Predictive factors affecting outcome after cervical laminoplasty

Long-Term Outcomes of One-Stage Combined Posteroanterior Procedure and Laminoplasty-Alone for Multilevel Degenerative Cervical Myelopathy With Concomitant Anterior and Posterior Compression: A Propensity Score Matching Analysis of 8-year Follow-Up

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

This study aimed to investigate the long-term outcomes of laminoplasty-alone (LP) and combined procedure (CP), consisting of laminoplasty and single-level anterior cervical discectomy and fusion, in comparable patients who had multilevel degenerative cervical myelopathy (MDCM) with concomitant anterior and posterior compression (CAPC).

METHODS

Consecutive MDCM patients with CAPC underwent LP or CP between 2012 and 2015 from a same surgical group were enrolled and followed up for a minimum of 8 years. Preoperative demographic, radiological, and clinical variables were collected. Propensity score matching (PSM) analysis was performed to match patients with comparable conditions. The outcomes were evaluated by postoperative Japanese Orthopedic Association (JOA) score improvement, JOA recovery rate (JOARR) and complications.

RESULTS

A total of 230 patients were included, of whom 146 underwent LP and 84 underwent CP. After PSM, 84 pairs of comparable patients were matched. The matched groups presented fair comparability in preoperative conditions. The CP group had significantly prolonged surgery time and greater blood loss. At the final follow-up, the postoperative JOA scores of LP and CP groups were 14.51 ± 1.79 and 15.47 ± 1.81 (P < 0.001) and the JOARR were 42.5% ± 53.3% and 68.5% ± 35.4%, respectively (P < 0.001). Three (3.6%) patients in the LP group underwent reoperations because of recurrent symptoms (P = 0.081).

CONCLUSION

Both LP and CP demonstrated considerable long-term neurological recovery in patients with CAPC. The CP showed a significantly higher JOA improvement and JOARR. The combined decompression might be a safe and effective alternative in treating MDCM with CAPC in experienced hands.

Incidence and Risk Factors for the Development of Axial Symptoms Following Posterior Single-Door Laminoplasty: A Retrospective Analysis

OBJECTIVE

Posterior single-door laminoplasty is a widely practiced clinical procedure, but the occurrence of postoperative axial syndrome (AS) remains a significant concern. The aim of this study was to identify risk factors associated with AS and develop a risk prediction model.

METHODS

Clinical data from 226 patients who underwent posterior single-door laminoplasty between June 2017 and June 2022 were collected. Through Logistic model analysis, the risk factors of AS are clarified and the intensity of each risk factor is explained in the form of forest plot. Subsequently, we constructed a predictive model and plotted receiver operating characteristic curves to assess the model's predictive value.

RESULTS

In the end, 87 cases were diagnosed with AS, resulting in an incidence rate of 38.5%. Logistic regression analysis revealed that preoperative encroachment rate of anterior spinal canal (pre-op ERASC), intraoperative facet joints destruction, intraoperative open-door angle, postoperative loss of cervical curvature, and postoperative loss of cervical range of motion were independent risk factors for AS. Conversely, preoperative cervical curvature (pre-op CC) and postoperation early function training were protective factors against AS. The Youden index indicated that the cutoff values for pre-op ERASC and pre-op CC were 26.6°and 16.5, respectively. The risk prediction model for AS was constructed and a nomogram was plotted. The model has high clinical value.

CONCLUSIONS

Pre-op ERASC, pre-op CC, intraoperative facet joints destruction, intraoperative open-door angle, postoperative loss of cervical curvature, postoperative loss of cervical range of motion, and postoperation early function training are independent influencing factors for AS occurrence. The risk model has good practicability.

Developing predictive models for surgical outcomes in patients with degenerative cervical myelopathy: a comparison of statistical and machine learning approaches

BACKGROUND CONTEXT

Machine learning (ML) is widely used to predict the prognosis of numerous diseases.

PURPOSE

This retrospective analysis aimed to develop a prognostic prediction model using ML algorithms and identify predictors associated with poor surgical outcomes in patients with degenerative cervical myelopathy (DCM).

STUDY DESIGN

A retrospective study.

PATIENT SAMPLE

A total of 406 symptomatic DCM patients who underwent surgical decompression were enrolled and analyzed from three independent medical centers.

OUTCOME MEASURES

We calculated the area under the curve (AUC), classification accuracy, sensitivity, and specificity of each model.

METHODS

The Japanese Orthopedic Association (JOA) score was obtained before and 1 year following decompression surgery, and patients were grouped into good and poor outcome groups based on a cut-off value of 60% based on a previous study. Two datasets were fused for training, 1 dataset was held out as an external validation set. Optimal feature-subset and hyperparameters for each model were adjusted based on a 2,000-resample bootstrap-based internal validation via exhaustive search and grid search. The performance of each model was then tested on the external validation set.

RESULTS

The Support Vector Machine (SVM) model showed the highest predictive accuracy compared to other methods, with an AUC of 0.82 and an accuracy of 75.7%. Age, sex, disease duration, and preoperative JOA score were identified as the most commonly selected features by both the ML and statistical models. Grid search optimization for hyperparameters successfully enhanced the predictive performance of each ML model, and the SVM model still had the best performance with an AUC of 0.93 and an accuracy of 86.4%.

CONCLUSIONS

Overall, the study demonstrated that ML classifiers such as SVM can effectively predict surgical outcomes for patients with DCM while identifying associated predictors in a multivariate manner.

Analysis of risk factors for axial symptoms after posterior cervical open-door laminoplasty

BACKGROUND

Laminoplasty (LP), a procedure commonly used to treat cervical spondylotic myelopathy (CSM), often results in the development of axial symptoms (AS) postoperatively. This study aims to analyze the risk factors associated with the occurrence of AS after LP.

METHODS

We collected and evaluated clinical data from 264 patients with CSM who underwent LP treatment at our institution from January 2018 to January 2022 through a single-center retrospective study. Of the patients, 153 were male and 111 were female, with an average age of 58.1 ± 6.7 years. All patients underwent C3-7 posterior laminoplasty. Based on the occurrence of postoperative axial symptoms, the patients were divided into an AS group and a non-AS group. General information, including age, gender, disease duration, Japanese Orthopaedic Association (JOA) score, postoperation early function training, and collar-wearing time, was recorded and compared between the two groups. Surgical-related data, such as operative segments, surgical time, intraoperative blood loss, intraoperative facet joint destruction, and destruction of the C7 spinous process muscle insertion, were also compared. Imaging data, including preoperative cervical curvature, cervical range of motion, preoperative encroachment rate of the anterior spinal canal, and angle of laminar opening, were collected. Univariate and multivariate logistic regression analyses were used to identify risk factors for the development of AS after LP, and receiver operator characteristic (ROC) curves were utilized to explore the optimal preoperative parameters.

RESULTS

All 264 patients successfully underwent surgery and were followed up for an average of 19.5 ± 6.8 months. At the 6-month follow-up, 117 patients were diagnosed with AS, resulting in an incidence rate of 40.2%. The multivariate logistic regression analysis identified that preoperative encroachment rate of anterior spinal canal (Pre-op ERASC), intraoperative facet joints destruction (Intra-op FJD), intraoperative open-door angle (Intra-op OA), destroy the C7 spinous process muscle insertion (Destroy C7 SPMI), postoperative loss of cervical curvature (Post-op LCC), and postoperative loss of cervical range of motion (Post-op LCROM) were independent risk factors for AS. Conversely, preoperative cervical curvature (Pre-op CC) and postoperation early function training (Post-op EFT) were protective factors against AS. According to the ROC curve, the cutoff values for preoperative anterior spinal canal occupation rate and preoperative cervical curvature were 28.5% and 16.5°, respectively. When the preoperative anterior spinal canal occupation rate was greater than 28.5% or the preoperative cervical curvature was less than 16.5°, AS was more likely to occur after surgery.

CONCLUSION

High preoperative anterior spinal canal occupation rate, facet joint damage during surgery, C7 spinous process muscle stop point damage, larger angle of laminar opening, and greater postoperative cervical curvature loss and cervical range of motion loss are associated with an increased risk of developing AS after cervical laminoplasty. Conversely, a larger preoperative cervical curvature and early postoperative functional exercises can help reduce the occurrence of AS.

