Surgery For Cervical Spondylotic Myelopathy Research Articles

Surgery vs Conservative Care for Cervical Spondylotic Myelopathy: Surgery Is Appropriate for Progressive Myelopathy.

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction.1 The condition presents insidiously and is defined in terms of its clinical symptoms (gait instability, bladder dysfunction, fine finger motor difficulties) and signs (hyperreflexia, weakness, alteration of joint position sense). CSM is caused by dynamic repeated compression of the spinal cord from degenerative arthritis of the cervical spine.2 Proposed mechanisms include axonal stretch-associated injury2 and spinal cord ischemia from compression of larger vessels and impaired microcirculation.3,4 Surgery to decompress and stabilize the spine is often advocated for severe or progressive symptoms, with mixed results. About two-thirds of patients improve with surgery, while surgery does not result in improvement in 15%-30%.5 Over 112,400 cervical spine operations for degenerative spondylosis are performed annually in the US (100% increase over the past decade),6 with CSM accounting for nearly 20% of cervical spine operations in the US.7 Annual hospital charges for CSM surgery exceeds 2 billion dollars per year.6 In addition, CSM is associated with substantial postoperative outpatient expenses (e.g., physician visits, imaging, physical therapy, medications). Recently, the Institute of Medicine designated CSM as one of the top 100 national health research priorities for comparative effectiveness research.8 There is a great need for modern prospective studies with validated outcomes tools to assess the effectiveness of surgical treatments for CSM. Most American cervical spine experts (both orthopaedic and neurological surgeons) believe that there is sufficient clinical equipoise to support a comparative randomized clinical trial (RCT) if the study population is carefully defined.9 Most experts feel that surgery can prevent the progression of spinal cord dysfunction and can, in many cases, improve the symptoms of cervical spondylotic myelopathy. It is unclear, however, what the optimal surgical technique might be (ventral versus dorsal), and in up to 30% of cases the clinical outcome is not satisfactory.5 Furthermore, the complication rate for CSM surgery is high (17% in a recent prospective study),10 particularly in patients over 74 years of age,11 which is a growing segment of the US population.12 Lastly, the 5-year re-operation rate following surgery for CSM is nearly 15%.13

Use of multivariate linear regression and support vector regression to predict functional outcome after surgery for cervical spondylotic myelopathy

This study introduces the use of multivariate linear regression (MLR) and support vector regression (SVR) models to predict postoperative outcomes in a cohort of patients who underwent surgery for cervical spondylotic myelopathy (CSM). Currently, predicting outcomes after surgery for CSM remains a challenge. We recruited patients who had a diagnosis of CSM and required decompressive surgery with or without fusion. Fine motor function was tested preoperatively and postoperatively with a handgrip-based tracking device that has been previously validated, yielding mean absolute accuracy (MAA) results for two tracking tasks (sinusoidal and step). All patients completed Oswestry disability index (ODI) and modified Japanese Orthopaedic Association questionnaires preoperatively and postoperatively. Preoperative data was utilized in MLR and SVR models to predict postoperative ODI. Predictions were compared to the actual ODI scores with the coefficient of determination (R2) and mean absolute difference (MAD). From this, 20 patients met the inclusion criteria and completed follow-up at least 3months after surgery. With the MLR model, a combination of the preoperative ODI score, preoperative MAA (step function), and symptom duration yielded the best prediction of postoperative ODI (R2=0.452; MAD=0.0887; p=1.17×10−3). With the SVR model, a combination of preoperative ODI score, preoperative MAA (sinusoidal function), and symptom duration yielded the best prediction of postoperative ODI (R2=0.932; MAD=0.0283; p=5.73×10−12). The SVR model was more accurate than the MLR model. The SVR can be used preoperatively in risk/benefit analysis and the decision to operate.

Cervical spondylotic myelopathy: the prediction of outcome following surgical intervention in 93 patients using T1- and T2-weighted MRI scans.

