Relationship between cervical curvature index (Ishihara) and cervical spine angle (C2--7)

Would the one-stage combined approach lead to better long-term neurological outcomes than the posterior approach alone in multilevel degenerative cervical myelopathy patients with T2-Weighted increased signal intensity? An 8-year follow-up results and propensity score matching analysis

BACKGROUND

T2-weighted increased signal intensity (ISI) is commonly recognized as a sign of more severe spinal cord lesions, usually accompanied by worse neurological deficits and possibly worse postoperative neurological recovery. The combined approach could achieve better decompression and better neurological recovery for multilevel degenerative cervical myelopathy (MDCM). The choice of surgical approach for MDCM with intramedullary T2-weighted ISI remains disputed. This study aimed to compare the neurological outcomes of posterior and one-stage combined posteroanterior approaches for MDCM with T2-weighted ISI.

METHODS

A total of 83 consecutive MDCM patients with confirmed ISI with at least three intervertebral segments operated between 2012 and 2014 were retrospectively enrolled. Preoperative demographic, radiological and clinical condition variables were collected, and neurological conditions were evaluated by the Japanese Orthopedic Assessment score (JOA) and Neck Disability Index (NDI). Propensity score matching analysis was conducted to produce pairs of patients with comparable preoperative conditions from the posterior-alone and combined groups. Both short-term and mid-term surgical outcomes were evaluated, including the JOA recovery rate (JOARR), NDI improvements, complications, and reoperations.

RESULTS

A total of 83 patients were enrolled, of which 38 and 45 patients underwent posterior surgery alone and one-stage posteroanterior surgery, respectively. After propensity score matching, 38 pairs of comparable patients from the posterior and combined groups were matched. The matched groups presented similar preoperative clinical and radiological features and the mean follow-up duration were 111.6 ± 8.9 months. The preoperative JOA scores of the posterior and combined groups were 11.5 ± 2.2 and 11.1 ± 2.3, respectively (p = 0.613). The combined group presented with prolonged surgery duration(108.8 ± 28.0 and 186.1 ± 47.3 min, p = 0.028) and greater blood loss(276.3 ± 139.1 and 382.1 ± 283.1 ml, p<0.001). At short-term follow-up, the combined group presented a higher JOARR than the posterior group (posterior group: 50.7%±46.6%, combined group: 70.4%±20.3%, p = 0.024), while no significant difference in JOARR was observed between the groups at long-term follow-up (posterior group: 49.2%±48.5%, combined group: 59.6%±47.6%, p = 0.136). No significant difference was found in the overall complication and reoperation rates.

CONCLUSIONS

For MDCM patients with ISI, both posterior and one-stage posteroanterior approaches could achieve considerable neurological alleviations in short-term and long-term follow-up. With greater surgical trauma, the combined group presented better short-term JOARR but did not show higher efficacy in long-term neurological function preservation in patients with comparable preoperative conditions.

The clinical efficacy of laminectomy fusion fixation and posterior single open-door laminoplasty in the treatment of multilevel cervical ossification of the posterior longitudinal ligament (OPLL): a retrospective study

BACKGROUND

To compared the clinical efficacy of two surgical methods, posterior laminectomy fusion fixation, and posterior single open-door laminoplasty, in treating multilevel cervical ossification of the posterior longitudinal ligament (OPLL).

METHODS

The study retrospectively included 102 patients treated between December 2016 and December 2020. The patients were included into an observation group (56 cases) treated with total laminectomy and lateral screw fixation, and a control group (46 cases) treated with single open-door laminoplasty.

RESULTS

After 24 months, both groups showed significant improvement in Japanese Orthopaedic Association (JOA) scores and Visual Analogue Scale (VAS) scores, indicating better clinical symptoms and functional recovery. There was no significant difference in preoperative JOA and VAS scores between the two groups (P > 0.05). At 24 months after surgery, there was no significant difference in JOA and VAS scores between the two groups (P > 0.05). However, the observation group had a significantly higher cervical curvature index (CCI) and lower range of motion (ROM) of the cervical spine compared to the control group (P < 0.05). The CCI in control group was lower than before surgery, while the CCI in observation group was higher than before surgery, and CCI in the control group was considerably lower than that in the observation group (P < 0.05). The complication rate was lower in the control group, with fewer cases of axial symptoms, fifth cervical nerve root palsy, and overall complications. The overall complication rate was 25.0% (14/56) in the observation group and 10.8% (5/46) in the control group (P < 0.05).

CONCLUSIONS

Both posterior laminectomy fusion fixation and posterior single open-door laminoplasty yield positive outcomes in improving clinical neurological function, cervical curvature, range of motion of the cervical spine, and cervical sagittal balance. Although open-door laminoplasty is less effective than total laminectomy in maintaining CCI and sagittal balance, it excels in preserving cervical range of motion, less surgical trauma and complications. Thus, open-door laminoplasty may be a suitable first-choice treatment for multi-segmental cervical OPLL, especially for patients with lordotic cervical spine physiological curvature.

Analysis of abnormal muscle activities in patients with loss of cervical lordosis: a cross-sectional study

BACKGROUND

This study aimed to detect the differences in cervical muscle activation patterns in people with versus without cervical lordosis and explore the possible mechanism of cervical pain originating therein.

METHODS

This cross-sectional design included 39 participants without and 18 with normal cervical lordosis. Muscular activation was measured for 5 s in both groups using surface electromyography. Subsequently, the root mean square (RMS) of muscle amplitude was obtained at the bilateral splenius capitis, upper and lower parts of the splenius cervicis, upper and lower parts of the semispinalis cervicis, sternocleidomastoid, upper trapezius, and rhomboid muscles in five cervical positions: 0° (resting), 30° of flexion, 30° of extension, 60° of extension, and upon a 1-kg load on the head in a resting posture.

RESULTS

The RMS values of the upper trapezius muscle at all postures and the rhomboid muscles at 60° of extension were significantly lower in the loss of lordosis than control group. Comparing the RMS ratio of each posture to the resting position, the ratio of the upper trapezius at flexion was significantly higher and that of the rhomboids at 60° of extension and upon loading was significantly lower in the loss of lordosis than control group. Moreover, the pattern changes in the RMS values according to posture showed a similar shape in these two muscles, and lower in the loss of lordosis than the normal group.

CONCLUSIONS

The loss of normal cervical alignment may correlate with predisposed conditions such as reduced muscle activation of the trapezius and rhomboid muscle, and may also provoke over-firing of the upper trapezius muscle, possibly increasing neck musculoskeletal pain.

TRIAL REGISTRATION

CLINICALTRIALS

gov, registration number: NCT03710785.

Cervical collar use following anterior cervical hybrid surgery: protocol for a prospective randomized, time-controlled trial

INTRODUCTION

Cervical hybrid surgery (HS) combines anterior cervical discectomy and fusion (ACDF) and cervical disc arthroplasty (CDA) to establish an individualized surgical plan for patients with multiple cervical disc degenerative diseases. In order to maintain the stability of the spine after HS, an external cervical collar is often used. However, there is still controversy regarding the importance of a cervical collar following surgery. This study aims to determine whether the cervical collar is effective and how long it should be worn after surgery.

METHODS

This is a randomized, single-center, prospective, parallel-controlled trial. Eligible participants will be selected according to the inclusion and exclusion criteria. The primary outcome is the neck disability index, which will be evaluated before surgery and at one week, 3 weeks, 6 weeks, 3 months, 6 months, and 12 months following surgery. The secondary outcomes consist of the Japanese Orthopedic Association Scores, MOS 36-item short-form health survey (SF-36), visual analog scale, Pittsburgh Sleep Quality Index (PSQI), Bazaz dysphagia scoring system, Falls Efficacy Scale, cervical collar satisfaction score, neck soft tissue assessment, and Braden Scale, as well as radiologic assessments for cervical lordosis, disc height of the operative levels, fusion rate, range of motion (ROM), and complications including anterior bone loss, prosthesis migration, and heterotopic ossification. The clinical and radiologic examinations were performed by investigators with no therapeutic relationship with the individual patient. All radiographs were examined by one independent radiologist.

ETHICS AND DISSEMINATION

The results of this study will be published in peer-reviewed journals and presented at conferences. Upon completion of this trial, our findings could provide an appropriate cervical collar-wearing guideline for patients receiving HS.

TRIAL REGISTRATION

ChiCTR.org.cn ChiCTR2000033002. Registered on 2020-05-17.

Effectiveness of manual therapy and cervical spine stretching exercises on pain and disability in myofascial temporomandibular disorders accompanied by headaches: a single-center cohort study

BACKGROUND

Previous studies have demonstrated a relationship between headaches and temporomandibular disorders (TMDs). Moreover, recent studies have shown functional, anatomical, and neurological associations between the temporomandibular joint (TMJ) and upper cervical spine. This study aimed to investigate the effectiveness of manual therapy and cervical spine stretching exercises for pain and disability in patients with myofascial TMDs accompanied by headaches.

METHODS

Thirty-four patients recruited from Gyeryong Hospital with headaches and diagnosed with TMDs were randomly assigned to the experimental (n = 17) and control (n = 17) groups. Headache impact was assessed using the Korean Headache Impact Test-6. Masseter myofascial pain was measured using the visual analog scale, and TMJ pressure pain threshold levels were evaluated using an algometer. Neck pain intensity was assessed using the numerical rating scale. Once per week for 10 weeks, the experimental group received cervical spine-focused manual therapy and stretching exercises alongside conservative physical therapy, and the control group received conservative physical therapy alone. Patients were evaluated at baseline and 5 and 10 weeks post-intervention.

RESULTS

After the intervention, the experimental group exhibited significant reductions in the cervical kyphotic angle, Korean Headache Impact Assessment score, neck pain intensity, TMJ pain pressure threshold, Neck Disability Index score, and Jaw Functional Limitation Scale level compared with the control group (p < 0.01).

CONCLUSION

Manual therapy and stretching exercises could help resolve TMDs accompanied by headaches through biomechanical changes in the cervical spine. These findings may guide protocols and clinical trials involving manual therapy that align morphological structures.