Degenerative Cervical Myelopathy: An Overview

Degenerative cervical myelopathy (DCM) is a spinal condition of growing importance due to its increasing prevalence within the ageing population. DCM involves the degeneration of the cervical spine due to various processes such as disc ageing, osteophyte formation, ligament hypertrophy or ossification, as well as coexisting congenital anomalies. This article provides an overview of the literature on DCM and considers areas of focus for future research. A patient with DCM can present with a variety of symptoms ranging from mild hand paraesthesia and loss of dexterity to a more severe presentation of gait disturbance and loss of bowel/bladder control. Hoffman's sign and the inverted brachioradialis reflex are also important signs of this disease. The gold standard imaging modality is MRI which can identify signs of degeneration of the cervical spine. Other modalities include dynamic MRI, myelography, and diffusion tensor imaging. One important scoring system to aid with the diagnosis and categorisation of the severity of DCM is the modified Japanese Orthopaedic Association score. This considers motor, sensory, and bowel/bladder dysfunction, and categorises patients into mild, moderate, or severe DCM. DCM is primarily treated with surgery as this can halt disease progression and may even allow for neurological recovery. The surgical approach will depend on the location of degeneration, the number of cervical levels involved and the pathophysiological process. Surgical approach options include anterior cervical discectomy and fusion, corpectomy, or posterior approach (laminectomy ± fusion). Conservative management is also considered for some patients with mild or non-progressive DCM or for patients where surgery is not an option. Conservative treatment may include physical therapy, traction, or neck immobilisation. Future recommendations include research into the prevalence rate of DCM and if there is a difference between populations. Further research on the benefit of conservative management for patients with mild or non-progressive DCM would be recommended.

Increased blood flow of spinal cord lesion after decompression improves neurological recovery of degenerative cervical myelopathy: an intraoperative ultrasonography-based prospective cohort study

INTRODUCTION

Surgical decompression is a highly effective therapy for degenerative cervical myelopathy (DCM), but the mechanisms of neurological recovery following decompression remain unclear. This study aimed to evaluate the spinal cord blood flow status after sufficient decompression by intraoperative contrast-enhanced ultrasonography (CEUS) and to analyze the correlation between neurological recovery and postdecompressive spinal cord blood perfusion in DCM.

MATERIALS AND METHODS

Patients with multilevel DCM were treated by ultrasound-guided modified French-door laminoplasty using a self-developed rongeur. Neurological function was evaluated using the modified Japanese Orthopaedic Association (mJOA) score preoperatively and at 12 months postoperatively. Spinal cord compression and cervical canal enlargement before and after surgery were assessed by magnetic resonance imaging and computerized tomography. The decompression status was evaluated in real time by intraoperative ultrasonography, while the spinal cord blood flow after sufficient decompression was assessed by CEUS. Patients were categorized as favourable (≥50%) or unfavourable (<50%) recovery according to the recovery rate of the mJOA score at 12 months postoperatively.

RESULTS

Twenty-nine patients were included in the study. The mJOA scores were significantly improved in all patients from 11.2±2.1 preoperatively to 15.0±1.1 at 12 months postoperatively, with an average recovery rate of 64.9±16.2%. Computerized tomography and intraoperative ultrasonography confirmed adequate enlargement of the cervical canal and sufficient decompression of the spinal cord, respectively. CEUS revealed that patients with favourable neurological recovery had a greater increased blood flow signal in the compressive spinal cord segment after decompression.

CONCLUSIONS

In DCM, intraoperative CEUS can clearly reflect spinal cord blood flow. Patients with increased blood perfusion of the spinal cord lesion immediately after surgical decompression tended to achieve greater neurological recovery.

What Is the Impact of Surgical Approach in the Treatment of Degenerative Cervical Myelopathy in Patients With OPLL? A Propensity-Score Matched, Multi-Center Analysis on Inpatient and Post-Discharge 90-Day Outcomes

STUDY DESIGN

Retrospective cohort.

OBJECTIVE

Provide a comparison of surgical approach in the treatment of degenerative cervical myelopathy in patients with OPLL.

METHODS

A national database was queried to identify adult (≥18 years) patients with OPLL, who underwent at least a 2-level cervical decompression and fusion for cervical myelopathy from 2012-2014. A propensity-score-matching algorithm was employed to compare outcomes by surgical approach.

RESULTS

After propensity-score matching, 627 patients remained. An anterior approach was found to be an independent predictor for higher inpatient surgical complications(OR 5.9), which included dysphagia:14%[anterior]vs.1.1%[posterior] P-value < 0.001, wound hematoma:1.7%[anterior]vs.0%[posterior] P-value = 0.02, and dural tear:9.4%[anterior]vs.3.2%[posterior] P-value = 0.001. A posterior approach was an predictor for longer hospital length of stay by nearly 3 days(OR 3.4; 6.8 days[posterior]vs.4.0 days[anterior] P-value < 0.001). The reasons for readmission/reoperation did not vary by approach for 2-3-level fusions; however, for >3-level fusions, patients with an anterior approach more often had respiratory complications requiring mechanical ventilation(P-value = 0.038) and required revision fusion surgery(P-value = 0.015).

CONCLUSIONS

The national estimates for inpatient complications(25%), readmissions(9.9%), and reoperations(3.5%) are substantial after the surgical treatment of multi-level OPLL. An anterior approach resulted in significantly higher inpatient surgical complications, but this did not result in a longer hospital length of stay and the overall 90-day complication rates requiring readmission or reoperation was similar to those seen after a posterior approach. For patients requiring >3-level fusion, an anterior approach is associated with significantly higher risk for respiratory complications requiring mechanical ventilation and revision fusion surgery. Precise neurological complications and functional outcomes were not included in this database, and should be further assessed in future studies.

A Comparison of Various Surgical Treatments for Degenerative Cervical Myelopathy: A Propensity Score Matched Analysis

STUDY DESIGN

Retrospective Cohort.

OBJECTIVE

To compare the short-term outcomes for Laminoplasty, Laminectomy/fusion, and ACDF.

METHODS

We utilized a prospectively-collected, multi-center national database with a propensity score matching algorithm to compare the short-term outcomes for laminoplasty, laminectomy/fusion, and multi-level (>3) ACDF (with and without corpectomy). Bivariate analyses involved both chi-square/fisher exact test and t-test/ANOVA on perioperative factors. Multivariate analyses were performed to determined independent risk factors for short term outcomes.

RESULTS

546 patients remained after propensity score matching, with 182 patients in each cohort. ACDF required the longest operative time 188 ± 79 versus laminectomy/fusion (169 ± 75, p = 0.017), and laminoplasty (167 ± 66, p = 0.004). ACDF required the shortest hospital stay (LOS ≥ 2: ACDF 56.6%, laminoplasty 89.6%, laminectomy/fusion 93.4%, p < 0.05). ACDF had lower overall complications (ACDF 3.9%, laminoplasty 7.7%, laminectomy/fusion 11.5%, p < 0.05), mortality (ACDF 0%, laminoplasty 0.55%, laminectomy/fusion 2.2%, p < 0.05), and unplanned readmissions (ACDF 4.4%, laminoplasty 4.4%, laminectomy/fusion 9.9%, p < 0.05). No significant differences were seen in the other outcomes including DVT/PT, acute renal failure, UTI, stroke, cardiac complications, or sepsis. In the multivariate analysis, laminectomy/fusion (OR 17, reference: ACDF) and laminoplasty (OR10, reference: ACDF) were strong independent risk factors for LOS ≥ 2 days. Laminectomy/fusion (OR 3.2, reference: ACDF) was an independent predictor for any adverse events 30-days after surgery.

CONCLUSIONS

Laminectomy/fusion carries the highest risk for morbidity, mortality, and unplanned readmissions in the short-term postoperative period. Laminoplasty and ACDF cases carry similar short-term complications risks. ACDF is significantly associated with the longest operative duration and shortest LOS without an increase in individual or overall complications, readmissions, or reoperations.

Risk factors for poor neurological outcomes after unilateral open-door laminoplasty: an analysis of the characteristics of ectopic bone

Background

The factors affecting neurological outcomes with unilateral open-door laminoplasty have been controversial. The purpose of this study was to evaluate the impact of the characteristics of ectopic bone on poor neurological outcomes after unilateral open-door laminoplasty.

Methods

We retrospectively analyzed the clinical data of 112 patients who underwent unilateral open-door laminoplasty from September 2017 to September 2020. According to the Japanese Orthopedic Association score recovery rate after surgery (Japanese Orthopedic Association recovery rate ≥ 50% and < 50%, respectively), all patients were divided into “poor” and “good” groups. The characteristics of ectopic bone and the position relationship between the open side and ectopic bone (for lateral ossification) in the two groups were compared and analyzed. Univariate and multivariate analyses were used to determine the risk factors for poor neurological outcome.

Results

We identified patients with a mean age of 58.39 years and a mean follow-up of 25.43 months. Sixty (53.6%) patients experienced recovery of poor neurological function. On univariable analysis, significant predictors of poor neurological recovery were occupation rate of spinal canal > 60% (p = 0.000), ossification extending to C2 (p = 0.006), lateral ossification (p = 0.032) and opening side on the ipsilateral side of the ectopic bone (p = 0.011). Multivariate logistic regression analysis revealed that the occupation rate of spinal canal > 60% (P = 0.003), ossification extending to C2 (P = 0.041) and opening the door on the ipsilateral side for lateral ossification (P = 0.013) were independent risk factors for poor prognosis of neurological function.

