Clinical results of cervical laminectomy and fusion for the treatment of cervical spondylotic myelopathy in 58 consecutive patients

Cervical kyphosis after posterior cervical laminectomy with and without fusion

BACKGROUND

Cervical posterior instrumentation and fusion is often performed to avoid post-laminectomy kyphosis. However, larger comparative analyses of cervical laminectomy with or without fusion are sparse.

METHODS

A retrospective, two-center, comparative cohort study included patients after stand-alone dorsal laminectomy with (n = 91) or without (n = 46) additional fusion for degenerative cervical myelopathy with a median follow-up of 59 (interquartile range (IQR) 52) months. The primary outcome was the C2-7 Cobb angle and secondary outcomes were Neck Disability Index (NDI), modified Japanese Orthopaedic Association (mJOA) scale, revision rates, T1 slope and C2-7 sagittal vertical axis (C2-7 SVA) at final follow-up. Logistic regression analysis adjusted for potential confounders (i.e. age, operated levels, and follow-up).

RESULTS

Preoperative C2-7 Cobb angle and T1 slope were higher in the laminectomy group, while the C2-7 SVA was similar. The decrease in C2-7 Cobb angle from pre- to postoperatively was more pronounced in the laminectomy group (- 6° (IQR 20) versus -1° (IQR 7), p = 0.002). When adjusting for confounders, the decrease in C2-7 Cobb angle remained higher in the laminectomy group (coefficient - 12 (95% confidence interval (CI) -18 to -5), p = 0.001). However, there were no adjusted differences for postoperative NDI (- 11 (- 23 to 2), p = 0.10), mJOA, revision rates, T1 slope and C2-7 SVA.

CONCLUSION

Posterior cervical laminectomy without fusion is associated with mild loss of cervical lordosis of around 6° in the mid-term after approximately five years, however without any clinical relevance regarding NDI or mJOA in well-selected patients (particularly in shorter segment laminectomies of < 3 levels).

Spinal Cord Drift Following Laminoplasty Versus Laminectomy and Fusion for Cervical Spondylotic Myelopathy

BACKGROUND

Cervical laminoplasty and laminectomy and fusion (LF) are posterior-based surgical techniques for the surgical treatment of cervical spondylotic myelopathy (CSM). Interestingly, the comparative amount of spinal cord drift obtained from these procedures has not been extensively described. The purpose of this study is to compare spinal cord drift between cervical laminoplasty and LF in patients with CSM.

METHODS

The laminoplasty group consisted of 22 patients, and the LF group consisted of 44 patients. Preoperative and postoperative alignment was measured using the Cobb angle (C2-C7). Spinal cord position was measured on axial T2-magnetic resonance imaging of the cervical spine preoperatively and postoperatively. Spinal cord drift was quantified by subtracting preoperative values from postoperative values. Functional improvement was assessed using the modified Japanese Orthopaedic Association (mJOA) score.

RESULTS

Mean spinal cord drift was higher following LF compared to laminoplasty (2.70 vs 1.71 mm, P < .01). Using logistic regression analysis, there was no correlation between sagittal alignment and spinal cord drift. Both groups showed an improvement in mJOA scores postoperatively compared to their preoperative values (laminoplasty, +2.0, P = .012; LF, +2.4, P < .01). However, there was no difference in mJOA score improvement postoperatively between both groups (P = .482).

CONCLUSIONS

This study demonstrates that patients who had LF for CSM achieved more spinal cord drift postoperatively compared to those who had laminoplasty. However, the increased drift did not translate into superior functional outcome as measured by the mJOA score.

LEVEL OF EVIDENCE

3.

CLINICAL RELEVANCE

Spinal cord drift following LF may differ from laminoplasty in patients undergoing surgery for CSM. This finding should be considered when assessing CSM patients for surgical intervention.

Adverse events and their risk factors 90 days after cervical spine surgery: analysis from the Michigan Spine Surgery Improvement Collaborative

OBJECTIVE

The Michigan Spine Surgery Improvement Collaborative (MSSIC) is a statewide, multicenter quality improvement initiative. Using MSSIC data, the authors sought to identify 90-day adverse events and their associated risk factors (RFs) after cervical spine surgery.

