Anterior Surgical Techniques for Cervical Spondylotic Myelopathy: WFNS Spine Committee Recommendations

Screw loosening and subsequent expectoration without anatomical defect following anterior cervical discectomy and fusion for cervical myelopathy: illustrative case

BACKGROUND

Anterior cervical discectomy and/or corpectomy with fusion is a standard treatment approach for cervical myelopathy and radiculopathy caused by anterior degenerative and compressive pathology. Serious complications are rare, but esophageal and pharyngeal injuries relating to anterior cervical operations can cause significant morbidity and mortality. The authors present the case of delayed anterior plate screw loosening with eventual expectoration of a screw without anatomical defect.

OBSERVATIONS

A 52-year-old male presented to the neurosurgery clinic with cervical myeloradiculopathy. He had severe cervical stenosis with associated myelomalacia. Conservative management failed, and the patient underwent C4 corpectomy and C5-6 and C6-7 anterior cervical discectomy and fusion (ACDF) with anterior plating. He experienced backing out of some of his screws, refused revision, and eventually expectorated his right C3 screw 14 months after surgery with minimal symptoms. He showed no anatomical defects on evaluation and experienced no major morbidity.

LESSONS

Hardware expectoration is a rare complication of ACDF. The lack of an esophageal or laryngeal defect could possibly be explained by gradual healing of the injury given the chronicity of his problem. A patient with screw loosening after ACDF should be carefully monitored and evaluated postoperatively due to the potential for significant morbidity and mortality from screw migration and expectoration. https://thejns.org/doi/10.3171/CASE24340.

Proposal of a new score system (Cervical Surgical Score) for management of degenerative cervical myelopathy

BACKGROUND

To date, no shared algorithms with the aim of guiding surgical strategy in complex cases of degenerative cervical myelopathy (DCM) exist. Our purpose is to present the Cervical Surgical Score (CSS) which could help in identifying complex DCM cases, suggesting a surgical strategy.

METHODS

We created the CSS based on multidisciplinary and literature-focused discussions, based on eight parameters including number of levels of cervical pathology and myelopathy, type and predominance of compression and grade of clinical myelopathy. We prospectively enrolled surgical DCM patients in a 15-months period, collecting clinical and radiological data. During outpatient clinic a specific surgical indication was offered to DCM patients. To validate the score, each outpatient clinic surgical indication was compared a posteriori to the one that resulted from multidisciplinary CSS scoring, focusing on patients for which both an anterior and posterior approach were considered suitable.

RESULTS

A total of 100 patients operated on for DCM at our Institution between December 2021 and February 2023 were prospectively enrolled. In 53% of patients the pathology was present at more than two levels. According to CSS calculation, 14% of patients resulted in the "grey zone", where both an anterior and posterior approach were deemed feasible. Among them, in 42.8% of cases the CSS allowed a modification of the originally planned surgery. Looking at outcome, an improvement of m-JOA score in 62% of patients was disclosed.

CONCLUSIONS

This preliminary study showed the reliability and usefulness of CSS in detecting complex DCM cases, requiring further analysis by expert spine surgeons, suggesting a surgical strategy.

Fusion Free Median Corpectomy - Long-Term Consequence of Foregoing Fusion and Fixation: A Serendipitous Observation

BACKGROUND

Anterior cervical corpectomy and fusion (ACCF) involves placement of a graft/implant to ensure fusion and stabilization along with neural decompression. We share our experience with a subset of ACCF patients in whom graft/implant could not be placed post decompression for varying reasons but had a favorable long-term outcome. The necessity for routine fusion after corpectomy is critically analyzed, and the feasibility of an alternative surgical option without graft/implant is discussed.

MATERIAL AND METHODS

A retrospective observational study of long-term outcomes of five patients with cervical compressive myelopathy who underwent neural decompression alone without an in situ graft/implant was done. All the patients underwent the modified cervical corpectomy technique, involving a smaller wedge size (12 × 15 mm) corpectomy. Pre- and postoperative clinical, radiological, electrophysiological, and operative findings were meticulously evaluated and analyzed.

RESULTS

This retrospective observational study reviewed records of 124 patients who underwent ACCF between 1998 and 2012. The surgical procedure involved a wedge median cervical corpectomy. In seven patients, graft/implant could not be placed or had to be removed for various reasons. Long-term follow-up was available for five of these patients who were included in the study. In two patients, the graft could not be placed intraoperatively due to hemodynamic complications. In one patient, the graft had to be removed due to postoperative infection, and in two patients, the graft had to be removed due to graft extrusion. Four patients showed marked improvement, and one patient showed minimal improvement on long-term follow-up in clinical, radiological, and electrophysiological parameters.

CONCLUSION

This small case series suggests that a modified cervical corpectomy technique, involving a smaller wedge size (12 × 15 mm), may be considered in selected cases without radicular symptoms. This approach helps to provide neural decompression without compromising stability and avoids graft-related complications. While promising, further research, including prospective randomized-controlled trials, is essential to validate the biomechanical properties and clinical outcomes of this modified technique compared to traditional ACCF.

Anatomic Research of the Safe Space Between the Cervical Uncinate Process and the V2 Vertebral Artery

OBJECTIVE

A retrospective study was performed to observe and measure the safe distance between the uncinate process (UP) and the V2 vertebral artery (VA).

METHODS

Two hundred and sixteen patients who underwent head and neck computed tomography angiography were selected and measured. The upper tip (UT) of the UP, the posterior tip of the UP (PT), and the center of the VA (CA) were identified. Then, the width between the UT and the CA, the depth between the UT and the CA, and the distance between the UT and the CA were measured. The width between the PT and the CA, the depth between the PT and the CA, and the length between the PT and the CA were measured. These values were compared between the left and right sides of the same vertebral body and also the results of the same side from C3 to C6 were compared.

RESULTS

The width between the UT and the CA fluctuates between 6.1 and 4.4 mm on the left side with the narrowest at C5 and C6 (4.4 mm) and between 6.5 and 4.6 mm on the right side with the narrowest at C5 (4.6 mm). It could be concluded that the safe space for operation outside UP is about 4 mm and more care should be taken when operating on the caudal spine. The width between the PT and the CA fluctuates between 10.6 and 10.0 mm on the left side with the narrowest at C3 (10 mm) and between 11.0 and 9.9 mm on the right side with the narrowest at C4 (9.9 mm). The safe space for operation outside the PT is about 10 mm and more care should be taken when operating on the cephalad spine. Depth between the PT and the CA fluctuates between 6.5 and 4.6 mm on the left and is narrowest at C3 (4.6 mm) and between 6.5 and 4.7 mm on the right and narrowest at C3 (4.7 mm). The safe space for operation from the PT to the ventral side is about 4.5 mm, and more care should be taken when operating on the cephalad side of the cervical spine.

CONCLUSIONS

UP and PT could be seen as landmarks in the operations of anterior cervical discectomy and fusion. The safe space outside UP is about 4 mm and more care should be taken when operating on the caudal spine. The safe space outside PT is about 10 mm and more care should be taken when operating on the cephalad spine. The safe space for operation from the PT to the ventral side is about 4.5 mm, and more care should be taken when operating on the cephalad side of the cervical spine.

The efficacy and safety of mini-open (air/water medium) endoscopy-assisted anterior cervical discectomy and fusion for the treatment of cervical spondylotic myelopathy

PURPOSE

To compare the clinical efficacy of mini-open (air/water medium) endoscopy-assisted anterior cervical discectomy and fusion (MOEA-ACDF) and anterior cervical decompression and fusion (ACDF) for cervical spondylotic myelopathy (CSM).