Cervical spondylotic myelopathy (CSM) can lead to significant disability through a spectrum of clinical manifestations ranging from dexterity loss to more profound weakness, incontinence and paralysis. To determine the outcome of surgical decompression for CSM and investigate pre-operative predictors of outcome. Prospectively collected data on all patients who underwent decompressive surgery for CSM and completed 12-month follow-up were reviewed. Data on age, MRI T1 and T2 signal changes pre-operatively, surgical approach and the Nurick's Myelopathy Grade (NMG) was analysed pre-operatively and 1 year post-surgery. Data on 93 consecutive patients who underwent surgery for CSM were reviewed. Median age was 62 (23-94) years and 59% were male. The median follow-up was 37 (17-88) months. The approach was anterior in 38 (42%) patients, posterior in 55 (58%); improvement was not significantly different when the two groups were compared. The number of levels decompressed increased with age (p value <0.0001). The group with a pre-operatively high signal on T1-weighted MRI images [n = 28 (30%)] was associated with less neurological recovery post-operatively compared to the patients with a normal T1 cord signal. None of the patients deteriorated neurologically post-operatively, while 66% improved by at least one NMG. Surgical decompressions for CSM stop the progress of symptoms at 12 months post-surgery and may result in a significant improvement of NMG in two-thirds of the patients. Changes in the T1-weighted MRI images predict worse outcomes following surgery.

Dlouhodobé výsledky operačního řešení cervikální spondylogenní myelopatie pomocí "open-door" laminoplastiky

Dlouhodobé výsledky operačního řešení cervikální spondylogenní myelopatie pomocí "open-door" laminoplastiky

Rationale, Design, and Early Trial Performance of AOSpine North America Multicenter Double Blind Randomized Controlled Trial of Safety and Efficacy of Riluzole in CSM (CSM—Protect Trial)

Introduction Although surgical decompression is an effective treatment for cervical spondylotic myelopathy (CSM), many patients have substantial residual neurological and functional impairment. Compelling evidence from preclinical models suggest a benefit of adding a neuroprotective drug which targets sodium/glutamate excitotoxicity to the treatment of patients with CSM. The purpose of this study is to evaluate efficacy and safety of sodium-glutamate antagonist riluzole in improving neurological outcomes in patients with CSM undergoing surgical treatment. Patients and Methods Prospective multicenter double-blind randomized controlled trial in which a total of 300 patients undergoing surgical decompression for CSM will be randomized 1:1 to riluzole 2 × 50 mg daily for 14 days before the surgery and 28 days after the surgery or to the placebo. Primary outcome measure is change in mJOA between baseline and 6 months. Secondary outcomes include ASIA, SF36v2, NDI, Eq. 5D, Pain VAS, and complications. Sample size was estimated based on data from recently completed prospective cohort study. The sample size of 270 completed subjects will have 80% power to detect absolute difference of 0.9 in mJOA score between the investigational and the control group. The statistical analysis is organized as a sequential adaptive trial with one interim analysis at 65% of the accrued sample for early futility and efficacy. Adaptive statistical design allows for sample size adjustment at the time of interim analysis. Results To date, 153 subjects have been enrolled. Average age of the enrolled subjects is 58.4 years (SD, 10.13). The baseline mJOA is 11.9 (SD, 1.5). Baseline NDI is 42.4 (SD, 20.1) and the baseline SF36v2 Physical Component Score (PCS) is 33.5 (SD, 9.3). Conclusion In spite of the benefits of the surgical intervention, patients with CSM experience significant residual impairment and neurological compromise. Adding neuroprotective treatment with riluzole may improve outcomes of surgery. This discussion will emphasize the unique study design and the biological rationale for considering riluzole as a potential neuroprotective adjunct for patients undergoing surgery for CSM.

A Comparison between Anterior and Posterior Surgical Approaches in the Treatment of Cervical Spondylotic Myelopathy