METHODS

A total of 8236 cervical spine surgery cases were analyzed. Multivariable generalized estimating equation regression models were constructed to identify RFs for adverse events; variables tested included age, sex, diabetes mellitus, disc herniation, foraminal stenosis, central stenosis, American Society of Anesthesiologists Physical Classification System (ASA) class > II, myelopathy, private insurance, anterior versus posterior approach, revision procedures, number of surgical levels, length of procedure, blood loss, preoperative ambulation, ambulation day of surgery, length of hospital stay, and discharge disposition.

RESULTS

Ninety days after cervical spine surgery, adverse events identified included radicular findings (11.6%), readmission (7.7%), dysphagia requiring dietary modification (feeding tube or nothing by mouth [NPO]) (6.4%), urinary retention (4.7%), urinary tract infection (2.2%), surgical site hematoma (1.1%), surgical site infection (0.9%), deep vein thrombosis (0.7%), pulmonary embolism (0.5%), neurogenic bowel/bladder (0.4%), myelopathy (0.4%), myocardial infarction (0.4%), wound dehiscence (0.2%), claudication (0.2%), and ileus (0.2%). RFs for dysphagia included anterior approach (p < 0.001), fusion procedures (p = 0.030), multiple-level surgery when considering anterior procedures only (p = 0.037), and surgery duration (p = 0.002). RFs for readmission included ASA class > II (p < 0.001), while preoperative ambulation (p = 0.001) and private insurance (p < 0.001) were protective. RFs for urinary retention included increasing age (p < 0.001) and male sex (p < 0.001), while anterior-approach surgery (p < 0.001), preoperative ambulation (p = 0.001), and ambulation day of surgery (p = 0.001) were protective. Preoperative ambulation (p = 0.010) and anterior approach (p = 0.002) were protective of radicular findings.

CONCLUSIONS

A multivariate analysis from a large, multicenter, prospective database identified the common adverse events after cervical spine surgery, along with their associated RFs. This information can lead to more informed surgeons and patients. The authors found that early mobilization after cervical spine surgery has the potential to significantly decrease adverse events.

Postoperative Walking Ability of Non-ambulatory Cervical Myelopathy Patients

STUDY DESIGN

A retrospective analysis.

OBJECTIVE

The aim of this study was to clarify the postoperative improvement of walking ability and prognostic factors in nonambulatory patients with cervical myelopathy.

SUMMARY OF BACKGROUND DATA

Many researchers have reported the surgical outcome in compressive cervical myelopathy. However, regarding severe gait disturbance,, it has not been clarified yet how much improvement can be expected.

METHODS

One hundred thirty-one nonambulatory patients with cervical myelopathy were treated surgically and followed for an average of 3 years. Walking ability was graded according to the lower-extremity function subscore (L/E subscore) in Japanese Orthopedic Association score. We divided patients based on preoperative L/E subscores: group A, L/E subscore of 1 point (71 patients); and group B, 0 or 0.5 point (60 patients). The postoperative walking ability was graded by L/E subscore: excellent, ≥2 points; good, 1.5 points; fair, 1 point; and poor, 0.5 or 0 points. We compared preoperative and postoperative scores. The cutoff value of disease duration providing excellent improvement was investigated.

RESULTS

Overall, 50 patients were graded as excellent (38.2%), and 21 patients were graded as good (16.0%). In group B, 17 patients (28.3%) were graded as excellent. Seventeen patients who were graded as excellent had shorter durations of myelopathic symptoms and/or gait disturbance (7.9 and 3.8 months respectively) than the others (29.5 and 8.9 months, respectively) (P < 0.05). Receiver-operating characteristic curve showed that the optimal cutoff values of the duration of myelopathic symptoms and gait disturbance providing excellent improvement were 3 and 2 months, respectively.

CONCLUSION

Even if the patients were nonambulatory, 28.3% of them became able to walk without support after operation. If a patient becomes nonambulatory within 3 months from the onset of myelopathy or 2 months from the onset of gait disturbance, surgical treatment should be performed immediately to raise the possibility to improve stable gait.

LEVEL OF EVIDENCE

3.