Anterior bone loss: A common phenomenon which should be considered as bone remodeling process existed not only in patients underwent cervical disk replacement but also those with anterior cervical diskectomy and fusion

OBJECTIVE

Anterior bone loss (ABL) was considered as a non-progressive process secondary only to motion-preserving implant and has been noticed recently in cervical disk replacement (CDR) let alone patients with anterior cervical diskectomy and fusion (ACDF). Our purpose is to reveal this unnoticed phenomenon in ACDF and further explore its clinical and radiological outcomes.

METHODS

A total of 77 patients underwent ACDF with a minimum follow-up of at least one year were retrospectively reviewed. The average follow-up time was 22.51 ± 16.31 months. There were 50 patients in group A with ABL, while there were 27 patients in group B without ABL. ABL was measured and classified into four grades according to Kieser's methods. Clinical evaluation, radiological parameters and fusion rate were recorded.

RESULTS

The incidence of bone ABL was 64.9% of Zero-P and 55.2% of endplates. The incidence of upper and lower endplates was 61% and 49%, respectively, and such difference was not significant. Mild ABL occurred in 22%, moderate ABL in 38% and severe ABL of 40% patients underwent ACDF with ABL. ABL would not affect both clinical outcomes and fusion rate. However, ABL would result in a higher incidence of subsidence.

CONCLUSION

ABL should be considered as a common phenomenon that both CDR and ACDF owned a non-progressive process which confined in one year. ABL would result in a higher incidence of subsidence. Luckily, this phenomenon does not have an effect on postoperative clinical and fusion rate.

The application of three-dimensional printed patient-specific drilling templates for expansive open-door laminoplasty: A single-center, prospective randomized controlled study

Background

The choice of trough position in Expansive open-door laminoplasty (EOLP) mostly relied on bony landmarks and surgeons' experience. The present study was to validate the efficacy of the three-dimensional (3D) printed patient-specific drilling templates with the function of locating and depth control for EOLP.

Materials and Methods

A single-center, prospective randomized controlled study was conducted on the patients who underwent unilateral EOLP from August 2019 to December 2020. The 3D printed patient-specific drilling template was fabricated and used in the template group. All the EOLP were performed by a senior surgeon and a junior surgeon. The clinical outcomes and radiographic results were evaluated.

Results

A total of 37 patients who completed the 12-month follow-up were analyzed. The clinical outcomes were significantly improved after surgery in both groups (P < 0.05). The visual analogue scale (VAS) scores were significantly lower in the template group at 12 months postoperatively (P < 0.05). The anteroposterior diameter, Pavlov's ratio and Open angle were all higher in the template group than those in the control group at 3 days and 12 months postoperatively (P < 0.05). The satisfaction of the trough position on both sides and incomplete fracture rate on the hinge side were higher in the template group based on the CT scans taken 3 days after surgery (P < 0.05). To the junior surgeon, the satisfaction and the incomplete fracture rate were significantly higher in the template group compared with those in the control group (P < 0.05).

Conclusion

The application of 3D printed patient-specific drilling templates with the function of locating and depth control for EOLP could improve the outcome of neck pain relief and expand the decompression. It can also improve the satisfaction of the trough position on the open-door side and the hinge side and decrease the complete fracture rate on the hinge side, especially for the junior surgeon.

Cervical disc arthroplasty combined with two-level ACDF for the treatment of contiguous three-level cervical degenerative disc disease: A comparative study

To compare the differences among constructs with one-level cervical disc arthroplasty (CDA) and two-level anterior cervical discectomy and fusion (ACDF). A retrospective study was conducted involving patients who underwent one-level CDA and two-level ACDF between June 2012 and July 2020. According to the different locations of CDA and ACDF, we divided the constructs into three types: type Ⅰa: CDA-ACDF-ACDF; type Ⅰb: ACDF-CDA-ACDF; type Ⅰc: ACDF-ACDF-CDA. The differences of clinical and radiological outcomes were evaluated. Fifty-three patients were included with 29 in type Ⅰa group, 11 in type Ⅰb group, and 13 in type Ⅰc group. After surgery, all groups showed significant improvement in apanese Orthopedic Association, Neck Disability Index, and Visual Analog Scale scores (p < 0.001). Range of motion (ROM) of the total cervical spine in type Ⅰc group decreased significantly compared with those in type Ⅰa and type Ⅰb groups (p < 0.05). No significant differences in ROM of the arthroplasty segment and the variations in ROM of the superior adjacent segment were observed among the three groups. The fusion rates of the superior ACDF segments were significantly higher at 6 and 12 months postoperatively than those of the inferior ACDF segments (p < 0.05). The clinical outcomes were similar among constructs concerning different locations of CDA and ACDF in three-level hybrid surgery. ROM of the cervical spine in type Ⅰc group decreased significantly compared with that in type Ⅰa and type Ⅰb groups. The fusion rates of superior ACDF segments were higher at early time points after surgery than those of inferior ACDF segments.

Does cervical curvature affect neurological outcome after incomplete spinal cord injury without radiographic abnormality (SCIWORA): 1-year follow-up

Background

At present, surgery is the primary clinical treatment for SCIWORA patients, but conservative treatment still plays an important role in patients with incomplete spinal cord injury. As an important index of cervical spine degeneration, cervical curvature has an impact on the prognosis of spinal cord injury patients. This paper studied the prognosis of conservatively treated patients with SCIWORA and the correlation between cervical curvature and neurological prognosis.

Methods

A retrospective study was conducted in all the patients with SCI admitted to the Third Affiliated Hospital of Hebei Medical University between January 2017 and June 2020. Data were recorded in 106 eligible patients, including sex, age, injury factors, Cobb angle, CCI, CSA, and ASIA motor and sensory scores. The Wilcoxon sign rank sum test was used to analyze the data postinjury and at the 1-year follow-up. Pearson correlation analysis was performed for the Cobb angle, CCI and CSA. Simple linear regression analysis and multiple linear regression analysis were performed for each group of variables.

Results

The Wilcoxon signed rank sum test confirmed that the Cobb angle, the CCI and the CSA of the patients were not significantly different at the 1-year follow-up when compared with the postinjury values, and the ASIA motor and sensory scores were significantly improved. The Pearson correlation analysis showed correlations among the Cobb angle, the CCI and the CSA. Simple linear regression analysis and multiple linear regression analysis showed that the nerve recovery rate was negatively correlated with age and was positively correlated with the Cobb angle.

Conclusion

Conservative treatment of incomplete SCIWORA can achieve a good prognosis. There is a clear correlation between the Cobb angle, CCI and CSA, and the Cobb angle, as an important influencing factor, needs to be considered. For SCIWORA patients undergoing nonsurgical treatment, improving cervical curvature is beneficial to the prognosis of patients. Age negatively affects the neurological prognosis.

Classification of three-level hybrid surgery for the treatment of cervical degenerative disc disease: a retrospective study of 108 patients

INTRODUCTION

According to the different numbers and locations of cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF), three-level hybrid surgery (HS) has many constructs. The purpose of the present study was to introduce a classification system for three-level HS and compare the two types with each other and with ACDF.

METHODS

A retrospective study was conducted involving patients with three-level cervical degenerative disc disease (CDDD) who underwent ACDF or HS in our hospital between June 2012 and May 2019. According to the different numbers and locations of ACDFs and CDAs, we classified the three-level HS into two types (type I: one-level CDA and two-level ACDF, and type II: two-level CDA and one-level ACDF). The differences of clinical and radiological outcomes were compared with each other and with three-level ACDF.

RESULTS

A total of 108 patients were analyzed. The Neck Disability Index (NDI) of the ACDF group at 3 months postoperatively was significantly higher than that in the type I and type II groups (p < 0.05). The cervical lordosis was significantly lower in the ACDF group than that in the type I and II groups at 3 days, 6, 12 months postoperatively and the final follow-up (p < 0.05). The range of motion (ROM) of the total cervical spine decreased significantly in all three groups at 3, 6, and 12 months postoperatively and at the final follow-up (p < 0.05). The ACDF group was observed with the most severe loss of ROM of the total cervical spine, followed by the type I group. The type II group could preserve the most ROM of the total cervical spine. The ROM of adjacent segments increased most in the ACDF group, followed by the type I group.

CONCLUSIONS

Compared with ACDF, three-level HS may yield a faster recovery rate and superior radiological outcomes, such as a superiority in maintaining the cervical curvature and ROM of the total cervical spine and a smaller increase in the ROM of adjacent segments. The advantages were most remarkable in the type II group.

Clinical and Radiological Outcomes of Two Modified Open-door Laminoplasties Based on a Novel Paraspinal Approach for Treatment of Multilevel Cervical Spondylotic Myelopathy

STUDY DESIGN

A case-control study.

OBJECTIVES

The aim of this study was to evaluate the outcomes of two modified laminoplasties (LPs) based on a novel paraspinal approach for treating multilevel cervical spondylotic myelopathy.

SUMMARY OF BACKGROUND DATA

No laminoplasty through a natural intermuscular plane mimicking Wiltse approach to minimize intraoperative injury to extensor muscles has ever been developed and studied.

METHODS

Ninety-two patients were enrolled, including patients treated with either modified LP and patients treated with concurrent conventional LP. Operation time, blood loss, and complications were recorded. Clinical outcomes were evaluated by VAS, JOA scores, and recovery rate. Cervical sagittal alignment was measured on cervical radiographs. Spinal canal expansion was assessed on CT scans. Cross-sectional area (CSA) and atrophy rate (AR) of cervical deep extensors were evaluated on MRI.

RESULTS

The average follow-up duration was 33.05, 31.55, 33.02, and 32.52 months, respectively in each group. Compared to concurrent conventional procedure, unilateral muscle-preserving procedure displayed similar, whereas bilateral muscle-preserving procedure showed significantly increased operation time and blood loss; each modified procedure resulted in comparable and satisfied perioperative clinical scores, spinal canal expansion while achieving significantly lower axial pain incidence, better cervical lordosis maintenance, and better deep extensor preservation. AR of deep extensors on the open side was significantly lower than that on the hinge side. Bilateral paraspinal approach demonstrated significantly better muscle-preservation on the open side and increased operation duration, with similar clinical scores, axial pain incidence, cervical lordosis maintenance, and spinal canal expansion compared to unilateral paraspinal approach. Loss of cervical lordosis was strongly correlated with AR of deep extensors.