Introduction Cervical spondylotic myelopathy (CSM) is a common problem in our aging population. We aim to compare the efficacy and safety of anterior and posterior approaches in the surgical treatment of CSM using validated outcome measures in a prospective cohort study. Materials and Methods Patients with defined clinical features of CSM were recruited from three hospitals in Singapore between October 2009 and December 2010. A total of 17 participants were recruited, and baseline demographic variables and outcome measure scores were established. Namely, the modified Japanese Orthopaedic Association (mJOA) score, Nurick, Short Form-36 (SF-36) Health Survey Questionnaire score, and Neck Disability Index (NDI). Participants underwent decompressive surgery by anterior or posterior approach, with choice of technique left to surgeon preference. Scores were retaken at 6, 12, and 24 months after surgery for comparison against baseline, within and between groups through the follow-up period. Results Patients who underwent anterior approach surgery were younger, had fewer comorbidities, less extensive disease, better SF-36 physical functioning, and mJOA scores at baseline. Both groups had clinically significant improvement in scores based on validated minimum clinically important difference (MCID) values at the end of the 2-year follow-up period. Score improvement was more sustained in the anterior group, whereas in the posterior group improvement in scores was greatest at 6 months post-decompression, but declined thereafter (albeit to values still three times that at baseline). A patient who underwent posterior approach surgery developed anemia secondary to perioperative blood loss. There were no cases of implant-related complications or cases of revision surgery. Conclusion This study highlights the differences in patient and disease factors influencing choice of surgical approach and shows the safety and efficacy of CSM surgery regardless of approach.

Predicting Complications after Cervical Spondylotic Myelopathy Surgery: Perception Equals Reality?

Predicting Complications after Cervical Spondylotic Myelopathy Surgery: Perception Equals Reality?

Transcranial magnetic stimulation but not MRI predicts long-term clinical status in cervical spondylosis: a case series.

Case series. To compare transcranial magnetic stimulation (TMS) and magnetic resonance imaging (MRI) findings between patients who underwent surgery for cervical spondylotic myelopathy and those with spondylosis who were not operated upon, and to correlate these findings with clinical functionality at follow-up. Private practice. Of 16 consecutive patients with cervical spondylosis 8 underwent surgery (group I) and 8 were treated conservatively (group II). We compared TMS and MRI findings between these groups and we correlated central motor conduction times (CMCTs) and MRI-measured sagittal and parasagittal diameters of the spinal canal at baseline evaluation, with clinical functionality at 2-year follow-up. Group I CMCTs at the lower limbs correlated significantly with modified-JoA 2 years post surgery (r=-0.71, P<0.05), but MRI-measured diameters did not. In group II baseline TMS was unrevealing, contrary to significant spinal stenosis disclosed by MRI. The condition of none of these patients deteriorated at 2 years. CMCTs at the lower limbs, but not cervical spinal canal diameters, correlate with long-term functional outcome following surgical or conservative treatment.

Association of APOE ε4 with poor outcome following decompressive surgery for cervical spondylotic myelopathy

Possession of apolipoprotein E ε4 allele (APOE ε4) has been associated with poor outcome after different forms of acute brain injury. Here we investigate whether patients with APOE ε4 have a poor prognosis following surgery for cervical spondylotic myelopathy (CSM).

Posterior atlantoaxial 'facetal' instability associated with cervical spondylotic disease.

Aim:The association of single or multiple level cervical spondylotic disease with atlantoaxial instability is assessed. The implications of identifying and treating atlantoaxial instability in such an association are highlighted.Materials and Methods:The analysis is based on an experience with 11 patients treated during the period June 2013-June 2014. All patients had single or multilevel cervical spondylotic disease. The spinal canal compromise and evidence of cord compression was evident on imaging in the cervical subaxial spine and was related to disc bulges and osteophytic bars. There was no or relatively insignificant compression of the cervicomedullary cord by the odontoid process. There was no evidence of odontoid process-related instability on dynamic imaging. Apart from presence of features of cervical spondylosis, investigations and surgical exploration and direct manual handling of the facets revealed evidence of Type B (posterior) atlantoaxial ‘facetal’ instability in all patients. Our 5-point clinical grading system and Japanese Orthopaedic Association (JOA) scores were used to monitor the patients both before and after surgery and at follow-up. Surgery involved both at lantoaxial and subaxial cervical fixation. During the average period of follow-up of 9 months (5-17 months), all patients showed remarkable and gratifying neurological recovery.Conclusion:We conclude that atlantoaxial facetal instability can be ‘frequently’ associated with cervical spondylosis and needs surgical stabilization. Our surgical outcome analysis suggests that missing or ignoring the presence of atlantoaxial facetal instability can be an important cause of suboptimal result or failure of surgery for cervical spondylotic myelopathy.

Dysphagia that occurred after posterior cervical surgery for cervical spondylotic myelopathy with DISH and anterior osteophytes

Dysphagia that occurred after posterior cervical surgery for cervical spondylotic myelopathy with DISH and anterior osteophytes

Postoperative cervical sagittal imbalance negatively affects outcomes after surgery for cervical spondylotic myelopathy.