Surgical and general complications in 2,961 Japanese patients with cervical spondylotic myelopathy: Comparison of different age groups

Introduction: Details of surgical and general complications for patients with cervical spondylotic myelopathy (CSM) are still uncertain. The purpose of this study was to describe surgeries and their complications among Japanese patients with CSM. Methods: The Japanese Society for Spine Surgery and Related Research performed a nationwide survey on spine surgery and complications in 2011. Data of patients with 2,961 CSM >40 years old were included. The clinicopathological variables were basic demographic and clinical information, surgical information, and surgical and general complications. To examine the influence of age, variables were compared among three age groups: patients 40-64 (n=1,123), 65-74 (n=966), and ≥75 (n=872) years of age. Results: The study included 1,970 males and 991 females and the mean age was 64.3 years old. There were 168 anterior (5.7%) and 2,770 posterior (94.2%) approach surgeries. The vast majority of patients with CSM were treated using the posterior approach, 89.4% of whom had decompression surgery only. Anterior surgeries were more common in the younger age group, but posterior surgeries were equally distributed. The incidence of total complications including surgical/general complications was similar for the anterior (16/168; 9.5%) and posterior (295/2,770; 10.6%) approaches. No patient died on the operating table, but four patients (0.1%) died within one month after surgery. No association was detected between complications and age, comorbidity, and other surgical factors. The incidence of complications was similar for the different age groups. However general complications were predominantly observed in the older group and those who had instrumented surgery. Conclusions: The results indicate that the indication and surgical performance for patients with CSM is favorable in Japan, despite the super-aging population. Few serious complications were reported in this study. However, more detailed informed consent about surgical and, in particular, general complications is necessary for the older patients with CSM.

Prevalence of complications after surgery in treatment for cervical compressive myelopathy: A meta-analysis for last decade

PURPOSE

We aim to perform a meta-analysis on prevalence of all kinds of operation-related complications following surgery treating cervical compressive myelopathy (CCM) and to provide reference for surgeons making surgical plan.

METHODS

An extensive search of literature was performed in PubMed/MEDLINE, Embase, the Cochrane library, CNKI, and WANFANG databases on incidence of operation-related complications from January 2007 to November 2016. Data was calculated and data analysis was conducted with STATA 12.0 and Revman 5.3.

RESULTS

A total of 107 studies included 1705 of 8612 patients (20.1%, 95% CI 17.3%-22.8%) on overall complications. The incidence of C5 plasy, cerebrospinal fluid (CSF), infection, axial pain, dysphagia, hoarseness, fusion failure, graft subsidence, graft dislodgment, and epidural hematoma is 5.3% (95% CI 4.3%-6.2%), 1.9% (95% CI 1.3%-2.4%), 2.8% (95% CI 1.7%-4.0%), 15.6% (95% CI 11.7%-19.5%), 16.8% (95% CI 13.6%-19.9%), 4.0% (95% CI 2.3%-5.7%), 2.6% (95% CI 0.2%-4.9%), 3.7% (95% CI 2.0%-5.5%), 3.4% (95% CI 2.0%-4.8%), 1.1% (95% CI 0.7%-1.5%), respectively. Patients with ossification of posterior longitudinal ligament (OPLL) (6.3%) had a higher prevalence of C5 plasy than those with cervical spondylotic myelopathy (CSM) (4.1%), and a similar trend in CSF (12.2% vs 0.9%). Individuals after laminectomy and fusion (LF) had highest rate of C5 plasy (15.2%), while those who underwent anterior cervical discectomy and fusion (ACDF) had the lowest prevalence (2.0%). Compared with patients after other surgical options, individuals after anterior cervical corpectomy and fusion (ACCF) have the highest rate of CSF (4.2%), infection (14.2%), and epidural hematoma (3.1%). Patients after ACDF (4.8%) had a higher prevalence of hoarseness than those with ACCF (3.0%), and a similar trend for dysphagia between anterior corpectomy combined with discectomy (ACCDF) and ACCF (16.8% vs 9.9%).

CONCLUSIONS

Based on our meta-analysis, patients with OPLL have a higher incidence of C5 palsy and CSF. Patients after LF have a higher incidence of C5 palsy, ACCDF have a higher incidence of dysphagia, ACCF have a higher incidence of CSF and infection and ACDF have a higher incidence of hoarseness. These figures may be useful in the estimation of the probability of complications following cervical surgery.