CONCLUSION

Paraspinal approach is a good manner to protect deep extensor muscles; the two modified LPs have similar effects on clinical outcomes.Level of Evidence: 3.

Etiology and treatment of cervical kyphosis: state of the art review-a narrative review

Objective

To provide state of the art review regarding cervical kyphosis.

Background

Cervical spine kyphosis has been increasingly common due to the growing elderly population. Clinicians should comprehensively understand its symptoms, biomechanics, etiology, radiographic evaluation, classification, and treatment options and complications of each treatment. Comprehensive review will help clinicians improve the management for patients with cervical kyphosis.

Methods

The available literature relevant to cervical kyphosis was reviewed. PubMed, Medline, OVID, EMBASE, and Cochrane were used to review the literature.

Conclusions

This article summarizes current concepts regarding etiology, evaluation, surgical treatment, complications and outcomes of cervical kyphosis. Major etiologies of cervical kyphosis include degenerative, post-laminectomy, and ankylosing spondylitis. Clinical presentations include neck pain, myelopathy, radiculopathy, and problems with horizontal gaze, swallowing and breathing. Cervical lordosis, C2-7 sagittal vertical axis, chin-brow to vertical angle, and T1 slope should be evaluated from upright lateral 36-inch film. The most widely used classification system includes a deformity descriptor and 5 modifiers. A deformity descriptor provides a basic grouping of the deformity consisting of five types, cervical, cervicothoracic, thoracic, coronal cervical deformity, and cranio-vertebral junction deformity. The 5 modifiers include C2-7 sagittal vertical axis, chin-brow to vertical angle, T1 slope minus cervical lordosis, myelopathy based on modified Japanese Orthopaedic Association score, and SRS-Schwab classification for thoracolumbar deformity. Current treatment options include anterior discectomy and fusion, anterior osteotomy, Smith-Peterson osteotomy, pedicle subtraction osteotomy, or a combination of these based on careful preoperative evaluation.

Mid- and Long-Term Follow-Up Efficacy Analysis of 3D-Printed Interbody Fusion Cages for Anterior Cervical Discectomy and Fusion

OBJECTIVE

To evaluate the safety and stability of 3D-printed interbody fusion cages (3D-printed cages) in anterior cervical discectomy and fusion (ACDF) by investigating the mid- and long-term follow-up outcomes.

METHODS

In this prospective study, the clinical data of 30 patients with CSM admitted to the Second Hospital of Shanxi Medical University from May 2012 to May 2014 were analyzed. The cohort comprised 18 males and 12 females with an average age of 60.22 ± 3.2 years. All patients were examined by X-ray, CT and MRI before the operation. A total of 30 cases of CSM were treated by ACDF with 3D printed cage implantation. Mid- and long-term follow-ups were performed after the surgery. Clinical efficacy was evaluated by comparing the JOA score, SF-36 score, change in neurological function, cervical curvature index (CCI), vertebral intervertebral height (VIH) and fusion rate before the operation, 6 months after the operation, and at the last follow-up.

RESULTS

Two of the 30 patients were lost to follow-up. The remaining patients were followed up for 48-76 (65.23 ± 3.54) months. The patients recovered satisfactorily with a significant clinical effect. The JOA score increased meanfully and the improvement rate was 89.4% at the final follow-up. The SF-36 score increased significantly from pre- to postoperatively. The height of the intervertebral space at the last follow-up was not statistically significantly different from that at 6 months after surgery (P > 0.05), showing that the height of the intervertebral space did not change much and the severity of cage subsidence (CS) decreased. The CCI improved from pre- to postoperatively. The CCI did not change much from the 6-month follow-up to the last follow-up. and the cage rate (CR) was 100% at the 6-month and last follow-ups. No severe complications, such as spinal cord injury, esophageal fistula, cerebrospinal fluid leakage, cervical hematoma or wound infection, occurred in any of the patients.

CONCLUSION

The clinical and radiological results show that the application of 3D-printed cages in ACDF can significantly relieve symptoms. Moreover, 3D-printed cages can restore the curvature of the cervical spine, effectively maintain the intervertebral height for a long time, and prevent complications related to postoperative subsidence.

Risk Factors for Axial Symptoms After Anterior Surgery Treating for Multilevel Cervical Disorder with kyphosis

STUDY DESIGN

A retrospective study.

OBJECTIVE

The aim of this study was to investigate the risk factors associated with axial symptoms (AS) after anterior surgery in treatment of multilevel cervical disorder with kyphosis based on subgroup of follow-up time.

SUMMARY OF BACKGROUND DATA

Although many scholars reported on AS after cervical surgery, the risk factors associated with AS are controversial. Few studies have investigated the risk factors of AS after anterior cervical surgery treating multilevel cervical disorder with kyphosis.

METHODS

Totally, 103 patients who suffered from multilevel cervical disorder with kyphosis receiving anterior surgery from July 2015 to June 2017 were reviewed for clinical and radiological outcomes. These data were collected at the time of before surgery, 1 week, 3 months, 6 months, 1 year, and 2 years after surgery. Data were performed to compare between the patients with and without AS.

RESULTS

In our study, the occurrence of AS was 46.6%, 34.0%, 20.4%, 12.6%, and 10.7% at the time of 1 week, 3 months, 6 months,1 year, and 2 years after surgery, respectively. Our findings showed that patients with smoking, disease duration, preoperative Modic changes (Mcs), post-operative Cobb angle of C2-7, cervical range of motion (ROM) and T1 slope, and change of Cobb angle of C2-7, cervical ROM and T1 slope were associated with AS within 1 year after surgery. However, patients with smoking and preoperative Mcs were found to be risk factors associated with AS at at any follow-up.

CONCLUSION

In the present study, many factors were related to AS during 1-year after surgery. What's more, patients with smoking and preoperative Mcs were associated with AS at any follow-up. We hope this article can provide a reference for spinal surgeons to predict which patients were susceptible to suffer from AS after anterior surgery in treatment of multilevel cervical disorder with kyphosis.Level of Evidence: 3.

Radiophobia Overreaction: College of Chiropractors of British Columbia Revoke Full X-Ray Rights Based on Flawed Study and Radiation Fear-Mongering

Fears over radiation have created irrational pressures to dissuade radiography use within chiropractic. Recently, the regulatory body for chiropractors practicing in British Columbia, Canada, the College of Chiropractors of British Columbia (CCBC), contracted Pierre Côté to review the clinical use of X-rays within the chiropractic profession. A "rapid review" was performed and published quickly and included only 9 papers, the most recent dating from 2005; they concluded, "Given the inherent risks of radiation, we recommend that chiropractors do not use radiographs for the routine and repeat evaluation of the structure and function of the spine." The CCBC then launched an immediate review of the use of X-rays by chiropractors in their jurisdiction. Member and public opinion were gathered but not presented to their members. On February 4, 2021, the College announced amendments to their Professional Conduct Handbook that revoked X-ray rights for routine/repeat assessment and management of patients with spine disorders. Here, we highlight current and historical evidence that substantiates that X-rays are not a public health threat. We also point out critical and insurmountable flaws in the single paper used to support irrational and unscientific policy that discriminates against chiropractors who practice certain forms of evidence-based X-ray-guided methods.

The ratio of C2-C7 Cobb angle to T1 slope is an effective parameter for the selection of posterior surgical approach for patients with multisegmental cervical spondylotic myelopathy

BACKGROUND

To our knowledge, laminectomy with fusion (LCF) and laminoplasty alone (LP) are both effective posterior surgical approaches for decompression of cervical spondylotic myelopathy (CSM). However, which one is suitable for patients has no standard answer. This study estimated whether the ratio of C2-C7 Cobb angle to T1 slope (CL/T1S) could be an indication of posterior surgical approach.

METHODS

We retrospectively reviewed 128 patients with at least 6 months of follow-up who underwent LCF or LP. Radiological measurements, including C2-C7 Cobb angle, decompressed Cobb angle, T1 slope, cervical sagittal vertical axis, and curvature index (CI), and clinical outcomes, including Japanese Orthopedic Association score and visual analogue scale were evaluated. ROC curve analysis was used to identify discriminative power of CL/T1S ratio to predict kyphotic deformity and severe lordosis loss. The t-test and Mann-Whitney U-test were used to evaluate the difference between LCF and LP. Kruskal-Wallis H - test and ANOVA were used to evaluate the difference among different ratio CL/T1S groups.

RESULTS

The cervical lordosis decreased after LCF or LP (p < 0.001, p < 0.001, respectively). Based on ROC curve analysis, CL/T1S ratio had a good discriminative power to predict kyphotic deformity and severe lordosis loss (AUC = 0.70, AUC = 0.88, respectively). According to CI value changes, cervical lordosis losses in group LP were larger than that in group LCF (p = 0.006). However, there was no significant difference in CI changes of fair-ratio CL/T1S group between LCF and LP. For patients with low CL/T1S ratio or high CL/T1S ratio, CI changes in group LP were greater than that in group LCF (p = 0.037, p = 0.042, respectively).

CONCLUSIONS

CL/T1S ratio could be an indication of posterior surgical approach. Compared with LP, LCF reduces postoperative cervical lordosis losses in low-ratio and high-ratio CL/T1S groups.

Comparison of long-term clinical and radiographic outcomes between alternative-level and all-level fixation unilateral open-door laminoplasty

BACKGROUND CONTEXT

Titanium mini-plate has been used in unilateral open-door laminoplasty to maintain the open angle of laminae. Previously, both all-level fixation (C3-C7) and alternative-level (C3, C5, C7) unilateral open-door laminoplasty have been proven to have satisfactory clinical outcomes. However, whether they could achieve similar long-term clinical and radiographic efficacy is still questionable.

