Surgical approach to cervical spondylotic myelopathy on the basis of radiological patterns of compression: prospective analysis of 129 cases

Prospective Investigation of the Posterior Longitudinal Ligament and Disc Complex after Posterior Stabilization and Decompression Surgery in Patients With Non-OPLL (Ossification of the Posterior Longitudinal Ligament) Cervical Spondylotic Myelopathy

BACKGROUND

Cervical spondylotic myelopathy (CSM) is a prevalent cause of spinal cord dysfunction in adults, primarily from degenerative changes. The efficacy of treatment strategies, especially surgical approaches, remains debated.

OBJECTIVE

This study aimed to assess the long-term impact of posterior fusion laminectomy on the posterior longitudinal ligament (PLL) thickness, disc complex, and myelomalacia signal changes in CSM patients.

METHODS

A single-centre, prospective study from January 2020 to December 2021 included CSM patients without ossified posterior longitudinal ligament (OPLL). Magnetic resonance imaging (MRI) data from baseline, 6, and 12 months postoperatively were collected. Measurements on the MRI were performed using the Osirix MD software, focusing on the PLL width, myelopathic foci dimensions, and canal diameter.

RESULTS

Out of the 82 initially enrolled patients, 64 were considered for analysis. Postoperatively, a significant reduction in PLL width and myelopathic foci dimensions was observed, alongside a considerable increase in the canal diameter. Clinical outcomes based on the Modified Japanese Orthopaedic Association (mJOA) scale also showcased marked improvements post-surgery.

CONCLUSIONS

Posterior fusion laminectomy effectively reduces anterior pressure in CSM patients. This treatment may represent an optimal surgical approach for selected CSM cases. Furthermore, more extensive studies with extended follow-up are advocated.

Clinical and radiographic characteristics of increased signal intensity of the spinal cord at the vertebral body level in patients with cervical myelopathy

BACKGROUND

Increased signal intensity (ISI) is usually recognized at the disc level of the responsible lesion in the patients with cervical myelopathy. However, it is occasionally seen at the vertebral body level, below the level of compression. We aimed to investigate the clinical significance and the radiographic characteristics of ISI at the vertebral body level.

METHODS

This retrospective study included 135 patients with cervical spondylotic myelopathy who underwent surgery and with local ISI. We measured the local and C2-7 angle at flexion, neutral, and extension. We also evaluated the local range of motion (ROM) and C2-7 ROM. The patients were classified into group D (ISI at disc level) and group B (ISI at vertebral body level).

RESULTS

The prevalence was 80.7% (109/135) and 19.3% (26/135) for groups D and B, respectively. Local angle at flexion and neutral were more kyphotic in group B than in group D. The local ROM was larger in group B than in group D. Moreover, C2-7 angle at flexion, neutral and extension were more kyphotic in group B than in group D. Two years later, local angle at flexion, neutral, and extension were also kyphotic in group B than group D; however, local and C2-7 ROM was not significantly different between the two groups. There was no significant difference of clinical outcomes 2 years postoperatively between both groups.

CONCLUSIONS

Group B was associated with the kyphotic alignment and local greater ROM, compared to group D. As the spinal cord is withdrawn in flexion, the ISI lesion at vertebral body might be displaced towards the disc level, which impacted by the anterior components of the vertebrae. ISI at the vertebral body level might be related to cord compression or stretching at flexion position. This should be different from the conventionally held pincer-mechanism concept.

Anterior cervical corpectomy for the treatment of spondylotic myelopathy: results of a prospective double-armed study with a three-year follow-up

BACKGROUND

Since the first description in the 1950s, cervical spondylotic myelopathy (CSM) has posed many challenges to neurosurgeons and spine surgeons. Direct comparison among different operative approaches has failed to produce valuable results due to either an insufficient number of enrolled patients or a lack of standardization of baseline conditions. This prospective double-armed non-randomized study with a 3-year follow-up involved 80 patients with degenerative cervical myelopathy surgically and conservatively treated. The primary aim was to determine the efficacy of corpectomy in mild-moderate and severe CSM and to compare the outcomes of conservative and surgical treatment.

METHODS

Eighty patients were stratified into two arms, on the basis of the mJOA score: mild-moderate (mJOA ≥12) and severe myelopathy (mJOA score <12). Each arm was subdivided into two treatment groups (operative or conservative): A1, mild-moderate myelopathy treated with corpectomy; A2, mild-moderate myelopathy treated conservatively; B1, severe myelopathy treated with corpectomy; B2, severe cervical myelopathy treated conservatively. The clinical outcome was evaluated with the modified JOA score, timed 10-meter walk, Mehalic grade, motor evoked potentials, the SF-12, and further assessed by external observers blinded to the type of treatment.

RESULTS

No significant differences in the recovery rates were found between the A1 and A2 groups at 6 months, although better results were recorded in the surgical groups (A1 and B1) at 12 months and at the final follow-up, as suggested by the significantly higher recovery rates. Multivariate analysis showed an inverse correlation between the duration of symptoms and the recovery rate (P<0.0001). Moreover, the preoperative timed 10-meter walk (P<0.004), the preoperative hypointensity on T1-weighted MR images (P<0.001), a higher Mehalic grade (P<0.02), the pre-treatment MEP (P<0.002), and the preoperative spinal canal diameter (P<0.004) significantly influenced the recovery rate.

CONCLUSIONS

This prospective double-armed non-randomized study demonstrates that corpectomy is an effective and safe treatment, especially for severe forms of myelopathy. In mild-moderate conditions, a discrepancy between neurological improvement and expressed level of satisfaction was found. The present results also show that a multiparametric evaluation is crucial for proper patient selection for corpectomy.

The role of intraoperative extensor digitorum brevis muscle MEPs in spinal surgery

PURPOSE

Intraoperative muscle motor evoked potentials (m-MEPs) are widely used in spinal surgery with the aim of identifying a damage to spinal cord at a reversible stage. Generally, lower limb m-MEPs are recorded from abductor hallucis [AH] and the tibialis anterior [TA]. The purpose of this work is to study an unselected population by recording the m-MEPs from TA, AH and extensor digitorum brevis (EDB), with the aim of identifying the most adjustable and stable muscles responses intraoperatively.

METHODS

Transcranially electrically induced m-MEPs were intraoperative recorded in a total of 107 surgical procedures. m-MEPs were recorded by a needle electrode placed in the muscle from TA, AH and EDB muscles in the lower extremities.

RESULTS

Overall monitorability (i.e., at least 1 Lower Limb m-MEP recordable) was 100/107 (93.5%). In the remaining 100 surgeries in 3 cases, the only muscle that could be recorded at baseline was one AH, and in other 2 the EDB. Persistence (i.e., the recordability of m-MEP from baseline to the end of surgery) was 88.7% for TA, 89.8% for AH and 93.8% for EDB.

CONCLUSION

In our series, EDB m-MEPs have demonstrated a recordability superior to TA and a stability similar to AH. The explanations may be different and range from changes in the excitability of the cortical motor neuron to the different sensitivity to ischemia of the spinal motor neuron. EDB can be used alternatively or can be added to TA and AH as a target muscle of the lower limb in spinal surgery.

Residual anterior cord compression after laminoplasty for cervical spondylotic myelopathy: evaluation of risk factors according to the most severely stenotic vertebral segment

OBJECTIVE

Residual anterior spinal cord compression (RASCC) after cervical laminoplasty, which has been confirmed on postoperative MRI, is reportedly associated with poor clinical outcomes. To date, only a few studies have described the risk factors associated with RASCC. The aim of this study was to identify the factors that can predict the occurrence of RASCC after laminoplasty for cervical spondylotic myelopathy (CSM), focusing on the location of the most stenotic segment.

METHODS

In this retrospective, single-center study, 120 patients who underwent C3-7 laminoplasty for multilevel CSM were included. Different techniques were used for C3 decompression, i.e., partial (dome-laminotomy) or complete (laminoplasty/laminectomy) decompression. RASCC was diagnosed using MRI conducted 3 weeks postoperatively. The patients were divided into two groups according to the segment with the most severe stenosis (Seg-MSS; C3-4 vs C4-7). Demographics, radiological data, and C3 decompression technique were compared between the two groups. Furthermore, intergroup comparisons were performed based on Seg-MSS. A logistic regression model was constructed to identify the factors predicting RASCC after patient stratification according to Seg-MSS.

RESULTS

Forty patients (33.3%) had RASCC. The patients with Seg-MSS at C3-4 (51.3%) had a significantly higher incidence of RASCC (p = 0.003) than those with Seg-MSS at C4-7 (24.7%). Logistic regression analysis showed that in patients with Seg-MSS at C3-4, C3 partial decompression demonstrated a greater association with RASCC as opposed to complete decompression. Conversely, in patients with Seg-MSS at C4-7, kyphotic segmental lordotic angle was associated with an increased risk of RASCC.

CONCLUSIONS

The risk factors for RASCC differed depending on the location of the most stenotic segment (C3-4 vs C4-7). If there is segmental kyphosis at the most stenotic segment at C4-7, anterior decompression and fusion should be considered. If C3-4 is the most stenotic segment, anterior surgery is also recommended, but alternatively, one can choose laminoplasty with complete C3 laminectomy and resection of the C2-3 ligamentum flavum.

The Impact of Obstructive Sleep Apnea on Clinical, Perioperative, and Cost Outcomes in Patients Who Underwent Posterior Cervical Decompression and Fusion: A Single-Center Retrospective Analysis From 2008 to 2016

BACKGROUND

Obstructive sleep apnea (OSA) is a pervasive problem that can result in diminished neurocognitive performance, increased risk of all-cause mortality, and significant cardiovascular disease. While previous studies have examined risk factors that influence outcomes following cervical fusion procedures, to our knowledge, no study has examined the cost or outcome profiles for posterior cervical decompression and fusion (PCDF) procedures in patients with OSA.

