Single level cervical fusion by an anterior approach using autologous bone graft influences the adjacent levels degenerative changes: clinical and radiographic results at 10-year minimum follow-up

Do the Choice of Fusion Construct With and Without Autograft Influence the Fusion and Complication Rates in Patients Undergoing 1 or 2-Level Anterior Cervical Discectomy and Fusion Surgery? A PRISMA-Compliant Network Meta-Analysis

STUDY DESIGN

Network meta-analysis.

OBJECTIVES

To compare the fusion outcome and complications of different 1 or 2-level anterior cervical decompression and fusion (ACDF) constructs performed with and without the application of autografts.

METHODS

We performed an independent and duplicate search in electronic databases including PubMed, Embase, Web of Science, Cochrane, and Scopus for relevant articles published between 2000 and 2020. We included comparative studies reporting fusion rate and complications with and without the use of autografts in ACDF across 5 different fusion constructs. A network meta-analysis was performed in Stata, categorized based on the type of fusion constructs utilized. Fusion constructs were ranked based on p-score approach and surface under cumulative ranking curve (SUCRA) scores. The confidence of results from the analysis was appraised with Cochrane's CINeMA approach.

RESULTS

A total of 2216 patients from 22-studies including 6 Randomized Controlled Trials (RCTs) and 16 non-RCTs were included in network analysis. The mean age of included patients was 49.3 (±3.62) years. Based on our meta-analysis, we could conclude that use of autograft in 1- or 2-level ACDF did not affect the fusion and mechanical implant-related complications. The final fusion and mechanical complication rates were also not significantly different across the different fusion constructs. The use of plated constructs was associated with a significant increase in post-ACDF dysphagia rates [OR 3.42; 95%CI (.01,2.45)], as compared to stand-alone constructs analysed.

CONCLUSION

The choice of fusion constructs and use of autografts does not significantly affect the fusion and overall complication rates following 1 or 2-level ACDF surgery.

The effect of cage type on local and total cervical lordosis restoration and global spine alignment in single-level anterior cervical discectomy and fusion based on EOS® imaging: A comparison between standalone conventional interbody polyether ether ketone cage and integrated cage and plate (Perfect-C®)

Background

There is a small level of evidence regarding the alterations in global spine alignment following the restoration of cervical lordosis using anterior cervical discectomy and fusion (ACDF). Different cage types are available to restore cervical lordosis through ACDF. In this study, we evaluate the impact of two types of these cages on local and global spine alignments.

Patients and Methods

Thirty-two patients with a mean age of 46 ± 10 who underwent ACDF for cervical disc herniation were included in this retrospective study. Patients were divided according to their cage type into two groups, 17 patients with standalone conventional polyether ether ketone cages and 15 patients with integrated cage and plate (ICP) (Perfect-C®). Cervical alignment and global spine alignment were evaluated on the pre- and post-operative EOS® images.

Results

Three months after the ACDF, total cervical lordosis correction was higher in patients with ICP (P = 0.001), while the local cervical lordosis correction was not significantly different between conventional cages and prefect-C cages (P = 0.067). Lumbar lordosis and pelvic tilt change were significantly higher among patients with Perfect-c cages (P = 0.043).

Conclusion

In patients undergoing ACDF, alignment of the global spine changes along with the restoration of the cervical spine. Cage type affects this association, mainly through the compensatory alteration of pelvic tilt.

Anterior cervical corpectomy and fusion with stand-alone cages in patients with multilevel degenerative cervical spine disease is safe

Background

In case of spinal cord compression behind the vertebral body, anterior cervical corpectomy and fusion (ACCF) proves to be a more feasible approach than cervical discectomy. The next step was the placement of an expandable titanium interbody in order to restore the vertebral height. The need for additional anterior plating with ACCF has been debatable and such technique has been evaluated by very few studies. The objective of the study is to evaluate radiographic and clinical outcomes in patients with multilevel degenerative cervical spine disease treated by stand-alone cages for anterior cervical corpectomy and fusion (ACCF).