PURPOSE

To compare the long-term clinical and radiological outcomes between alternative-level and all-level fixation unilateral open-door laminoplasty with a mini-plate fixation system.

STUDY DESIGN/SETTING

Retrospective comparative study.

PATIENT SAMPLE

Ninety-one patients who underwent unilateral open-door laminoplasty.

OUTCOME MEASURES

Clinical results including Japanese Orthopedic Association score, Visual Analogue Score, Neck Dysfunction Index score. Radiographic results including cervical curvature index, cervical range of motion, and the spinal canal expansive parameters, including anteroposterior diameter, Pavlov's ratio, and open angle.

METHODS

Between April 2007 and June 2011, 91 patients with minimum 7-year postoperative follow-up were included. Thirty-eight underwent alternative-level fixation (group A) and 53 underwent all-level fixation (group B). Demographic data, including age, gender, operative time, blood loss, and cost, were collected and compared between the two groups. Clinical and radiographic data were obtained preoperatively, at 3 and 6 months and 1 and 3 years postoperatively, as well as at final follow-up. The difference between the two groups and between different time points within one group was compared.

RESULTS

Both groups obtained satisfactory clinical outcomes till the final follow-up. No statistic difference was found in Japanese Orthopedic Association, Visual Analogue Score, and Neck Dysfunction Index between the two groups throughout the whole follow-up. Both groups maintained APD and Pavlov's ratio well till follow-up. However, statistic difference was found in the open angle between two groups at final follow-up (34.17±2.75° vs. 36.19±1.80°, p<.05). When we subdivided the cervical segments in group A, we found the mini-plate segments showed maintenance in open angle but a 4.52° decrease in suture segments. The mean cost in group B (17,669.82±1,157.65 $) was significantly higher than in group A (11,452.19±871.07 $; p<.05).

CONCLUSIONS

Despite a difference in the maintenance of open angle, both fixation methods achieved satisfactory clinical outcomes. We believe alternative-level fixation is also a safe, effective, and economical fixation method.

Stand-alone polyetheretherketone cages for anterior cervical discectomy and fusion for successive four-level degenerative disc disease without plate fixation

Background:

Anterior cervical discectomy with fusion became the most frequently performed technique for the treatment of symptoms related to cervical disc prolapse. Multilevel anterior cervical discectomy has been combined with anterior cervical plate application to help maintain the cervical lordosis and enhance fusion. This was associated with more soft-tissue separation and retraction with increased incidence of surgically related complications and postoperative dysphagia.

Aim of the Study:

The aim of this study is to evaluate the safety and efficacy of the stand-alone cervical polyetheretherketone (PEEK) cages in four-level discectomy and to determine if it is possible to avoid anterior plate fixation and to achieve satisfactory outcomes.

Methodology:

This is a retrospective study which was performed between June 2011 and December 2018 at one institute. The clinical and radiological data were collected from patients who underwent successive four-level anterior cervical discectomy and fusion with PEEK cages for degenerative cervical disc disease without plate fixation.

Results:

This study included 66 patients, 35 males and 31 females. The follow-up period was 24 months. Mean Japanese Orthopedic Association scores were 13.3 ± 1.41 preoperative and 15.9 ± 0.86 postoperative (P = 0.046). The cervical curvature index “Ishihara” (ICI) was 9.9 ± 5.90 preoperative and the mean of ICI was 10.5 ± 6.65 postoperative, which is insignificant, P = 0.7). The lordotic curvature according to these results was preserved till the end of the year and half of the follow-up period postoperative.

Conclusion:

Consecutive four-level anterior discectomy with PEEK cage interbody fusion without plate and screw is a safe and effective procedure in the absence of instability, and it may be a reliable alternative for the treatment of multilevel cervical disc.

Risk factor analysis of axial symptoms after single-segment anterior cervical discectomy and fusion: A retrospective study of 113 patients

Objective

This retrospective study was performed to investigate the risk factors for axial symptoms (AS) after single-segment anterior cervical discectomy and fusion (ACDF).

Methods

One hundred thirteen patients with cervical spondylosis who had undergone single-segment ACDF from January 2012 to December 2015 were divided into those with and without AS (n = 34 and n = 79, respectively). Clinical data and radiological evaluation results were recorded.

Results

The occurrence rate of AS was 30.1% (34/113), and the average visual analog scale score was 4.5 points. Bony fusion was achieved in all cases during follow-up. There were no differences in age, sex, disease duration, diagnostic categories, operative segment, Japanese Orthopaedic Association score, or adjacent segment degeneration. However, cervical range of motion (CROM), cervical curvature, and disc space enlargement significantly differed between the groups. Logistic regression analysis revealed that CROM, cervical curvature, and disc space enlargement were independently associated with AS.

Conclusions

AS after single-segment ACDF is not rare. Disc space enlargement is a risk factor for AS, while higher CROM and lordotic cervical curvature are protective factors. Excessive or insufficient disc space enlargement could increase the incidence of AS. Maintaining CROM within the normal range and restoring cervical lordosis might help to prevent AS.

Treatment of Mild Cervical Myelopathy: Factors Associated With Decision for Surgical Intervention

STUDY DESIGN

Prospective Cohort OBJECTIVE.: The aim of this study was to evaluate which demographic, clinical, or radiographic factors are associated with selection for surgical intervention in patients with mild cervical spondylotic myelopathy (CSM).

SUMMARY OF BACKGROUND DATA

Surgery has not been shown superior to best conservative management in mild CSM comparative studies; trials of conservative management represent an acceptable alternative to surgical decompression. It is unknown what patients benefit from surgery.

METHODS

This is a prospective study of patients with mild CSM, defined as modified Japanese Orthopaedic Association Score (mJOA) ≥15. Patients were recruited from seven sites contributing to the Canadian Spine Outcomes Research Network. Demographic, clinical, radiographic and health related quality of life data were collected on all patients at baseline. Multivariate logistic regression modeling was used to identify factors associated with surgical intervention.

RESULTS

There were 122 patients enrolled, 105 (86.0%) were treated surgically, and 17 (14.0%) were treated nonoperatively. Overall mean age was 54.8 years (SD 12.6) with 80 (65.5%) males. Bivariate analysis revealed no statistically significant differences between surgical and nonoperative groups with respect to age, sex, BMI, smoking status, number of comorbidities and duration of symptoms; mJOA scores were significantly higher in the nonoperative group (16.8 [SD 0.99] vs. 15.9 [SD 0.89], P < 0.001). There was a statistically significant difference in Neck Disability Index, SF12 Physical Component, SF12 Mental Component Score, EQ5D, and PHQ-9 scores between groups; those treated surgically had worse baseline questionnaire scores (P < 0.05). There was no difference in radiographic parameters between groups. Multivariable analysis revealed that lower quality of life scores on EQ5D were associated with selection for surgical management (P < 0.018).

CONCLUSION

Patients treated surgically for mild cervical myelopathy did not differ from those treated nonoperatively with respect to baseline demographic or radiographic parameters. Patients with worse EQ5D scores had higher odds of surgical intervention.

LEVEL OF EVIDENCE

3.

Comparative effectiveness of all levels miniplate fixation versus a modified hybrid fixation in cervical expansive open-door laminoplasty

In this study, we first reported of a modified hybrid fixation method in expansive open-door laminoplasty (EOLP) in order to reduce medical costs. The purpose of the present study is to compare the surgical outcomes and cost-effectiveness of the modified fixation with all levels miniplate fixation in EOLP for multilevel cervical spondylotic myelopathy.Data of 67 patients who underwent EOLP from July 2015 to June 2016 were retrospectively analyzed, with 33 in the modified group and 34 in the all miniplate group based on their surgical approaches. Laminae were kept open with alternate levels miniplate and anchor fixation in the modified group, while with all levels miniplate fixation in the all miniplate group. Medical costs and clinical results including Japanese Orthopedic Association (JOA) scores, Visual Analogue Scale (VAS) scores and occurrences of complications were investigated and compared between the 2 groups. After evaluation on X-ray, CT, and MRI, radiographic data reflecting cervical alignments, spinal canal enlargement and spinal cord decompression were collected and compared within each group and between the 2 groups.After a follow-up period of about 18 months, no significant differences in operation time, intraoperative blood loss, complication rates, VAS scores, neurological recovery rates and postoperative hospital stays were observed between the 2 groups. However, EOLP with the modified fixation costed less. When comparing the 2 groups, cervical curvature index (CCIs) which reflected cervical alignments and anteroposterior diameters (APDs) reflecting spinal canal enlargement at all the follow-ups had no significant differences. Postoperative open angles which reflected spinal cord decompression of C4 and C6 were significantly smaller in the modified group. However, that difference was no longer detected at the final follow-up. Within each group, APDs increased significantly after surgery. However, no significant differences in CCIs and open angles at different follow-ups were observed in each group.Compared with all miniplate fixation, the modified hybrid fixation in EOLP showed almost the same clinical and radiographic results. However, the modified hybrid fixation method could reduce costs.

Sagittal Alignment Outcomes in Lordotic Cervical Spine: Does Three-Level Anterior Cervical Discectomy and Fusion Outperform Laminoplasty?

STUDY DESIGN

A prospective cohort study.

OBJECTIVE

To compare the radiological outcomes between three-level anterior cervical discectomy and fusion (ACDF) and plate-only open-door laminoplasty (LAMP) in patients with lordotic cervical spine.

SUMMARY OF BACKGROUND DATA

Both three-level ACDF and LAMP are important surgical methods for multilevel cervical spondylotic myelopathy, but the cervical sagittal alignment outcomes and the lordosis preserving abilities between the two specific approaches have not been carefully compared.

METHODS

Sixty patients, all of whom had lordotic cervical spines and underwent three-level ACDF (n = 22) or LAMP (n = 38) for the treatment of multilevel cervical spondylotic myelopathy, were prospectively studied. Upright neutral cervical lateral radiographs were assessed preoperatively, at 3 days after surgery, and at the last follow-up (1.5 years). The primary radiological outcomes are C2-7 Cobb angle, and the secondary outcomes include C2-7 sagittal vertical axis , disc height, Harrison angle, and Ishihara index. The relationship between preoperative parameters and follow-up outcomes were assessed.