METHODS

All cases at a single institution between 2008 and 2016 involving a PCDF were included. The primary outcome was prolonged extubation, defined as an extubation that took place outside of the operating room. Secondary outcomes included admission to the intensive care unit (ICU), complications, extended hospitalization, nonhome discharge, readmission within 30 and 90 days, emergency room visit within 30 and 90 days, and higher total costs.

RESULTS

We reviewed 1191 PCDF cases, of which 93 patients (7.81%) had a history of OSA. At the univariate level, patients with OSA had higher rates of ICU admissions (33.3% vs 16.8%, P < 0.0001), total complications (29.0% vs 19.0%, P = 0.0202), and respiratory complications (12.9% vs 6.6%, P = 0.0217). Multivariate regression analyses revealed no difference in the odds of a prolonged extubation (P = 0.4773) and showed that history of OSA was not predictive of higher costs. However, a significant difference was observed in the odds of having an ICU admission (P = 0.0046).

CONCLUSION

While patients with sleep apnea may be more likely to be admitted to the ICU postoperatively, OSA status a lone is not a risk factor for poor primary and secondary clinical outcomes following posterior cervical fusion procedures.

CLINICAL RELEVANCE

Various deformities of the cervical spine can exert extraluminal forces that partially collapse or obstruct the airway, thereby predisposing patients to OSA; however, no study has examined the cost or outcome profiles for PCDF procedures in patients with OSA. Therefore, this investigation highlights the ways in which OSA influences the risks, outcomes, and costs following PCDF using medical data from an institutional registry.

LEVEL OF EVIDENCE: 3

Comparison of Two Anterior Reconstructive Techniques in the Treatment of 3-Level and 4 Level Cervical Spondylotic Myelopathy: A Meta-analysis of Last Decade

Study Design

A meta-analysis.

Objective

Anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) are widely used in the treatment of cervical spondylotic myelopathy (CSM). However, the clinical outcomes and complications between ACDF and ACCF treating multi-level CSM remain poorly understood. Thus, we performed a meta-analysis to compare the clinical outcomes and complications of the two procedures in the treatment of 3-level and 4-level CSM.

Methods

An extensive search of the literature was performed in the English databases of PubMed, Embase, and Cochrane Library and the Chinese databases of CNKI and WANFANG. We collected factors, including demographic data, surgical factors, and complications. Data analysis was conducted with RevMan 5.3 and STATA 12.0.

Results

Finally, 14 articles (5429 patients) were included in our study. No significant difference was found in preoperative and 3-month follow-up Japanese Orthopedic Association (JOA) scores, neck disability index, preoperative C2-C7, segmental angle, operation time, as well as the number of dysphagia, hoarseness, cerebral fluid leakage, infection, epidural hematoma, axial pain, hardware breakage, and pseudarthrosis between ACDF and ACCF. However, our findings showed that blood loss (P < 0.00001), the number of total complications (P < 0 .00001), C5 palsy (P = 0.0004), graft dislodgement (P = 0.02), graft subsidence (P = 0.0003), and revision surgery (P = 0.0008) in ACDF were significantly less than in ACCF. Additionally, postoperative and change of C2-C7 (P < 0.00001), segment angle (P < 0.00001), and fusion rate (P = 0.001) in ACDF were significantly higher than in ACCF. Post-operative JOA in ACDF was significantly higher than in ACCF (P = 0.02).

Conclusions

Although the clinical efficacy of both surgeries was similar, ACDF was superior to ACCF in the reconstruction of cervical lordosis and the number of complications in the treatment of 3-level and 4-level CSM.

A Systematic Review of Definitions for Dysphagia and Dysphonia in Patients Treated Surgically for Degenerative Cervical Myelopathy

STUDY DESIGN

Systematic review. Surgical decompression for degenerative cervical myelopathy (DCM) is associated with perioperative complications, including difficulty or discomfort with swallowing (dysphagia) as well as changes in sound production (dysphonia). This systematic review aims to (1) outline how dysphagia and dysphonia are defined in the literature and (2) assess the quality of definitions using a novel 4-point rating system.

METHODS

An electronic database search was conducted for studies that reported on dysphagia, dysphonia or other related complications of DCM surgery. Data extracted included study design, surgical details, as well as definitions and rates of surgical complications. A 4-point rating scale was developed to assess the quality of definitions for each complication.

RESULTS

Our search yielded 2,673 unique citations, 11 of which met eligibility criteria and were summarized in this review. Defined complications included odynophagia (n = 1), dysphagia (n = 11), dysphonia (n = 2), perioperative swelling complications (n = 2), and soft tissue swelling (n = 3). Rates of dysphagia varied substantially (0.0%-50.0%) depending on whether this complication was patient-reported (4.4%); patient-reported using a modified Swallowing Quality of Life questionnaire (43.1%) or the Bazaz criteria (8.8%-50.0%); or diagnosed using an extensive protocol consisting of clinical assessment, a bedside swallowing test, evaluation by a speech and language pathologist and a modified barium swallowing test/fiberoptic endoscopy (42.9%). The reported incidences of dysphonia also ranged significantly from 0.6% to 38.0%.

CONCLUSION

There is substantial variability in reported rates of dysphagia and dysphonia due to differences in data collection methods, diagnostic strategies, and definitions. Consolidation of nomenclature will improve evaluation of the overall safety of surgery.

K-line (-) in the neck-flexed position negatively affects surgical outcome of expansive open-door laminoplasty for cervical spondylotic myelopathy

BACKGROUND

The K-line in the neck-flexed position (FK-line) on radiography reflects dynamic factors and cervical alignment. Although the FK-line has been reported to affect the neurological recovery after muscle-preserving selective laminectomy for cervical spondylotic myelopathy (CSM), its influence on surgical outcomes after expansive open-door laminoplasty (ELAP) has not been investigated.

METHODS

We reviewed the surgical outcomes in 81 patients with multilevel CSM who underwent C4-C6 ELAP combined with C3 and C7 partial laminectomy using a laminoplasty plate and were followed up for at least 2 years. We defined the K-line (-) as some portion of a bony spur or the vertebral body crossing the FK-line, whereas the FK-line (+) was defined as that never crossing the FK-line. Patients were divided into the FK-line (+) (n = 61) and FK-line (-) groups (n = 20), and the surgical outcomes were compared between the groups. A multivariate analysis was performed to identify the factors that influenced the neurological outcomes.

RESULTS

The FK-line (-) group had a smaller C2-C7 angle, smaller C7 slope, greater postoperative increase in the C2-C7 sagittal vertical axis, greater kyphosis in cervical flexion and less lordosis in cervical extension, and higher incidence of postoperative residual spinal cord compression. The preoperative-to-postoperative changes in the Japanese Orthopedic Association (JOA) score and JOA score recovery rate (RR) were lower in the FK-line (-) group. The multiple linear regression analysis revealed that the K-line (-) (β = -0.327, P = 0.011) and high signal intensity (SI) changes on T2-weighted imaging (WI) combined with the low SI changes on T1-WI in the spinal cord (β = -0.320, P = 0.013) negatively affected the JOA score RR.

CONCLUSIONS

The FK-line can be used for patients with CSM as a simple indicator of neurological outcomes after ELAP.

CERVICAL SPONDYLOTIC MYELOPATHY: IS A COMBINED APPROACH NECESSARY?

ABSTRACT Objective: Cervical spondylotic myelopathy (CSM) is the main cause of spinal dysfunction in adults. The type of surgical approach to treatment is not well defined in the literature. The objective is to report the results obtained through isolated posterior decompression in patients with a previous indication of the combined approach for the treatment of cervical spondylotic myelopathy. Methods: This is a therapeutic study with level of evidence II, according to the Oxford classification table. Ten patients who underwent isolated posterior approach surgery for the treatment of cervical spondylotic myelopathy were evaluated through imaging and questionnaires (visual analog scale, mJOA-Br scale – Brazilian Portuguese version of the Modified Japanese Orthopedic Association Scale, and Neck Disability Index (NDI)), comparing pre- and postoperative results. Results: Late evaluation of the 10 patients was performed in the period ranging from 24 to 36 months (mean of 30.3 months ± 7.25) following surgery. The comparison of the clinical and radiological parameters in all patients showed a statistical difference in relation to the preoperative scales applied and to the degree of cervical lordosis (p <0.05), evidencing improvement after decompression and posterior fixation of the cervical spine. Conclusions: The isolated posterior approach (decompression, fixation and arthrodesis) allowed the clinical and radiological improvement of patients with cervical spondylotic myelopathy and who had an indication of the complementary anterior approach. Level of evidence II; Retrospective study.

Surgical Outcomes Following Laminectomy With Fusion Versus Laminectomy Alone in Patients With Degenerative Cervical Myelopathy

STUDY DESIGN

.: Post-hoc analysis of a prospective observational cohort study.

OBJECTIVE

.: To compare clinical outcomes following laminectomy and fusion versus laminectomy alone in an international series of individuals suffering from degenerative cervical myelopathy (DCM).

SUMMARY OF BACKGROUND DATA

.: Significant controversy exists regarding the role of instrumented fusion in the context of posterior surgical decompression for DCM. A previous study comparing laminectomy and fusion with laminoplasty showed no differences in outcomes between groups after adjusting for preoperative characteristics.

METHODS

.: Based on the operation they received, 208 of the 757 patients prospectively enrolled in the AO Spine North America or International studies at 26 global sites were included in the present study. Twenty-two patients were treated with laminectomy alone and 186 received a laminectomy with fusion. Patients were evaluated using the modified Japanese Orthopedic Association scale (mJOA), Nurick score, Neck Disability Index, and SF36 quality of life measure. Baseline and surgical characteristics were compared using a t test for continuous variables and a chi-square test for categorical variables. A mixed model analytic approach was used to evaluate differences in outcomes at 24 months between patients undergoing laminectomy and fusion versus laminectomy alone.