Conclusions

An occupation ratio > 60% is the most important risk factor. Another one is ossification of the posterior longitudinal ligament extending to C2. Meanwhile, opening the door on the ipsilateral side is indeed a risk factor for lateral ossification. Better neurological function may be obtained by choosing the opposite side of the heterotopic bone as the open side. Therefore, the design of the surgical plan should comprehensively consider these factors.

Severity of Myelopathy is Closely Associated With Advanced Age and Signal Intensity Change in Cervical Ossification of the Posterior Longitudinal Ligament: A Prospective Nationwide Investigation

STUDY DESIGN

Prospective, nationwide case series.

OBJECTIVE

To identify preoperative factors associated with myelopathy and neurological impairment in patients with cervical ossification of the posterior longitudinal ligament (OPLL).

SUMMARY OF BACKGROUND DATA

Various studies have reported clinical outcomes following the surgical treatment of OPLL. However, there has been no large-scale study of preoperative clinical features in patients with cervical OPLL.

MATERIALS AND METHODS

Data were prospectively collected from 28 institutions nationwide in Japan. In total, 512 patients with neurological impairment caused by cervical OPLL requiring surgery were enrolled. Basic demographic and clinical data, including age, sex, diabetes status, body mass index, smoking history, and disease duration were collected. C2-7 lordotic angle, canal narrowing ratio, range of motion in flexion-extension at C2-7, and type of OPLL were evaluated on lateral radiographs to identify factors influencing the clinical features of patients with OPLL in whom surgery was planned.

RESULTS

Complete documentation was available for 490 patients (362 male, 128 female). In total, 34 patients had the localized type, 181 had the segmental type, 64 had the continuous type, and 211 had the mixed type. Although there were no significant differences in age, body mass index, disease duration, Japanese Orthopedic Association (JOA) score, and lordotic angle at C2-7 according to the type of OPLL, significant differences were observed in a range of motion at C2-7 and the canal narrowing ratio among the 4 types. Multiple regression analysis revealed that the JOA score was significantly associated with age and signal intensity change on magnetic resonance imaging.

CONCLUSIONS

This is the first large-scale, prospective, multicenter case series study to investigate factors influencing preoperative neurological status in patients with OPLL. Age and signal intensity change on magnetic resonance images were significantly associated with JOA score in patients requiring surgery.

LEVEL OF EVIDENCE

Level II.

The impact of ossification spread on cervical spine function in patients with ossification of the posterior longitudinal ligament

Ossification of the posterior longitudinal ligament (OPLL) is a progressive disease. The bridging of ossified lesions to the vertebral body gradually increases, thereby decreasing the mobility of the cervical spine; thus, cervical spine function may decrease over time. However, cervical spine function in patients with cervical OPLL has not been evaluated in large prospective studies. Therefore, we conducted a prospective multicenter study to clarify whether ossification spread can influence cervical spine function and quality of life (QOL) in patients with cervical OPLL. In total, 238 patients (162 men, 76 women; mean age, 63.9 years) were enrolled from 16 institutions. Each patient underwent whole spine computed tomography and was evaluated for cervical spine function and QOL using the Japanese Orthopaedic Association Cervical Myelopathy Evaluation Questionnaire (JOACMEQ). In the multivariate regression analysis, a higher neck VAS score and a larger number of bridge formations of OPLL in the whole spine were significant predictors of adverse outcomes related to cervical spine function. This is the first prospective multicenter study to reveal the impact of ossification spread on cervical spine function. These findings are important to understand the natural course of OPLL and can serve as controls when evaluating postoperative cervical spine function.

Cervical laminoplasty with unilateral C4-5 foraminotomy: Technical note and case series

OBJECTIVE

The open-door laminoplasty technique is widely used in the treatment of multilevel cervical myelopathy. Despite the satisfactory functional and radiological results of this technique, postoperative C5 palsy is still a severe and disabling complication with a variable incidence in the literature. The objective of this article is to describe and demonstrate the surgical technique step by step with the addition of unilateral C4-5 foraminotomy and to evaluate the results obtained to date, with special emphasis on C5 palsy.

MATERIAL AND METHODS

Retrospective study of 20 patients operated on for cervical myelopathy using the "extended" laminoplasty technique, which is described step by step.

RESULTS

Between January 2013 and April 2019, 20 patients were operated on using the extended laminoplasty technique. Only one patient (5%) presented postoperative C5 palsy. The postoperative recovery rate of the modified JOA (Japanese Orthopaedic Association) score was 54.5%, similar to that observed in other series.

CONCLUSION

The extended cervical laminoplasty technique with unilateral C4-5 foraminotomy was developed and demonstrated for the prevention of C5 palsy. The results were analysed and an incidence of C5 palsy coinciding with the lowest percentage reported in the literature was obtained. A prospective randomised study would be useful to assess the role of preventive unilateral C4-5 foraminotomy.

Expansion of Spinal Canal with Lift-Open Laminoplasty: A New Method for Compression Cervical Myelopathy

OBJECTIVE

This study is to introduce lift-open laminoplasty and verify the increase of the spinal canal area following this surgical technique according to the preoperative anatomical measurement.

METHODS

There are 82 patients (43 male and 39 female) analyzed in our study from January 2019 to December 2020. The average age was 63.2 ± 3.21 years (from 41 to 84 years). All of them were treated with open-door laminoplasty, with a decompression segment range from C3 to C6. The increase of the spinal canal area after open-door laminoplasty was measured on postoperative CT images of the patients, and the distances between both lamina-facet junctions and lamina length was measured on preoperative CT images. Using the Pythagorean theorem for the equation of calculation area after the expansile open-door laminoplasty. Based on previous measurement parameters, spinous process length, lateral mass width, distance between osteotomy line and lamina-facet junctions line were additionally measured on preoperative CT images. Pythagorean theorem was used for calculating the area after the expansile lift-open laminoplasty. The results were recorded and a statistical analysis was undertaken. Then, there were six patients (five male and one female) treated with lift-open laminoplasty on C6, open-door on C3-C5, who suffer from cervical spondylotic myelopathy from December 2020 to January 2021. The average age was 60.3 ± 1.7 years (from 56 to 71 years). Operation time, blood loss, and Japanese Orthopaedic Association (JOA) score recovery rate were recorded. Intraoperative and postoperative complications were observed.

RESULTS

The increase of the spinal canal area after open-door laminoplasty measured on postoperative CT images was 123.01 ± 17.06 mm² and the calculation of the increase of the spinal canal areausing the Pythagorean theorem after open-door laminoplasty was 122.86 ± 15.86 mm² . A comparison of the actual value with calculative value showed no significant difference (T value = 0.057, P value = 0.955). The calculation of the increase of the spinal canal area after lift-open laminoplasty was 183.57 ± 62.99 mm² , which was larger than that after open-door laminoplasty (T value = 8.462, P value < 0.001). Mean operation time was 153.3 min and operative blood loss was 600 mL of the six patients treated with lift-open laminoplasty. At 1 month follow-up, all patients had recovered well. JOA score recovery rate was 37.6% and no intraoperative and postoperative complications occurred.

CONCLUSION

Lift-open laminoplasty could preserve nearly 100% of extensor muscle, avoid damaging C7 paraspinal muscles and C6-7 posterior muscle-ligament complex, reconstruct the spinous process firmly in the midline, and expand adequate spinal canal area after operation. These advantages could reduce the incidence rate of complications and bring better clinical results than traditional laminoplasty.

Inadequate spinal cord expansion in intraoperative ultrasound after decompression may predict neurological recovery of degenerative cervical myelopathy

OBJECTIVE

To compare the neurological recovery between patients with adequate and inadequate immediate spinal cord expansion after sufficient decompression in degenerative cervical myelopathy (DCM).

METHODS

Twenty-seven patients subjected to French-door laminoplasty underwent the guidance of intraoperative ultrasound (IOUS) and were prospectively included. The modified Japanese Orthopedic Association (mJOA) score was evaluated before surgery and at 12 months postoperatively. The maximum spinal cord compression (MSCC) after sufficient decompression was calculated on the IOUS image; patients were divided into adequate (MSCC ≥ 0.95) and inadequate (MSCC < 0.95) expansion groups according to the MSCC. The mJOA score, spinal cord hyperechogenicity, age at surgery, symptom duration, occupational rate of the spinal canal, and the minimum anteroposterior diameter of the spinal cord between the two groups were compared.

RESULTS

Initially, 2 cases showed residual compression on IOUS; after further decompression, all patients acquired sufficient decompression. All patients achieved improvements in mJOA scores with an average recovery rate of 68.6 ± 20.3%. The recovery rate of the mJOA score of the inadequate expansion group was significantly inferior to that of the adequate expansion group (59.2 ± 21.7% versus 76.2 ± 16.2%, p = 0.028). The spinal cord hyperechogenicity was more common in the inadequate expansion group, while the spinal cord anteroposterior diameter of the inadequate expansion group was significantly smaller than that of the adequate expansion group.