METHODS

This study retrospectively analysed the clinical data of CSM patients who received surgical treatment from January 1, 2020, to December 31, 2022. Patients were divided into two groups according to the surgical method: the MOEA-ACDF group and the ACDF group. The preoperative and postoperative imaging results at one week and the last follow-up examination were compared between the two groups. The Japanese Orthopaedic Association (JOA) score, visual analogue scale (VAS) score and neck disability index (NDI) score were used to evaluate the clinical outcomes preoperatively, one week postoperatively and at the last follow-up examination. The minimum follow-up duration was 12 months.

RESULTS

A total of 131 CSM patients who underwent surgery at our institution were included, including 61 patients in the MOEA-ACDF group and 70 patients in the ACDF group. In the MOEA-ACDF group, the postoperative C2-C7 Cobb angle and HAVB were significantly greater than the preoperative values (P < 0.05). In the ACDF group, the postoperative C2-C7 Cobb angle was also significantly greater than the preoperative value, and the C2-C7 ROM and HAVB significantly decreased (P < 0.05). The postoperative neurological function of the patients in both groups improved, and the postoperative VAS score and NDI score significantly decreased. Compared with ACDF, MOEA-ACDF is associated with a significantly larger postoperative C2-C7 Cobb angle and significantly better C2-C7 ROM and HAVB, as well as better clinical efficacy (P < 0.05).

CONCLUSIONS

MOEA-ACDF combines endoscopic systems with ACDF technology to treat CSM, but its clinical efficacy is not inferior to that of ACDF in the short- to intermediate-term. It can effectively and safely restore the cervical intervertebral height, physiological curvature, and range of motion.

A minimum data set-Core outcome set, core data elements, and core measurement set-For degenerative cervical myelopathy research (AO Spine RECODE DCM): A consensus study

BACKGROUND

Degenerative cervical myelopathy (DCM) is a progressive chronic spinal cord injury estimated to affect 1 in 50 adults. Without standardised guidance, clinical research studies have selected outcomes at their discretion, often underrepresenting the disease and limiting comparability between studies. Utilising a standard minimum data set formed via multi-stakeholder consensus can address these issues. This combines processes to define a core outcome set (COS)-a list of key outcomes-and core data elements (CDEs), a list of key sampling characteristics required to interpret the outcomes. Further "how" these outcomes should be measured and/or reported is then defined in a core measurement set (CMS). This can include a recommendation of a standardised time point at which outcome data should be reported. This study defines a COS, CDE, and CMS for DCM research.

METHODS AND FINDINGS

A minimum data set was developed using a series of modified Delphi processes. Phase 1 involved the setup of an international DCM stakeholder group. Phase 2 involved the development of a longlist of outcomes, data elements, and formation into domains. Phase 3 prioritised the outcomes and CDEs using a two-stage Delphi process. Phase 4 determined the final DCM minimal data set using a consensus meeting. Using the COS, Phase 5 finalised definitions of the measurement construct for each outcome. In Phase 6, a systematic review of the literature was performed, to scope and define the psychometric properties of measurement tools. Phase 7 used a modified Delphi process to inform the short-listing of candidate measurement tools. The final measurement set was then formed through a consensus meeting (Phase 8). To support implementation, the data set was then integrated into template clinical research forms (CRFs) for use in future clinical trials (Phase 9). In total, 28 outcomes and 6 domains (Pain, Neurological Function, Life Impact, Radiology, Economic Impact, and Adverse Events) were entered into the final COS. Thirty two outcomes and 4 domains (Individual, Disease, Investigation, and Intervention) were entered into the final CDE. Finally, 4 outcome instruments (mJOA, NDI, SF-36v2, and SAVES2) were identified for the CMS, with a recommendation for trials evaluating outcomes after surgery, to include baseline measurement and at 6 months from surgery.

CONCLUSIONS

The AO Spine RECODE-DCM has produced a minimum data set for use in DCM clinical trials today. These are available at https://myelopathy.org/minimum-dataset/. While it is anticipated the CDE and COS have strong and durable relevance, it is acknowledged that new measurement tools, alongside an increasing transition to study patients not undergoing surgery, may necessitate updates and adaptation, particularly with respect to the CMS.

Comparison of Anterior Cervical Decompression and Fusion and Posterior Laminoplasty for Four-Segment Cervical Spondylotic Myelopathy: Clinical and Radiographic Outcomes

BACKGROUND

 Although anterior or posterior surgery for cervical spondylotic myelopathy (CSM) has been extensively studied, the choice of anterior or posterior approach in four-segment CSM remains poorly studied and controversial. We compared the clinical and radiographic outcomes of four-segment CSM by posterior laminoplasty (LAMP) and anterior cervical decompression fusion (ACDF) to further explore the merits and demerits of ACDF and LAMP for four-segment CSM in this study.

METHODS

 Patients with four-segment CSM who underwent ACDF or LAMP between January 2016 and June 2019 were retrospectively analyzed. We compared the preoperative and postoperative cervical Japanese Orthopaedic Association (JOA) scores, neck disability index (NDI), neck pain visual analog scale (VAS) score, sagittal vertical axis, cervical lordosis (CL), and range of motion.

RESULTS

 There were 47 and 79 patients in the ACDF and LAMP groups, respectively. Patients in the ACDF group had a significantly longer surgical time and lower estimated blood loss and length of stay than those in the LAMP group. There was no significant difference in the JOA, NDI, or neck pain VAS scores between the two groups preoperatively, but the NDI and neck pain VAS scores in the ACDF group were significantly lower than those in the LAMP group at the final follow-up. The preoperative C2-C7 Cobb angle of the ACDF group was significantly lower than that of the LAMP group but there was no significant difference between the two groups postoperatively. The improvement of C2-C7 Cobb angle (∆C2-C7 Cobb angle) in the ACDF group was significantly higher than that in the LAMP group. This indicated that ACDF can improve CL better than LAMP. The linear regression analysis revealed the ∆C2-C7 Cobb angle was negatively correlated with the final follow-up neck pain VAS scores and NDI. This indicated that patients with better improvement of CL may have a better prognosis.

CONCLUSIONS

 Although both ACDF and LAMP surgeries are effective for four-segment CSM, ACDF can better improve CL and neck pain. For patients with poor CL, we suggest ACDF when both approaches are feasible.

Intraoperative Neurophysiological Monitoring in Neurosurgery

Intraoperative neurophysiological monitoring (IONM) is a crucial advancement in neurosurgery, enhancing procedural safety and precision. This technique involves continuous real-time assessment of neurophysiological signals, aiding surgeons in timely interventions to protect neural structures. In addition to inherent limitations, IONM necessitates a detailed anesthetic plan for accurate signal recording. Given the growing importance of IONM in neurosurgery, we conducted a narrative review including the most relevant studies about the modalities and their application in different fields of neurosurgery. In particular, this review provides insights for all physicians and healthcare professionals unfamiliar with IONM, elucidating commonly used techniques in neurosurgery. In particular, it discusses the roles of IONM in various neurosurgical settings such as tumoral brain resection, neurovascular surgery, epilepsy surgery, spinal surgery, and peripheral nerve surgery. Furthermore, it offers an overview of the anesthesiologic strategies and limitations of techniques essential for the effective implementation of IONM.

Using Piezosurgery in Anterior Cervical Discectomy and Fusion to Treat Complex Cervical Spondylotic Myelopathy Is Safe and Effective

Objective

To investigate the safety and efficacy of piezosurgery in anterior cervical discectomy and fusion (ACDF) for cervical spondylotic myelopathy (CSM).