RESULTS

.: Surgical cohorts were comparable in terms of preoperative patient characteristics. Patients undergoing laminectomy with instrumented fusion had a significantly longer operative duration (P < 0.0001, 231.44 vs. 107.10 min) but a comparable length of hospital stay. In terms of outcomes, patients treated with laminectomy with fusion exhibited clinically meaningful improvements (in functional impairmentΔmJOA = 2.48, ΔNurick = 1.19), whereas those who underwent a laminectomy without fusion did not (ΔmJOA = 0.78; ΔNurick = 0.29). There were significant differences between surgical cohorts in the change in mJOA and Nurick scores from preoperative to 24-months postoperative (mJOA: -1.70, P = 0.0266; Nurick: -0.90, P = 0.0241). The rate of perioperative complications was comparable (P = 0.879).

CONCLUSION

.: Our findings suggest that cervical laminectomy with instrumented fusion is more effective than laminectomy alone at improving functional impairment in patients with DCM. These results warrant confirmation in larger prospective comparative studies.

LEVEL OF EVIDENCE

2.

Does Obesity Affect Outcomes of Multilevel ACDF as a Treatment for Multilevel Cervical Spondylosis?: A Retrospective Study

STUDY DESIGN

This was a retrospective study of the clinical and radiologic outcomes of multilevel anterior cervical discectomy and fusion (ACDF) surgery for multilevel cervical spondylosis patients.

OBJECTIVE

In this retrospective study, we intended to determine the relationship of neck circumference, neck length, and body mass index (BMI) with the outcomes of multilevel ACDF surgeries for patients with multilevel cervical spondylosis.

SUMMARY OF BACKGROUND DATA

Obesity has become a worldwide epidemic problem since the beginning of the 21st century. However, no study has focused on how local or whole-body obesity indexes (neck circumference, length of neck, and BMI) are related to the outcome of anterior cervical surgery.

METHODS

A total of 156 consecutive patients with multilevel cervical spondylosis who underwent anterior cervical surgery in our department from 2010 to 2016 were enrolled in our study. Preoperative parameters of patients such as the neck circumference, length of neck, height and weight were measured, and the BMI was also calculated. Neck circumference and length of neck in neutral position ratio was determined as an index for evaluated the neck situation. Preoperative and postoperative neurological functions were evaluated using the neck disability index (NDI) and Japan Orthopedic Association (JOA) scores. Postoperative complications during the follow-up period were also recorded. Correlations between the obesity indexes and the various factors were analyzed.

RESULTS

The mean follow-up duration was 3.9±1.4 years (2.0-7.3 y). Compared with the preoperative score, the NDI and JOA score had significantly improved. There were 46 patients (29.49%) developed complications after surgery. Patients in the obese group had the highest rate of complications. Neck circumference and length of neck in neutral position ratio, BMI, and number of operation levels were significant risk factors for the occurrence of dysphagia after multilevel ACDF.

CONCLUSIONS

Patients with a higher BMI, larger neck circumference, and shorter neck length may have a longer operation duration, more blood loss, and more postoperative complications. The authors recommended that the presence of obesity and neck circumference and length should be carefully considered in the perioperative risk assessment for a multilevel ACDF surgery.

Does K-line (-) in the Neck-flexed Position Predict Surgical Outcome of Cervical Spondylotic Myelopathy?: Results of a Multivariate Analysis After Muscle-preserving Selective Laminectomy

STUDY DESIGN

A retrospective single-center study.

OBJECTIVE

The aim of this study was to investigate the influence of the K-line in the neck-flexed position (flexion K-line) on the surgical outcome after muscle-preserving selective laminectomy (SL) for cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

Development of CSM is associated with dynamic factors and cervical alignment. The flexion K-line, which reflects both dynamic and alignment factors, provides an indicator of surgical outcome after posterior decompression surgery for patients with ossification of the posterior longitudinal ligament. However, the value of the flexion K-line for patients with CSM has not been evaluated.

METHODS

Our study group included 159 patients treated with SL for CSM. Patients were divided into a flexion K-line (+) group and a flexion K-line (-) group. The influence of the flexion K-line on radiological and surgical outcomes was analyzed, with multivariate analysis conducted to identify factors affecting the surgical outcome.

RESULTS

Patients in the flexion K-line (-) group were younger (P = 0.003), had a less lordotic cervical alignment (pre-and postoperatively, P < 0.001), a smaller C7 slope (pre-and postoperatively, P < 0.001), and a greater mismatch between the C7 slope and the C2-C7 angle (preoperatively, P = 0.047; postoperatively, P = 0.001). The postoperative increase in Japanese Orthopedic Association (JOA) score and the JOA score recovery rate (RR) were lower for the flexion K-line (-) than for the K-line (+) group (P < 0.001 and P < 0.001, respectively). On multivariate regression analysis, the flexion K-line (-) (β = -0.282, P < 0.001), high signal intensity (SI) changes on T2-weighted image (WI) combined with low SI changes on T1-WI in the spinal cord (β = -0.266, P < 0.001), and older age (β= -0.248, P = 0.001) were predictive of a lower JOA score RR.

CONCLUSION

The flexion K-line may be a useful predictor of surgical outcomes after SL in patients with CSM.

LEVEL OF EVIDENCE

4.

Cervical Spondylotic Myelopathy: When and Why the Cervical Corpectomy?

BACKGROUND

Cervical spondylotic myelopathy (CSM) is a degenerative disease that represents the most common spinal cord disorder in adults. The best treatment option has remained controversial. We performed a prospective study to evaluate the clinical, radiographic, and neurophysiologic outcomes for anterior cervical corpectomy in the treatment of CSM.

METHODS

From January 2011 to January 2017, 60 patients with CSM were prospectively enrolled in the present study. The patients were divided according to the modified Japanese Orthopaedic Association scale (mJOA) score into 2 groups: group A, patients with mild to moderate CSM (mJOA score ≥13); and group B, patients with severe myelopathy (mJOA score <13). Data were collected for each participating subject, including demographic information, symptoms, medical history, radiologic and neurophysiologic features, and functional impairment.

RESULTS

Of the 60 patients, 35 were men (58.3%) and 25 were women (41.7%). Their average age was 57.48 ± 10.60 years. The mean symptom duration was 25.33 ± 16.00 months; range, 3-57 months). Of the 60 patients, 22 had undergone single-level corpectomy and 36 multilevel corpectomy. A significant improvement in the motor evoked potentials was observed in both groups.

CONCLUSIONS

Single- and multilevel corpectomy are valid and safe options in the treatment of CSM. In the present prospective study, a statistically significant improvement in the mJOA score and neurophysiologic parameters was observed for both moderate and severe forms of CSM.

A National Snapshot Detailing the Impact of Parkinson's Disease on the Cost and Outcome Profiles of Fusion Procedures for Cervical Myelopathy

BACKGROUND

Studies suggest a higher prevalence of cervical deformities in Parkinson's Disease (PD) patients who predispose to cervical myelopathy (CM). Despite the profound effect of CM on function and quality of life, no study has assessed the influence of PD on costs and outcomes of fusion procedures for CM.

OBJECTIVE

To conduct the first national-level study that provides a snapshot of the current outcome and cost profiles for different fusion procedures for CM in PD and non-PD populations.

METHODS

Patients with or without PD who underwent cervical decompression and fusion anteriorly (ACDF), posteriorly (PCDF), or both (Frontback), for CM were identified from the 2013 to 2014 National Inpatient Sample using International Classification of Disease codes.

RESULTS

A total of 75 870 CM patients were identified, with 535 patients (0.71%) also having PD. Although no difference existed between in-hospital mortality rates, overall complication rates were higher in PD patients (38.32% vs 22.05%; P < .001). PD patients had higher odds of pulmonary (P = .002), circulatory (P = .020), and hematological complications (P = .035). Following ACDFs, PD patients had higher odds of complications (P = .035), extended hospitalization (P = .026), greater total charges (P = .003), and nonhome discharge (P = .006). Although PCDFs and Frontbacks produced higher overall complication rates for both populations than ACDFs, PD status did not affect complication odds for these procedures.

CONCLUSION

PD may increase risk for certain adverse outcomes depending on procedure type. This study provides data with implications in healthcare delivery, policy, and research regarding a patient population that will grow as our population ages and justifies further investigation in future prospective studies.

Clinical efficacy of laminectomy with instrumented fixation in treatment of adjacent segmental disease following ACCF surgery: a retrospective observational study of 48 patients

This study was designed to investigate the clinical efficacy of laminectomy with instrumented fixation in treatment of adjacent segmental diseases following anterior cervical corpectomy and fusion (ACCF) surgery. Between January 2008 and December 2015, 48 patients who underwent laminectomy with instrumented fixation to treat adjacent segmental diseases following ACCF surgery, were enrolled into this study. The patients were followed up at least 2 years. Pain assessment was determined by visual analogue scale (VAS) score and Neck Disability Index (NDI) score; neurological impairment was evaluated by Japanese Orthopaedic Association (JOA) score; and radiographic parameters were also compared. All comparisons were determined by paired t test with appropriate Bonferronni correction. VAS score preoperatively and at last follow-up was 5.28 ± 2.35 vs 1.90 ± 1.06 (P < 0.001). JOA score preoperatively and at last follow-up was 8.2 ± 3.6 vs 14.5 ± 1.1 (P < 0.001). NDI score preoperatively and at last follow-up was 30.5 ± 12.2 vs 10.6 ± 5.8 (P < 0.001). Moreover, the losses of cervical lordosis and C2-C7 range of motion after laminectomy were significant (both P < 0.005), but not sagittal vertical axis distance. Postoperative complications were few or mild. In conclusion, clinical effectiveness and safety can be guaranteed when the patients undergo laminectomy with instrumented fixation to treat adjacent segmental diseases following ACCF surgery.

Anterior cervical discectomy and fusion versus hybrid surgery in multilevel cervical spondylotic myelopathy: A meta-analysis

OBJECTIVE

A meta-analysis was performed to compare the radiographic and surgical outcomes between anterior cervical discectomy and fusion (ACDF) and hybrid surgery (HS, corpectomy combined with discectomy) in the treatment for multilevel cervical spondylotic myelopathy (mCSM).