RESULTS

Preoperative cervical sagittal alignment parameters were similar between the two groups. Patients in the ACDF group obtained larger C2-7 Cobb angles than those the LAMP group early after surgery. However, the lordosis in the ACDF group decreased significantly during follow-up, leading to similar outcomes between the two groups. The lordosis-preserving ability of ACDF is significantly poorer than that of LAMP. Secondary radiological parameters also showed similar trends. In both groups, the preoperated Ishihara index was significantly related to follow-up C2-7 Cobb angles. For patients with Ishihara index less than 20, ACDF is more likely to produce a larger C2-7 Cobb angled at the time of follow-up.

CONCLUSION

In patients with lordotic cervical spine, the sagittal alignment outcomes of the two approaches were similar, and the lordosis-preserving ability was poorer in ACDF. Further research should focus on the factors related to the lordosis-preserving ability of multilevel ACDF.

LEVEL OF EVIDENCE

3.

Cervical Spine Deformity: Indications, Considerations, and Surgical Outcomes

Cervical spinal deformity (CSD) in adult patients is a relatively uncommon yet debilitating condition with diverse etiologies and clinical manifestations. Similar to thoracolumbar deformity, CSD can be broadly divided into scoliosis and kyphosis. Severe forms of CSD can lead to pain; neurologic deterioration, including myelopathy; and cervical spine-specific symptoms such as difficulty with horizontal gaze, dysphagia, and dyspnea. Recently, an increased interest is shown in systematically studying CSD with introduction of classification schemes and treatment algorithms. Both major and minor complications after surgical intervention have been analyzed and juxtaposed to patient-reported outcomes. An ongoing effort exists to better understand the relationship between cervical and thoracolumbar spinal alignment, most importantly in the sagittal plane.

Anterior and Posterior Segmental Decompression and Fusion for Severely Localized Ossification of the Posterior Longitudinal Ligament of the Cervical Spine: Technical Note

The surgical strategy for severely localized ossification of the posterior longitudinal ligament (OPLL) of the cervical spine is still not straightforward. We describe the surgical technique of extended anterior cervical discectomy and fusion (ACDF) with partial resection of OPLL followed by posterior cervical segmental decompression and fusion (PCDF). This study investigated five patients with severely localized OPLL with an occupying ratio more than 60%. Extended ACDF comprising a modified technique with a trans-unco-discal approach and partial oblique corpectomy was first attempted to achieve neural decompression of the spinal cord and nerve roots at the most prominent level of the OPLL. The OPLL was partially resected to reduce the axial occupying ratio or ensure that the OPLL did not exceed the imaginary line between the midpoint between C2 and C7 on sagittal images. PCDF was then performed to achieve satisfactory decompression of neural elements and cervical stability. One patient underwent one-stage surgery and the remaining four patients underwent two-stage surgery. No patients received spinal cerebrospinal fluid (CSF) drainage and demonstrated CSF leakage after surgery. All patients showed acceptable or satisfactory functional recovery. No instrumentation-related complications were encountered. Radiological analysis demonstrated that all except one patient (OPLL associated with ankylosing spinal hyperostosis) revealed improvements in local angle, C2–7 angle and cervical tilt angle. This anterior and posterior segmental decompression and fusion for severely localized OPLL of the cervical spine remains technically demanding in some parts, but can offer satisfactory decompression of neural elements and stabilization of the cervical spine when applied appropriately.

Cervical lordosis in asymptomatic individuals: a meta-analysis

Background

Cervical lordosis has important clinical and surgical implications. Cervical spine curvature is reported with considerable variability in individual studies. The aim of this study was to examine the existence and extent of cervical lordosis in asymptomatic individuals and to evaluate its relationship with age and gender.

Methods

A comprehensive literature search was conducted in several electronic databases. Study selection was based on pre-determined eligibility criteria. Random effects meta-analyses were performed to estimate the proportion of asymptomatic individuals with lordosis and the effect size of cervical lordotic curvature in these individuals which followed metaregression analysis to examine the factors affecting cervical lordosis. Data from 21 studies (15,364 asymptomatic individuals, age 42.30 years [95% confidence interval 36.42, 48.18], 54.2% males) were used in the present study.

Results

In this population, 63.99% [95% confidence interval 44.94, 83.03] individuals possessed lordotic curvature. Degree of lordotic curvature differed by method of measurement; 12.71° [6.59, 18.84] with Cobb C2–C7 method and 18.55° [14.48, 22.63] with posterior tangent method. Lordotic curvature was not significantly different between symptomatic and asymptomatic individuals but was significantly higher in males in comparison with females. Age was not significantly associated with lordotic cervical curvature.

Conclusion

Majority of the asymptomatic individuals possesses lordotic cervical curvature which is higher in males than in females but have no relationship with age or symptoms.

Immediate reduction under general anesthesia and combined anterior and posterior fusion in the treatment of distraction-flexion injury in the lower cervical spine

BACKGROUND

Distraction-flexion of the lower cervical spine is a severe traumatic lesion, frequently resulting in paralysis. The optimal surgical treatment is controversial. It has been a challenge for orthopedic surgeons to manage distraction-flexion injury in the lower cervical spine while avoiding the risk of iatrogenic damage. Thus, safer strategies need to be designed and adopted.This study aimed to evaluate the clinical efficacy of immediate reduction under general anesthesia and combined anterior and posterior fusion in the treatment of distraction-flexion injury in the lower cervical spine.

METHODS

Twenty-four subjects of traumatic lower cervical spinal distraction-flexion were retrospectively analyzed from January 2010 to December 2013. Traffic accident was the primary cause of injury, with patients presenting with dislocated segments in C4-5 (n = 8), C5-6 (n = 10), and C6-7 (n = 6). Sixteen patients had unilateral facet dislocation and eight had bilateral facet dislocation. Spinal injuries were classified according to the American Spinal Injury Association (ASIA) impairment scale (2000 edition amended), with four cases of grade A, four cases of grade B, ten cases of grade C, four cases of grade D, and two cases of grade E. On admission, all patients underwent immediate reduction under general anesthesia and combined anterior and posterior fusion. The mean follow-up time was 3.5 years.

RESULTS

All operations were completed successfully, with no major complications. Postoperative X-rays showed satisfactory height for the cervical intervertebral space and recovery of the vertebral sequence. Bone fusion was completed within 4 to 6 months after surgery. Surgery also significantly improved neurological function in all patients.

CONCLUSION

Immediate reduction under general anesthesia and combined anterior and posterior fusion can be used to successfully treat distraction-flexion injury in the lower cervical spine, obtaining completed decompression, safe spinal re-alignment, and excellent immediate postoperative stability.

Clinical and radiographic outcome of dynamic cervical implant (DCI) arthroplasty for degenerative cervical disc disease: a minimal five-year follow-up

Background

To evaluate the mid- to long-term clinical and radiographic outcomes of anterior cervical discectomy and dynamic cervical implant (DCI) arthroplasty for degenerative cervical disc disease.

Methods

From April 2010 to October 2010, 38 patients with single- or double-level cervical disc herniation underwent anterior cervical discectomy and DCI arthroplasty. The clinical results and radiographic outcomes of these 38 patients (42 levels) were retrospectively evaluated. The clinical results included the visual analogue scale, Japanese Orthopaedic Association score, Neck Disability Index score, 36-item short form health survey questionnaire, and incidences of complications and neurological deterioration. Radiographic results including cervical alignment, intervertebral height, cervical range of motion (ROM), ROM of the functional spinal unit, adjacent intervertebral ROM, migration, subsidence, and heterotopic ossification (HO) were assessed on plain radiography, three-dimensional computed tomography, and magnetic resonance imaging.

Results

The mean follow-up period was 72.3 months (range 68–78 months). During follow-up, all patients showed significant improvements in the visual analogue scale score, Japanese Orthopaedic Association score, Neck Disability Index score, 36-item short form health survey physical component summary score and mental component summary score. The ROM of the functional spinal unit was partly reduced. The DCI migrated forward in 10 of 42 (23.8%) cases, and HO was detected in 24 of the 42 (57.1%) DCI segments. Subsidence was observed in 14 of 42 (33.3%) DCI segments. Two patients experienced symptom recurrence, and were treated conservatively.

Conclusions

The clinical efficacy of DCI arthroplasty was maintained during mid- to long-term follow-up. HO formation is a common phenomenon, leading to a substantial decrease in ROM at the index level and recurrence of neurological symptoms. The incidence of implant subsidence and migration is relatively high, leaving a potential risk of symptoms at the index level and adjacent segment degeneration. We consider that the first choice for patients with degenerative cervical disc disease should still be total disc replacement or anterior cervical discectomy and fusion, rather than DCI arthroplasty.

Cervical Spine Deformity-Part 1: Biomechanics, Radiographic Parameters, and Classification

Cervical spine deformities can have a significant negative impact on the quality of life by causing pain, myelopathy, radiculopathy, sensorimotor deficits, as well as inability to maintain horizontal gaze in severe cases. Many different surgical options exist for operative management of cervical spine deformities. However, selecting the correct approach that ensures the optimal clinical outcome can be challenging and is often controversial. We aim to provide an overview of cervical spine deformity in a 3-part series covering topics including the biomechanics, radiographic parameters, classification, treatment algorithms, surgical techniques, clinical outcome, and complication avoidance with a review of pertinent literature.