Methods

47 patients with complex CSM (cCSM) underwent ACDF surgery from 2014 to 2017. Among these patients, 26 underwent ACDF using piezosurgery (group A) and 21 underwent ACDF by using traditional tools such as high-speed air drill, bone curette, and Kerrison bone punch (group B). Average surgical time, intraoperative blood loss, surgical complications, preoperative and postoperative Japanese Orthopaedic Association (JOA) scores, and improvement rate were measured.

Results

Average surgical time and intraoperative blood loss were significantly lower in group A than those in group B (P < 0.01). The incidences of surgical complications were 3.8% and 23.8% in the A and B groups (P < 0.05), respectively. There were no significant differences in JOA scores and improvement rates between data collection periods at preoperative, 3-day postoperative, and 1-year postoperative follow-ups (P > 0.05).

Conclusion

For treating cCSM, both the piezosurgery and traditional tools led to significant neurological improvement. However, the piezosurgery was superior to the traditional tools in terms of surgical time, blood loss, and complication rate. Hence, piezosurgery was a safe and effective adjunct for ACDF treating cCSM.

Risk Factors for Significant Intraoperative Blood Loss during Anterior Cervical Decompression and Fusion for Degenerative Cervical Diseases

OBJECTIVES

Anterior cervical decompression and fusion (ACF) has become a widely accepted surgical treatment for degenerative cervical diseases, but occasionally, significant intraoperative blood loss (SIBL), which is defined as IBL of 500 mL or more, will occur. We aimed to investigate the independent risk factors for SIBL during ACF for degenerative cervical diseases.

METHODS

We enrolled 1150 patients who underwent ACF for degenerative cervical diseases at our hospital between 2013 and 2019. The patients were divided into two groups: the SIBL group (n = 38) and the non-SIBL group (n = 1112). Demographic, surgical and radiographic data were recorded prospectively to investigate the independent risk factors for SIBL. For counting data, the chi-square test or Fisher's exact probability test was used. Student's t-test or the Mann-Whitney rank sum test was used for comparisons between groups of measurement data. Univariate analysis and multivariate logistic regression analysis were further used to analyze the significance of potential risk factors.

RESULTS

The incidence of SIBL during ACF was 3.3% (38/1150). A multivariate analysis revealed that female sex (odds ratio [OR], 6.285; 95% confidence interval [CI], 2.707-14.595; p < 0.001), corpectomy (OR, 3.872; 95% CI, 1.616-9.275; p = 0.002), duration of operation ≥150 min (OR, 8.899; 95% CI, 4.042-19.590; p < 0.001), C3 involvement (OR, 4.116; 95% CI, 1.808-9.369; p = 0.001) and ossification of posterior longitudinal ligament (OPLL) at the surgical level (OR, 6.007; 95% CI, 2.218-16.270; p < 0.001) were independent risk factors for SIBL. Patients with SIBL had more days of first-degree/intensive nursing (p = 0.003), longer length of stay (p = 0.003) and higher hospitalization costs (p = 0.023).

CONCLUSION

Female sex, corpectomy, duration of operation, C3 involvement and OPLL at the surgical level were independent risk factors for SIBL during ACF. SIBL in ACF was associated with more days of first-degree/intensive nursing, longer length of stay and higher hospitalization costs.

Secondary analysis of a James Lind Alliance priority setting partnership to facilitate knowledge translation in degenerative cervical myelopathy (DCM): insights from AO Spine RECODE-DCM

OBJECTIVES

To explore whether a James Lind Alliance Priority Setting Partnership could provide insights on knowledge translation within the field of degenerative cervical myelopathy (DCM).

DESIGN

Secondary analysis of a James Lind Alliance Priority Setting Partnership process for DCM.

PARTICIPANTS AND SETTING

DCM stake holders, including spinal surgeons, people with myelopathy and other healthcare professionals, were surveyed internationally. Research suggestions submitted by stakeholders but considered answered were identified. Sampling characteristics of respondents were compared with the overall cohort to identify subgroups underserved by current knowledge translation.

RESULTS

The survey was completed by 423 individuals from 68 different countries. A total of 22% of participants submitted research suggestions that were considered 'answered'. There was a significant difference between responses from different stakeholder groups (p<0.005). Spinal surgeons were the group which was most likely to submit an 'answered' research question. Respondents from South America were also most likely to submit 'answered' questions, when compared with other regions. However, there was no significant difference between responses from different stakeholder regions (p=0.4).

CONCLUSIONS

Knowledge translation challenges exist within DCM. This practical approach to measuring knowledge translation may offer a more responsive assessment to guide interventions, complementing existing metrics.

Cervical Spondylotic Myelopathy: From the World Federation of Neurosurgical Societies (WFNS) to the Italian Neurosurgical Society (SINch) Recommendations

Cervical spondylotic myelopathy (CSM) is a progressively growing pathology to afford by a spinal surgeon due to the aging of the population, associated with better treatment management and the best diagnosis and treatment solutions are greatly discussed. Nowadays that scientific literature is progressively increasing to identify the gold standard in diagnosis and treatment can be very challenging. This is particularly evident in spinal surgery with many different indications not only in different countries but also in the same local reality. In this scenario, many neurosurgical societies works to identify some guideline or recommendations to help spinal surgeons in daily practice. Furthermore, in an era in which legal issues are increasingly present in clinical practice to have some indications globally accepted can be very useful. World Federation of Neurosurgical Societies (WFNS) few years ago starts this process creating a list of recommendations originating from a worldwide steering committee to respect all the local reality. The spinal section of Italian Neurosurgical Society decides to adopt the WFNS recommendations with some revision basing on Italian scenario. The steering committee of the Spinal Section of Italian Neurosurgical Society identify 7 groups to review the literature of the last 10 years about different topics on CSM and to analyses the WFNS recommendations to adapt it to the Italian daily practice. The statements were discussed and voted in 2 sessions to obtain the final version. A list of recommendations on natural course and clinical presentation; diagnostic tests; conservative and surgical treatment; anterior, posterior and combined surgical treatment; role of neurophysiological monitoring and follow-up and outcome was created with only few new or revised statements respect the ones of WFNS. The Spine Section of Italian Neurosurgical Society create a list of recommendations that represent the more contemporary treatment concepts for CSM as presented in the highest quality clinical literature and best clinical practices available on this subject.

Endoscopic Posterior Cervical Decompression for Ossified Posterior Longitudinal Ligament: A Technical Note

BACKGROUND

Ossification of the posterior longitudinal ligament (OPLL) may cause cervical myelopathy. In its multilevel form, it may not be easy to manage. Minimally invasive endoscopic posterior cervical decompression may be an alternative to traditional laminectomy surgery.

METHODS

Thirteen patients with multilevel OPLL and symptomatic cervical myelopathy were treated with endoscopic spine surgery from January 2019 to June 2020. In this consecutive observational cohort study, pre- and postoperative Japanese Orthopaedic Association (JOA) score and Neck Disability Index (NDI) were analyzed at a final follow-up of 2 years postoperatively.

RESULTS

There were 13 patients consisting of 3 women and 10 men. The patient's average age was 51.15 years. At the final 2-year follow-up, the JOA score improved from a preoperative value of 10.85 ± 2.91 to 14.77 ± 2.13 postoperatively (P < 0.001). The corresponding NDI scores decreased from 26.61 ± 12.88 to 11.12 ± 10.85 (P < 0.001). There were no infections, wound complications, or reoperations.