SUMMARY OF BACKGROUND DATA

Both ACDF and HS are used to treat mCSM, however, which one is better treatment for mCSM remains considerable controversy.

METHODS

An extensive search of literature was searched in PubMed/Medline, Embase, the Cochrane library, CNKI, and WANFANG databases on ACDF versus HS treating mCSM from January 2011 to December 2017. The following variables were extracted: blood loss, operation time, fusion rate, Cobb angles of C2-C7, total complications, dysphagia, hoarseness, C5 palsy, infection, cerebral fluid leakage, epidural hematoma, and graft subsidence. Data analysis was conducted with RevMan 5.3 and STATA 12.0.

RESULTS

A total of 4 studies including 669 patients were included in our study. The pooled analysis showed that there were no significant difference in the operation time, fusion rate, Cobb angles of C2-C7, dysphagia, hoarseness, C5 palsy, infection, cerebral fluid leakage, epidural hematoma, and graft subsidence. However, there were significant difference between 2 groups in blood loss [P < .00001, SMD = -30.29 (-45.06, -15.52); heterogeneity: P = .38, I = 0%= and total complications [P = .04, OR = 0.66 95%CI (0.44, 0.98); heterogeneity: P = .37, I = 4%].

CONCLUSIONS

Based on our meta-analysis, except for blood loss and total complications, both ACDF and hybrid surgery are effective options for the treatment of multilevel cervical spondylotic myelopathy.

EPIDEMIOLOGICAL PANORAMA OF ORTHOPEDIC SPINE PATHOLOGY IN MEXICO

ABSTRACT Objective: To determine the epidemiology of orthopedic spine pathology in a national reference hospital in Mexico. Methods: Retrospective, observational and cross-sectional study, using the database and hospitalization census of the orthopedic spine service from January 2009 to December 2016. The data analysis was performed with SPSS version 22 measuring the central frequency and percentages. The demographic variables age and sex, and those related to the diagnosis, type of pathology, affected segment and degrees of affection were obtained. The sampling technique was non-probabilistic sampling by convenience of consecutive cases. Results: We analyzed 7,771 cases: 50.34% males, with a mean age of 53.51 years. The prevalence of the most frequent diseases in hospitalized patients was stenosis of the lumbar canal with 25.85% (1,834 patients), followed by lumbar disc herniation (23.12%), spondylolisthesis (22.63%), cervical spondylotic myelopathy (8.76%), lumbar pain and lumbosciatalgia (4.10%), cervical disc herniation (3.96%), primary infection (3.80%), loosening of material (3.16%), spinal tumors (2.53%) and cervical instability (2.04%). Conclusions: This is the largest series of cases of spinal pathology treated in a hospital in Latin America. The most frequent condition was the stenosis of the lumbar canal, the most affected segment was the lumbar, and the most affected age group was 51 to 60 years. The estimate is an increase in the incidence of spinal diseases, so it is necessary to identify the risk factors and the behavior of each disease for its prevention. Level of Evidence IV; Retrospective, observational and descriptive study.

Patterns of Neurological Recovery After Anterior Decompression With Fusion and Posterior Decompression With Laminoplasty for the Treatment of Multilevel Cervical Spondylotic Myelopathy

STUDY DESIGN

The pattern of neurological recovery in the overall modified Japanese Orthopedic Association scores, upper limb function score, and lower limb function score after surgical decompression for patients suffering from multilevel cervical spondylotic myelopathy (CSM) were analyzed in this independent retrospective study.

OBJECTIVE

The primary objective of this retrospective study was to compare the upper and lower limb function changes after anterior decompression with fusion versus posterior decompression with laminoplasty for patients suffering from multilevel CSM. An additional objective was to describe the neural recovery speed.

SUMMARY OF BACKGROUND DATA

Few comparative studies have been conducted to evaluate the outcome of anterior versus posterior surgery in multilevel CSM. However, these assessments tend to be of a more global perspective, looking at a composite score for upper limb, lower limb, and bladder function. No reports have separately analyzed the upper and lower limb function changes after anterior and posterior decompression for multilevel CSM.

MATERIALS AND METHODS

A total of 132 patients were classified into anterior and posterior decompression groups based on the different surgical approach they underwent. The pattern of neurological recovery in the overall modified Japanese Orthopedic Association scores, upper limb function score, and lower limb function score after surgical decompression were documented and analyzed.

RESULTS

There was no significant difference in the overall neurological recovery between anterior and posterior decompression groups. But in terms of the upper or lower limb function changes after operation, it appeared that the upper limbs recovered better with anterior decompression. The surgical approach did not significantly alter lower extremity recovery potential. In addition, most of the neurological recovery occurred in the first 9 months after surgical decompression.

CONCLUSIONS

We recommend a individualized approach when it is difficult to determine an anterior or posterior surgery for multilevel CSM. Rehabilitation training should be carried out as early as possible.

Change in Functional Impairment, Disability, and Quality of Life Following Operative Treatment for Degenerative Cervical Myelopathy: A Systematic Review and Meta-Analysis

STUDY DESIGN

Systematic review.

OBJECTIVES

The primary objective of this systematic review was to define the change in impairment, disability, and pain following surgical intervention in patients with degenerative cervical myelopathy (DCM). Secondary objectives included to assess the impact of preoperative disease severity and duration of symptoms on outcomes and to summarize complications associated with surgery.

METHODS

A systematic literature search was conducted to identify prospective studies evaluating the effectiveness and safety of operative treatment in patients with DCM. Outcomes of interest were functional status, disability, pain, and complications. The quality of each study was evaluated using the Newcastle-Ottawa Scale, and the strength of the overall body of evidence was rated using guidelines outlined by the Grading of Recommendation Assessment, Development and Evaluation (GRADE) Working Group.

RESULTS

Of the 385 retrieved citations, 32 met inclusion criteria and are summarized in this review. Based on our results, pooled standard mean differences showed a large effect for improvement in Japanese Orthopaedic Association or modified Japanese Orthopaedic Association score from baseline at short-, medium-, and long-term follow-up: 6 to 12 months (1.92; 95% confidence interval [CI] = 1.41 to 2.43), 13 to 36 months (1.40; 95% CI = 1.12 to 1.67), and ≥36 months (1.92; 95% CI = 1.14 to 2.69) (moderate evidence). Surgery also resulted in significant improvements in Nurick, Neck Disability Index, and Visual Analogue Scale scores (low to very low evidence). The cumulative incidence of complications was low (14.1%; 95% CI = 10.1% to 18.2%).

CONCLUSION

Surgical intervention for DCM results in significant improvements in functional impairment, disability, and pain and is associated with an acceptably low rate of complications.

Comparison of Three Reconstructive Techniques in the Surgical Management of Patients With Four-Level Cervical Spondylotic Myelopathy

STUDY DESIGN

Retrospective clinical series.

OBJECTIVE

To compare perioperative parameters, clinical outcomes, radiographic parameters, and complication rates of three reconstructive techniques after the anterior decompression of four-level cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

At present, the decision to treat multilevel CSM, especially four-level CSM, remains controversial. No one compares multilevel anterior cervical discectomy and fusion (mACDF), segmental anterior cervical corpectomy and fusion (sACCF) to multilevel anterior cervical discectomy and fusion with cage alone (mACDF-CA) in four-level constructs.

METHODS

Between July 2006 and February 2014, 97 consecutive patients with four-level CSM were enrolled in this study and divided into sACCF (n = 39) group, mACDF (n = 31) group, and mACDF-CA (n = 27) group. The study compared perioperative parameters, complication rates, clinical and radiologic parameters of three reconstructive techniques after the anterior decompression of four-level CSM.

RESULTS

The mACDF-CA group had the least bleeding and cost of index surgery compared with the sACCF group having the most bleeding and cost. Although significant pain relief and functional activity improvement have been achieved in the three groups at the final follow-up, there was no significant difference in the Japanese Orthopedic Association, SF-36 and NDI scores among the three groups (P >0.05). The mACDF group maintained the best cervical lordosis at the final follow-up, compared with the sACCF group maintained the worst cervical lordosis. Solid fusion was achieved in 87.1% of subjects in sACCF group, 90.3% in mACDF, and in 88.9% in mACDF-CA. The mACDF-CA group had a higher rate of subsidence and lower rate of dysphagia than other two groups.

CONCLUSION

mACDF-CA can be considered an effective and safe alternative procedure in the treatment of the four-level CSM.

LEVEL OF EVIDENCE

4.

Correlation between Preoperative Magnetic Resonance Imaging Signal Intensity Changes and Clinical Outcomes in Patients Surgically Treated for Cervical Myeloradiculopathy

Study Design

This was a single surgeon, single center-based retrospective study with prospective data collection.

Purpose

To assess the correlation between T2-weighted magnetic resonance imaging (MRI) signal intensity (SI) changes and factors such as age, duration of symptoms, baseline modified Japanese Orthopedic Association (mJOA) score and to determine its prognostic value in predicting recovery after surgery.

Overview of Literature

Whether intramedullary cord T2-weighted MRI SI changes can predict operative outcomes of cervical myeloradiculopathy remains debatable, with only a few prospective studies analyzing the same.

Methods

Forty-six consecutive patients who underwent cervical myeloradiculopathy were included and were followed up for an average of 1 year. Preoperative T2-weighted MRI SI grading was performed for all patients. The correlation between MRI SI changes and age, duration of symptoms, preoperative mJOA score, and mJOA score at 1-year follow-up were analyzed.

Results

Fifteen patients had single-level (21.73%) or double-level (10.86%) prolapsed discs; 54.34% had degenerative cervical spondylosis with canal stenosis or multilevel disc prolapse and 13.07% had ossified posterior longitudinal ligaments. The mean age was 56.17±9.53 years (range, 35–81 years). The mean baseline mJOA score was 10.83±2.58 (range, 6–16), which postoperatively improved to 13.59±2.28 (range, 8–17; p<0.001). There was a statistically significant correlation between mJOA score at 1 year and MRI T2 SI grading (p=0.017).