Prospective observational cohort study. To determine if postoperative cervical sagittal balance is an independent predictor of health-related quality of life outcome after surgery for cervical spondylotic myelopathy. Both ventral and dorsal fusion procedures for CSM are effective at reducing the symptoms of myelopathy. The importance of cervical sagittal balance in predicting overall health-related quality of life outcome after ventral versus dorsal surgery for CSM has not been previously explored. A prospective, nonrandomized cohort of 49 patients undergoing dorsal and ventral fusion surgery for CSM was examined. Preoperative and postoperative C2-C7 sagittal vertical axis was measured on standing lateral cervical spine radiographs. Outcome was assessed with 2 disease-specific measures-the modified Japanese Orthopedic Association scale and the Oswestry Neck Disability Index and 2 generalized outcome measures-the Short-Form 36 physical component summary (SF-36 PCS) and Euro-QOL-5D. Assessments were performed preoperatively, and at 3 months, 6 months, and 1 year postoperatively. Statistical analyses were performed using SAS version 9.3 (SAS Institute). Most patients experienced improvement in all outcome measures regardless of approach. Both preoperative and postoperative C2-C7 sagittal vertical axis measurements were independent predictors of clinically significant improvement in SF-36 PCS scores (P = 0.03 and P = 0.02). The majority of patients with C2-C7 sagittal vertical axis values greater than 40 mm did not improve from an overall health-related quality of life perspective (SF-36 PCS) despite improvement in myelopathy. The postoperative sagittal balance value was inversely correlated with a clinically significant improvement of SF-36 PCS scores in patients undergoing dorsal surgery but not ventral surgery (P = 0.03 vs. P = 0.93). Preoperative and postoperative sagittal balance measurements independently predict clinical outcomes after surgery for CSM. 2.

Consensus statement: systematic reviews of value-based surgical spine care: what do we know? Where are the limitations?

Consensus statement: systematic reviews of value-based surgical spine care: what do we know? Where are the limitations?

Do quantitative magnetic resonance imaging parameters correlate with the clinical presentation and functional outcomes after surgery in cervical spondylotic myelopathy? A prospective multicenter study.

A prospective multicenter cohort study. To establish the relationship between preoperative quantitative magnetic resonance imaging (MRI) parameters and clinical presentation and postoperative outcomes in patients with cervical spondylotic myelopathy. Correlation of magnetic resonance imaging with clinical presentation and outcomes in cervical spondylotic myelopathy is poorly understood. A total of 134 magnetic resonance imaging scans were reviewed from 12 sites across North America. The transverse area (TA) of the spinal cord at the site of maximal compression was computed, and spinal cord signal intensity (SI) changes on T1-/T2-weighted imaging (WI) were evaluated. Detailed clinical assessments--neurological signs, symptoms, Nurick grade, modified Japanese Orthopaedic Association, segmental-tract score, and long-tract score of modified Japanese Orthopaedic Association, 30-m walk test, Short-Form 36 questionnaire, and neck disability index were performed at admission, 6 months, and 12 months postoperatively. The total number of neurological signs in a patient correlated with TA (P = 0.01) and SI changes on T1-/T2WI (P = 0.05). Pre- and postoperative Nurick grade (P = 0.03, P = 0.02), modified Japanese Orthopaedic Association score (P = 0.005, P = 0.001), segmental-tract score (P = 0.05, P = 0.006), and long-tract score (P = 0.006, P = 0.002), 30-m walk test (P = 0.002, P = 0.01) correlated with TA. There was no significant difference in pre- and postoperative clinical scores in patients with/without SI changes. Patients with severe cord compression showed SI changes on T1-/T2WI more frequently (r =-0.27, r =-0.38). Pyramidal signs--plantar response, Hoffmann reflex and hyper-reflexia correlated with TA (P = 0.003, P = 0.0004, P = 0.024, respectively) and SI changes on T1/T2WI (P = 0.02). TA closely mirrors the clinical presentation of cervical spondylotic myelopathy and may be used in predicting surgical outcomes. Pyramidal signs correlated with TA and/or SI changes on T1-/T2WI. The total number of neurological signs in a patient correlated with TA. There was no significant relationship between TA, age and duration of symptoms. 3.