CONCLUSION

Direct posterior endoscopic decompression for multilevel OPLL is feasible in symptomatic patients when executed at a high skill level. While 2-year outcomes were encouraging and on par with historic data obtained with traditional laminectomy, future studies will need to show whether any long-term shortcomings exist.

Optimal anatomical angle and distance for drilling in cervical oblique corpectomy: A surgical anatomical study

Background

One of the difficulties of oblique corpectomy, less discussed in the literature, is the problem of how to achieve an optimum corpectomy. Therefore, this anatomico-radiological study was conducted to shed light on the use of the microscope at an appropriate angle and optimum drill distances in clinical cases undergoing cervical oblique corpectomy surgery.

Materials and Methods

We examined the average distance of the diagonal line extending from the medial aspect of the ipsilateral vertebral foramen to the contralateral pedicle in cervical computed tomography -angiography axial scans in four cervical vertebrae, C3, C4, C5, and C6. We also measured the average angle between this diagonal trajectory and the horizontal line, making a total of 712 measurements in 89 patients.

Results

We found that horizontal drilling with an average length of 23-26 mm at an acute angle of about 22° -23° is optimal for adequate decompression of the spinal cord in the oblique corpectomy approach. Depending on the patient and the level of the vertebra, the distance and the angle of the horizontal drilling may range from 18 mm to 31 mm and from 15° to 33°, respectively.

Conclusions

For an optimum cervical oblique corpectomy that provides adequate spinal cord decompression and maintains spinal stability, it is necessary to operate under a surgical microscope positioned at an acute angle and to know the horizontal drilling distance.

Biomechanical Effect of Osteoporosis on Adjacent Segments After Anterior Cervical Corpectomy and Fusion

BACKGROUND

Adjacent segmental degeneration (ASD) is one common long-term complication of anterior cervical corpectomy and fusion (ACCF), and osteoporosis is one basic disease in the elderly. After ACCF, patients may experience osteoporosis with age. However, the influence of osteoporosis on ASD remains unclear. The purpose of this study was to determine whether osteoporosis could affect the development of ASD following ACCF.

METHODS

Three finite element models of the cervical spine, including 1 normal model, 1 ACCF model, and 1 ACCF with osteoporosis model, were constructed. ACCF was simulated at the C4-C6 level. A 73.6 N follower load and a 1 Nm moment were imposed on the normal model, and the same follower load together with an adjusted moment was applied to the ACCF model and the ACCF with osteoporosis model, to simulate movement in each direction. The range of motion, intradiscal pressure, shear stress on anulus fibrosus, and facet joint stress at C3-C4 and C6-C7 levels of the models were calculated.

RESULTS

In this study, the normal model was well validated. In flexion, extension, right lateral bending, and right axial rotation, the overall range of motion was 8.92°, 19.7°, 15.37°, and 45.27° in the normal model, and the adjusted moment was 1.4 Nm, 2.7 Nm, 1.1 Nm, and 2.6 Nm in the ACCF model, and 1.3 Nm, 2.5 Nm, 1.1 Nm, and 2.4 Nm in the ACCF with osteoporosis model. Despite of a few exceptions, the maximum values of the outcome measurements were mostly found in the ACCF model, and the minimum values in the normal model. Compared with the ACCF model, most of the outcome measurements were decreased in the ACCF with osteoporosis model.

CONCLUSIONS

Osteoporosis can retard the adverse influence of ACCF on adjacent segments.

Life expectancy in patients with degenerative cervical myelopathy is currently reduced but can be restored with timely treatment

PURPOSE

Degenerative cervical myelopathy is a progressive slow-motion spinal cord injury. Surgery is the mainstay of treatment. Baseline disability predicts surgical recovery; therefore, timely treatment is critical to restoring function. However, current challenges mean most patients present with advanced disease and are instead left with life changing disabilities. While short-term mortality is rarely reported, the long-term effects of this on life expectancy are unknown, including whether function could be modifiable with timely treatment. This article investigates the effect of DCM on life expectancy.

METHODS

The survival of patients from an observational study of patients undergoing surgery from 1994 to 2007 was compared to their expected survival using a gender- and aged -matched cohort. Comparisons were made by one sample log-rank test and standardised mortality ratios. Factors associated with survival were explored using a Cox regression analysis, including disease severity.

RESULTS

A total of 357 patients were included in the analysis. After a median follow-up of 15.3 years, 135 of 349 patients had died; 114.7 deaths would have been expected. The DCM cohort had an increased risk of death compared to the non-DCM cohort (standardised mortality ratio 1.18 [95% CI: 1.02-1.34]. Age at operation 1.08 (95% CI: 1.07 to 1.1, p < 0.001) and severe DCM 1.6 (95% CI: 1.06 to 2.3, p = 0.02) were associated with worse survival (N = 287). In those surviving at least 2 years after surgery, only severe DCM was associated with conditional survival (HR 1.6, 95% CI 1.04 2.4, p = 0.03).

CONCLUSION

Life expectancy is reduced in those undergoing surgery for DCM. This is driven by premature mortality among those left with severe disability. As disability can be reduced with timely treatment, these findings reinforce the need for collective and global action to raise awareness of DCM and enable early diagnosis.

Effect of Anterior Cervical Decompression Fusion and Partial Resection of Uncinate Vertebra Joint on Cervical Sagittal Sequence in Patients with Non-Single-Segment Radiculopathy and its Correlation with Curative Effect: A Retrospective Analysis

OBJECTIVE

Analyze the effect of preservation or resection of the partial uncinate joint on the sagittal sequence of the cervical vertebrae in patients with non-single-segment radiculopathy and the correlation between the sagittal sequence of the cervical vertebrae and the long-term effect after surgery, we explored whether it is necessary to perform partial resection of the uncinate joint in patients with cervical spondylotic radiculopathy undergoing anterior cervical decompression and fusion (ACDF).

METHODS

The study retrospectively analyzed 96 patients with cervical spondylotic radiculopathy with more than two segments from August 2016 to January 2021, who underwent ACDF (ACDF group, 45 patients) or ACDF combined with partial uncinate joint resection (ACDF + UT group, 51 patients). Partial resection of the uncinate joint indicated removal of part of the uncinate joint and osteophyte based on the compression of the nerve root during surgery, whereas the uncinate joints in the ACDF group were retained completely. The imaging data and functional scores of the two groups were recorded before surgery, 1 month after surgery, and at the last follow-up. A paired t-test or rank sum test was applied to analyze the data. In addition, the correlation between the imaging parameters and functional scores was validated using the Pearson's test.

RESULTS

All 96 patients successfully completed the surgery and were followed up for at least 12 months, with an average follow-up time of 14 months. At the last follow-up, the pain visual analog scale (VAS), neck disability index (NDI), and neck pain and disability scale (NPAD) scores of the two groups were significantly lower than those before surgery, and the Japanese Orthopaedic Association (JOA) score was significantly higher than that before surgery. At the last follow-up, compared with the ACDF+UT group, the NDI and NPAD scores in the ACDF group decreased more significantly (p < 0.05), and C2-7SVA, △C2-7SVA (the difference between C2-7 SVA at last follow-up and before operation), and T1S values decreased significantly (p < 0.05). The C2-7 Cobb angle was positively correlated with the JOA score and T1S (p < 0.05) and negatively correlated with the VAS, NDI, and NPAD scores and CGH-C7SVA (p < 0.05). C2-7SVA was positively correlated with CGH-C7SVA and T1S (p < 0.05).