Methods

Thirty-one patients (66.5 ± 9.75 years, range 53–85 years) were analyzed. Visual Analog Scale (VAS) and the 10-item Neck Disability Index (NDI) were assessed preoperatively and during follow-up on a regular basis after surgery and after one year at least. Assessment of radiographic fusion, subsidence, and lordosis measurement of Global cervical lordosis (GCL); fusion site lordosis (FSL); the anterior interbody space height (ant. DSH); the posterior interbody space height (post. DSH); the distance of the cage to the posterior wall of the vertebral body (CD) were done retrospectively. Mean clinical and radiographic follow-up was 20.0 ± 4.39 months.

Results

VAS-neck (p = 0.001) and VAS-arm (p < 0.001) improved from preoperatively to postoperatively. The NDI improved at the final follow-up (p < 0.001). Neither significant subsidence of the cages nor significant loss of lordotic correction were seen. All patients showed a radiographic union of the surgically addressed segments at the last follow up.

Conclusions

Application of a stand-alone expandable cage in the cervical spine after one or two-level ACCF without additional posterior fixation or anterior plating is a safe procedure that results in fusion. Neither significant subsidence of the cages nor significant loss of lordotic correction were seen.

Trial registration

Retrospectively registered. According to the Decision of the ethics committee, Jena on 25th of July 2018, that this study doesn’t need any registration. https://www.laek-thueringen.de/aerzte/ethikkommission/registrierung/.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04883-5.

Occurrence, Risk Factors, and Time Trends for Late Reoperations due to Degenerative Cervical Spine Disease: A Finnish National Register Study of 19 377 Patients Operated on Between 1999 and 2015

BACKGROUND

Surgery for degenerative cervical spine disease has escalated since the 1990s. Fusion has become the mainstay of surgery despite concerns regarding adjacent segment degeneration. The patient-specific trends in reoperations have not been studied previously.

OBJECTIVE

To analyze the occurrence, risk factors, and trends in reoperations in a long-term follow-up of all the patients operated for degenerative cervical spine disease in Finland between 1999 and 2015.

METHODS

The patients were retrospectively identified from the Hospital Discharge Registry. Reoperations were traced individually; only reoperations occurring >365 d after the primary operation were included. Time trends in reoperations and the risk factors were analyzed by regression analysis.

RESULTS

Of the 19 377 identified patients, 9.2% underwent a late reoperation at a median of 3.6 yr after the primary operation. The annual risk of reoperation was 2.4% at 2 yr, 6.6% at 5 yr, 11.1% at 10 yr, and 14.2% at 15 yr. Seventy-five percent of the late reoperations occurred within 6.5 yr of the primary operation. Foraminal stenosis, the anterior cervical decompression and fusion (ACDF) technique, male gender, weak opiate use, and young age were the most important risk factors for reoperation. There was no increase in the risk of reoperations over the follow-up period.

CONCLUSION

The risk of reoperation was stable between 1999 and 2015. The reoperation risk was highest during the first 6 postoperative years and then declined. Patients with foraminal stenosis had the highest risk of reoperation, especially when ACDF was performed.

0.5- to 1-Fold Intervertebral Distraction Is a Protective Factor for Adjacent Segment Degeneration in Single-level Anterior Cervical Discectomy and Fusion

STUDY DESIGN

Retrospective analysis.

OBJECTIVE

This study aimed to compare the clinical and radiological outcomes of different degrees of distraction in anterior cervical discectomy and fusion (ACDF) and evaluate the risk factors for adjacent segment degeneration (ASD).

SUMMARY OF BACKGROUND DATA

ASD is a common complication following ACDF. Inadequate distraction of the intervertebral space during surgery is associated with ASD; however, there is still an ongoing debate regarding what degree of distraction is appropriate.