Change in morphology of intramedullary T2-weighted increased signal intensity after anterior decompressive surgery for cervical spondylotic myelopathy.

Retrospective study. To study the change in morphology of T2-weighted (T2W) increased signal intensity (ISI) and its association with functional outcome after central corpectomy for cervical spondylotic myelopathy (CSM) and ossified posterior longitudinal ligament (OPLL). There are limited data on change in T2W ISI morphology after anterior decompressive surgery. It is unclear whether change in T2W ISI carries prognostic significance in patients with CSM/OPLL. We reviewed patients who underwent central corpectomy for CSM/OPLL between 1996 and 2010, and underwent a follow-up magnetic resonance imaging (MRI) at 6 months or later postoperatively. T2W ISI on sagittal images was classified as type 0 no ISI; type 1, predominantly (>50%) faint with an indistinct border; and type 2, predominantly (>50%) intense with a sharp border. The length of T2W ISI and the presence of T1-weighted hypointensity were also recorded on preoperative and follow-up images. Functional outcomes as measured by the Nurick grade were correlated with change in morphology of MR signal changes. Sixty-four patients (60 males, mean age = 50 ± 1.1 yr) were reviewed. The mean follow-up duration was 29 ± 3.5 months. The majority of patients (71.9%) had no change in the type of ISI at follow-up. The type of ISI improved in 13 patients (20.3%), and worsened in 5 patients (7.8%). The mean length of ISI was 26.2 ± 3.4 mm preoperatively and 13.7 ± 1.8 mm at follow-up in 53 patients (P = 0.002). Change in ISI grade or length was not associated with change in Nurick grade at follow-up (P = 0.74, P = 0.5). The type of T2W ISI does not change, but the length of T2W ISI decreases for the majority of patients undergoing anterior cervical decompression for CSM/OPLL. In our series, change in morphology of T2W ISI did not correlate with functional outcome as measured by Nurick grade. 4.

The evolution of T2-weighted intramedullary signal changes following ventral decompressive surgery for cervical spondylotic myelopathy: Clinical article.

T2-weighted intramedullary increased signal intensity (ISI) on MRI in patients with cervical spondylotic myelopathy (CSM) appears to represent a wide spectrum of pathological changes that determine reversibility of cord damage. Although sharp T2-weighted ISI on preoperative imaging may correlate with poorer surgical outcomes, there are limited data on how these changes progress following surgery. In this study, the authors characterized pre-and postoperative ISI changes in patients undergoing surgery for CSM and studied their postoperative evolution in an attempt to quantify their clinical significance. The preoperative and postoperative MR images obtained in 56 patients who underwent oblique cervical corpectomy for CSM were reviewed, and the ISI was classified into 4 subtypes based on margins and intensity: Type 0 (none), Type 1 ("fuzzy"), Type 2 ("sharp"), and Type 3 ("mixed"). The locations of the ISI were further classified as focal if they represented single discrete lesions, multifocal if there were multiple lesions with intervening normal cord, and multisegmental if the lesions were continuous over more than 1 segment. The maximum craniocaudal length of the ISI was measured on each midsagittal MR image. The Nurick grade and Japanese Orthopaedic Association (JOA) score were used to assess clinical status. The mean duration of follow-up was 28 months. T2-weighted ISI changes were noted preoperatively in 54 patients (96%). Most preoperative ISI changes were Type 1 (41%) or Type 3 (34%), with a significant trend toward Type 2 (71%) changes at follow-up. Multi-segmental and Type 3 lesions tended to regress significantly after surgery (p = 0.000), reducing to Type 2 changes at follow-up. Clinical outcomes did not correlate with ISI subtype; however, there was a statistically significant trend toward improvement in postoperative Nurick Grade in patients with a > 50% regression in ISI size. In addition, patients with more than 18 months of follow-up showed significant regression in ISI size compared with patients imaged earlier. On logistic regression analysis, preoperative Nurick grade and duration of follow-up were the only significant predictors of postoperative improvement in functional status (OR 4.136, p = 0.003, 95% CI 1.623-10.539 and OR 6.402, p = 0.033, 95% CI 1.165-35.176, respectively). There is a distinct group of patients with multisegmental Type 3 intramedullary changes who show remarkable radiological regression after surgery but demonstrate a residual sharp focal ISI at follow-up. A regression of the ISI by > 50% predicts better functional outcomes. Patients with a good preoperative functional status remain the most likely to show improvement, and the improvement continues to occur even at remote follow-up. The clinical relevance of the quality of the T2-weighted ISI changes in patients with CSM remains uncertain; however, postoperative regression of the ISI change is possibly a more important correlate of patient outcome than the quality of the ISI change alone.