Management of Severe Lower Cervical Facet Dislocation without Vertebral Body Fracture Using Skull Traction and an Anterior Approach

BACKGROUND Cervical facet dislocation is the anterior displacement of one cervical vertebral body on another. The aim of this study was to evaluate the clinical efficacy of skull traction through an anterior cervical approach in the treatment of severe lower cervical facet dislocation without vertebral body fracture. MATERIAL AND METHODS Forty subjects with severe lower cervical facet dislocation, without vertebral body fracture, were treated between February 2010 and December 2013. Road traffic accident was the primary cause of injury. Patients presented with dislocated segments in C3-C4 (n=4), C4-C5 (n=4), C5-C6 (n=12), and C6-C7 (n=20). Twenty-six patients had unilateral facet dislocation, and 14 patients had bilateral facet dislocation. Spinal injuries were graded according to the American Spinal Injury Association (ASIA) impairment scale and included grade A (eight cases), grade B (six cases), grade C (six cases), grade D (12 cases), and grade E (eight cases). The mean follow-up time was 4.2 years. RESULTS All procedures were completed successfully, with no major complications. Postoperative X-rays showed satisfactory height for the cervical intervertebral space and recovery of the vertebral sequence. Bone fusion was completed within four to six months after surgery. Surgery significantly improved neurological function in all patients. CONCLUSIONS Skull traction and an anterior approach can be used to successfully treat severe lower cervical facet dislocation, obtaining complete decompression, good reduction, and maintenance of intervertebral height with retention of the physiological curvature of the cervical spine.

The Reliabilities of Several Measurement Methods of Cervical Sagittal Alignment in Cases with Cervical Spine Rotation Using X-ray Findings in Cervical Spine Disorders

Introduction

Several measurement methods designed to provide an understanding of cervical sagittal alignment have been reported, but few studies have compared the reliabilities of these measurement methods. The purpose of the present study was to investigate the intraexaminer and interexaminer reliabilities of several cervical sagittal alignment measurement methods and of the rotated cervical spine using plain lateral cervical spine X-rays of patients with cervical spine disorders.

Methods

Five different measurement methods (Borden's method; Ishihara index method (Ishihara method); C2-7 Cobb method (C2-7 Cobb); posterior tangent method: absolute rotation angle C2-7 (ARA); and classification of cervical spine alignment (CCSA)) were applied by seven examiners to plain lateral cervical spine X-rays of 20 patients (10 randomly extracted cases from a rotated cervical spine group and 10 from a nonrotated group) with cervical spine disorders. Case 1 and Case 2 intraclass correlation coefficients (ICCs) were used to analyze intraexaminer and interexaminer reliabilities. The necessary number of measurements and the necessary number of examiners were also determined. The target coefficient of correlation was set at ≥0.81 (almost perfect ICC).

Results

In both groups, an ICC(1, 1) ≥ 0.81 was obtained with Borden's method, the Ishihara method, C2-7 Cobb, and ARA by all examiners. The necessary number of measurements was 1. With CCSA, a kappa coefficient of at least 0.9 was obtained. In both groups, with Borden's method, the Ishihara method, C2-7 Cobb, and ARA, the ICC(2, 1) was ≥0.9, indicating that the necessary number of examiners was 1. The standard error of measurement (SEM) was lowest with Borden's method, and the Ishihara method and C2-7 Cobb had almost the same values.

Conclusions

Among cervical sagittal alignment measurement methods for cervical spine disorders, regardless of cervical spine rotation, Borden's method, Ishihara method, and C2-7 Cobb offer stronger reliability in terms of the ICC and SEM.

Incidence and risk factors of poor clinical outcomes in patients with cervical kyphosis after cervical surgery for spinal cord injury

Objective

This retrospective study investigated the incidence and risk factors of poor clinical outcomes after cervical surgery for cervical spinal cord injury in a large population of patients with global or segmental cervical kyphosis.

Methods

The clinical and radiological evaluation results of 269 patients with cervical kyphosis who underwent either anterior or posterior surgery between 2008 and 2013 were collected, preoperatively and at each follow-up after surgery.

Results

All patients were followed for an average of 2.5 years. Outcomes were classified as good or poor (n=156 and 113 patients, respectively), based on the Japanese Orthopedic Association (JOA) recovery ratios. The rates of patients with good or poor outcomes were statistically comparable with regard to gender ratio, type of injury, history of diabetes or cardiovascular disease, interval between injury and surgery, and follow-up time. The multivariate logistic regression analysis indicated that the following were independent predictors of poor improvement: patient age (P=0.016, odds ratio [OR] =1.0261); preoperative JOA scores (P=0.003, OR =0.1932); and cervical instability (P=0.004, OR =2.1562).

Conclusion

This study showed that advanced age, low preoperative JOA score, and cervical instability are closely associated with a poor surgical outcome in patients with cervical kyphosis. However, these results do not suggest that the type of cervical kyphosis influences the clinical outcome of surgery.

Comparing the Effectiveness of Sagittal Balance, Foraminal Stenosis, and Preoperative Cord Rotation in Predicting Postoperative C5 Palsy

STUDY DESIGN

Retrospective cohort review.

OBJECTIVE

To determine whether preoperative cord rotation is independently correlated with C5 palsy when analyzed alongside measures of sagittal balance and foraminal stenosis.

SUMMARY OF BACKGROUND DATA

Postoperative C5 palsy is a well-documented complication of cervical procedures with a prevalence of 4%-8%. Recent studies have shown a correlation with preoperative spinal cord rotation. There have been few studies, however, that have examined the role of sagittal balance and foraminal stenosis in the development of C5 palsy.

METHODS

A total of 77 patients who underwent cervical decompression-10 of whom developed C5 palsy-were reviewed. Sagittal balance was assessed using curvature angle and curvature index on radiographs and magnetic resonance image (MRI). Cord rotation was assessed on axial MRI. C4-C5 foraminal stenosis was assessed on sagittal MRI using area measurements and a grading scale. Demographics and information on surgical approach were gathered from chart review. Correlation with C5 palsy was performed by point-biserial, χ, and regression analyses.

RESULTS

Point-biserial analysis indicated that only cord rotation showed significance (P<0.01). There was no statistical significance shown with surgical approach, sex, or age. In addition, changes in sagittal balance did not correlate with presence of C5 palsy. Logistic regression model yielded cord rotation as the only significant independent predictor of C5 palsy. For every degree of axial cord rotation, the likelihood ratio for suffering a C5 palsy was 3.93 (95% confidence interval, 2.01-8.66; P<0.05).

CONCLUSIONS

This supports the independent capability of preoperative cord rotation to predict postoperative C5 palsy. Lack of correlation with measures of neuroforaminal stenosis potentially points to mechanisms other than direct compression as the etiology. In addition, the lack of correlation with postoperative changes in sagittal balance hints that measures of curvature angle and curvature index may not be appropriate to accurately predict this complication.

LEVEL OF EVIDENCE

Level 3.

Characteristics of Modic changes in cervical kyphosis and their association with axial neck pain

BACKGROUND

The purpose of this study was to evaluate characteristics of Modic changes in cervical kyphosis (CK) and their association with axial neck pain.

METHODS

Study participants included 286 asymptomatic or symptomatic patients with CK (mean age = 54.2 ± 12.2 years) who were consecutively enrolled from March 2009 to October 2015. Clinical and radiographic evaluations were performed at a university outpatient department. CK was classified as global type, reverse sigmoid type, or sigmoid type.

RESULTS

There were 138 participants with global type CK, 103 with reverse sigmoid type CK, and 45 with sigmoid type CK. Of the 286 participants, 102 had Modic changes (Modic-1 in 38 segments and Modic-2 in 75 segments). Spinal cord compression grade and disc degeneration occurred more frequently in the group with axial neck pain compared to the group without pain. Angular motion was decreased in those with axial neck pain (mean ± standard deviation [SD] 7.8°±4.6°) compared to those who were asymptomatic (mean ± SD 8.9°±5.1°; P<0.001). In multivariate logistic regression analysis, Modic changes were associated with axial neck pain (odds ratio =5.356; 95% confidence interval =1.314-12.800; P<0.001).

CONCLUSION

Modic changes occur most commonly in association with CK global type and less commonly with reverse sigmoid type and sigmoid type. Modic changes are associated with axial neck pain in patients with CK.

A Radiographic Analysis of Cervical Sagittal Alignment in Adolescent Idiopathic Cervical Kyphosis

OBJECTIVE

The aim of this study was to analyze the radiologic features of adolescent idiopathic cervical kyphosis.

SUMMARY OF BACKGROUND DATA

There are few previous reports about radiographic analysis of cervical sagittal alignment of adolescent idiopathic cervical kyphosis. A new method was proposed in this article to evaluate the severity of cervical kyphosis.

PATIENTS AND METHODS

A total of 41 adolescent patients with cervical kyphosis were reviewed. Several angles were measured from the radiographs utilizing the 2-line Cobb method and Harrison posterior tangent method. Ishihara's Curvature Index (CI), Kyphosis Index (KI), kyphosis levels, and the apex of the kyphosis were also measured.

RESULTS

The results showed that the apex of the kyphosis is located at the posterior-superior edge of C4 (70.7%) and C5 (29.3%). C2-C7 angles ranged from 4.7 to 71.3 degrees (36.2±13.6 degrees) and from 9.8 to 83.1 degrees (36.4±15.1 degrees) in the above 2 methods, respectively. Local angles of kyphotic area ranged from 21.8 to 96.3 degrees (50.5±23.7 degrees) in 2-line Cobb method and from 19.8 to 105.6 degrees (52.0±19.5 degrees) in Harrison posterior tangent method. CI and KI ranged from 8.6 to 79.8 (36.8±16.7) and 15.2 to 141.9 (50.6±23.7), respectively. Statistical analysis showed that there was significant positive correlation between KI and kyphosis angle.

CONCLUSIONS

In adolescent idiopathic cervical kyphosis, the alteration of the sagittal profile only occurs on partial cervical alignment rather than the whole cervical spine. The apex of the kyphosis locates at posterior-superior edge of the vertebrae. It seems that KI can accurately depict the severity of cervical kyphosis.

Safe placement of lateral mass screw in the subaxial cervical spine: a case series

PURPOSE

Laminectomy with lateral mass screw fixation has been proven to be an effective method to treat the multilevel cervical degenerative myelopathy and severe cervical spondylosis. However, accurate and safe insertion of the lateral mass screw is technically demanding due to the individual variations of the anatomy of the lateral mass of the subaxial cervical spine. Misplaced lateral mass screw is not uncommon, and operation-related complications still beset the surgeons, which may impair the clinical outcomes. This study aimed to introduce a novel strategy for safe and accurate insertion of lateral mass screw in the subaxial cervical spine.