METHODS

This retrospective study enrolled 130 patients who underwent single-level ACDF for cervical degenerative disc disease and were followed up at least 2 years. The patients were divided into the following three groups according to the degree of distraction (≤0.5, 0.5-1, ≥1): insufficient distraction group (ID group), appropriate distraction group (AD group), and excessive distraction group (ED group). The clinical outcomes and radiological parameters were evaluated before and after operation and at the last follow-up. Risk factors for ASD were identified through logistic regression analysis.

RESULTS

A significant difference was found in the Visual Analog Scale values between the AD group and ED group at the final follow-up. Moreover, the highest upper segmental disc height (DH), highest lower segmental DH, and lowest incidence of ASD were found in the AD group among the three groups at last follow up. Logistic regression analysis revealed that segmental kyphosis (odds ratio = 2.821, P = 0.020) was a risk factor for the occurrence of ASD and 0.5- to 1-fold distraction (odds ratio = 0.350, P = 0.025) was a protective factor.

CONCLUSION

Good clinical and radiological outcomes were achieved in ACDF with 0.5- to 1-fold distraction. Segmental kyphosis is a risk factor for ASD in ACDF, whereas 0.5- to 1-fold distraction is a protective factor of ASD.

LEVEL OF EVIDENCE

4.

Radiographic measurements of cervical alignment, fusion and subsidence after ACDF surgery and their impact on clinical outcome

BACKGROUND

Some recent studies indicate correlations between cervical alignment and clinical outcome after anterior cervical discectomy and fusion (ACDF) surgery. However, there still are no established criteria for the interpretation of alignment, fusion and subsidence in relation to clinical outcome.

METHODS

A retrospective analysis of 208 radiographs of patients following ACDF with stand-alone PEEK cage implantation was performed. The measurements were obtained on plain radiographs in lateral and anteroposterior projections as well as flexion/extension radiographs. Cervical alignment was measured using the Gore, Laing and Cobb methods; fusion was evaluated by an assortment of radiographic hallmarks: the presence of bridging bone, the Cobb angle and the distances between the tips and bases of the spinous processes of the operated segments, respectively. For assessment of subsidence, we used the Mochida method in addition to ventral and dorsal segmental height reduction. Correlation analysis between the different radiological characteristics and clinical outcome at a minimum follow-up of 12 months was conducted.

RESULTS

Two hundred and eight patients were evaluated for alignment, fusion and subsidence. Cervical alignment using the Gore and Cobb methods correlated among each other, but failed to exhibit significant correlation with clinical outcome. Interpretation of fusion rates varied greatly (43.9 to 89.4%) depending on the criteria used. Pearson coefficients between radiographic presence of pseudarthrosis and the measurements of the spinous process distances (0.595; p < 0.001), the Cobb angles (0.187; p = 0.007) and the presence of bridging bone (0.224; p < 0.001) each exhibited statistical significance. None of the methods employed significantly correlated with clinical outcome. Regarding subsidence, we found rates of 62%, 48% and 27% using the Mochida, ventral and dorsal segmental height reduction assessment methods, respectively. Pearson correlations between pairs of Mochida/ventral (r = 0.39; p = 0.66) and Mochida/dorsal (r = 0.007; p = 0.921) height reduction assessment methods were weak and no significant correlation between subsidence rates and clinical outcome was shown.

CONCLUSION

All measured parameters varied depending in the measurement method used. This was most pronounced for fusion. There was a moderate positive correlation between neck pain and subsidence as measured by the Mochida method.

Cervical alignment after single-level anterior cervical corpectomy and fusion using autologous bone graft without spinal instrumentation for cervical pyogenic spondylitis

BACKGROUND

Subsidence in anterior cervical corpectomy and fusion (ACCF) for cervical degenerative disease (CDD) are constantly observed during the postoperative course. Although kyphotic change of cervical alignment occurred frequently in cervical pyogenic spondylitis (CPS) postoperatively, studies on the postoperative change in segmental angle for CPS are limited. This study aimed to analyze cervical alignment after single-level ACCF using autologous bone graft without spinal instrumentation for CPS compared with that for CDD.