Conclusions

Patients with longer symptom durations had high grades of intramedullary cord T2-weighted MRI SI changes. Age and preoperative neurological status were not significantly correlated with the existence of intramedullary cord SI changes. However, patients without or with mild and diffuse intramedullary cord T2-weighted MRI SI changes had better postoperative neurological recovery than those with sharp and focal SI changes.

Misplaced Cervical Screws Requiring Reoperation

STUDY DESIGN

A multicenter, retrospective case series.

OBJECTIVE

In the past several years, screw fixation of the cervical spine has become commonplace. For the most part, this is a safe, low-risk procedure. While rare, screw backout or misplaced screws can lead to morbidity and increased costs. We report our experiences with this uncommon complication.

METHODS

A multicenter, retrospective case series was undertaken at 23 institutions in the United States. Patients were included who underwent cervical spine surgery from January 1, 2005, to December 31, 2011, and had misplacement of screws requiring reoperation. Institutional review board approval was obtained at all participating institutions, and detailed records were sent to a central data center.

RESULTS

A total of 12 903 patients met the inclusion criteria and were analyzed. There were 11 instances of screw backout requiring reoperation, for an incidence of 0.085%. There were 7 posterior procedures. Importantly, there were no changes in the health-related quality-of-life metrics due to this complication. There were no new neurologic deficits; a patient most often presented with pain, and misplacement was diagnosed on plain X-ray or computed tomography scan. The most common location for screw backout was C6 (36%).

CONCLUSIONS

This study represents the largest series to tabulate the incidence of misplacement of screws following cervical spine surgery, which led to revision procedures. The data suggest this is a rare event, despite the widespread use of cervical fixation. Patients suffering this complication can require revision, but do not usually suffer neurologic sequelae. These patients have increased cost of care. Meticulous technique and thorough knowledge of the relevant anatomy are the best means of preventing this complication.

Anterior cervical discectomy and fusion versus anterior cervical corpectomy and fusion in multilevel cervical spondylotic myelopathy: A meta-analysis

BACKGROUND

Both anterior cervical discectomy and fusion (ACDF) and anterior cervical corpectomy and fusion (ACCF) are used to treat multilevel cervical spondylotic myelopathy (mCSM); however, which one is better treatment for mCSM remains considerable controversy. A meta-analysis was performed to compare clinical outcomes, radiographic outcomes, and surgical outcomes between ACDF and ACCF in treatment for mCSM.

METHODS

An extensive search of literature was performed in Pubmed/MEDLINE, Embase, the Cochrane library, CNKI, and WANFANG databases on ACDF versus ACCF treatment for mCSM from January 2011 to August 2016. The following variables were extracted: length of hospital stay, blood loss, operation time, Japanese Orthopedic Association (JOA) scores, Neck Disability Index (NDI) score, fusion rate, Cobb angles of C2 to C7, dysphagia, hoarseness, C5 palsy, infection, cerebral fluid leakage, donor site pain, epidural hematoma, graft subsidence, graft dislodgment, pseudoarthrosis, and total complications. Data analysis was conducted with RevMan 5.3 and STATA 12.0.

RESULTS

A total of 8 studies containing 878 patients were included in our study. The results showed that ACDF is better than ACCF in the angle of C2 to C7 at the final follow-up (P < 0.00001, standardized mean difference = 4.76 [3.48, 6.03]; heterogeneity: P = 0.17, I = 43%), C5 plasy (P = 0.02, odds ratio [OR] 0.42, 95% confidence interval [CI] 0.21, 0.86; heterogeneity: P = 0.52, I = 0%), blood loss (P < 0.00001, standardized mean difference = -53.12, 95% CI -64.61, -41.64; heterogeneity: P = 0.29, I = 20%), fusion rate (P = 0.04, OR 2.54, 95% CI 1.05, 6.11; heterogeneity: P = 0.29, I = 20%), graft subsidence (P = 0.004, OR 0.11, 95% CI 0.02, 0.48; heterogeneity: P = 0.94, I = 0%), and total complications (P = 0.0009, OR 0.56, 95% CI 0.40, 0.79; heterogeneity: P = 0.29, I = 18%).However, there are no significant differences in length of hospital stay, operation time, JOA scores, NDI scores, preoperative angle of C2 to C7, dysphagia, hoarseness, infection, cerebral fluid leakage, donor site pain, epidural hematoma, graft dislodgment, and pseudoarthrosis (all P > 0.05).

CONCLUSIONS

Based on our meta-analysis, our results suggest that both ACDF and ACCF are good plans in clinical outcomes; however, ACDF is a better choice in radiographic outcomes and total complications for the treatment of multilevel CSM.

Agreement on the Level Selection in Laminoplasty among Experienced Surgeons: A Survey-Based Study

Study Design

Survey based study.

Purpose

To assess the degree of agreement in level selection of laminoplasty (LP) for the selected cervical myeloradiculopathy cases between experienced spine surgeons.

Overview of Literature

Although, cervical LP is a widely used surgical technique for multi-level spinal cord compression, until now there is no consensus about how many segments or which segments should be opened to achieve a satisfactory decompression.

Methods

Thorough clinical and radiographic data (plain X-ray, computed tomography, and magnetic resonance imaging) of 30 patients who had cervical myelopathy were prepared. The data were provided to three independent spine surgeons with over 10 years experience in operation of their own practices. They were questioned about the most preferable surgical method and suitable decompression levels. The second survey was carried out after 6 months with the same cases. If the level difference between respondents was a half level or below, agreement was considered acceptable. The intraobserver and interobserver agreements in level selection were assessed by kappa statistics.

Results

Three respondents selected LP as an option for 6, 8, and 22 cases in the first survey and 10, 21, and 24 cases in the second survey. The reasons for selection of LP were levels of ossification of the posterior longitudinal ligament (p=0.004), segmental kyphotic deformity (p=0.036) and mean compression score (p=0.041). Intraobserver agreement showed variable results. Interobserver agreement was poor to fair by perfect matching (kappa=0.111–0.304) and fair to moderate by acceptable matching (kappa=0.308–0.625).

Conclusions

The degree of agreement for level selection of LP was not high even though experienced surgeons would choose the opening segments on the basis of same criteria. These results suggest that more specific guidelines in determination of levels for LP should be required to decrease unnecessary wide decompression according to individual variance.

Is more lordosis associated with improved outcomes in cervical laminectomy and fusion when baseline alignment is lordotic?

BACKGROUND CONTEXT

In cervical spondylotic myelopathy (CSM), cervical sagittal alignment (CSA) is associated with disease severity. Increased kyphosis and C2-C7 sagittal vertical axis (SVA) correlate with worse myelopathy and poor outcomes. However, when alignment is lordotic, it is unknown whether these associations persist.

PURPOSE

The study aimed to investigate the associations between CSA parameters and patient-reported outcomes (PROs) following posterior decompression and fusion for CSM when baseline lordosis is maintained.

STUDY DESIGN/SETTING

This is an analysis of a prospective surgical cohort at a single academic institution.

PATIENT SAMPLE

The sample includes adult patients undergoing primary cervical laminectomy and fusion for CSM over a 3-year period.

OUTCOME MEASURES

The PROs included EuroQol-5D, Short-Form-12 (SF-12) physical composite (PCS) and mental composite scales (MCS), Neck Disability Index, and the modified Japanese Orthopaedic Association scores. Radiographic CSA parameters measured included C1-C2 Cobb, C2-C7 Cobb, C1-C7 Cobb, C2-C7 SVA, C1-C7 SVA, and T1 slope.

METHODS

The PROs were recorded at baseline and at 3 and 12 months postoperatively. The CSA parameters were measured on standing radiographs in the neutral position at baseline and 3 months. Wilcoxon rank test was used to test for changes in PROs and CSA parameters, and Pearson correlation coefficients were calculated for CSA parameters and PROs preoperatively and at 12 months. No external sources of funding were used for this work.

RESULTS

There were 45 patients included with an average age of 63 years who underwent posterior decompression and fusion of 3.7±1.3 levels. Significant improvements were found in all PROs except SF-12 MCS (p=.06). Small but statistically significant changes were found in C2-C7 Cobb (mean change: +3.6°; p=.03) and C2-C7 SVA (mean change: +3 mm; p=.01). At baseline, only C2-C7 SVA associated with worse SF-12 PCS scores (r=-0.34, p=.02). Postoperatively, there were no associations found between PROs and any CSA parameters. Similarly, no CSA parameters were associated with changes in PROs.

CONCLUSIONS

Although creating more lordosis and decreasing SVA are associated with improved myelopathy and outcomes in patients with kyphosis, our study did not find such associationsin patients with lordosis undergoing posterior laminectomy and fusion for CSM. This suggests that any amount of lordosis may be sufficient.

Efficacy and Safety of One-Stage Selective Discectomy Combined with Expansive Hemilaminectomy in the Treatment of Cervical Spondylotic Myelopathy

OBJECTIVES

We designed a novel surgical strategy named one-stage selective discectomy combined with expansive hemilaminectomy, which might theoretically reduce the postoperative complications of cervical spondylotic myelopathy (CSM). The objective of this study is to evaluate its efficacy and safety.

METHODS

Sixty-two patients with CSM were enrolled in this study. The procedure includes selective discectomy with fusion at 1 or 2 segments of maximal cord compression and expansive hemilaminectomy on the symptomatic or severe side of the body. Neurologic function was evaluated using the Japanese Orthopedics Association Score before and after surgery. Midsagittal dural sac diameter, dural sac transverse area at segments of discetomy on magnetic resonance imaging, and lordosis of the cervical spine on lateral plain film were measured. All patients were followed up for more than 1 year.