CONCLUSION

Patients with non-single-segmental cervical spondylotic radiculopathy and ACDF with or without uncinate joint resection can have effective improvement in the clinical effect and sagittal balance; however, partial uncinate joint resection has a certain negative impact on the long-term reconstruction of sagittal balance and long-term effects in patients after surgery.

Comparison Between Sagittal Balance Outcomes After Corpectomy, Laminectomy, and Fusion for Cervical Spondylotic Myelopathy: A Matched Cohort Study

Cervical spondylotic myelopathy (CSM) can be successfully decompressed via either anterior cervical corpectomy and fusion (ACCF) or posterior laminectomy with fusion (LMF). However, few studies have compared the isolated effect of both techniques on cervical sagittal balance, a surrogate end point for clinical outcomes.We aimed to compare the sagittal balance radiological outcomes of ACCF against LMF. A case-matched controlled study of radiological cervical alignment parameters (C0-2, C2-3, index angles, T1 slope, and sagittal vertical axis (SVA)) in two groups of patients was performed by using pre- and postoperative neutral cervical X-rays.In total, 34 patients were enrolled (ACCF n = 17; LMF n = 17). The mean preoperative C2-7 angle was similar (11.58 ± 16.00° for ACCF; 13.36 ± 12.21° for LMF) in both cohorts. Both led to a loss of lordosis (-2.68 ± 13.8°, p = 0.43; -2.94 ± 11.5°, p = 0.31, respectively). At the C0-2, the two operations induced opposite variations (-0.9 ± 8.0°, p = 0.709 for ACCF; 3.5 ± 15.4°, p = 0.357 for LMF). ACCF led to a significant increase in SVA (7.1 ± 11.9 mm, p = 0.002). The C2-3 disk angle more pronouncedly increased with LMF.Both techniques show an equivalent kyphotic effect, with a greater disadvantage for ACCF. The negative impact on SVA changes is greater with ACCF. Both affect the C0-2 unit, with a tendency for kyphosis with ACCF and one for lordosis with LMF. When choosing the appropriate decompression and fusion technique, preoperative sagittal balance parameters should be included in the decision-making process.

Comparison of anterior cervical discectomy and fusion versus anterior cervical corpectomy and fusion in the treatment of localized ossification of the posterior longitudinal ligament

BACKGROUND

The retrospective study was conducted to compare the efficacy of anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) for localized ossification of the posterior longitudinal ligament (OPLL) by evaluating clinical and radiologic outcomes.

METHODS

We reviewed 151 patients to assess the effects of treatment for one or two levels localized OPLL. Perioperative parameters, such as blood loss, operation time and complications, were recorded. Radiologic outcomes, such as the occupying ratio (OR), fusion status, cervical lordosis angle, segmental angle, disc space height, T1 slope, and C2-C7 sagittal vertical axis (SVA), were assessed. Clinical indices, such as the JOA scores and VAS scores, were investigated to compare the two surgical options.

RESULTS

There were no significant differences in the JOA scores or VAS scores between the two groups (p > 0.05). The operation time, volume of blood loss and incidence of dysphagia were significantly less in the ACDF group than in the ACCF group (p < 0.05). In addition, cervical lordosis, segmental angle and disc space height were significantly different from their preoperative evaluations. No adjacent segment degenerated in the ACDF group. The subsidence rates of implants were 5.2% in the ACDF group and 28.4% in the ACCF group. The degeneration of the ACCF group was 4.1%. The incidence of CSF leaks was 7.8% in the ACDF group and 13.5% in the ACCF group. All the patients ultimately achieved successful fusion.

CONCLUSION

Although both options achieved satisfactory primary clinical and radiographic efficacies, ACDF was associated with a shorter surgical procedure, less intraoperative blood loss, better radiologic outcomes, and lower incidence of dysphagia than ACCF.

Fifty Years of Cervical Myelopathy Research: Results from a Bibliometric Analysis

We performed bibliometric analysis of the research papers published on clinical cervical spondylotic myelopathy (CSM) in the last 50 years. We extracted bibliometric data from Scopus and PubMed from 1970 to 2020 pertaining to clinical studies of CSM. The predominant journals, top cited articles, authors, and countries were identified using performance analysis. Science mapping was also performed to reveal the emerging trends, and conceptual and social structures of the authors and countries. Bibliometrix R-package was deployed for the study. The total numbers of clinical studies available in PubMed and Scopus were 1,302 and 3,470, respectively. The most cited article was published by Hilibrand AS, as observed in Scopus. Regarding the conceptual structure of the research, two main research themes were identified, one involving symptomatology, scientific-scale-based objective evaluation of symptoms, and surgical removal of the offending culprit, while the other was based on patho-etiology, relevant diagnostic modalities, and the surgery commonly performed for CSM. In terms of emerging trends, in recent times there is an increasing trend of scale-based objective evaluations, along with investigations of advanced nonoperative management. The United States is the most productive country, whereas Canada tops the list for inter-country collaboration. The trend of research showed a shift toward noninvasive procedures.

Classification of expert-level therapeutic decisions for degenerative cervical myelopathy using ensemble machine learning algorithms

Background

Therapeutic decisions for degenerative cervical myelopathy (DCM) are complex and should consider various factors. We aimed to develop machine learning (ML) models for classifying expert-level therapeutic decisions in patients with DCM.

Methods

This retrospective cross-sectional study included patients diagnosed with DCM, and the diagnosis of DCM was confirmed clinically and radiologically. The target outcomes were defined as conservative treatment, anterior surgical approaches (ASA), and posterior surgical approaches (PSA). We performed the following classifications using ML algorithms: multiclass, one-versus-rest, and one-versus-one. Two ensemble ML algorithms were used: random forest (RF) and extreme gradient boosting (XGB). The area under the receiver operating characteristic curve (AUC-ROC) was the primary metric. We also identified the variable importance for each classification.

Results

In total, 304 patients were included (109 conservative, 66 ASA, 125 PSA, and 4 combined surgeries). For multiclass classification, the AUC-ROC of RF and XGB models were 0.91 and 0.92, respectively. In addition, ML models showed AUC-ROC values of >0.9 for all types of binary classifications. Variable importance analysis revealed that the modified Japanese Orthopaedic Association score and central motor conduction time were the two most important variables for distinguishing between conservative and surgical treatments. When classifying ASA and PSA, the number of involved levels, age, and body mass index were important contributing factors.

Conclusion

ML-based classification of DCM therapeutic options is valid and feasible. This study can be a basis for establishing generalizable ML-based surgical decision models for DCM. Further studies are needed with a large multicenter database.

The adjustable aiming device for caspar pin insertion in anterior cervical spine surgery

BACKGROUND

Creating a rectangular disc space is an important step during anterior cervical discectomy and fusion or cervical total disc replacement. The study aims to determine the accuracy of Caspar pin insertion by using a novel Adjustable Caspar Pin Aiming Device in anterior cervical procedures.

METHODS

Forty Caspar pins were placed using an Adjustable Caspar Pin Aiming Device in 20 human cadaveric cervical vertebral bodies from C3 to C7 after performing anterior discectomies. Accuracy of pin placement was assessed by lateral fluoroscopy, considering superior endplate slope (SE), inferior endplate slope (IE), Caspar pin slope (CP), and endplate-Caspar pin slope difference (SE/CP, IE/CP).

RESULTS

The mean superior endplate slope (SE), inferior endplate slope (IE), and Caspar pin slope (CP) were 10.82 ± 2.3°, 10.32 ± 3.2°, and 15.58 ± 7.9°, respectively. The average superior endplate-Caspar pin slope difference (SE/CP) and inferior endplate-Caspar pin slope difference (IE/CP) were 6.6 ± 0.8° and 7.7 ± 0.8°, respectively. The greatest slope difference was observed at the superior and inferior endplates of C3. No cervical endplate violations occurred.