METHODS

Six patients underwent single-level ACCF using autologous bone graft without spinal instrumentation for CPS. The control group included 18 age-matched patients who underwent single-level ACCF using autologous bone graft for CDD without spinal instrumentation for the same duration. Cervical and lateral plain radiographs and computed tomography scans were taken. The Frankel classification was used to assess the neurological status preoperatively, postoperatively, and at 2-year follow-up for CPS.

RESULTS

At 2-year follow-up, the average segmental angle at the fusion level was - 12.2° ± 6.9° for CPS and - 5.2° ± 7.6° for CDD (p = 0.04). Changes in segmental angle at the fusion level were - 7.2 ± 9.0° for CPS and - 1.1° ± 7.1° for CDD (p = 0.02). At 2-year follow-up, the average anterior segmental fusion height was 23.4 ± 1.7 mm for CPS and 29.1 ± 5.1 mm for CDD (p < 0.001). At 2-year follow-up, bone fusion in the CPS group was classified as grade 5 (complete fusion) in 4 patients (66.7%) and grade 4 (probable fusion) in 2 (33.3%). In the CDD group, it was grade 5 in 13 patients (72.2%) and grade 4 in 5 patients (27.8%). Overall, both groups achieved 100% bone fusion rate. The Frankel classification in all CPS cases improved or leveled off.

CONCLUSION

Progression of segmental kyphosis angle and subsidence of graft bone were observed postoperatively on all CPS cases. However, the neurological recovery and bone union were satisfactory.

Surgical Strategies to Prevent Adjacent Segment Disease in the Cervical Spine

The most popular approach to treating symptomatic cervical disk disease is anterior cervical discectomy and fusion. Although this procedure has significant long-term clinical success, it is associated with progressive adjacent segment degeneration with an annual incidence of ∼3%. Total disk arthroplasty was designed as an alternative to fusion that could preserve segmental motion at the operative level and potentially delay or prevent adjacent-level breakdown. The etiology of adjacent segment pathology (ASP) is multifactorial, and it is likely that most cases of ASP are unavoidable. When attempting to surgically prevent ASP, it is important to consider nonfusion alternatives, be judicious in one's level selection, and attempt to restore sagittal alignment. When ASP becomes a clinical problem, it is important to have an algorithm for how best to treat it.

Integral Fixation Titanium/Polyetheretherketone Cages for Cervical Arthrodesis: Evolution of Cage Design and Early Radiological Outcomes and Fusion Rates

Objective

To evaluate the initial outcomes of a composite cage with integral fixation using the Redmond titanium (Ti)/polyetheretherketone (PEEK) anterior cervical discectomy and fusion (ACDF) device.

Methods

Data from 50 consecutive patients were prospectively collected from a single senior surgeon cohort. All cages were between 5 and 8 mm in height, and were packed with supercritical CO₂ sterilized allograft. Patients were followed up for a minimum of 6 months, and implant complications were assessed.

Results

From the original cohort, three were unavailable for follow‐up. Forty‐seven patients with a total of 58 operative levels were observed for a mean of 7.9 months. A fusion rate of 96% was achieved. Good to excellent outcomes were seen in 92% of patients. There were no cases of implant Ti/PEEK delamination or implant failure, with excellent early fusion rates using supercritical CO₂ allograft.

Conclusions

The present study demonstrates the development of a composite ACDF cage design that is a safe and effective treatment option with the potential for early osseointegration and interbody fusion. Supercritical CO₂ sterilized allograft was an effective graft material supporting fusion.