RESULTS

A total of 88 discs and 272 hemilaminas were resected from 62 patients. The Japanese Orthopedics Association Score improved from 8.7 ± 1.76 preoperatively to 13.4 ± 1.61 at 1 year follow-up (P < 0.001). The mean midsagittal dural sac diameter, dural sac area, and lordotic angle also increased from 0.45 ± 0.10 cm, 0.83 ± 0.14 cm², and 7.9 ± 2.60° to 0.81 ± 0.08 cm, 0.96 ± 0.14 cm², and 11.7 ± 3.06°, respectively (P < 0.05). No case of postoperative axial pain, C5 palsy, nonunion, or kyphosis was reported.

CONCLUSIONS

One-stage selective discectomy combined with expansive hemilaminectomy is an effective surgical approach for the treatment of CSM in patients whose neurologic function, midsagittal dura sac diameter, and dura transverse area can be improved and has few postoperative complications.

Expansion Open-door Laminoplasty With Foraminotomy Versus Anterior Cervical Discectomy and Fusion for Coexisting Multilevel Cervical Myelopathy and Unilateral Radiculopathy

STUDY DESIGN

This was a clinical prospective study.

OBJECTIVE

To assess whether clinical and radiologic outcomes differ between expansion open-door laminoplasty with foraminotomy (EOLF) and anterior cervical discectomy and fusion (ACDF) in the treatment of coexisting multilevel cervical myelopathy and unilateral radiculopathy (CMUR).

SUMMARY OF BACKGROUND DATA

No reports to date have compared clinical outcomes between anterior and posterior decompression for CMUR.

MATERIALS AND METHODS

We prospectively performed ACDF (n=59) in 2004, 2006, and 2008 and EOLF (n=62) in 2005, 2007, and 2009. The Japanese Orthopedic Association (JOA) score and recovery rate were evaluated. For radiographic evaluation, the lordotic angle and range of motion at C2-C7 were investigated.

RESULTS

Only 110 patients could be followed for >3 years (EOLF/ACDF: 56/54; follow-up rate, 90.9%). Demographics were similar between the 2 groups. Compared with ACDF, in EOLF group there were shorter operating time (144 vs. 178 min), less bleeding (175 vs. 192 mL), and fewer complications (P<0.05). Results of JOA score and recovery rate, at 3-year postoperative follow-up, showed no statistical difference for the 2 groups. Cervical lordosis of ACDF increased from 13.7 to 16.2 degrees, whereas that of EOLF group decreased from 14.6 to 13.3 degrees (P<0.05). The percentage of range of motion declined in the 2 groups (ACDF/EOLF), 57.4% versus 74.7% (P<0.05).

CONCLUSIONS

The 2 surgical procedures have similar clinical effects in treating multisegmental CMUR. However, the EOLF group demonstrated shorter operative time, less blood loss, and fewer complications; therefore, it proved to be a more effective and safer method.

Value of intraoperative neurophysiological monitoring to reduce neurological complications in patients undergoing anterior cervical spine procedures for cervical spondylotic myelopathy

The primary aim of this study was to conduct a systematic review of reports of patients with cervical spondylotic myelopathy and to assess the value of intraoperative monitoring (IOM), including somatosensory evoked potentials, transcranial motor evoked potentials and electromyography, in anterior cervical procedures. A search was conducted to collect a small database of relevant papers using key words describing disorders and procedures of interest. The database was then shortlisted using selection criteria and data was extracted to identify complications as a result of anterior cervical procedures for cervical spondylotic myelopathy and outcome analysis on a continuous scale. In the 22 studies that matched the screening criteria, only two involved the use of IOM. The average sample size was 173 patients. In procedures done without IOM a mean change in Japanese Orthopaedic Association score of 3.94 points and Nurick score by 1.20 points (both less severe post-operatively) was observed. Within our sub-group analysis, worsening myelopathy and/or quadriplegia was seen in 2.71% of patients for studies without IOM and 0.91% of patients for studies with IOM. Variations persist in the existing literature in the evaluation of complications associated with anterior cervical spinal procedures. Based on the review of published studies, sufficient evidence does not exist to make recommendations regarding the use of different IOM modalities to reduce neurological complications during anterior cervical procedures. However, future studies with objective measures of neurological deficits using a specific IOM modality may establish it as an effective and reliable indicator of injury during such surgeries.

Anterior surgical options for the treatment of cervical spondylotic myelopathy in a long-term follow-up study

OBJECTIVE

To provide a basis for the choice of anterior surgery procedures in the treatment of cervical spondylotic myelopathy (CSM) through long-term follow-up.

METHODS

A consecutive series of 89 patients with CSM having complete follow-up data were analyzed retrospectively. All patients were treated with anterior cervical discectomy and fusion (ACDF), and anterior cervical corpectomy and fusion (ACCF) from July 2000 to June 2007. The lesions were located in one segment (n = 25), two segments (n = 56), and three segments (n = 8). Preoperative and postoperative, the C2-C7 angle, cervical intervertebral height, radiographic fusion status, result of the adjacent segment degeneration, the Japanese Orthopaedic Association (JOA), and the Short Form 36-item (SF36) questionnaire scores were used to evaluate the efficacy of the surgery.

RESULTS

According to the different compression conditions of the 89 cases, different anterior operation procedures were chosen and satisfactory results were achieved, indicating that direct anterior decompressions were thorough and effective. The follow-up period was 60-108 months, and the average was 79.6 months. The 5-year average symptom improvement rate, effectiveness rate, and fineness rate were 78.36 %, 100 % (89/89), and 86.52 % (77/89), respectively.

CONCLUSIONS

For CSM with compression coming from the front side, proper anterior decompression based on the specific conditions could directly eliminate the compression. Through long-term follow-up, the effect of decompression became observable.

Modified K-line in magnetic resonance imaging predicts insufficient decompression of cervical laminoplasty

STUDY DESIGN

A retrospective single-center study.

OBJECTIVE

To clarify preoperative factors predicting unsatisfactory indirect decompression after laminoplasty in patients with cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

Many authors have shown that inadequate indirect decompression after laminoplasty can inhibit neural recovery and should be considered a complication. We previously demonstrated that residual anterior compression of the spinal cord (ACS) impaired recovery of upper extremity motor function. Although the K-line has been established as a predictive index indicating that laminoplasty is required in patients with ossification of the posterior longitudinal ligament, it remains unclear what preoperative factors can predict insufficient posterior cord decompression in patients with cervical spondylotic myelopathy.

METHODS

Forty-six consecutive patients who underwent laminoplasty for the treatment of cervical spondylotic myelopathy at our hospital were reviewed. A modified K-line was defined as the line connecting the midpoints of the spinal cord at C2 and C7 on a T1-weighted sagittal magnetic resonance image. We also determined the minimum interval between the tip of local kyphosis and a line connecting the midpoint of the cord at the level of the inferior endplates of C2 and C7 (INTmin) on the midsagittal image. Data analysis involved logistic regression and receiver operating characteristic curve analysis to select the most valuable index for predicting postoperative ACS.

RESULTS

Ten patients had ACS immediately after laminoplasty. Logistic regression analysis showed that INTmin was a significant predictive factor for the occurrence of postoperative ACS (odds ratio = 0.485; 95% confidence interval = 0.29-0.81; P = 0.02). Receiver operating characteristic curve analysis showed an area under the curve of 0.871. A cutoff of 4.0 mm had a sensitivity of 80% and a specificity of 80.6% for prediction of postoperative ACS.

CONCLUSION

The parameter INTmin correlated with the occurrence of postoperative ACS. A cutoff point of 4.0 mm is most appropriate for alerting spine surgeons to a high likelihood of postoperative ACS.

Measurement of volume-occupying rate of cervical spinal canal and its role in cervical spondylotic myelopathy

PURPOSE

To compare volume-occupying rate of cervical spinal canal between patients with cervical spondylotic myelopathy (CSM) and normal subjects, and to investigate its significance in cervical spine disease.

METHODS

Spiral computed tomography (CT) scan (C4-C6 cervical spine unit) was performed in 20 normal subjects and 36 cases of CSM at a neutral position, and data were transferred to the Advantage Workstation Version 4.2 for assessment. Bony canal area and fibrous canal area in each cross section, and sagittal diameters of cervical spinal canal and cervical spinal body were measured. Volume-occupying rate of cervical spinal canal was calculated using MATLAB. Cervical spinal canal ratio and effective cervical spinal canal ratio were calculated, and Japanese Orthopaedic Association score was used to assess cervical spinal cord function.

RESULTS

Volume-occupying rate of cervical spinal canal at a neutral position was significantly higher in CSM patients as compared to normal subjects (P < 0.01). There was no correlation between cervical spinal canal ratio and JOA score in CSM patients, with a Pearson's correlation coefficient of 0.171 (P > 0.05). However, sagittal diameter of secondary cervical spinal canal, effective cervical spinal canal ratio and volume-occupying rate of cervical spinal canal were significantly associated to JOA score, with Pearson's coefficient correlations of 0.439 (P < 0.05), 0.491 (P < 0.05) and -0.613 (P < 0.01), respectively.

CONCLUSIONS

Volume-occupying rate of cervical spinal canal is an objective reflection of compression on cervical spine and spinal cord, and it is associated with cervical spinal cord function. These suggest that it may play a significant role in predicting the development of CSM.

Comparative analysis of complications of different reconstructive techniques following anterior decompression for multilevel cervical spondylotic myelopathy

PURPOSE

Anterior approach was extensively used in surgical treatment of multilevel cervical spondylotic myelopathy. Following anterior decompression, many different reconstructive techniques (multilevel ACDF, hybrid construct and long corpectomy) all had satisfied outcomes. However, there are few studies focusing on the comparison of these three reconstructed techniques. The aim of this retrospective study was to analyze the complications of these three different methods.

METHODS

This study retrospectively reviewed the complications in 286 consecutive patients with multilevel CSM who underwent anterior cervical surgery from 2005 to 2010. This case series had 166 men and 120 women whose mean age at surgery was 53.8 years (range from 33 to 74 years). Radiographic evaluation was taken the day after surgery, and the flexion-extension X-rays were added 3, 12 and 24 months postoperatively to evaluate the fusion condition. Preoperative versus postoperative neurologic function and clinical outcome were evaluated using scoring systems such as the Japanese Orthopedic Association (JOA score), Neck Disability Index (NDI score) and 36-Item Short-Form Health Survey (SF-36 score).

