of CSM provides for neurological recovery and disease stabilization in a cost-effective way. Although both retrospective and prospective data support management of CSM by anterior cervical decompression and fusion, the choice decision between various anterior surgical options remains unclear. We conducted a systematic search in MEDLINE and the Cochrane Collaboration Library for human studies in the English-language literature published through September 2012. We included studies comparing multiple discectomies with single or multiple corpectomy, multiple discectomies with discectomy-corpectomy hybrid, and multiple corpectomies with discectomy-corpectomy hybrid, comparing effectiveness and safety outcomes of each procedure, and defining the ancillary stabilization techniques used. Exclusion criteria included patients with degenerative disc disease or degenerative joint disease without CSM, single-level CSM, ossified posterior longitudinal ligament (OPLL), spinal tumor, concomitant infection, and ankylozing spondylitis. Case series, case reports, data not reported separately for each comparison group, or studies that consisted of an N less than 10 for either comparison group were excluded. The evidence strength was rated using the GRADE (Grades of Recommendation Assessment, Development, and Evaluation) criteria. Of the 49 citations identified from our search, 10 studies were initially found suitable for inclusion. Patients undergoing any of the 3 procedures generally experienced improvements in clinical outcomes (neck disability index, Japanese Orthopaedic Association score, and Visual Analogue Scale score for pain) as well as overall sagittal alignment, with minimal perioperative morbidity. There is moderate evidence supporting selection of multiple discectomies compared with corpectomy or discectomy-corpectomy hybrid procedures with regard to superior clinical outcomes and postoperative sagittal alignment. Furthermore, if more extensive operation is needed, there is evidence to support the selection of discectomy-corpectomy hybrid procedures compared with multiple corpectomies if it is technically feasible to accomplish the requisite decompression. The multiple discectomies approach also may have a lower incidence of C5 palsy than corpectomy or discectomy-corpectomy hybrid approaches. All 3 operative approaches are effective strategies for the anterior surgical management of CSM. When the patient pathoanatomy permits, selection of multiple discectomies is favored compared with corpectomy or discectomy-corpectomy hybrid approaches. EVIDENCE-BASED CLINICAL RECOMMENDATIONS: When pathoanatomically appropriate with minimal retrovertebral disease, we recommend the selection of multiple discectomy over corpectomy or discectomy-corpectomy hybrid procedures. Low. Strong. When retrovertebral disease is significant, we recommend, when possible, that discectomy-corpectomy hybrid procedures be performed instead of multiple corpectomies. Moderate. Strong. SUMMARY STATEMENTS: There is no evidence to guide choice of ancillary external immobilization techniques following multilevel anterior decompression and fusion procedures for CSM.

The application of a zero-profile implant in anterior cervical discectomy and fusion

We analyzed the clinical efficacy of the Zero-P implant (Synthes GmbH Switzerland, Oberdorf, Switzerland) in the treatment of single level cervical spondylotic myelopathy. The clinical data of 47 patients with single level cervical spondylotic myelopathy were retrospectively analyzed. Twenty-two patients were treated with a Zero-P implant (Group A) and 25 with a titanium plate with cage (Group B) between January 2009 and September 2010. Operative time, intraoperative blood loss, preoperative and postoperative Japanese Orthopaedic Association (JOA) scores and JOA recovery rate, dysphagia incidence and adjacent segment degeneration rate were measured. The mean operative time in Group A and Group B was 98.18minutes and 105.4minutes, respectively. The average intraoperative blood loss in Group A and Group B was 87.95ml and 92.4ml, respectively. There were no statistical differences in operation time and intraoperative blood loss between the two groups (p>0.05). The JOA score was significantly improved in the two groups (p<0.001), and the recovery rate was similar (60.86% for Group A versus 62.95% for Group B, p>0.05). Dysphagia was experienced by one (4.5%) patient in Group A and eight (32%) patients in Group B, which was significantly different (p=0.044). There was no statistical significance found in the adjacent level degeneration rates between Group A and Group B (p=0.330). The Zero-P implant and traditional titanium plate with cage are effective treatments for single level cervical spondylotic myelopathy, but the Zero-P implant has a lower dysphagia incidence.

Anterior cervical discectomy plus intervertebral polyetheretherketone cage fusion over three and four levels without plating is safe and effective long-term

Anterior cervical discectomy and fusion (ACDF) is an established treatment for single-level cervical spondylotic myelopathy and radiculopathy, yet its stand-alone use for multi-level disease of the subaxial cervical spine remains controversial. We report a prospectively studied case series of 30 patients receiving polyetheretherketone (PEEK) cage fusion over three and four cervical levels without anterior plating. Seven (23.3%) four-level procedures (all C3 to C7) were performed, the other 23 (76.7%) being three-level, with 19 (64.4%) at C4 to C7 and four (12.3%) at C3 to C6. Long-term follow-up of more than 2years was available in 67% of patients. This cohort showed statistically significant improvements in visual analogue score for neck pain (p=0.0006), arm pain (p=0.0003) and Japanese Orthopaedic Association myelopathy score (p=0.002). Fused segment heights increased by 0.6–1.1%. Adjacent segment disease requiring ACDF at C3–4 was seen in 6.7% of patients (one after trauma) at a mean follow-up of 62months. Same segment recurrence requiring posterior decompression with instrumented fusion was found in 10% of patients at a mean follow-up of 49months, only one of whom had radiological evidence of cage subsidence. The results suggest the procedure is safe and effective with potentially less morbidity than anterior plating, shorter inpatient stays than posterior approaches, acceptable same segment recurrence and lower than predicted adjacent segment disease rates.

Prognosis significance of focal signal intensity change on MRI after anterior decompression for single-level cervical spondylotic myelopathy

The prognosis significance of signal intensity changes remains controversial, and several reports showed that focal-increased signal intensity is of little significance in prediction of the surgical outcome after the treatment of cervical spondylotic myelopathy (CSM). The purpose of this study was to investigate whether focal ISI can help assess the prognosis in patients with single-level CSM by means of measuring the ratio of T2/T1 signal intensity. The participants in this study were 59 patients who underwent anterior cervical decompression and fusion for single-level CSM. MRI was performed in all the patients. The values of signal intensity of the spinal cord on T2WI and T1WI of sagittal view were respectively measured at the same level of the spinal cord and with similar area, and the ratio of signal intensity values of T2WI/T1WI (T2/T1 ratio) was then calculated. Patients were divided into 3 groups by hierarchical clustering analysis according to T2/T1 ratio. Compression rate, Japanese Orthopedic Association (JOA) scores, and recovery rate were compared among three groups. The range of T2/T1 ratio of 59 patients was from 1.26 to 2.85. Twenty patients were divided into group 1, 16 into group 2, and 23 into group 3. Significant difference was noted in age at surgery, duration of disease, recovery rate, and pre- and postoperative JOA scores (P < 0.05) among three different groups. Spearman’s rank correlation showed that T2/T1 ratio was correlated with age at surgery, duration of disease, compression rate, pre- and postoperative JOA scores, and recovery rate (P < 0.05). Stepwise regression analysis showed that the best combination of surgical outcome predictors included preoperative JOA score and duration of disease. Patients with higher T2/T1 ratio tend to have relatively poor prognosis after surgical intervention. Focal spinal cord signal intensity change on T2-weighted MRI might be a predictor of a poor outcome in terms of functional recovery rate in patients underwent operations for single-level CSM.