Titanium/Polyetheretherketone Cages for Cervical Arthrodesis with Degenerative and Traumatic Pathologies: Early Clinical Outcomes and Fusion Rates

OBJECTIVE

Anterior cervical discectomy and fusion is the most commonly employed surgical technique for treating cervical spondylosis. Although autologous bone grafts are considered the gold standard in achieving fusion, associated short- and long-term morbidities have led to a search for alternative materials. These have included carbon-fiber, titanium alloy (Ti) and ceramic and polyetheretherketone (PEEK) based implants. Recent attempts to optimize cage implants through using composite designs have combined Ti and PEEK. However, there are few published reports on the clinical and radiological outcomes of commercially available composite cages. Our study aimed to provide and evaluate initial outcomes of a composite Ti/PEEK cage.

METHODS

In this prospective single senior surgeon cohort study, 31 consecutive patients underwent a modified Smith-Robinson technique under general anesthesia and relevant data were collected. The study patients were aged between 18 and 75 years and underwent surgery from November 2013 to May 2014. Indications for surgery included traumatic and degenerative cervical disease that was unsuitable for or unresponsive to conservative management. All cages were between 5 and 8 mm and packed with super critical fluid sterilized allograft and bone marrow aspirate before insertion. Patients were followed-up for a minimum of 12 months. Fusion was assessed using fine cut CT and anteroposterior and lateral radiographs. Clinical outcomes were measured using a Visual Analogue Scale, Neck Oswestry Disability Index and Patient's Satisfaction Index.

RESULTS

Six of the original cohort were unavailable for adequate follow-up. The remaining 25 patients (17 men, 8 women; 33 operative levels) were observed for a mean of 14.6 months (range, 12-16 months). All operation levels were between C4 and C7 . Single-level operations were performed in 19 patients and additional plating in 14 patients. A fusion rate of 96% was achieved. Patients in both plated and non-plated groups experienced statistically significant improvements; good to excellent outcomes being seen in 92% of patients. There was one complication, namely recurrent laryngeal nerve palsy, which had partially resolved at 6 months follow-up.

CONCLUSION

The present study shows that enhancement of PEEK cages with Ti endplates is a safe and effective treatment with the potential for early osseointegration and early radiological evidence of fusion.

Adjacent Segment Pathology after Anterior Cervical Fusion

Anterior cervical fusion has become a standard of care for numerous pathologic conditions of the cervical spine. However, subsequent development of clinically significant disc disease at levels adjacent to fused discs is a serious long-term complication of this procedure. As more patients live longer after surgery, it is foreseeable that adjacent segment pathology (ASP) will develop in increasing numbers of patients. Also, ASP has been studied more intensively with the recent popularity of motion preservation technologies like total disc arthroplasty. The true nature and scope of ASP remains poorly understood. The etiology of ASP is most likely multifactorial. Various factors including altered biomechanical stresses, surgical disruption of soft tissue and the natural history of cervical disc disease contribute to the development of ASP. General factors associated with disc degeneration including gender, age, smoking and sports may play a role in the development of ASP. Postoperative sagittal alignment and type of surgery are also considered potential causes of ASP. Therefore, a spine surgeon must be particularly careful to avoid unnecessary disruption of the musculoligamentous structures, reduced risk of direct injury to the disc during dissection and maintain a safe margin between the plate edge and adjacent vertebrae during anterior cervical fusion.

Radiologic Findings and Risk Factors of Adjacent Segment Degeneration after Anterior Cervical Discectomy and Fusion : A Retrospective Matched Cohort Study with 3-Year Follow-Up Using MRI

Objective

The purpose of this study was to figure out the radiologic findings and risk factors related to adjacent segment degeneration (ASD) after anterior cervical discectomy and fusion (ACDF) using 3-year follow-up radiography, computed tomography (CT), and magnetic resonance image (MRI).

Methods

A retrospective matched comparative study was performed for 64 patients who underwent single-level ACDF with a cage and plate. Radiologic parameters, including upper segment range of motion (USROM), lower segment range of motion (LSROM), upper segment disc height (UDH), and lower segment disc height (LDH), clinical outcomes assessed with neck and arm visual analogue scale (VAS), and risk factors were analyzed.