CONCLUSIONS

The application of IOUS in French-door laminoplasty could help to confirm sufficient decompression for the treatment of DCM. Inadequate spinal cord expansion after sufficient decompression had the high possibility of predicting less satisfactory neurological recovery of DCM.

KEY POINTS

• The intraoperative ultrasound revealed that not all degenerative cervical myelopathy patients acquired adequate spinal cord expansion after sufficient decompression. • Patients who failed to acquire adequate spinal cord expansion commonly combined with spinal cord hyperechogenicity and trended to achieve less satisfactory neurological recovery after surgical decompression. • Inadequate spinal cord expansion after sufficient decompression had the high possibility of predicting less satisfactory neurological recovery of patients with degenerative cervical myelopathy.

Risk Factors for Poor Outcome of Cervical Laminoplasty: Multivariate Analysis in 505 Patients with Cervical Spondylotic Myelopathy

The risk factors for poor outcome after cervical laminoplasty in patients with cervical spondylotic myelopathy (CSM) were demonstrated. These findings suggest that advanced age, long-term CSM symptoms, and lower score of preoperative 10-second step test are risk factors for poor cervical laminoplasty outcomes in patients with CSM.

Study Design..

A prospective study.

Objective..

The aim of this study was to characterize the risk factors for poor outcome following cervical laminoplasty in patients with cervical spondylotic myelopathy (CSM).

Summary of Background Data..

Previous research has identified a variety of potential predictive factors that might affect outcomes after cervical laminoplasty. However, no study till date has assessed the effects of such risk factors, including internal medicine comorbidity and quantitative performance tests, on the outcome of laminoplasty in a large series of patients with CSM.

Methods..

A total of 505 consecutive patients with CSM (311 males; 194 females; mean age, 66.6 years; age range, 41–91 years) who underwent double-door laminoplasty were prospectively included. The average postoperative follow-up period was 26.5 months (range, 12–66 months). We evaluated the recovery rate (RR) on the basis of the Japanese Orthopaedic Association score. Logistic regression analysis was performed to identify the risk factors for poor outcome, which was defined as a postoperative RR of <50%. Relationship between outcome and various clinical and imaging predictors was examined.

Results..

Two hundred ninety-five patients had good outcomes with RR >50%, whereas 210 patients had poor outcomes with RR <50%. Compared with the good-outcome group, the poor-outcome group had a significantly higher prevalence of diabetes and hypertension and use of anticoagulant/antiplatelet agent and smoking history (P < 0.05). Multivariate logistic regression analysis showed independent risks associated with increased age (odds ratio [ORs]  = 1.029, 95% confidence interval [CI] = 1.004–1054, P = 0.023). Logistic regression analysis determined that symptom duration of CSM (OR = 1.017, 95% CI = 1.008–1.026, P < 0.001) and preoperative 10-second step test (OR = 0.922, 95% CI = 0.865–0.983, P = 0.013) were significant risk factors for poor outcome.

Conclusion..

These findings suggest that advanced age, long-term CSM symptoms, and lower score of preoperative 10-second step test are risk factors for poor outcome in patients with CSM.

Level of Evidence: 2

Comparison of Spinal Canal Expansion Following Cervical Laminoplasty Based on the Preoperative Lamina Angle : A Simulation Study

OBJECTIVE

Expansion in the spinal canal area (SCA) after laminoplasty is one of the critical factors to relieve the preoperative symptoms. No previous study has compared the increases in SCA achieved by open-door laminoplasty (ODL) and double door laminoplasty (DDL) according to the preoperative lamina angle (LA). This study was designed to clarify the relationship between the laminoplasty opening angle (OA)/laminoplasty opening size (OS) and increases in the SCA following ODL and DDL according to the preoperative LA using a simulation model.

METHODS

The simulation model was constructed and validated by comparing the clinical data of 64 patients who had undergone C3-C6 laminoplasty (43 patients with ODL and 21 patients with DDL). SCA expansion was predicted with a verified simulation model at various preoperative LAs (from 28° to 32°) with different OAs (40° to 44°) and OSs (10 mm to 14 mm) recruited from patient data.

RESULTS

The constructed simulation model was validated by comparing clinical data and revealed a very high degree of correlation (r=0.935, p<0.001). In this validated model, at the same OA, the increase in SCA was higher following ODL than following DDL in the usual LA (p<0.05). At the same OS, the increase in SCA was slightly larger following DDL than following ODL, but the difference was not significant (p>0.05). The difference was significant when the preoperative LA was narrower or much wider.

CONCLUSION

Based on clinical data, a simulation model was constructed and verified that could predict increases in the SCA following ODL and DDL. When applying this model, prediction in SCA increase using the OS parameter was more practical and compatible with clinical data. Both laminoplasties achieved enough SCA, and there was no significant difference between them in the usual range.

Cervical laminoplasty with unilateral C4-5 foraminotomy: Technical note and case series

OBJECTIVE

The open-door laminoplasty technique is widely used in the treatment of multilevel cervical myelopathy. Despite the satisfactory functional and radiological results of this technique, postoperative C5 palsy is still a severe and disabling complication with a variable incidence in the literature. The objective of this article is to describe and demonstrate the surgical technique step by step with the addition of unilateral C4-5 foraminotomy and to evaluate the results obtained to date, with special emphasis on C5 palsy.

MATERIAL AND METHODS

Retrospective study of 20 patients operated on for cervical myelopathy using the "extended" laminoplasty technique, which is described step by step.

RESULTS

Between January 2013 and April 2019, 20 patients were operated on using the extended laminoplasty technique. Only one patient (5%) presented postoperative C5 palsy. The postoperative recovery rate of the modified JOA (Japanese Orthopaedic Association) score was 54.5%, similar to that observed in other series.

CONCLUSION

The extended cervical laminoplasty technique with unilateral C4-5 foraminotomy was developed and demonstrated for the prevention of C5 palsy. The results were analysed and an incidence of C5 palsy coinciding with the lowest percentage reported in the literature was obtained. A prospective randomised study would be useful to assess the role of preventive unilateral C4-5 foraminotomy.

Prediction of outcome following laminoplasty of cervical spondylotic myelopathy: Focus on the minimum clinically important difference

The minimum clinically important difference (MCID) of the Japanese Orthopaedic Association (JOA) score has been reported to be around 2.5 points in cervical myelopathy. This study sought to define significant predictive factors on achieving the MCID following laminoplasty in a large series of patients with cervical spondylotic myelopathy (CSM). A total of 485 consecutive patients with CSM (295 males and 190 females; mean age: 67.0 years; age range: 42-91 years) who underwent laminoplasty were prospectively enrolled. The average postoperative follow-up period was 26.6 months (range: 12-66 months). We calculated the achieved JOA score. The relationships between outcomes and various clinical and imaging predictors including comorbidity and quantitative performance tests were examined. Logistic regression analysis was conducted to identify the predictors correlated with a JOA score of 2.5 points or more. Clinically meaningful gains were exhibited in 299 patients (61.6%) with a JOA score of ≥2.5 points, whereas 186 patients (38.4%) achieved a JOA score of <2.5 points. Univariate logistic regression analysis showed the predictive factors with a shorter duration of CSM symptoms, lower preoperative JOA scores, absence of hypertension, no use of anticoagulant/antiplatelet agents, and nonsmoking status. Multivariate logistic regression analysis determined that the duration of CSM symptoms (odds ratio: 0.771, 95% confidence interval: 0.705-0.844; p < 0.01) was the only significant predictive factor for achieving JOA scores of ≥2.5 points. An important predictor of MCID achievement following laminoplasty was shorter duration of CSM symptoms.

Assessment of standing balance in normal versus cervical spondylotic myelopathy patients

Background

The Romberg test is used to identify balance issues in patients with Cervical Spondylotic Myelopathy (CSM), but has subjective interpretation. The purpose of this study is to evaluate force plate pressure readings during a Romberg test to quantify postural control.

Methods

Quantitative Romberg force plate readings with eyes open and closed in patients with CSM were obtained and changes in balance measurements were compared to a normal population (N = 28, mean age 39 ± 7 years).

Results

We identified 30 CSM patients with a mean age of 58 ± 10 years. Majority of patients presented with pain (90%) and neurologic symptoms (83%). Cord compression on imaging was identified in 90%. Mean eyes closed Romberg measurements were larger compared to eyes open measurements in CSM patients (p < 0.01). There was a larger change in Romberg (∆R) measurements in CSM compared to normals for total sway area (TSA, 14.18 vs 0.02 cm², p < 0.001) and average speed (AS, 2.07 vs 0.23 cm/s, p < 0.001). The presence of long tract signs produced larger ∆R (TSA, 15.35 vs 0.02 cm², p = 0.003; AS, 2.21 vs 0.23 cm/s, p = 0.001), and those with identified cord compression on imaging also had larger ∆R (TSA, 15.1 vs 0.02 cm², p < 0.001; AS, 2.17 vs 0.23 cm/s, p < 0.001).