CONCLUSION

Adjustable Caspar Pin Aiming Device allowed for a highly accurate Caspar pin placement with the average endplate-Caspar pin slope difference of less than 7.7°. It results in accurate placement of the superior and inferior Caspar pins parallel to the index vertebral endplates. Furthermore, it appears to facilitate the safe and effective insertion of Caspar pins for anterior cervical procedures.

Improving Awareness Could Transform Outcomes in Degenerative Cervical Myelopathy [AO Spine RECODE-DCM Research Priority Number 1]

STUDY DESIGN

Literature Review (Narrative).

OBJECTIVE

To introduce the number one research priority for Degenerative Cervical Myelopathy (DCM): Raising Awareness.

METHODS

Raising awareness has been recognized by AO Spine RECODE-DCM as the number one research priority. This article reviews the evidence that awareness is low, the potential drivers, and why this must be addressed. Case studies of success from other diseases are also reviewed, drawing potential parallels and opportunities for DCM.

RESULTS

DCM may affect as many as 1 in 50 adults, yet few will receive a diagnosis and those that do will wait many years for it. This leads to poorer outcomes from surgery and greater disability. DCM is rarely featured in healthcare professional training programs and has received relatively little research funding (<2% of Amyotrophic Lateral Sclerosis or Multiple Sclerosis over the last 25 years). The transformation of stroke and acute coronary syndrome services, from a position of best supportive care with occasional surgery over 50 years ago, to avoidable disability today, represents transferable examples of success and potential opportunities for DCM. Central to this is raising awareness.

CONCLUSION

Despite the devastating burden on the patient, recognition across research, clinical practice, and healthcare policy are limited. DCM represents a significant unmet need that must become an international public health priority.

Radiological Changes in Adjacent and Index Levels after Cervical Disc Arthroplasty

PURPOSE

The purpose of this retrospective study was to evaluate radiological and clinical outcomes in patients undergoing cervical disc arthroplasty (CDA) for cervical degenerative disc disease. The results may assist in surgical decision-making and enable more effective and safer implementation of cervical arthroplasty.

MATERIALS AND METHODS

A total of 125 patients who were treated with CDA between 2006 and 2019 were assessed. Radiological measurements and clinical outcomes included the visual analogue scale (VAS), the Neck Disability Index (NDI), and the Japanese Orthopaedic Association (JOA) myelopathy score assessment preoperatively and at ≥2 years of follow-up.

RESULTS

The mean follow-up period was 38 months (range, 25-114 months). Radiographic data demonstrated mobility at both the index and adjacent levels, with no signs of hypermobility at an adjacent level. There was a non-significant loss of cervical global motion and range of motion (ROM) of the functional spinal unit at the operated level, as well as the upper and lower adjacent disc levels, compared to preoperative status. The cervical global and segmental angle significantly increased. Postoperative neck VAS, NDI, and JOA scores showed meaningful improvements after one- and two-level CDA. We experienced a 29.60% incidence of heterotrophic ossification and a 3.20% reoperation rate due to cervical instability, implant subsidence, or osteolysis.

CONCLUSION

CDA is an effective surgical technique for optimizing clinical outcomes and radiological results. In particular, the preservation of cervical ROM with an artificial prosthesis at adjacent and index levels and improvement in cervical global alignment could reduce revision rates due to adjacent segment degeneration.

Morphology of Herniated Disc as a Predictor for Outcomes of Posterior Percutaneous Full-endoscopic Cervical Discectomy in Treating Cervical Spondylotic Radiculopathy

OBJECTIVE

To quantitively characterize the morphology of cervical disc herniation (CDH) causing cervical spondylotic radiculopathy (CSR) and investigate whether the morphological features of CDH are associated with clinical outcomes in CSR patients treated by posterior percutaneous full-endoscopic cervical discectomy (PPECD).

METHODS

This is a single-center retrospective study. Eighty-seven PPECD-treated patients meeting the inclusion criteria were included between May 2017 and May 2019. Based on preoperative T2-weighted magnetic resonance imaging (MRI), we designed and measured six morphological parameters of CDH for all patients to reflect its relative position to cervical spinal cord and protruding degree: DC-SC distance from the center of disc (DC) and the center of spinal cord (SC); DC-DP distance from the center of cervical disc (DC) to the peak of herniation (DP); internal diameter of the disc; axial length of CDH; central angle of CDH formed by central axes of CDH and spinal cord; the modified index of CDH. We recorded general information, neck disability index (NDI) scores, visual analog scale (VAS) scores of neck and arm of all patients preoperatively and postoperatively at 1-year follow-up. The association of preoperative general variables and morphological parameters with clinical outcomes were explored by utilizing logistic regression and receiver operating characteristic curve (ROC) analysis.

RESULTS

The preoperative neck-VAS, arm-VAS, and NDI were significantly decreased after PPECD and remained at a low value at follow-up. In regards to the morphological parameters of CDH, the mean value of DC-SC distance, DC-DP distance, internal diameter of the disc, axial length of CDH, central angle of CDH, and modified index of CDH were 1.61 ± 0.30 cm, 1.66 ± 0.32cm, 1.04 ± 0.21 cm, 0.63 ± 0.19cm, 39.38° ± 11.94°, and 0.39 ± 0.24, respectively. For patients grouped by difference in the recovery rate of NDI and arm-VAS (excellent improved group, EI; and limited improved group, LI), there were no differences in the age, gender, surgical segments, and morphological parameters, except for the central angle of CDH. According to binary logistic regression analysis, only the preoperative central angle of CDH was significantly associated with postoperative NDI recovery (odds ratio: 0.873; 95% confidence interval: 0.819-0.931, P = 0.002). ROC analysis showed the optimal cut-off value of the central angle of CDH for predicting the postoperative improvement of functional outcomes is 33.788°.

CONCLUSION

Preoperative morphology of CDH is related to the outcomes of CSR patients after PPECD. Patients with a large central angle of CDH (>33.788°) have more likelihood of ameliorating neurological symptoms of CSR. There is the potential to select the central angle of CDH as a predictor for outcomes of PPECD in treating CSR.

Efficiency of minimal oblique resection of the uncinate process during an anterior cervical discectomy and fusion

ABSTRACT

Hypertrophy of the uncinate process (UP) can cause radiculopathy. Minimal UP resection is considered to remove the lesion while minimizing the risk of complications. This study aimed to elucidate the surgical results of minimal oblique resection of the UP. This study is a retrospective review of about sixty segments in 34 patients who underwent anterior cervical discectomy and fusion (ACDF) with minimal oblique uncinectomy between 2016 and 2018. The cross-sectional area of the UP was measured pre- and postoperatively. The interspinous distance, segmental Cobb angle, subsidence, fusion rate, surgical time, estimated blood loss, and postoperative complications were evaluated. The mean resected areas of the UP were 17.4 ± 8.7 mm2 (25.9%) on the right and 17.3 ± 11.2 mm2 (26.2%) on the left. The difference in interspinous distance in flexion-extension was 7.1 ± 3.2 and 1.6 ± 0.6 mm pre- and postoperatively, respectively (P = .000). The fusion rate after ACDF was 91.7% when measured according to segment (55/60) and 91.2% when measured according to patients (31/34). The difference in the segmental Cobb angle in flexion-extension was 8.3 ± 6.2° and 1.9 ± 0.3° pre and postoperatively, respectively (P = .000). Subsidence occurred in 4 (11.8%) patients and 5 (8.3%) segments. The average surgical time per segment was 68.8 ± 9.3 minute, and the estimated blood loss was 48.5 ± 25.0 mL. Postoperative complications comprised 1 case each of neck swelling, wound infection, pneumonia, and gastrointestinal bleeding. Our findings therefore revealed that minimal oblique uncinectomy during an ACDF can maintain the stability of the uncovertebral joint while sufficiently decompressing the neural foramen.