RESULTS

There were no significant differences in JOA scores, NDI scores and SF-36 scores of the pairwise comparison among the three groups. The complications in our series included graft migration, collapse or displacement, hoarseness, dysphagia, C5 palsy, cerebral fluid leakage and wound infection. Sixty-one patients developed complications after surgery and the rate of complication was 21.33 %. Patients in the long corpectomy group had the highest rate of complications; the other two groups had a much lower rate of complications by the latest follow-up. The patients in the multilevel ACDF group had the highest fusion rate by the last follow-up. Patients who had C2-3 and C3-4 segments involved had a higher rate of postoperative hoarseness and dysphagia.

CONCLUSIONS

Most of the complications of the three reconstructive techniques subsided gradually after conservative treatment; none of them needed revision surgery. The multilevel ACDF approach has the lowest rate of non-union, but a slightly higher morbidity of the laryngeal nerve-related complication if proximal segments were involved. The long corpectomy approach should be selected prudently because of the high rate of complication.

Relevance of expandable titanium cage for the treatment of cervical spondylotic myelopathy

BACKGROUND

In patients with cervical spondylotic myelopathy, ventral disease and loss of physiological cervical lordosis are indications for anterior approach. As bone graft and titanium cage present many drawbacks, expandable titanium cage has been recently introduced for this indication. The authors present the clinical and radiological outcomes in patients undergoing the placement of an expandable cage in the treatment of spondylotic myelopathy with straight or kyphotic cervical spine alignment.

METHODS

This was a retrospective review of prospectively collected data. A total of 26 patients underwent cervical corpectomy and reconstruction using an expandable titanium cage and anterior plate between 2005 and 2008. Pain and functional disability were measured using VAS and mJOA preoperatively and at 3 months, 6 months, 1 year and 2 years. Kyphosis was measured using lateral radiographs at the same points of follow-up. Fusion was evaluated on flexion-extension radiographs at 2 years.

RESULTS

The mean VAS improved from 4.2 to 1.7 and the mean mJOA increased from 12.85 to 16.04 at 2 years postoperatively (p < 0.05). The mean kyphosis angle decreased from 17° to 2° at the last follow-up (p < 0.05). The fusion rate was 100% at 2 years. Three complications were reported including a transient dysphagia, an epidural hematoma and an early hardware migration.

CONCLUSION

Expandable titanium cage is an effective device, which achieves good clinical and radiological outcomes at a minimum 2-year follow-up.

Comparison between anterior and posterior decompression for cervical spondylotic myelopathy: subjective evaluation and cost analysis

OBJECTIVE

To compare anterior and posterior approaches for treating cervical spondylotic myelopathy (CSM) involving more than two levels, especially in regard to quality of life and cost effectiveness.

METHODS

The authors studied 116 CSM patients who underwent decompressive surgery by either an anterior or a posterior approach with instrumentation. In the anterior group, 1-3 levels subtotal vertebrectomy was followed by bone graft and Orion anterior cervical locking plate fixation. In the posterior group, multilevel laminectomy with posterior screw-rod fixation was performed. Follow-up, which included radiographic assessment, clinical examination and documentation of length of any hospitalization and cost and incidence of complications, was performed 1 day before discharge, 6 months after leaving hospital, and at final follow-up.

RESULTS

Both groups had improved clinical outcomes. The anterior group showed greater satisfaction but lower visual analog scale scores than the posterior group, whereas SF-36 emotional role and mental health scores were higher in the anterior group. There was no marked difference between the two groups in length of hospitalization and most of the costs of treating CSM, however treatment and examination fees were significantly higher in the posterior group.

CONCLUSIONS

Both anterior and posterior decompressions (with instrumentation) are effective procedures for improving the neurological outcomes of patients with CSM. However, although the two approaches have similar health care costs, anterior cervical corpectomy (with instrumentation) seems to be subjectively assessed by patients as better.

Presence of anterior compression of the spinal cord after laminoplasty inhibits upper extremity motor recovery in patients with cervical spondylotic myelopathy

STUDY DESIGN

A retrospective single-center study.

OBJECTIVE

To investigate how functional recovery is influenced by anterior compression of the spinal cord (ACS) and instability at the level of ACS after laminoplasty in patients with cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

There have been many reports that patients whose spinal cord cannot be decompressed sufficiently after laminoplasty are likely to show unsatisfactory neurologic outcomes. Notably, postoperative ACS is well known to cause problems. Clinically, however, it remains unknown how functional recovery is inhibited by postoperative ACS.

METHODS

Sixty-four consecutive patients who underwent expansive laminoplasty for the treatment of myelopathy at our hospital between 1998 and 2005 were reviewed. All 64 patients were available for follow-up. The average follow-up period was 97 months (60-156 months). Patients were divided into 2 groups: the ACS(+) group comprised 16 patients who had ACS 3 years postoperatively, and the ACS(-) group comprised 48 patients with no ACS. Clinical outcome was compared in terms of the Japanese Orthopaedic Association score (mean total score, mean score of each item, and recovery rates).

RESULTS

Demographics were similar between the 2 groups. Mean Japanese Orthopaedic Association score at final follow-up was 12.1 points (recovery rate 34.0%) in the ACS(+) group and 13.8 points (recovery rate 56.6%) in the ACS(-) group, and there was a significant difference in recovery rate between the groups (P < 0.05). Notably, a significant difference was found between the 2 groups in improvement of upper extremity motor function (P < 0.05). In addition, we found that not only the presence of ACS but also postoperative hypermobility of the intervertebral segment with ACS influenced clinical outcome negatively.

CONCLUSION

These results demonstrate that ACS after laminoplasty could be a risk factor for clinical outcome and might prevent improvement in upper extremity motor function in patients with myelopathy.

Perioperative and delayed complications associated with the surgical treatment of cervical spondylotic myelopathy based on 302 patients from the AOSpine North America Cervical Spondylotic Myelopathy Study

OBJECT

Rates of complications associated with the surgical treatment of cervical spondylotic myelopathy (CSM) are not clear. Appreciating these risks is important for patient counseling and quality improvement. The authors sought to assess the rates of and risk factors associated with perioperative and delayed complications associated with the surgical treatment of CSM.

METHODS

Data from the AOSpine North America Cervical Spondylotic Myelopathy Study, a prospective, multicenter study, were analyzed. Outcomes data, including adverse events, were collected in a standardized manner and externally monitored. Rates of perioperative complications (within 30 days of surgery) and delayed complications (31 days to 2 years following surgery) were tabulated and stratified based on clinical factors.

RESULTS

The study enrolled 302 patients (mean age 57 years, range 29-86) years. Of 332 reported adverse events, 73 were classified as perioperative complications (25 major and 48 minor) in 47 patients (overall perioperative complication rate of 15.6%). The most common perioperative complications included minor cardiopulmonary events (3.0%), dysphagia (3.0%), and superficial wound infection (2.3%). Perioperative worsening of myelopathy was reported in 4 patients (1.3%). Based on 275 patients who completed 2 years of follow-up, there were 14 delayed complications (8 minor, 6 major) in 12 patients, for an overall delayed complication rate of 4.4%. Of patients treated with anterior-only (n = 176), posterior-only (n = 107), and combined anterior-posterior (n = 19) procedures, 11%, 19%, and 37%, respectively, had 1 or more perioperative complications. Compared with anterior-only approaches, posterior-only approaches had a higher rate of wound infection (0.6% vs 4.7%, p = 0.030). Dysphagia was more common with combined anterior-posterior procedures (21.1%) compared with anterior-only procedures (2.3%) or posterior-only procedures (0.9%) (p < 0.001). The incidence of C-5 radiculopathy was not associated with the surgical approach (p = 0.8). The occurrence of perioperative complications was associated with increased age (p = 0.006), combined anterior-posterior procedures (p = 0.016), increased operative time (p = 0.009), and increased operative blood loss (p = 0.005), but it was not associated with comorbidity score, body mass index, modified Japanese Orthopaedic Association score, smoking status, anterior-only versus posterior-only approach, or specific procedures. Multivariate analysis of factors associated with minor or major complications identified age (OR 1.029, 95% CI 1.002-1.057, p = 0.035) and operative time (OR 1.005, 95% CI 1.002-1.008, p = 0.001). Multivariate analysis of factors associated with major complications identified age (OR 1.054, 95% CI 1.015-1.094, p = 0.006) and combined anterior-posterior procedures (OR 5.297, 95% CI 1.626-17.256, p = 0.006).

CONCLUSIONS

For the surgical treatment of CSM, the vast majority of complications were treatable and without long-term impact. Multivariate factors associated with an increased risk of complications include greater age, increased operative time, and use of combined anterior-posterior procedures.

Middle-term results of a prospective comparative study of anterior decompression with fusion and posterior decompression with laminoplasty for the treatment of cervical spondylotic myelopathy

STUDY DESIGN

A clinical prospective study.

OBJECTIVE

To assess whether clinical and radiologic outcomes differ between anterior decompression and fusion (ADF) and laminoplasty (LAMP) in the treatment of cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

No reports to date have accurately and prospectively compared middle-term clinical outcomes after anterior and posterior decompression for CSM.

METHODS

We prospectively performed LAMP (n = 50) in 1996, 1998, 2000, and 2002, and ADF (n = 45) in 1997, 1999, 2001, and 2003. The Japanese Orthopedic Association (JOA) score, recovery rate, and each item of the JOA score were evaluated. For radiographic evaluation, the lordotic angle and range of motion (ROM) at C2-C7 and residual anterior compression to the spinal cord (ACS) after LAMP on magnetic resonance imaging were investigated.