Results

Patients were categorized into the ASD (32 patients) and non-ASD (32 patients) group. The decrease of UDH was significantly greater in the ASD group at each follow-up visit. At 36 months postoperatively, the difference for USROM value from the preoperative one significantly increased in the ASD group than non-ASD group. Preoperative other segment degeneration was significantly associated with the increased incidence of ASD at 36 months. However, pain intensity for the neck and arm was not significantly different between groups at any post-operative follow-up visit.

Conclusion

The main factor affecting ASD is preoperative other segment degeneration out of the adjacent segment. In addition, patients over the age of 50 are at higher risk of developing ASD. Although there was definite radiologic degeneration in the ASD group, no significant difference was observed between the ASD and non-ASD groups in terms of the incidence of symptomatic disease.

Cervical spine alignment in disc arthroplasty: should we change our perspective?

PURPOSE

The alignment at the cervical spine has been considered a determinant of degeneration at the adjacent disc, but this issue in cervical disc replacement surgery is poorly explored and discussed in this patient population. The aim of this systematic review is to compare anterior cervical fusion and total disc replacement (TDR) in terms of preservation of the overall cervical alignment and complications.

METHODS

A systematic review of the current literature was performed, together with the evaluation of the methodological quality of all the retrieved studies.

RESULTS

In most of the retrieved studies, a tendency towards a more postoperative kyphotic alignment in TDR was reported. The reported mean complication rate was of 12.5 % (0-66.2 %). Complications associated with cervical prosthesis included heterotopic ossification, device migration, mechanical instability, failure, implant removal, reoperations and revision.

CONCLUSIONS

Even though cervical disc arthroplasty leads to similar outcomes compared to arthrodesis in the middle term follow-up, no evidence of superiority of cervical TDR is available up to date. We understand that the overall cervical alignment after TDR tends towards the loss of lordosis, but only longer follow-up can determine its influence on the clinical results.

Evidence-based analysis of adjacent segment degeneration and disease after ACDF: a systematic review

BACKGROUND CONTEXT

Follow-up studies of patients undergoing anterior cervical discectomy and interbody fusion (ACDF) have demonstrated varying degrees of radiographic degeneration at adjacent levels, with most cases being asymptomatic (adjacent segment degeneration, ASDeg) and far fewer being symptomatic (adjacent segment disease, ASDz). Controversy remains as to whether these conditions are related to altered biomechanics or represent the natural history of cervical spondylosis at the adjacent segment.

PURPOSE

To provide an evidence-based analysis of the peer-reviewed literature on clinical studies of ASDeg and ASDz after ACDF.

STUDY DESIGN/SETTING

Systematic review of existing literature.

METHODS

The MEDLINE database was queried for clinical studies reporting ASDeg and/or ASDz after ACDF. Articles written in the English language with a minimum follow-up of 2 years were independently reviewed and analyzed by two authors, and the level of evidence was assigned. Data were pooled to generate summary outcomes and organized by number of levels, technique, and graft/implants.

RESULTS

Of the 238 articles returned from the MEDLINE database query, 14 met inclusion criteria. An average of 168 patients was enrolled per study with an average follow-up of 106.5 months. Graft materials, cage design, plate fixation system, and length of fusion varied widely. Additionally, no clear standard was seen for radiographic assessment modalities (eg, plain lateral radiograph, flexion-extension radiographs, computed tomography, or magnetic resonance imaging). Validated clinical outcome measures were used in 43% (6/14) of the studies. The average incidence of ASDeg was 47.33% (459.14/970) with a range from 16% to 96%. The frequency-weighted average for ASDz was 11.99% (263.70/2,199) with a range from 1.80% to 36.00%. Follow-up ranged from 24 to 296 months with no reliable commonalities, which prohibited a meta-analysis.