Conclusions

Standing balance can be quantified in patients with CSM and is worse when compared to a normal population. Long tract signs and cord compression in imaging translates to worse balance in myelopathic patients. The use of quantitative Romberg measurements help evaluate balance in CSM.

Cervical laminoplasty: indication, technique, complications

Cervical laminoplasty is a non-fusion, decompression procedure for cervical spondylotic myelopathy (CSM). It is most commonly indicated for patients with multilevel stenosis who have preserved sagittal alignment and minimal to no axial neck pain related to spondylosis. Expansion of the laminar arch can allow for direct and indirect decompression of the spinal canal. Relative contraindications include those patients with significant preoperative neck pain, kyphotic alignment and substantial instability. Potential advantages over laminectomy and fusion include avoiding fusion-related complications, and the preservation of motion. Important technical considerations include meticulous extensor muscle management, with special attention being given to preserving the soft tissue attachments to C2. In the properly selected patient, outcomes are comparable, and in some studies superior, to other operations for CSM.

Genetics of Degenerative Cervical Myelopathy: A Systematic Review and Meta-Analysis of Candidate Gene Studies

Degenerative cervical myelopathy (DCM) is estimated to be the most common cause of adult spinal cord impairment. Evidence that is suggestive of a genetic basis to DCM has been increasing over the last decade. A systematic search was conducted in MEDLINE, EMBASE, Cochrane, and HuGENet databases from their origin up to 14th December 2019 to evaluate the role of single genes in DCM in its onset, clinical phenotype, and response to surgical intervention. The initial search yielded 914 articles, with 39 articles being identified as eligible after screening. We distinguish between those contributing to spinal column deterioration and those contributing to spinal cord deterioration in assessing the evidence of genetic contributions to DCM. Evidence regarding a total of 28 candidate genes was identified. Of these, 22 were found to have an effect on the radiological onset of spinal column disease, while 12 genes had an effect on clinical onset of spinal cord disease. Polymorphisms of eight genes were found to have an effect on the radiological severity of DCM, while three genes had an effect on clinical severity. Polymorphisms of six genes were found to have an effect on clinical response to surgery in spinal cord disease. There are clear genetic effects on the development of spinal pathology, the central nervous system (CNS) response to bony pathology, the severity of both bony and cord pathology, and the subsequent response to surgical intervention. Work to disentangle the mechanisms by which the genes that are reviewed here exert their effects, as well as improved quality of evidence across diverse populations is required for further investigating the genetic contribution to DCM.

Clinical and Radiographic Outcomes of Modified Unilateral Open-door Laminoplasty with Posterior Muscle-Ligament Complex Preservation for Cervical Spondylotic Myelopathy

MINI: The surgical results of modified and traditional open-door laminoplasties were retrospectively compared. There were no differences in neurological outcomes and postoperative complications. However, compared with traditional laminoplasty, modified laminoplasty was associated with better maintenance of cervical curvature and ROM, as well as a lower incidence of postoperative axial symptoms.

STUDY DESIGN

A retrospective comparative study.

OBJECTIVE

The aim of this study was to evaluate the efficacy of modified unilateral open-door laminoplasty with posterior muscle-ligament complex preservation in treating cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

The prevalence of axial symptoms after open-door laminoplasty ranges from 5% to 86%. Current modified laminoplasty techniques cannot satisfactorily reduce postoperative axial symptoms.

METHODS

From June 2014 to July 2016, 36 patients with CSM underwent modified laminoplasty with posterior muscle-ligament complex preservation (modified group) and 27 patients underwent traditional laminoplasty (control group). The demographics, operation duration, blood loss volume, cervical curvature, cervical curvature index (CCI), range of motion (ROM), cervical posterior muscle volume on magnetic resonance imaging (MRI), axial symptoms, visual analog scale (VAS) score, Japanese Orthopedic Association (JOA) score, neck disability index (NDI), and complications were recorded and analyzed before operation, after operation, and at the final follow-up.

RESULTS

Cervical flexion curvature, cervical curvature, ROM, and CCI were better in the modified group than in controls at the final follow-up (P < 0.01). Postoperative VAS and NDI scores were significantly reduced in the modified group compared with controls (1.15 ± 0.76 vs. 2.63 ± 1.06, 5.67 ± 2.57 vs. 8.89 ± 5.37, respectively) (P < 0.01). Posterior muscle volume at the hinge side in the modified group was not different at final follow-up relative to that before the operation, whereas it was reduced in controls (P < 0.01). Finally, the incidence of axial symptoms was significantly lower in the modified group than in controls (6% vs. 22%) (P = 0.03).

CONCLUSION

Modified unilateral open-door laminoplasty with posterior muscle-ligament complex preservation is effective for treating CSM with good recovery of neurological functions and satisfactory maintenance of cervical curvature and ROM. Furthermore, it reduces the incidence of postoperative axial symptoms compared with conventional open-door laminoplasty.

LEVEL OF EVIDENCE

3.

The Efficacy of Ultrasonic Bone Scalpel for Unilateral Cervical Open-Door Laminoplasty: A Randomized Controlled Trial

BACKGROUND

In cervical open-door laminoplasty for cervical myelopathy, a high-speed rotatory drill and rongeurs are used to make unicortical troughs and bicortical openings in the laminae. The lamina is reflected at the trough to enlarge the spinal canal, followed by bone healing on the hinge side to stabilize laminoplasty. The ultrasonic bone scalpel (UBS) has been used due to theoretical advantages including a better hinge union rate, less soft tissue trauma, less neurological injury, and shorter operative time.

OBJECTIVE

To assess the superiority of UBS for hinge union compared to the drill through randomized controlled trial.

METHODS

In 190 randomly allocated cervical myelopathy patients, the trough and opening at the lamina were made using either the drill (n = 95) or UBS (n = 95) during 2015 to 2018. The primary outcome was the hinge union rate on 6-mo postoperative computed tomography. Secondary outcomes included the hinge union rate at 12 mo, the operative time, intraoperative/postoperative bleeding, neurological injury, complications, and clinical outcomes over a 24-mo follow-up.

RESULTS

Hinge union in all laminae was achieved in 60.0% (drill) and 43.9% (UBS) of patients at 6 mo (intention-to-treat analysis; P = .02; odds ratio, 2.1) and in 91.9% (drill) and 86.5% (UBS) at 12 mo. Dural injury only occurred in the drill group (2.1%), and the UBS group showed significantly less intraoperative bleeding (P < .01). The other secondary outcomes did not differ between groups.

CONCLUSION

The hinge union rate was inferior in the UBS group at 6 mo postoperatively, but UBS was efficacious in reducing dural injuries and bleeding.

Surgical treatment of cervical spondylosis in patients 80 years of age and older-A retrospective observational study

The older adult population in developed countries is rapidly increasing, as is the number of older adults with cervical spondylosis. Previous studies on the surgical outcomes of older adults with cervical spondylosis have reported contradictory results. This study aimed to compare the surgical outcomes in adults with cervical spondylosis who were <80 and ≥80 years old. We retrospectively investigated data from adults who underwent surgical treatment for cervical spondylosis between 2006 and 2016. The clinical outcomes and postoperative complications of patients who were <80 years old were compared to those of patients who were ≥80 years old. Of the 108 patients included in the study, 14 (13.0%) were ≥80 years old. The preoperative neurosurgical cervical spine score was significantly different between patients who were <80 (9.1 ± 2.4) and ≥80 (6.1 ± 2.1) years old (p < .001). The recovery rate was 58.2 ± 30.0% and 41.3 ± 24.7% in patients who were <80 and ≥80 years old, respectively (p = .05). However, the number of recovery points scored was 2.8 ± 2.0 and 3.4 ± 2.3 in patients who were <80 and ≥80 years old, respectively, which was not significantly different. Although 12 patients had medical comorbidities, they had no surgical complications. This study clarifies the benefits of surgical treatment for older adults with cervical spondylosis. Generally, older adults have lower recovery rates and are unlikely to experience full recovery; however, surgery for cervical spondylosis appears to improve patients’ quality of life.

Posterior Revision Surgery for Cervical Open-Door Laminoplasty Because of Poor Expansion of the Spinal Canal

OBJECTIVE

Few studies have addressed the causes of poor expansion of the spinal canal after open-door laminoplasty (ODL) that require revision surgery. The aim of this study is to identify the reasons of poor expansion of the spinal canal after ODL and to discuss the surgical methods and clinical outcomes of the posterior revision surgery.

METHODS

All patients who underwent posterior revision surgery because of poor expansion of the spinal canal after ODL were retrospectively reviewed at our spine center. Clinical data, radiologic findings, method of surgical revision, interval between surgeries, Japanese Orthopaedic Association (JOA) score, and complications were analyzed.