Anterior Cervical Discectomy and Fusion: A Surgical Intervention for Treating Cervical Disc Disease

Cervical disc disease includes chronic disc degeneration, stenosis, spondylosis, and disc herniation; providers initially treat these conditions conservatively through symptomatic care. When conservative measures fail, surgery may be indicated. It is important to explore all the surgical options available and the risks and benefits of each procedure. An anterior cervical discectomy and fusion (ACDF) is a procedure involving the removal of disc material to achieve neural tissue decompression and placement of a bone graft or interbody implant and a cervical plate and screws to stabilize the spinal column at one or more vertebral levels. This article briefly reviews the anatomy of the spine and treatment options for cervical disc disease; presents an in-depth review of the ACDF procedure, including the expected perioperative course and care considerations; and concludes with a case report of a 37-year-old woman who underwent an ACDF at the C5-C6 and C6-C7 vertebral levels of the spine.

Cervical Oblique Corpectomy: Revitalizing the Underused Surgical Approach With Step-By-Step Simulation in Cadavers

ABSTRACT

Recently, the World Federation of Neurosurgical Societies Spine committee recommended that additional research on cost-benefit analysis of various surgical approaches for cervical spondylotic myelopathy be carried out and their efficacy with long-term outcomes be compared. Unfortunately, it is highly probable that the oblique corpectomy (OC) will not be included in cost-benefit investigations due to its infrequent application by neurosurgeons dealing with the spine. In this cadaveric study, head and necks of 5 adult human cadavers stained with colored latex and preserved in 70% alcohol solution were dissected under a table-mounted surgical microscope using 3× to 40× magnifications. The OC approach was performed to simulate real surgery, and the neurovascular structures encountered during the procedure and their relations with each other were examined. Oblique corpectomy was performed unilaterally, although neck dissections were performed bilaterally on 10 sides in all 5 cadavers. At each stage of the dissection, multiple three-dimensional photographs were obtained from different angles and distances. For an optimal OC, both the anterior spinal cord must be sufficiently decompressed and sufficient bone must be left in place to prevent instability in the cervical spine. Oblique corpectomy is a valid and potentially low cost alternative to other anterior and posterior approaches in the surgical treatment of cervical spondylotic myelopathy. However, meticulous cadaver studies are essential before starting real surgical practice on patients in order to perform it effectively and to avoid the risks of the technique.

Preoperative Radiological Parameters to Predict Clinical and Radiological Outcomes after Laminoplasty

Many studies have focused on pre-operative sagittal alignment parameters which could predict poor clinical or radiological outcomes after laminoplasty. However, the influx of too many new factors causes confusion. This study reviewed sagittal alignment parameters, predictive of clinical or radiological outcomes, in the literature. Preoperative kyphotic alignment was initially proposed as a predictor of clinical outcomes. The clinical significance of the K-line and K-line variants also has been studied. Sagittal vertical axis, T1 slope (T1s), T1s-cervical lordosis (CL), anterolisthesis, local kyphosis, the longitudinal distance index, and range of motion were proposed to have relationships with clinical outcomes. The relationship between loss of cervical lordosis (LCL) and T1s has been widely studied, but controversy remains. Extension function, the ratio of CL to T1s (CL/T1s), and Sharma classification were recently proposed as LCL predictors. In predicting postoperative kyphosis, T1s cannot predict postoperative kyphosis, but a low CL/T1s ratio was associated with postoperative kyphosis.

Predictors of neurologic outcome after surgery for cervical ossification of the posterior longitudinal ligament differ based on myelopathy severity: a multicenter study

OBJECTIVE

The purpose of this retrospective multicenter study was to compare prognostic factors for neurological recovery in patients undergoing surgery for cervical ossification of the posterior longitudinal ligament (OPLL) based on their presenting mild, moderate, or severe myelopathy.

METHODS

The study included 372 consecutive patients with OPLL who underwent surgery for cervical myelopathy between 2006 and 2016 in East Asian countries with a high OPLL prevalence. Baseline and postoperative clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA) myelopathy score and recovery ratio. Radiographic assessment included occupying ratio, cervical range of motion, and sagittal alignment parameters. Patient myelopathy was classified as mild, moderate, or severe based on the preoperative JOA score. Linear and multivariate regression analyses were performed to identify patient and surgical factors associated with neurological recovery stratified by baseline myelopathy severity.

RESULTS

The mean follow-up period was 45.4 months (range 25-140 months). The mean preoperative and postoperative JOA scores and recovery ratios for the total cohort were 11.7 ± 3.0, 14.5 ± 2.7, and 55.2% ± 39.3%, respectively. In patients with mild myelopathy, only age and diabetes correlated with recovery. In patients with moderate to severe myelopathy, older age and preoperative increased signal intensity on T2-weighted imaging were significantly correlated with a lower likelihood of recovery, while female sex and anterior decompression with fusion (ADF) were associated with better recovery.

CONCLUSIONS

Various patient and surgical factors are correlated with likelihood of neurological recovery after surgical treatment for cervical OPLL, depending on the severity of presenting myelopathy. Older age, male sex, intramedullary high signal intensity, and posterior decompression are associated with less myelopathy improvement in patients with worse baseline function. Therefore, myelopathy-specific preoperative counseling regarding prognosis for postoperative long-term neurological improvement should include consideration of these individual and surgical factors.

Pattern and Rate of Functional Recovery After Surgery for Cervical Spondylotic Myelopathy: Egyptian Prospective Study

OBJECTIVE

To study pattern and rate of neurological functional recovery after surgery for cervical spondylotic myelopathy (CSM).

METHODS

This prospective study comprised 25 patients with CSM who underwent surgical decompression at our institution. Upper limb, lower limb, and sphincter functions were assessed using the modified Japanese Orthopaedic Association score (mJOA). Assessment was done before the operation and at 1 month, 3 months, and 1 year after surgery.

RESULTS

The mJOA score did not significantly increase at 1 month after surgery (P = 0.051); however, increase in mJOA score was statistically significant at 3 and 1 year after surgery (P < 0.001 and P < 0.001, respectively). Upper limb motor dysfunction improved in 65% of patients, lower limb motor dysfunction improved in 52% of patients, upper limb sensory dysfunction improved in 48% of patients, and sphincter dysfunction improved in 14.2% of patients. There was a significant positive correlation between preoperative and postoperative mJOA score at 1 month, 3 months, and 1 year after surgery.

CONCLUSIONS

Minimal improvement occurred in the first month after CSM surgery to reach a peak at 3 months after surgery and steady improvement up to 1 year after surgery. Upper limbs recovered better and earlier than lower limbs and sphincter function. Preoperative severity of CSM is one of the main predictors of postoperative neurological outcome.

Anterior cervical spine surgical complications: Safety comparison between teacher and student

Background

Anterior cervical surgery has a widespread use. Despite its popularity, this surgery can lead to serious and life-threatening complications, and warrants the attention of skilled attending spinal surgeons with many years of experience.