CONCLUSIONS

This review highlights the heterogeneous methodology of the peer-reviewed literature on ASDeg and ASDz after ACDF and the paucity of high-level clinical data published on these conditions. Despite the low level of evidence to define the incidence of ASDeg and ASDz, it is clear that radiographic ASDeg is more common than symptomatic ASDz, indicating that adjacent segment pathology remains subclinical in a large subset of patients. This analysis underscores the need for standardized radiographic measures in the assessment of ASDeg and validated clinical outcome measures for ASDz after ACDF. Consistent methodology and multi-surgeon collaboration may improve the quality of clinical data on ASDeg and ASDz and elucidate the true etiology and incidence of these conditions.

Prevalence of adjacent segment degeneration after spine surgery: a systematic review and meta-analysis

STUDY DESIGN

Systematic review of published prevalence of adjacent segment degeneration (ASD) after spine surgery.

OBJECTIVE

To evaluate the prevalence of ASD in patients after cervical and lumbar spine surgery.

SUMMARY OF BACKGROUND DATA

ASD is a common complication after spine surgery in long-term follow-up. A large body of literature has been reported on the topic, but no meta-analysis of the epidemiological data on ASD has been published

METHODS

We searched the MEDLINE until March 2012 published in English language that reported the prevalence of ASD after spine surgery. We determined the ASD rates by calculating proportions and 95% confidence interval (CI) for each study and then pooled the data to derive a pooled proportion and 95% CI.

RESULTS

A total of 94 studies with 34,716 patients from 19 countries were included. The occurrence of radiograph ASD ranged from 4.8% to 92.2%, and the pooled prevalence was 29.3% (95% CI, 22.7%-35.8%) by the random-effects model. The occurrence of symptoms ASD ranged from 0.0% to 30.3%, and the pooled prevalence was 7.4% (95% CI, 6.4%-8.5%). In cervical position, the occurrence of radiograph ASD and symptoms ASD was 32.8% (95% CI, 17.8%-47.9%) and 6.3% (95% CI, 4.8%-7.8%); in lumbar position, the occurrence of radiograph ASD and symptoms ASD was 26.6% (95% CI, 21.3%-31.9%) and 8.5% (95% CI, 6.4%-10.7%). In the 0.5- to 2- or less, more than 2- to 5- or less, and more than 5- to 20- or less year diagnosis time, the radiograph ASD prevalence was 21.8% (16.0%-27.6%), 33.6% (21.8%-45.4%), and 37.4% (10.7%-64.1%), respectively; and the symptoms ASD prevalence was 6.5% (4.8%-8.1%), 12.1% (8.2%-16.0%), and 3.2% (2.5%-4.0%), respectively.

CONCLUSION

Spine surgery is associated with significant risk of ASD. These figures may be useful in the estimation of the burden of the ASD after spine surgery.

Long-term follow-up results of the Cloward procedure for cervical spondylotic myelopathy

PURPOSE

To assess the long-term results of anterior cervical discectomy and fusion using the Cloward procedure for the treatment of cervical spondylotic myelopathy, and to identify possible clinical outcome predictors.

METHODS

A total of 14 cases with a 10-year postoperative follow-up were available (82.4 % of the surviving patients). Patients underwent preoperative and postoperative neurological examination. The symptom severity was graded according to the Nurick scale. MRI measurements were obtained preoperatively. Cervical spine radiographs were obtained preoperatively and at the time of follow-up.

RESULTS

The mean improvement of the clinical status of patients on the Nurick scale was 1.43 ± 0.51 (range 1-2) with respect to the baseline values (p < 0.001), with a 62.5 % recovery rate. A positive association between the improvement of the Nurick scale and the length of follow-up was detected with an age-adjusted univariate analysis (p = 0.042). The Nurick grade improvement was also directly related to preoperative lower limb hyperreflexia (p = 0.039), spasticity (p = 0.017), and bladder dysfunction (p = 0.048). At the time of follow-up, an adjacent discopathy was noted above and below the operated level(s) in eight and six patients, respectively.

CONCLUSIONS

The Cloward technique is a safe and effective procedure for the treatment of cervical spondylotic myelopathy. The patients' preoperative neurological status and the length of follow-up affect the grade of postoperative ambulatory improvement.