RESULTS

We identified 16 patients that underwent posterior revision surgery because of poor expansion of the spinal canal after ODL. The main causes of poor expansion of the spinal canal included inadequate expansion degree of the spinal canal (75%, 12/16) and improper expansion range of the spinal canal (25%, 4/16). Revision surgery was performed with posterior ODL, laminectomy and fusion (LCF), or laminectomy of responsible lamina. The interval between the initial procedure and revision surgery was 72.2 months (range, 0.5-168 months). The mean JOA score was restored from 10.6 (range, 8-13) to 14.3 (range, 13-17) after the revision surgery.

CONCLUSIONS

The main causes of poor expansion of the spinal canal after ODL were inadequate expansion degree of the spinal canal and improper expanded range of the spinal canal. Posterior revision surgeries, such as ODL, LCF, and laminectomy of responsible lamina, could guarantee fine clinical results.

Medium-term clinical outcomes of laminoplasty with adjunct short anterior fusion in multilevel cervical myelopathy

OBJECTIVES

Expansive open-door laminoplasty (EOLP) is effective for multilevel cervical spondylotic myelopathy (MCSM). When MCSM is combined with one- or two-level segmental kyphosis, instability, or major anterior foci, EOLP with short-segment anterior cervical fusion (ACF) results in good short-term neurological recovery and can preserve postoperative range of motion (ROM). The objective of this study was to evaluate the medium-term clinical outcomes of this procedure and to analyze the risk factors affecting the neurological function at the last follow-up.

MATERIALS AND METHODS

A total of 87 patients were enrolled in this retrospective study conducted from January 2007 to May 2011. These patients exhibited MCSM with combined short segmental kyphosis, instability, or major anterior pathology, and received EOLP and short-segment anterior fusion. The follow-up period lasted at least 60 months. The radiographic outcomes were collected from plain radiographs with dynamic views checked preoperatively and at the last follow-up. Neurological status and visual analog scale scores for neck pain were evaluated. Logistic regression analysis was then applied to determine the correlation between radiographic parameters and rates of neurological recovery.

RESULTS

The mean Japanese Orthopedics Association recovery rate at the last follow-up was 77.8%. The improvement in functional scores and reduction in neck pain were statistically significant. The most influential risk factor affecting neurologic recovery was preoperative functional status.

CONCLUSIONS

EOLP followed by short-segment ACF is a favorable treatment for patients with MCSM with concomitant short-segment kyphosis, instability, or major anterior pathology.

Cervical spondylosis in patients presenting with "severe" myelopathy: Analysis of treatment by multisegmental spinal fixation - A case series

Background:

Surgical strategy of multisegmental spinal fixation that includes atlantoaxial joint for patients having cervical spondylosis-related symptoms of severe myelopathy is analyzed.

Objective:

Surgical outcome of patients presenting with “severe” symptoms of cervical myelopathy having multisegmental degenerative cervical spondylosis and treated by multisegmental spinal fixation is analyzed. Atlantoaxial joint was included in the fixation construct in majority of patients. No bone, soft tissue, osteophyte, or disc resection for decompression was done.

Materials and Methods:

Sixty-four patients having multisegmental cervical spondylosis who presented with symptoms of severe myelopathy were surgically treated during the period from March 2013 to December 2018. On the basis of the concept that instability is the primary cause of spinal degeneration, multisegmental spinal fixation was done in all patients. Atlantoaxial joint was included in the fixation construct in 48 patients. The levels of spinal fixation were determined on the basis of direct observation of facet joints and by manual manipulation and were guided by the presenting clinical features and radiological information. Clinical monitoring was done using Goel clinical grading, modified Japanese Orthopedic Association Score, and visual analog score parameters. Patient satisfaction index assessed the functional and symptomatic improvement.

Results:

During the follow-up that ranged from 6 to 75 months, all patients improved in their clinical status. Fifty-five (85.9%) patients could walk independently or with mild support.

Conclusions:

Multisegmental spinal fixation that includes atlantoaxial joint in most patients forms a rational treatment strategy for patients of cervical spondylosis presenting with severe symptoms of myelopathy.

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 outcomes after laminoplasty for cervical spondylotic myelopathy: A focus on the dynamic factors and signal intensity changes in the intramedullary spinal cord on MRI

OBJECTIVE

We aimed to analyze the relationship between the dynamic factors and signal intensity changes in the intramedullary spinal cord on MRI, and surgical outcomes, following double-door laminoplasty for cervical spondylotic myelopathy (CSM).

PATIENTS AND METHODS

This retrospective study included 100 consecutive patients who underwent double-door laminoplasty for CSM. The following factors were analyzed: JOA score recovery rate, age, duration from onset to surgery, intraoperative bleeding, signal intensity changes in the intramedullary spinal cord on MRI, pre and postoperative C2-7 lordotic angle (LA), changes in C2-7 LA, pre and postoperative C2-7 range of motion (ROM), and pre and postoperative segmental ROM. The Charlson Comorbidity Index (CCI) was also used for the assessment of complications.

RESULTS

Age, CCI, preoperative segmental ROM, and pre and postoperative MRI grade significantly correlated with JOA score recovery rate (P<0.01), whereas number of expanded laminae, duration from onset to surgery, surgery time, intraoperative bleeding, preoperative and postoperative C2-7 LA, change in C2-7 LA, and preoperative C2-7 ROM did not. Multivariate analysis showed that the preoperative segmental ROM (OR=-0.988, P=0.017) and preoperative MRI grade (OR=-7.170, P=0.042) were significantly associated with JOA score recovery rate.

CONCLUSION

Considering the dynamic factors, there was no correlation with C2-7 ROM and surgical outcome, but preoperative segmental ROM and a change in signal intensity of the intramedullary spinal cord on MRI were negatively correlated with surgical outcome. From these results, we suggest that preoperative segmental ROM is possibly associated with spinal cord damage due to repeated minor trauma and affects surgical outcome of laminoplasty.

Which Technique Is Better Option for C3 Segment in Multilevel Open-Door Laminoplasty of the Cervical Spine?: Laminectomy Versus Laminoplasty

STUDY DESIGN

A post-hoc comparative study.

OBJECTIVE

To evaluate postoperative clinical, radiological, and surgical outcomes after laminoplasty (LP) involving the C3 segment and to compare outcomes with those of patients who underwent LP with C3 laminectomy (LN).

SUMMARY OF BACKGROUND DATA

In many of the pathologies that require LP involving C3 segment, most spine surgeons perform LP at C3 and other cervical segments. Considering the peculiarities of the C2-C3 level, spine surgeons should take into account those in LP involving the C3 segment, but the particular aspects of the C2-C3 levels have not been fully evaluated.

METHODS

Of 93 patients, 66 patients (39 in group A, LP involving C3; 27 in group B, LP with C3 LN) were enrolled in the study. The primary outcome measure was pain intensity of the posterior neck measured with visual analog scale. Secondary endpoints included the following: (1) radiologic outcomes based on the cervical range of motion and rate of bony impingement and spontaneous fusion between C2 and C3, (2) clinical outcomes based on the 12-item short-form health survey and Japanese Orthopedic Association scale, and (3) surgical outcomes.

RESULTS

The primary end-point of the present study, posterior neck pain, exhibited a greater improvement in the group with C3 LN than in the group with C3 LP at 6 months and 1 year after surgery (P = 0.03 and 0.01, respectively). The cervical range of motion of C3 LN group was significantly greater than C3 LP group at postoperative 1 year (P = 0.02). Radiologic evidences of bony impingement and spontaneous fusion between C2 and C3 were significantly greater in C3 LP group than in C3 LN group. Clinical outcomes and surgical outcomes did not differ significantly between groups.

CONCLUSION

We recommend performing LN instead of LP for the C3 segment in cases requiring multilevel LP surgery involving C3.

LEVEL OF EVIDENCE

3.

Two-Year Results of the Prospective Spine Treatment Outcomes Study: An Analysis of Complication Rates, Predictors of Their Development, and Effect on Patient Derived Outcomes at 2 Years for Surgical Management of Cervical Spondylotic Myelopathy

OBJECTIVES

To investigate the baseline patient characteristics, nonoperative modalities, surgical procedures, and complications rates of surgical cervical spondylotic myelopathy (CSM) patients. To evaluate risk factors for developing complications and compare the changes in health-related quality of life (HRQOL) from baseline to 2 years postoperatively.

METHODS

A retrospective review was performed on a prospectively collected database of CSM patients. Baseline patient demographic data, comorbidities, clinical information, nonoperative treatment modalities, surgical procedures, and complication rates were collected. HRQOL outcomes were assessed using the Short Form 36 (SF-36) Physical Score Component (PCS) and Mental Score Component (MCS) and the Neck Disability Index (NDI) at baseline and 2 years postoperatively. Statistical analyses included paired-sample t tests and multivariate logistic regression controlling for age, sex, and body mass index (BMI).