METHODS

From July 2014 to March 2015, 24 patients with multilevel cervical degenerative myelopathy at C3-C6 levels received laminectomy. Before the operation, the screw insertion technique depended on the pre-operative imaging and operative exploration. Following this strategy, the lateral mass screws were inserted into the subaxial cervical spines. Post-operative radiograph was performed to observe the locations of the lateral mass screws and the cervical curvature. Patients were followed up, and the functional neurological recovery was evaluated by the modified Japanese Orthopedic Association (JOA) disability scale, the Neck Disability Index (NDI) and NDI ranking system.

RESULTS

All screws were inserted into the lateral mass of C3-C6 cervical vertebrae following the current technique. Post-operative CT scans confirmed all screws inserted into the safe zone and relative safe zone of the lateral mass without any screw placed into the transverse foramen. The angle between the lateral mass screw and the vertical line was 40.49 ± 5.44 degrees on the axial CT images. Twenty-four patients were followed up for an average of 25.79 months (range, 20-30 months), and 22 cases evaluated as no or mild disability. According to the JOA score, NDI score and NDI ranking system, the postoperative function of the patients was significantly better when compared with their preoperative corresponding data (all p < 0.001) CONCLUSION: Inserting lateral mass screw following this new strategy is safe and easy to perform without any screw-related neurovascular complications, which contribute to the rigid fixation of the subaxial cervical spine and the satisfactory functional recovery.

Magnetic Resonance Imaging of the Cervical Spine Under-Represents Sagittal Plane Deformity in Degenerative Myelopathy Patients

BACKGROUND

In treating patients with cervical myelopathy, surgical approach may be dictated by sagittal balance, highlighting the need for accurate pre-operative assessment. Magnetic Resonance Imaging (MRI) is widely-recognized for its utility in the diagnosis and surgical planning of cervical myelopathy. Plain radiographs (X-rays) are a reliable tool to assess bony alignment. However, they may not always be included in standard pre-operative evaluation, especially in an era of restricted payer-environments. Failure to appropriately acknowledge a patients' preoperative kyphotic deformity may cause the surgeon to choose a posterior-only approach, which would provide suboptimal sagittal plane correction and decompression of anterior pathology.

METHODS

101 patients with cervical myelopathy with MRI and plain radiographs were identified. Cervical lordosis and kyphosis were measured using the Cobb method on standing lateral x-ray and sagittal T2-weighted MRI. CI (Ishihara) was also measured on standing lateral x-ray, and sagittal T2-weighted MRI. Bland-Altman plots were generated and used to compare subtle differences in measurement techniques and modalities. Odom's criteria were recorded.

RESULTS

The average difference between plain radiograph and MRI measurements for curvature angle was 3.5± 7.2 degrees (p< 0.001), and the average difference between plain radiograph and MRI measurements for curvature index was 1.5± 5.9 degrees (p= 0.015).

CONCLUSIONS

MRI may under-represent the respective sagittal plane deformity in patients with degenerative cervical myelopathy.

CLINICAL RELEVANCE

We would recommend the use of standing x-rays when considering surgical planning in all myelopathy patients. This manuscript was reviewed and approved by an institutional review board. Informed consent was not obtained because patient specific identifying information was not used. It was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments.

Different Approaches for Treating Multilevel Cervical Spondylotic Myelopathy: A Retrospective Study of 153 Cases from a Single Spinal Center

Objective

The optimal surgical treatment for multilevel cervical spondylotic myelopathy (MCSM) remains controversial. This study compared the outcomes of three surgical approaches for MSCM treatment, focusing on the efficacy and safety of a combined approach.

Methods

This retrospective study included 153 consecutive MCSM patients (100 men, 53 women; mean age ± standard deviation, 55.7 ± 9.4 years) undergoing operations involving ≥3 intervertebral segments. The patients were divided into three groups according to surgical approach: anterior (n = 19), posterior (n = 76), and combined (n = 58). We assessed demographic variables, perioperative parameters, and clinical outcomes ≥12 months after surgery (20.5 ± 7.6 months), including Japanese Orthopaedic Association (JOA) score, improvement, recovery rate, and complications.

Results

The anterior group had the most favorable preoperative conditions, including the highest preoperative JOA score (12.95 ± 1.86, p = 0.046). In contrast, the combined group had the highest occupancy ratio (48.0% ± 11.6%, p = 0.002). All groups showed significant neurological improvement at final follow-ups, with JOA recovery rates of 59.7%, 54.6%, and 68.9% in the anterior, posterior, and combined groups, respectively (p = 0.163). After multivariable adjustments, the groups did not have significantly different clinical outcomes (postoperative JOA score, p = 0.424; improvement, p = 0.424; recovery rate, p = 0.080). Further, subgroup analyses of patients with occupancy ratios ≥50% showed similar functional outcomes following the posterior and combined approaches. Overall complication rates did not differ significantly among the three approaches (p = 0.600). Occupancy ratios did not have a significant negative influence on postoperative recovery following the posterior approach.

Conclusions

If applied appropriately, all three approaches are effective for treating MCSM. All three approaches had equivalent neurological outcomes, even in subgroups with high occupancy ratios. Further investigations of surgical approaches to MCSM are needed, particularly prospective multicenter studies with long-term follow-up.

The role of iatrogenic foraminal stenosis from lordotic correction in the development of C5 palsy after posterior laminectomy and fusion

Background

Post-operative C5 nerve root palsy is a known complication following cervical spine surgery. Although several theories have been proposed, there remains no consensus as to the etiology of the palsies. Multiple pre-operative radiographic measures have been assessed for utility in predicting palsy. The purpose of this study is to evaluate published radiographic parameters as well as specifically evaluate the effect of cervical lordosis in the development of C5 palsy to establish thresholds that reliably predict the incidence.

Methods

This study is a retrospective review of 54 consecutive multilevel cervical laminectomy and fusion surgeries performed by a single spine surgeon between June 2007 and February 2014. Pre-operative MRI and pre- and post-operative plain films were assessed to measure anteroposterior diameter (APD) of the spinal cord, cervical laminar angles, anteroposterior foraminal diameters (FD), cervical curvature index (Ishihara), cervical spine angle (C2-7), and C4-5 angle. Univariate analysis through independent t tests was used to compare differences between groups. Stepwise logistic regression was performed to identify pre-operative variables associated with C5 palsy. Receiver operating characteristic curves were created for significant variables to assess predictive accuracy through determining the area under the curve.

Results

There were 13 (24 %) palsies in the 54 patients in the study. All palsies completely resolved within 6 months. Among pre-operative measures, FD and APD were significantly different between the palsy and non-palsy groups. The average post-operative C4-5 angle was significantly different between the groups, though the cervical spine angle and curvature index, as well as the change in these measures from pre-operative measurements, did not differ significantly between groups.

Conclusions

Post-operative palsy is likely a result of iatrogenic nerve root compression from a decreased in cross-sectional area of the neuroforamen in a patient with pre-operative narrowing of the foramen. However, spinal cord drift back may also play a role from the combined effect of posterior decompression from laminectomy and relative slack afforded by increased lordosis. Accordingly, increased post-operative lordosis would increase the likelihood of effect from both of these mechanisms. We recommended limited conservative lordotic correction in patients with pre-operative foraminal narrowing.

Expansive Open-Door Cervical Laminoplasty: In Situ Reconstruction of Extensor Muscle Insertion on the C2 Spinous Process Combined With Titanium Miniplates Internal Fixation

Retrospective cohort study. To evaluate efficacy and relevant problems of in situ reconstruction of extensor muscle insertion on the C2 spinous process combined with titanium miniplates internal fixation in expansive open-door cervical laminoplasty in order to improve surgical treatment effect. Expansive open-door cervical laminoplasty has been widely applied in clinical practice, but there are a series of postoperative problems. Therefore, decreasing postoperative complications in order to more effectively relieve symptoms remains a subject for additional research. From October 2011 to September 2013, a total of 60 patients who suffered cervical canal stenosis were treated by expansive open-door laminoplasty with in situ reconstruction of extensor muscle insertion on the C2 spinous process combined with titanium miniplates internal fixation. Changes of cervical curvature index (CI) and range of motion (ROM) were calculated using data from preoperative and postoperative cervical spine X-ray examinations. Clinical function was scored using the Japanese Orthopedics Association Scoring System (JOA) and the neck disability index (NDI). The mean CI before the operation and at 1-year postoperation were 10.49% ± 3.93% and 14.14 ± 2.85 (P < 0.05). The mean ROM values were 43.35 ± 7.55 before the operation, 34.83 ± 7.41 at 1-year postoperation (P < 0.05). The NDI scores decreased from 19.42 ± 4.12 to 7.37 ± 2.58, and the JOA scores increased from 8.87 ± 1.99 to 13.55 ± 1.72, representing significant improvement (P < 0.05). One patient had postoperative C5 nerve root palsy and completely recovered 1 month later. Neither collapse nor door closure in the open-door side occurred in any of the patients. Expansive open-door cervical laminoplasty with in situ reconstruction of extensor muscle insertion on the C2 spinous process combined with titanium miniplates internal fixation is a safe and effective surgical method, and can effectively decrease postoperative complications and achieve satisfactory clinical results.