Methods

We retrospectively evaluated postoperative complications occurring in 110 patients who underwent anterior cervical surgery (anterior cervical discectomy without fusion, anterior cervical discectomy and fusion, and anterior cervical disc arthroplasty) between 2013 and 2020. These operations were performed by an either an attending surgeon with 30 years' experience versus a novice neurosurgeon (NN) with <5 years of training with the former surgeon. Complications were variously identified utilizing admission/discharge notes, surgical reports, follow-up visits, and phone calls. Complications for the two groups were compared for total and specific complication rates (using the Pearson's Chi-square and Fisher's test).

Results

The total cumulative complication rate was 15.4% and was not significantly different between the two cohorts. The most frequent postoperative complication was dysphagia. Notably, there were no significant differences in total number of postoperative instances of dysphagia, dysphonia, unintended durotomy, hypoasthenia, and hypoesthesia; the only difference was the longer operative times for NNs.

Conclusion

Surgeons' years of experience proved not to be a critical factor in determining complication rates following anterior cervical surgery.

Perioperative Outcomes in 17,947 Patients Undergoing 2-Level Anterior Cervical Discectomy and Fusion Versus 1-Level Anterior Cervical Corpectomy for Treatment of Cervical Degenerative Conditions: A Propensity Score Matched National Surgical Quality Improvement Program Analysis

Objective

To compare the perioperative morbidity of 2-level anterior cervical discectomy and fusion (ACDF) with that of 1-level anterior cervical corpectomy and fusion (ACCF) for the treatment of cervical degenerative conditions.

Methods

A retrospective study of the 2005–2016 National Surgical Quality Improvement Program database for patients undergoing 2-level ACDF and 1-level ACCF was performed. Patient data included: age, sex, body mass index (BMI), functional status, and American Society of Anesthesiologists (ASA) physical status (PS) classification. Hospital data included: operative time and length of hospital stay (LOS). Thirty-day outcome data included: any, serious, and minor adverse events, return to the operating room, readmission, and mortality. After propensity matching for age, sex, ASA PS classification, functional status, and BMI, multivariate logistic regression analysis was used to compare outcomes between the 2 propensity-matched subcohorts. Finally, multivariate logistic regression that additionally controlled for operative time was performed to compare the 2 propensity-matched subcohorts.

Results

A total of 17,497 cases were identified, with 90.20% undergoing 2-level ACDF and 9.80% undergoing 1-level ACCF. Patients undergoing 2-level ACDF were younger, more likely to be female, had higher functional status, and had shorter operative time and LOS (p < 0.001). After propensity score matching, cases undergoing 1-level ACCF had a statistically significant higher rate of serious adverse events (p = 0.005). This difference was no longer significant after controlling for operative time.

Conclusion

While there was noted to be additional morbidity in 1-level ACCF cases relative to 2-level ACDF cases, the lack of difference once controlling for the surgical time supports using the procedure that best accomplishes the surgical objectives.

Clinical and radiological outcomes of multilevel cervical laminoplasty versus three-level anterior cervical discectomy and fusion in patients with cervical spondylotic myelopathy

Background

Cervical spondylotic myelopathy (CSM) is one of the most common causes of spinal cord impairment in elderly patients. However, a consensus has yet to be reached on the ideal method of surgical intervention. In this study, we investigated serial changes of radiological findings after three-level anterior cervical discectomy and fusion (ACDF) and multilevel laminoplasty and attempted to identify the radiological parameters affecting long-term clinical outcomes in CSM.

Methods

Of the 152 patients with multilevel CSM treated with three-level ACDF and multilevel laminoplasty, 42 had complete radiological parameters both before and 2 years after surgery (three-level ACDF, 22 patients; multilevel laminoplasty, 20 patients). Radiological parameters included spinal cord signal intensity (SI) changes on magnetic resonance imaging (MRI). Clinical outcomes including the Japanese Orthopaedic Association (JOA) score, neck disability index (NDI), Oswestry disability index (ODI), and 36-Item Short Form Health Survey score were measured.

Results

The ACDF group showed significant restoration of segmental lordosis postoperatively (preoperatively: 2.21°, 6 months: 8.37°, P=0.026), and segmental and cervical range of motion (ROM) was markedly reduced and well maintained until the final follow-up (preoperatively: 25.48°, 24 months: 4.35°, P<0.001; preoperatively: 41.71°, 24 months: 20.18°, P<0.001). The recovery rates of the JOA score were 42.85% and 57.40% in the ACDF and laminoplasty groups, respectively, although this difference was not statistically significant. Multivariate regression analysis demonstrated that signal change on MRI significantly affected the recovery rate (P=0.003). The visual analog scale (VAS) score and NDI decreased considerably only in the laminoplasty group, and device complications were confirmed only in the ACDF group (incidence rate =36.5%).

Conclusions

Multilevel laminoplasty showed better radiological and similar clinical outcomes. ACDF had more surgical complications. Spinal cord SI change on preoperative MRI was the independent risk factor for poor clinical outcomes. We recommend laminoplasty instead of three-level ACDF to treat multilevel CSM.

Surgical Strategies for Cervical Deformities Associated With Neuromuscular Disorders

Neuromuscular disorders (NMDs) are diseases involving the upper and lower motor neurons and muscles. In patients with NMDs, cervical spinal deformities are a very common issue; however, unlike thoracolumbar spinal deformities, few studies have investigated these disorders. The patients with NMDs have irregular spinal curvature caused by poor balance and poor coordination of their head, neck, and trunk. Particularly, cervical deformity occurs at younger age, and is known to show more rigid and severe curvature at high cervical levels. Muscular physiologic dynamic characteristics such as spasticity or dystonia combined with static structural factors such as curvature flexibility can result in deformity and often lead to traumatic spinal cord injury. In addition, postoperative complication rate is higher due to abnormal involuntary movement and muscle tone. Therefore, it is important to control abnormal involuntary movement perioperatively along with strong instrumentation for correction of deformity. Various methods such as botulinum toxin injection, physical therapy, muscle division technique, or intrathecal baclofen pump implant may help control abnormal involuntary movements and improve spinal stability. Surgical management for cervical deformities associated with NMDs requires a multidisciplinary effort and a customized strategy.

Comparison of the effectiveness and safety of bioactive glass ceramic to allograft bone for anterior cervical discectomy and fusion with anterior plate fixation

Recently, a bioactive glass ceramic (BGC) has been developed for use as intervertebral cages for anterior cervical discectomy and fusion (ACDF). However, the effectiveness and safety of BGC cages remain to be evaluated. We completed a retrospective comparison of the radiological and clinical outcomes of 36 patients (52 levels) who underwent ACDF with a BGC cage and 35 patients (54 levels) using allograft bone. The following variables were compared between the two groups: the visual analog (VAS) neck and arm pain score and the neck disability index (NDI), measured before surgery and 1 year after; the change in Cobb's angle, between the C2 and C7 vertebrae, the global sagittal angle, and disc height compared from before surgery to 1 year after; and the rate of spinal fusion and cage subsidence at 1 and 2 years after surgery. The VAS and NDI scores were not different between the two groups. Similarly, the spinal fusion rate was not different between the BGC and allograft bone group at 1 year (73% and 87%, respectively; p = 0.07) and 2 years (94% and 91%, respectively; p = 0.54) after surgery. However, the rate of cage subsidence was higher in the allograft bone (43%) than the BGC (19%) group (p = 0.03), as was the rate of instrument-related failure (p = 0.028), with a specifically higher incidence of implant fracture or failure in the allograft bone group (p = 0.025). Overall, our findings indicate that BGC cages provide a feasible and safe alternative to allograft bone for ACDF.