RESULTS

A total of 203 surgical CSM patients were identified (43% female). Average age was 57.7 years and average BMI was 29.6 kg/m². Before surgical intervention, patients underwent various nonoperative treatment modalities, most commonly nonsteroidal anti-inflammatory drugs (34%), analgesics (32%), and physical therapy (26%). The overall rate of complications was 7.4%. Complications included cerebrospinal fluid leak (2.5%), postoperative radiculopathy (1.0%), and excessive bleeding (1.0%). A previous history of cervical spine surgery was the sole significant risk factor for developing a complication (odds ratio, 9.22; P = 0.034). Average HRQOL scores improved significantly from baseline to 2 years postsurgery.

CONCLUSIONS

The overall complication rate was 7.4% for the cohort. Baseline clinical information, comorbidities, use of nonoperative treatment modalities, and procedure type were not significantly associated with an increased risk of complications. Previous cervical spine surgery increased the risk of complications by 9-fold. The patients showed significantly improved SF-36 PCS, SF-36 MCS, and NDI scores at 2 years after surgery.

Surgical Outcome of Laminoplasty for Cervical Spondylotic Myelopathy in an Elderly Population - Potentiality for Effective Early Surgical Intervention: A Meta-analysis

A systematic review and meta-analysis was conducted to determine differences in surgical outcomes of laminoplasty for cervical spondylotic myelopathy (CSM) between elderly and non-elderly patients. PubMed and Google Scholar searches were performed using several key words and phrases related to cervical laminoplasty in elderly populations. Included studies were written in English, addressed laminoplasty for cervical spondylotic myelopathy, and evaluated outcomes of the treatment. Statistical analysis was performed using a random-effect model. The heterogeneity of the studies was assessed using Cochran's Q statistic and I² statistic, and a funnel plot was constructed to evaluate publication bias. The search initially identified 255 articles on this topic. Nine clinical studies that met all inclusion criteria were included in the meta-analysis. A total of 1817 patients in these studies underwent cervical laminoplasty. Elderly patients had lower preoperative and postoperative Japanese Orthopedic Association (JOA) scores, and lower recovery rates based on JOA scores. Shorter operation times and reductions in intraoperative blood loss were found in the elderly group compared to the non-elderly group. The incidence of C5 palsy was not different between these groups. We here report the differences in surgical outcomes of laminoplasty for CSM through systematic review and meta-analysis. This report found poor surgical outcomes and lower preoperative JOA scores in elderly patients. Therefore, early surgical intervention may be recommended in elderly patients with CSM.

Wedge-Shaped Resection of the Posterior Bony Arch During Open Door Laminoplasty to Prevent Postoperative Motion Limitation

STUDY DESIGN

Prospective randomized double-arm noninferiority study.

OBJECTIVE

To evaluate an additional surgical procedure (wedge-shaped resection of the cranial portion of the posterior bony arch) during open-door laminoplasty (ODLP), and to compare the outcomes with those of conventional ODLP surgery.

SUMMARY OF BACKGROUND DATA

In clinical practice, spine surgeons sometimes encounter patients who show bony impingement on lateral radiographs after ODLP; bony impingement may lead to reduced motion of the cervical spine and posterior neck pain. However, this problem has not been well studied, and no methods have been developed to prevent it.

METHODS

Of total 79 patients, 75 were enrolled and randomly assigned to either group A (additional procedure in ODLP, n = 38) or group B (ODLP alone, n = 37). The primary outcome measure was range of motion (ROM) of the cervical spine. Secondary endpoints included clinical outcomes based on pain intensity, 12-item short form health survey (SF-12), and modified Japanese Orthopedic Association scale; presence of bony impingement on dynamic lateral radiographs; surgical outcomes; and surgery-related complications.

RESULTS

ROM of the cervical spine was significantly greater at 6 months (P = 0.04) and 1 year (P = 0.02) postoperative in group A than in group B. Pain intensity at the posterior neck was significantly lower 1 year after surgery in group A than in group B (P = 0.03). In lateral radiographs 1 year after surgery, the presence of posterior bony impingement was 0% in group A and 32.4% in group B (P <0.01). Clinical outcomes and surgery-related complications were similar between groups.

CONCLUSION

Performing wedge-shaped resection of the cranial portion of the posterior bony arch in ODLP surgery can lead to better outcomes than ODLP alone in terms of preservation of cervical ROM, prevention of posterior bony impingement, and amelioration of posterior neck pain.

LEVEL OF EVIDENCE

2.

540° Cervical Realignment Procedure for Extensive Cervical OPLL With Kyphotic Deformity

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to present a novel, two-stage [posterior and anterior-posterior (P-AP) 540°] procedure for extensive cervical ossification of the longitudinal ligament (OPLL) with kyphotic deformity.

SUMMARY OF BACKGROUND DATA

The optimal surgical strategy for extensive cervical OPLL remains a controversial issue. Neurological injury and dural defect are complications of anterior surgery, while a posterior surgery can lead to poor clinical outcomes related to incomplete decompression.

METHODS

We analyzed consecutive cases of patients who underwent procedure described herein, which consists of two stages: the first (P: laminectomy and facet release with segmental screw fixations without rod assembly) and the second 1 week later (AP: multilevel anterior cervical discectomy with fusions (ACDFs) at the apex of the deformity without decompression, placement of lordotic grafts, and posterior fusion). To assess the radiographic parameters, extent of OPLL, maximal canal occupying ratio (%), the distances from the maximal compression to the K-line, and C2-7 angle were analyzed. Clinically, we analyzed visual analog scale of neck and arm pain, neck disability index (NDI), Japanese Orthopedic Association (JOA) score, and complications.

RESULTS

A total of 18 patients were enrolled (M:F = 15:3, mean age 64.5 yrs, mean follow-up was 30 months). The mean extent of the OPLL was 3.8 vertebral body levels. Posterior fusion was performed on a mean 4.5 segments and anterior fusion was on a mean 2.4 segments. The mean C2-7 Cobb angle was improved from 10.5° to -12.2° at follow-up. The K-line distance to the maximal compression and canal occupying ratio were improved from -3.3 mm, 73.5% to 3.8 mm, 38.4%, respectively. Preoperative NDI and JOA scores were significantly improved (18.5 to 9.4 and 8.2 to 14.8) at the last follow-up.

CONCLUSION

The 540° P-AP procedure could provide safe decompression, cervical realignment, and favorable outcomes without the disadvantages of the conventional anterior and/or posterior surgery for extensive cervical OPLL with kyphotic deformity.

LEVEL OF EVIDENCE

4.

Does Tobacco Use Attenuate Benefits of Early Decompression in Patients With Cervical Myelopathy?

STUDY DESIGN

A retrospective cohort.

OBJECTIVE

This study investigates the interplay between duration of preoperative symptoms and smoking status with respect to postoperative outcomes in patients with cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

Many studies have established the harms of smoking and several have identified the benefits of early decompression in patients with cervical myelopathy, but to our knowledge, none have assessed the relationship between these two variables.

METHODS

The medical records of all 212 patients operated on by the senior author between March 2005 and July 2012 were reviewed. Inclusion criteria were the diagnosis of CSM with a Nurick score, surgical intervention, and at least 2 years of follow-up. Patients were categorized according to smoking status and quantification of tobacco use by packs per day and pack-years, and duration of symptoms according to thresholds of 6, 12, or 24 months. Age, sex, preoperative Nurick score, duration of preoperative symptoms, duration of follow-up, procedure performed, prior surgery, number of levels operated on, diabetes status, ethanol use, and signal change on preoperative magnetic resonance imaging were also recorded for ordered logistical regression analysis.

RESULTS

One hundred twenty-five patients met all criteria. Eighty patients were smokers and 45 were nonsmokers. The median change in Nurick score for nonsmokers was 2 compared with 1 in smokers. Nonsmokers had a statistically significant likelihood of decreased change in Nurick score for symptom duration of greater than 24 months (odds ratio = 0.06, P = 0.0025). Smokers did not show a significant difference in the change in Nurick score for any threshold of symptom duration.

CONCLUSION

Increased duration of symptoms significantly affects outcomes in surgical decompression of CSM. A history of cigarette use may attenuate the benefit of early decompression and results in lower improvement in Nurick score regardless of symptom duration.

LEVEL OF EVIDENCE

3.

Degenerative cervical myelopathy

Cervical myelopathy is the most common cause of acquired spinal cord compromise. The concept of degenerative cervical myelopathy (DCM), defined as symptomatic myelopathy associated with degenerative arthropathic changes in the spine axis, is being introduced. Given its progressive nature, treatment options have to be chosen in a timely manner. Surgical options include anterior discectomy and fusion (ACDF), anterior corpectomy and fusion (ACCF), arthroplasty (in highly select cases), posterior laminectomy with/without fusion, and laminoplasty. Indications for each should be carefully considered in individual patients. Riluzole, a sodium-glutamate antagonist, is a promising option to optimize neurologic outcomes post-surgery and is being examined in the CSM-Protect Randomized Controlled Trial. Preoperative risk assessment is mandatory for prognostication. Sagittal alignment is known to play an important role to optimize surgical outcome. Guidelines for optimal management of DCM are in process. In principle, all but the mildest cases of DCM should be offered surgery for optimal outcome.