Surgical treatment of multilevel cervical spondylosis in patients with or without a history of syringomyelia

PURPOSE

Cervical spondylotic myelopathy (CSM) is the commonest spinal cord disease in adults. This paper compares patients who developed CSM after successful treatment of syringomyelia to those with CSM exclusively related to degenerative spinal disease.

METHODS

In this prospective study, 70 consecutive patients with CSM and spondylotic changes in at least three levels underwent 73 operations between 2005 and 2015 (mean follow-up: 39 ± 36 months). Patients with treated syringomyelia (group A, n = 30) and those without (group B, n = 40) were distinguished. Japanese Orthopaedic Association (JOA) and European Myelopathy scores (EMS), Karnofksy scores, and scores for individual symptoms were compared. Long-term outcomes were analyzed with progression-free survival rates.

RESULTS

Patients of group A were significantly younger with a significantly longer history and lower functional scores compared to group B. 59 laminectomies C3-C6 plus lateral mass fixations, six ventral decompressions with fusion, and eight combined approaches were performed. In both groups, mean JOA (A 9.5 ± 4.3-10.0 ± 4.7; B 11.3 ± 3.7-12.3 ± 4.3), EMS (A 11.4 ± 2.9-12.0 ± 3.1; B 12.2 ± 3.1-13.5 ± 3.3), and Karnofsky scores (A 59 ± 18-62 ± 18; B 68 ± 13-72 ± 15) increased in the first postoperative year with lower scores in group A throughout. Rates for progression-free survival for 5 years were similar in both groups (A 64.2%, B 65.6%).

CONCLUSION

Patients with CSM benefit from decompressive surgery. Surgery should be advocated early for all symptomatic patients with a history of syringomyelia. These patients are at risk for diagnostic delay and worse postoperative results.

Efficacy of the transtemporal approach with awake brain mapping to reach the dominant posteromedial temporal lesions

BACKGROUND

Surgeries for lesions in the dominant hippocampal and parahippocampal gyrus involving the posteromedial temporal regions are challenging to perform because they are located close to Wernicke's area; white matter fibers related with language; the optic radiations; and critical neurovascular structures. We performed a transtemporal approach with awake functional mapping for lesions affecting the dominant posteromedial temporal regions. The aim of this study was to assess the feasibility, safety, and efficacy of awake craniotomy for these lesions.

METHODS

We retrospectively reviewed four consecutive patients with tumors or cavernous angiomas located in the left hippocampal and parahippocampal gyrus, which further extended to the posteromedial temporal regions, who underwent awake surgery between December 2014 and January 2016.

RESULTS

Four patients with lesions associated with the left hippocampal and parahippocampal gyrus, including the posteromedial temporal area, who underwent awake surgery were registered in the study. In all four patients, cortical and subcortical eloquent areas were identified via direct electrical stimulation. This allowed determination of the optimal surgical route to the angioma or tumor, even in the language-dominant hippocampal and parahippocampal gyrus. In particular, this approach enabled access to the upper part of posteromedial temporal lesions, while protecting the subcortical language-related fibers, such as the superior longitudinal fasciculus.

CONCLUSIONS

This study revealed that awake brain mapping can enable the safe resection of dominant posteromedial temporal lesions, while protecting cortical and subcortical eloquent areas. Furthermore, our experience with four patients demonstrates the feasibility, safety, and efficacy of awake surgery for these lesions.

Cervical Laminectomy with Lateral Mass Screw Fixation in Cervical Spondylotic Myelopathy: Neurological and Sagittal Alignment Outcome: Do We Need Lateral Mass Screws at each Segment?

BACKGROUND

Anterior cervical decompression and fusion is the standard procedure used for treating patients with cervical myelopathy. However, these procedures are associated with complications such as pseudarthrosis, construct failure, and neurological complications. Posterior cervical laminectomy and instrumentation is an alternative procedure to treat multilevel cervical myelopathy. In this study, we raised questions whether instrumentation is required at all levels and whether stabilizing the spine in neutral or lordotic contour with indirect decompression leads to neurological improvement with radiological evidence of anterior decompression. The results of posterior cervical laminectomy and instrumentation with lateral mass screw in terms of radiological and functional outcome in patients with multilevel cervical myelopathy are prospectively evaluated.