P703: Modulation of cortical plasticity by decompression surgery for cervical spondylotic myelopathy

P703: Modulation of cortical plasticity by decompression surgery for cervical spondylotic myelopathy

Transcranial magnetic stimulation of the motor cortex correlates with objective clinical measures in patients with cervical spondylotic myelopathy.

Prospective cohort study. To assess the correlation between central motor conduction time (CMCT) and various subjective and objective clinical assessment measures in patients undergoing decompressive surgery for cervical spondylotic myelopathy (CSM). CSM can cause a spectrum of neurological deficits among individuals. Subjective clinical assessments of disease severity may lack the sensitivity of objective tests. Transcranial magnetic stimulation provides objective electrophysiological data on the integrity of the corticospinal tracts, which may be useful for monitoring disease progression or neurological improvement after surgery. Patients undergoing surgical decompression for CSM underwent subjective and objective testing before surgery and at 1, 3, 6, and 12 months after surgery. Subjective measures included modified Japanese Orthopaedic Association score, Neck Disability Index, Nurick grade, and visual analogue scale score. Objective measures included CMCT as measured using transcranial magnetic stimulation, the 10-m walk test, the 9-hole peg task, and the grip and release test. Primary outcome was the correlation between CMCT and subjective or objective measures at preoperative and postoperative time points. Secondary outcome was the correlation between preoperative CMCT and performance in subjective or objective testing after surgical intervention. Improvement in both subjective and objective measures was observed after surgery. CMCT correlated with other objective measures (10-m walk test, 9-hole peg task, and grip and release test) both at baseline and after decompressive surgery in these 17 patients with CSM. Patients with high baseline CMCTs were associated with poor performance on the 10-m walk test, 9-hole peg task, and grip and release test. Modified Japanese Orthopaedic Association score correlated with CMCT at baseline but not after surgical intervention. CMCT was not associated with other subjective measures, such as Neck Disability Index, Nurick grade, and visual analogue scale score, at preoperative or postoperative time points. CMCT as measured by transcranial magnetic stimulation is a responsive objective assessment of CSM. It can be used to monitor disease severity and neurological function before and after surgical intervention. Prolonged baseline CMCT may be associated with worse surgical outcomes. 2.

Three-dimensional gait analysis outcomes at 1 year following decompressive surgery for cervical spondylotic myelopathy

Gait impairment is an important feature of cervical sponydylotic myelopathy (CSM) as it can have a detrimental effect on function and quality of life. The aim of this study was to measure changes in gait in people with CSM following surgical decompression. Thirteen participants with clinical and radiological evidence of CSM underwent three-dimensional gait analysis, using a full lower limb kinematic, kinetic and electromyography protocol, before and 12 months after decompressive surgery. No significant post-operative changes were detected in temporal-spatial or kinematic parameters. Kinetic data showed significant improvements in knee power absorption [mean improvement, 0.42 watts per kilogram (W/kg)], ankle plantarflexor moment (0.1 Nm/kg) and ankle power generation (0.55 W/kg). Electromyography showed a 4.7 % increase in tibialis anterior activation time. These findings indicate that improvement in locomotor function can be achieved after surgery. Future studies should explore the potential for further recovery of gait through targeted neuro-rehabilitation.

Application of magnetic resonance imaging in cervical spondylotic myelopathy.

Cervical spondylotic myelopathy (CSM) is the most common cause of spinal cord dysfunction and is caused by static or dynamic repeated compression of the spinal cord resulting from degenerative arthritis of the cervical spine and some biological injuries to the cervical spine. The T2 signal change on conventional magnetic resonance imaging (MRI) is most commonly associated with neurological deficits. Diffusion tensor imaging and MR spectroscopy show altered microstructure and biochemistry that reflect patient-specific pathogenesis and can be used to predict neurological outcome and response to intervention. Functional MRI can help to assess the neurological functional recovery after decompression surgery for CSM.