Long-term outcomes and prognostic analysis of modified open-door laminoplasty with lateral mass screw fusion in treatment of cervical spondylotic myelopathy

OBJECTIVES

The purpose of the present study was to explore and analyze the long-term outcomes and factors that affect the prognosis of expansive open-door laminoplasty with lateral mass screw fusion in treatment of cervical spondylotic myelopathy (CSM).

METHODS

We retrospectively reviewed 49 patients with multilevel CSM who had undergone expansive open-door laminoplasty with lateral mass screws fixation and fusion in our hospital between February 2008 and February 2012. The average follow-up period was 4.6 years. The clinical data of patients, including age, sex, operation records, pre- and postoperation Japanese Orthopedic Association (JOA) scores, cervical spine canal stenosis, and cervical curvature, were collected. Increased signal intensity (ISI) on T2-weighted magnetic resonance imaging and ossification of the posterior longitudinal ligament were also observed. Paired t-test was used to analyze the treatment effectiveness and recovery of neuronal function. The prognostic factors were analyzed with multivariable linear regression model.

RESULTS

Forty-nine patients with CSM with a mean age of 59.44 years were enrolled in this study. The average of preoperative JOA score was 9.14±2.25, and postoperative JOA score was 15.31±1.73. There was significant difference between the pre- and postoperative JOA scores. The clinical improvement rate was 80.27%. On follow-up, five patients had complaints of neck and shoulder pain, but no evidence of C5 nerve palsy was found. Developmental cervical spine canal stenosis was present in all patients before surgery. Before surgery, ISI was observed in eight patients, while ossification of the posterior longitudinal ligament was found in 12 patients. The average of preoperative cervical curvature was 21.27°±8.37° and postoperative cervical curvature was 20.09°±1.29°, and there was no significant difference between the pre- and postoperative cervical curvatures. Multivariable linear regression analysis results showed that the postoperation JOA scores were significantly affected by age, preoperative JOA scores, and preoperative ISI. Except one case of epidural hematoma, there were no complications associated with the surgery.

CONCLUSION

Treatment of CSM with posterior open-door laminoplasty with lateral mass screw fusion is effective with few complications. In addition, the normal cervical lordosis was well maintained. Age, preoperative JOA scores, and preoperative ISI were the independent factors that significantly affect disease prognosis and surgical outcomes.

Pseudarthrosis of the Cervical Spine: Risk Factors, Diagnosis and Management

Cervical myelopathy and radiculopathy are common pathologies that often improve with spinal decompression and fusion. Postoperative complications include pseudarthrosis, which can be challenging to diagnose and manage. We reviewed the literature with regard to risk factors, diagnosis, controversies, and management of cervical pseudarthrosis.

Does age affect surgical outcomes in patients with degenerative cervical myelopathy? Results from the prospective multicenter AOSpine International study on 479 patients

BACKGROUND

In general, older patients with degenerative cervical myelopathy (DCM) are felt to have lower recovery potential following surgery due to increased degenerative pathology, comorbidities, reduced physiological reserves and age-related changes to the spinal cord. This study aims to determine whether age truly is an independent predictor of surgical outcome and to provide evidence to guide practice and decision-making.

METHODS

A total of 479 patients with DCM were prospectively enrolled in the CSM-International study at 16 centres. Our sample was divided into a younger group (<65 years) and an elderly (≥65 years) group. A mixed model analytic approach was used to evaluate differences in the modified Japanese Orthopaedic Association (mJOA), Nurick, Short Form-36 (SF-36) and Neck Disability Index (NDI) scores between groups. We first created an unadjusted model between age and surgical outcome and then developed two adjusted models that accounted for variations in (1) baseline characteristics and (2) both baseline and surgical factors.

RESULTS

Of the 479 patients, 360 (75.16%) were <65 years and 119 (24.84%) were ≥65 years. Elderly patients had a worse preoperative health status (p<0.0001) and were functionally more severe (p<0.0001). The majority of younger patients (64.96%) underwent anterior surgery, whereas the preferred approach in the elderly group was posterior (58.62%, p<0.0001). Elderly patients had a greater number of decompressed levels than younger patients (p<0.0001). At 24 months after surgery, younger patients achieved a higher postoperative mJOA (p<0.0001) and a lower Nurick score (p<0.0001) than elderly patients. After adjustments for patient and surgical characteristics, these differences in postoperative outcome scores decreased but remained significant.

CONCLUSIONS

Older age is an independent predictor of functional status in patients with DCM. However, patients over 65 with DCM still achieve functionally significant improvement after surgical decompression.

Cervical Anterolisthesis: A Predictor of Poor Neurological Outcomes in Cervical Spondylotic Myelopathy Patients After Cervical Laminoplasty

STUDY DESIGN

A retrospective cohort study.

OBJECTIVE

To clarify the influence of cervical spondylolisthesis on neurological outcomes in cervical spondylotic myelopathy (CSM) patients after cervical laminoplasty.

SUMMARY OF BACKGROUND DATA

Studies focusing on the surgical outcomes in CSM patients with cervical spondylolisthesis are limited.

METHODS

We retrospectively reviewed 125 CSM patients after cervical laminoplasty. Neurological outcomes were evaluated by calculating the Japanese Orthopedic Association (JOA) recovery rate at 2 years after surgery. We defined anterolisthesis as a more than 3-mm anterior vertebral displacement in a flexion radiograph and retrolisthesis as a more than 3-mm posterior vertebral displacement in an extension radiograph. We further assessed potential risk factors for poor neurological outcomes after cervical laminoplasty, including cervical alignment, degree of spinal cord compression, duration of myelopathic symptoms, diabetes mellitus, and preoperative JOA score. Multivariate logistic regression analysis was performed to investigate the risk factors for poor outcomes (JOA recovery rate <50%) after cervical laminoplasty.

RESULTS

Our study included 86 men and 39 women with mean age of 64 (range, 30-89) years. Average JOA scores were 9.9 and 13.3 points before and at 2 years after surgery, respectively. Average recovery rate was 47.2% (range, -68% to 100%), with 62 patients having poor outcomes (JOA recovery rate <50%) at 2 years after surgery. Anterolisthesis and retrolisthesis were observed in 13 and 24 patients, respectively. Multivariate logistic regression analysis revealed that the anterolisthesis was a significant risk factor for poor outcomes (JOA recovery rate <50%) after cervical laminoplasty (P = 0.01), whereas retrolisthesis did not affect the neurological outcomes (P = 0.6).

CONCLUSION

Anterolisthesis, but not retrolisthesis, is a significant risk factor for and predictor of poor neurological outcomes after cervical laminoplasty. Cervical laminoplasty should not be considered in CSM patients with anterolisthesis.

LEVEL OF EVIDENCE

2.

The Triangle Model of Congenital Cervical Stenosis

STUDY DESIGN

Retrospective Cross-Sectional Study OBJECTIVE.: Identify the pathoanatomical features of the cervical spine associated with congenital stenosis SUMMARY OF BACKGROUND DATA.: Congenital cervical stenosis (CCS) describes a patient with a decreased spinal canal diameter at multiple levels of the cervical spine in the absence of degenerative changes. Despite recognition of CCS throughout the literature, the anatomical features that lead to this condition have not been established. Knowledge of the pathoanatomy behind CCS may lead to alterations in surgical technique for this patient population that may improve outcomes.

METHODS

From 1000 cervical MRIs between January 2000 and December 2014, CCS was identified in 68 patients using a strict definition of age less than 50 years with mid-sagittal canal diameters (mid-SCD) (<10  mm) at multiple sub-axial cervical levels (C3-C7). A total of 68 patients met the inclusion criteria for this group. Fourteen controls with normal SCDs (>14  mm) at all cervical levels were used for comparison. Anatomic measurements obtained at each level (C3-C7) included: coronal vertebral body, AP vertebral body, pedicle width, pedicle length, laminar length, AP lateral mass, posterior canal distance, lamina-pedicle angle, and lamina-disc angle (LDA). Statistical significance was defined as P < 0.01.

RESULTS

CCS patients demonstrated significantly different anatomical measurements when compared with controls. Significantly smaller lateral masses, lamina lengths, lamina-pedicle angles, and larger LDAs were identified at levels C3 to C7 in the CCS group (P < 0.01). These anatomic components form a right triangle that illustrates the cumulative narrowing effect on space for the spinal cord.

CONCLUSION

The pathoanatomy of CCS is associated with a decrease in the lamina-pedicle angle and an increase in the LDA ultimately leading to a smaller SCD. The global changes in CCS are best illustrated by this triangle model and are driven by the posterior elements of the cervical spine.

LEVEL OF EVIDENCE

4.