MATERIALS AND METHODS

In this prospective study conducted between June 2006 and December 2015, we have evaluated 112 patients with multilevel cervical myelopathy who underwent multilevel cervical laminectomy and instrumentation with lateral mass screw. All patients were evaluated preoperatively and postoperatively with Nurick's grading and Modified Japanese Orthopaedic Association (mJOA) scale for neurological function. Cooper scale and British Medical Research Council grading system for motor function. Curvature index was used to measure the alignment of cervical spine preoperatively and postoperatively. Alignment of the cervical spine was done preoperatively and postoperatively by calculating the curvature index. Axial MRI was used to calculate the severity of compression preoperatively which was calculated as per Singh's criteria and postoperatively to assess the adequacy of decompression at the operated level.

RESULTS

In our study, there were 112 patients including 99 males and 13 females, with mean age of 59.53 years. The mean duration of followup of patients was 33.24 months. In total, cervical laminectomy was performed at 342 levels in 112 patients with an average of 3.05 laminectomies, and in total, 112 lateral mass screws were inserted. On postoperative followup, the mJOA and Nurick's grading showed improvement in all cases as compared to preoperative findings. The mean mJOA improved significantly from 8.56 preoperatively to 13.57 postoperatively (P < 0.001). The mean Nurick's grading also improved significantly from 2.59 preoperatively to 0.66 postoperatively (P < 0.001). The mean Cooper scale also showed significant improvement in both upper and lower limbs postoperatively (P < 0.001). The mean preoperative Cooper scale was 1.75 and postoperative was 0.31 for upper limbs, and the mean Cooper scale was 2.14 preoperatively and 0.56 postoperatively for lower limbs. X-rays done on routine followups showed good alignment of the cervical spine with maintenance of curvature index in all patients. The mean grade of compression as seen on preoperative MRI was 2.46 which reduced significantly postoperatively to 0.16 (P < 0.001).

CONCLUSION

The multilevel cervical laminectomy and instrumentation with lateral mass screw for multilevel cervical myelopathy is a safe technique that provides decompression of the spinal cord, prevents the development of kyphotic spinal deformity and posterior tension band of the spinal cord as associated with laminoplasty or uninstrumented laminectomy.

Restoration of Upper Limb Function in an Individual with Cervical Spondylotic Myelopathy using Functional Electrical Stimulation Therapy: A Case Study

Non-traumatic spinal cord pathology is responsible for 25–52% of all spinal cord lesions. Studies have revealed that spinal stenosis accounts for 16–21% of spinal cord injury (SCI) admissions. Impaired grips as well as slow unskilled hand and finger movements are the most common complaints in patients with spinal cord disorders, such as myelopathy secondary to cervical spondylosis. In the past, our team carried out couple of successful clinical trials, including two randomized control trials, showing that functional electrical stimulation therapy (FEST) can restore voluntary reaching and/or grasping function, in people with stroke and traumatic SCI. Motivated by this success, we decided to examine changes in the upper limb function following FEST in a patient who suffered loss of hand function due to myelopathy secondary to cervical spondylosis. The participant was a 61-year-old male who had C3–C7 posterior laminectomy and instrumented fusion for cervical myelopathy. The participant presented with progressive right hand weakness that resulted in his inability to voluntarily open and close the hand and to manipulate objects unilaterally with his right hand. The participant was enrolled in the study ~22 months following initial surgical intervention. Participant was assessed using Toronto Rehabilitation Institute’s Hand Function Test (TRI-HFT), Action Research Arm Test (ARAT), Functional Independence Measure (FIM), and Spinal Cord Independence Measure (SCIM). The pre–post differences in scores on all measures clearly demonstrated improvement in voluntary hand function following 15 1-h FEST sessions. The changes observed were meaningful and have resulted in substantial improvement in performance of activities of daily living. These results provide preliminary evidence that FEST has a potential to improve upper limb function in patients with non-traumatic SCI, such as myelopathy secondary to cervical spondylosis.

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 (R(2)) and mean absolute difference (MAD). From this, 20 patients met the inclusion criteria and completed follow-up at least 3 months 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 (R(2)=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 (R(2)=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.