RESULTS

Eighty-six patients (ADF n = 39; LAMP n = 47) could be followed for more than 5 years (follow-up rate 91.5%). Demographics were similar between the two groups. The mean JOA score and recovery rate in the ADF group were superior to those in the LAMP group from 2-year data collected after surgery. However, LAMP was safer and less invasive than ADF with respect to physical status and complications in the perioperative period. For individual items of the JOA score, the ADF group showed significantly more improvement of upper extremity motor function than the LAMP group (P < 0.05). There was a significant difference in maintenance of the lordotic angle in the ADF group compared with the LAMP group despite no difference in ROM.The LAMP group was divided into two subgroups: (1) LAMP(+) (n = 16) comprising patients who had ACS at 2 years after surgery, and (2) LAMP(-) (n = 31) comprising patients without ACS. Recovery rate differed significantly between the LAMP(+) and LAMP(-) groups despite there being no difference between the LAMP(-) and ADF groups.

CONCLUSION

The recovery rate of the JOA score in the ADF group was better than that in the LAMP group. The clinical outcomes after LAMP could be influenced by ACS.

Expansive open-door laminoplasty and selective anterior cervical decompression and fusion for treatment of multilevel cervical spondylotic myelopathy

OBJECTIVE

To evaluate the clinical results of combined expansive open-door laminoplasty by splitting of spinous processes and selective anterior cervical decompression and fusion in treatment of multilevel severe cervical spondylotic myelopathy (CSM).

METHODS

Twenty-eight patients (16 men and 12 women) underwent one-stage combined expansive open-door laminoplasty and selective anterior decompression and fusion for severe CSM; the average patient age was 51.3 years (range, 32-63 years). Clinical results were assessed by Japanese Orthopaedic Association (JOA) scores, number of finger grip and releases (G and R) in ten seconds, hand-grip strength, visual analog scale (VAS) of axial pain, and C2-C7 angle.

RESULTS

  There was no worsening of neurological symptoms due to cord injury, cerebrospinal fluid leakage, or wound infection. All cases completed one-year follow-up. The JOA scores, number of G and R in ten seconds, and hand-grip strength were all significantly improved (P < 0.05). Satisfactory decompression was shown by MRI or CT to have been achieved in all cases. The C2-C7 angle did not differ significantly from that found pre-operatively. The axial neck pain score was 2.0 ± 0.1 on VAS.

CONCLUSION

Combined expansive open-door laminoplasty by splitting of spinous processes and selective anterior decompression and fusion achieves complete spinal canal decompression with minimal morbidity; this strategy is effective in improving the surgical outcomes of CSM in one-year follow-up.

The relevance of intramedullary high signal intensity and gadolinium (Gd-DTPA) enhancement to the clinical outcome in cervical compressive myelopathy

PURPOSE

We prospectively investigated whether high intramedullary SI and contrast [gadolinium-diethylene-triamine-pentaacetic acid (Gd-DTPA)] enhancement in magnetic resonance imaging (MRI) are associated with postoperative prognosis in cervical compressive myelopathy (CCM) patients.

METHODS

Seventy-four patients with ventral cord compression at one or two levels underwent anterior cervical discectomy and fusion (ACDF) for CCM between March 2006 and June 2009. The mean follow-up period was 39.7 months (range, 12.7-55.7 months). The cervical cord compression ratio and clinical outcomes were measured using Japanese Orthopedic Association (JOA) scores for cervical myelopathy. Patients were classified into three groups based on the SI change in T2WI, T1-weighted images (T1WI), and contrast (Gd-DTPA) enhancement.

RESULTS

The mean preoperative and postoperative JOA scores were 10.5 ± 2.9 and 15.0 ± 2.1 (P < 0.05), respectively. The mean recovery ratio of the JOA score was 70.9 ± 20.2%. There were statistically significant differences in postoperative JOA and recovery ratio among three groups. However, post-surgical neurological outcomes were not associated with age, symptom duration, preoperative JOA, and cord compression.

CONCLUSIONS

We found that intramedullary SI change is a poor prognostic factor and the intramedullary contrast (Gd-DTPA) enhancement on preoperative MRI should be viewed as the worst predictor of surgical outcomes in cervical myelopathy. Contrast (Gd-DTPA) enhancement and postoperative MRI are useful for identifying the prognosis of patients with poor neurological recovery.

Increased in-hospital complications after primary posterior versus primary anterior cervical fusion

BACKGROUND

Although anterior (ACDF) and posterior cervical fusion (PCDF) are relatively common procedures and both are associated with certain complications, the relative frequency and severity of these complications is unclear. Since for some patients either approach might be reasonable it is important to know the relative perioperative risks for decision-making.

QUESTIONS/PURPOSES

The purposes of this study were to: (1) characterize the patient population undergoing ACDF and PCDF; (2) compare perioperative complication rates; (3) determine independent risk factors for adverse perioperative events; and (4) aid in surgical decision-making in cases in which clinical equipoise exists between anterior and posterior cervical fusion procedures.

METHODS

The National Inpatient Sample was used and entries for ACDF and PCDF between 1998 and 2006 were analyzed. Demographics and complication rates were determined and regression analysis was performed to identify independent risk factors for mortality after ACDF and PCDF.

RESULTS

ACDF had a shorter length of stay and their procedures were more frequently performed at nonteaching institutions. The incidence of complications and mortality was 4.14% and 0.26% among patients undergoing ACDF and 15.35% and 1.44% for patients undergoing PCDF, respectively. When controlling for overall comorbidity burden and other demographic variables, PCDF was associated with a twofold increased risk of a fatal outcome compared with ACDF. Pulmonary, circulatory, and renal disease were associated with the highest odds for in-hospital mortality.

CONCLUSIONS

PCDF procedures were associated with higher perioperative rates of complications and mortality compared with ACDF surgeries. Despite limitations, these data should be considered in cases in which clinical equipoise exists between both approaches.

LEVEL OF EVIDENCE

Level II, prognostic study. See Guidelines for Authors for a complete description of levels of evidence.

Anterior versus posterior surgery for multilevel cervical myelopathy, which one is better? A systematic review

The objective of the study is to perform a systematic review to compare the clinical outcomes and complications of anterior surgery with posterior surgery for multilevel cervical myelopathy (MCM). MEDLINE, EMBASE databases and other databases were searched for all the relevant original articles published from January 1991 to November 2009 comparing anterior with posterior surgery for MCM. Subgroup analysis was performed according to the follow-up years. The following end points were mainly evaluated: final follow-up JOA (Japanese Orthopaedic Association) scale, recovery rate and complication outcomes. Ten articles fulfilled all inclusion criteria. For multilevel CSM patients, the final follow-up JOA score for the anterior group was significantly higher than the posterior group (p < 0.05, WMD 0.83 [0.24, 1.43]) in the 'follow-up time ≤ 5 years' subgroup, but had no significant differences in the 'follow-up time > 5 years' subgroup (p > 0.05). The recovery rate for the anterior group was significantly higher than the posterior group (p < 0.05, WMD 10.08 [1.39, 18.78]) in the 'follow-up time ≤ 5 years' subgroup. No study reported the recovery rate for the follow-up time > 5 years. For multilevel OPLL patients, the final follow-up JOA score and recovery rate for the anterior group were both significantly higher than the posterior group in the 'follow-up time ≤ 5 years' subgroup (p < 0.05, WMD 2.50 [0.16, 4.85]; p < 0.05, WMD 29.48 [29.09, 29.87], respectively). One study [31] which mean follow-up time was 6 years was enrolled in the 'follow-up time > 5 years' subgroup. The results showed there was no significant difference in final follow-up JOA score and recovery rate between anterior and posterior group for patients with occupying ratio of OPLL <60% (p > 0.05), while in patients with occupying ratio ≥ 60%, the final follow-up JOA score and recovery rate of anterior surgery were both superior to that of posterior surgery (p < 0.05). For both multilevel CSM and OPLL patients, the complications for the anterior group were significantly more than the posterior group in the 'follow-up time ≤ 5 years' subgroup (p < 0.05, OR 7.33 [2.96, 18.20] for CSM patients; p < 0.05, OR 4.44 [1.80, 10.98] for OPLL patients), but were similar to the posterior group in the 'follow-up time >5 years' subgroup (p > 0.05). In conclusion, anterior surgery had better clinical outcomes and more complications at the early stage after operation for both multilevel CSM and OPLL patients. At the late stage, posterior surgery had similar clinical outcomes and complications to anterior surgery for CSM patients, and OPLL patients with occupying ratio of OPLL <60%. While for OPLL patients with occupying ratio ≥ 60%, anterior surgery had superior clinical outcome to posterior surgery.

Minimally invasive spine technology and minimally invasive spine surgery: a historical review

The trend of using smaller operative corridors is seen in various surgical specialties. Neurosurgery has also recently embraced minimal access spine technique, and it has rapidly evolved over the past 2 decades. There has been a progression from needle access, small incisions with adaptation of the microscope, and automated percutaneous procedures to endoscopically and laparoscopically assisted procedures. More recently, new muscle-sparing technology has come into use with tubular access. This has now been adapted to the percutaneous placement of spinal instrumentation, including intervertebral spacers, rods, pedicle screws, facet screws, nucleus replacement devices, and artificial discs. New technologies involving hybrid procedures for the treatment of complex spine trauma are now on the horizon. Surgical corridors have been developed utilizing the interspinous space for X-STOP placement to treat lumbar stenosis in a minimally invasive fashion. The direct lateral retroperitoneal corridor has allowed for minimally invasive access to the anterior spine.

In this report the authors present a chronological, historical perspective of minimal access spine technique and minimally invasive technologies in the lumbar, thoracic, and cervical spine from 1967 through 2009. Due to a low rate of complications, minimal soft tissue trauma, and reduced blood loss, more spine procedures are being performed in this manner. Spine surgery now entails shorter hospital stays and often is carried out on an outpatient basis. With education, training, and further research, more of our traditional open surgical management will be augmented or replaced by these technologies and approaches in the future.