Cervical interfacet spacers and maintenance of cervical lordosis

OBJECT The cervical interfacet spacer (CIS) is a relatively new technology that can increase foraminal height and area by facet distraction. These offer the potential to provide indirect neuroforaminal decompression while simultaneously enhancing fusion potential due to the relatively large osteoconductive surface area and compressive forces exerted on the grafts. These potential benefits, along with the relative ease of implantation during posterior cervical fusion procedures, make the CIS an attractive adjuvant in the management of cervical pathology. One concern with the use of interfacet spacers is the theoretical risk of inducing iatrogenic kyphosis. This work tests the hypothesis that interfacet spacers are associated with loss of cervical lordosis. METHODS Records from patients undergoing posterior cervical fusion at Rush University Medical Center between March 2011 and December 2012 were reviewed. The FacetLift CISs were used in all patients. Preoperative and postoperative radiographic data were reviewed and the Ishihara indices and cervical lordotic angles were measured and recorded. Statistical analyses were performed using STATA software. RESULTS A total of 64 patients were identified in whom 154 cervical levels were implanted with machined allograft interfacet spacers. Of these, 15 patients underwent anterior-posterior fusions, 4 underwent anterior-posterior-anterior fusions, and the remaining 45 patients underwent posterior-only fusions. In the 45 patients with posterior-only fusions, a total of 110 levels were treated with spacers. There were 14 patients (31%) with a single level treated, 16 patients (36%) with two levels treated, 5 patients (11%) with three levels treated, 5 patients (11%) with four levels treated, 1 patient (2%) with five levels treated, and 4 patients (9%) with six levels treated. Complete radiographic data were available in 38 of 45 patients (84%). On average, radiographic follow-up was obtained at 256.9 days (range 48-524 days). There was no significant difference in the Ishihara index (5.76 preoperatively and 6.17 postoperatively, p = 0.8037). The analysis had 80% power to detect a change of 4.25 in the Ishihara index at p = 0.05. There was no significant difference in the preand postoperative cervical lordotic angles (35.6° preoperatively and 33.6° postoperatively, p = 0.2678). The analysis had 80% power to detect a 7° change in the cervical lordotic angle at p = 0.05. The ANOVA of the Ishihara index and cervical lordotic angle did not show a statistically significant difference in degree of change in cervical lordosis among patients with a different number of levels of CIS insertion (p = 0.25 and p = 0.96, respectively). CONCLUSIONS In the authors' experience of placing CISs in more than 100 levels, they found no evidence of significant loss of cervical lordosis. The long-term impacts of these implants on fusion rates and clinical outcomes (particularly radiculopathy and postoperative C-5 palsies) remain active areas of interest and fertile ground for further studies.

Fusion-nonfusion hybrid construct versus anterior cervical hybrid decompression and fusion: a comparative study for 3-level cervical degenerative disc diseases

STUDY DESIGN

A retrospective analysis.

OBJECTIVE

This study aimed to compare the safety and efficacy between the fusion-nonfusion hybrid construct (HC: anterior cervical corpectomy and fusion plus artificial disc replacement, ACCF plus cADR) and anterior cervical hybrid decompression and fusion (ACHDF: anterior cervical corpectomy and fusion plus discectomy and fusion, ACCF plus ACDF) for 3-level cervical degenerative disc diseases (cDDD).

SUMMARY OF BACKGROUND DATA

The optimal anterior technique for 3-level cDDD remains uncertain. Long-segment fusion substantially induced biomechanical changes at adjacent levels, which may lead to symptomatic adjacent segment degeneration. Hybrid surgery consisting of ACDF and cADR has been reported with good results for 2-level cDDD. In this context, ACCF combining with cADR may be an alternative to ACHDF for 3-level cDDD.

METHODS

Between 2009 and 2012, 28 patients with 3-level cDDD who underwent HC (n=13) and ACHDF (15) were retrospectively reviewed. Clinical assessments were based on Neck Disability Index, Japanese Orthopedic Association disability scale, visual analogue scale, Japanese Orthopedic Association recovery rate, and Odom criteria. Radiological analysis included range of motion of C2-C7 and adjacent segments and cervical lordosis. Perioperative parameters, radiological adjacent-level changes, and the complications were also assessed.

RESULTS

HC showed better Neck Disability Index improvement at 12 and 24 months, as well as Japanese Orthopedic Association and visual analogue scale improvement at 24 months postoperatively (P<0.05). HC had better outcome according to Odom criteria but not significantly (P>0.05). The range of motion of C2-C7 and adjacent segments was less compromised in HC (P<0.05). Both 2 groups showed significant lordosis recovery postoperatively (P<0.05), but no difference was found between groups (P>0.05). The incidence of adjacent-level degenerative changes and complications was higher in ACHDF but not significantly (P>0.05).

CONCLUSION

HC may be an alternative to ACHDF for 3-level cDDD due to the equivalent or superior early clinical outcomes, less compromised C2-C7 range of motion, and less impact at adjacent levels.

LEVEL OF EVIDENCE

3.

Effect of cervical kyphotic deformity type on the motion characteristics and dynamic spinal cord compression

STUDY DESIGN

Retrospective analysis of kinematic magnetic resonance images.

OBJECTIVE

To provide baseline data on the segmental angular and translational motion of the degenerated cervical spine by subtype of kyphotic cervical deformity and to elucidate the relationship between motion and degree of spinal cord compression.

SUMMARY OF BACKGROUND DATA

Kyphotic deformities of the cervical spine are relatively common and are classified as either global or focal. Nevertheless, the effects of kyphotic subtype on cervical segmental motion and degree of spinal cord compression are unknown.

METHODS

A total of 1171 symptomatic patients (618 females, 553 males) underwent cervical kinematic magnetic resonance imaging in the neutral, flexion, and extension positions. Cervical spines demonstrating kyphosis were included and classified into 3 groups: (1) "global kyphotic deformity" (C-type) (n = 54); (2) "sigmoid deformity" (S-type) with kyphotic upper and lordotic lower cervical segments (n = 29); and (3) "reverse sigmoid deformity" (R-type) with lordotic upper and kyphotic lower cervical segments (n = 39). Translational motion, angular motion, and degree of spinal cord compression were evaluated for each cervical level along with the changes associated with flexion and extension.

RESULTS

In the C- and R-types, angular motion with extension was increased in the upper cervical spine, where there was kyphosis; when compared with the S-type, in which there was lordosis in the upper segments. The results were opposite for flexion angular motion. R-type displayed more translational motion at C3-C4 and C5-C6. Degree of static spinal cord compression of R-type was higher than the others at C3-C4. The dynamic spinal cord compression increased in extension more than flexion in all subtypes.

CONCLUSION

Cervical spine studies that aim to investigate kyphotic deformities should make efforts to discern the different subtypes of kyphotic deformities to more accurately characterize and study the effects that the sagittal alignment has on the kinematics of the spine and the degree of spinal cord compression.

Depression contributed an unsatisfactory surgery outcome among the posterior decompression of the cervical spondylotic myelopathy patients: a prospective clinical study

Posterior decompression surgery was performed on 610 patients (mean age 62 years) with clinically and radiologically defined cervical spondylotic myelopathy (CSM) at Tianjin Medical University General Hospital, between October 2007 and October 2011. After 2-year follow-up, we had a full data sets from 396 patients with normal mood or continued depression during the whole process to be compared. Depression was assessed with the 21-item Beck Depression Inventory. Physical functioning and pain were assessed with the modified Japanese Orthopedic Association (mJOA) scoring system, neck disability index (NDI), and visual analog scale (VAS). There were statistically significant differences from baseline to 2-year follow-up between normal mood (n = 258) and continuous depression (n = 138) groups in mJOA score (6.76 ± 3.12 vs. 1.42 ± 0.56, respectively; p < 0.01), VAS (23.85 ± 20.79 vs. 16.08 ± 19.76, respectively; p < 0.01), and NDI (21.11 ± 11.36 vs. 7.31 ± 2.18; p < 0.05). The adverse consequences of depression are supported by previous findings that patients with depression suffer more unsatisfactory surgery outcome than the patients with normal mood. We emphasize that patients with continuous depression show poorer improvement after posterior decompression in CSM patients with respect to symptom severity, pain intensity, and the disability score than patients without depression at any stage.

Enlarged laminectomy and lateral mass screw fixation for multilevel cervical degenerative myelopathy associated with kyphosis

BACKGROUND CONTEXT

Either an anterior approach or a posterior approach, which aims to decompress the spinal cord and restore the sagittal alignment, has been adopted to treat multilevel cervical degenerative myelopathy (CDM) associated with kyphosis. However, there is controversy on the optimal surgical strategy for the treatment of multilevel CDM with kyphotic deformity because of the complications of each surgical approach.

PURPOSE

The purpose of this study was to investigate the surgical efficacy of enlarged laminectomy (removing the inside edge of facet joints and decompressing the nerve foramina) and lateral mass screw fixation for the treatment of multilevel CDM associated with kyphosis.

STUDY DESIGN

A retrospective radiographic and clinical study to access the efficacy of enlarged laminectomy with lateral mass screw fixation in the treatment of multilevel CDM related to kyphosis.

PATIENT SAMPLE

A total of 43 patients (28 men and 15 women; average age, 59.6 years) with multilevel CDM correlated to kyphosis were obtained in the study.

OUTCOME MEASURES

All radiological data were recorded on computer-based measurement from preoperative or postoperative X-ray, magnetic resonance imaging (MRI), and computed tomography. All neurological parameters were accessed in each patient.

METHODS

Analysis consisted of: Japanese Orthopedic Association (JOA) score, recovery rate, curvature index (CI), the expansion degree and drift-back distance of the spinal cord, axial symptom severity, and C5 root palsy. The recovery rate based on the JOA score was calculated for each patient. Cervical CI as well as the expansion degree and drift-back distance of the spinal cord was measured using MRI. Axial symptom severity was quantified by a visual analog scale (VAS). Statistical analysis was performed using paired t test with significance set at p<.05.

RESULTS

Enlarged laminectomy was performed over a mean of 3.97 levels (range, 3-5 levels). Follow-up information was obtained at a mean of 2.8 years (range, 1.5-5 years) after surgery. Analysis of the final follow-up data showed significant differences before and after surgery in the JOA score (t=24.17, p<.001), CI improvement (t=21.89, p<.001), the anteroposterior diameter at the level of maximum compression of the spinal cord (t=9.54, p<.001), and VAS score (t=13.30, p<.001). The mean spinal cord posterior shift was 4.72±1.10 mm (range, 0-6.71 mm). X-rays confirmed that bone grafts were completely fused at a mean of 3 months after surgery. During the follow-up period, only two patients (4.7%) did not obtain complete recovery, four patients (9.3%) experienced axial symptoms; there were no C5 root palsy and instrument failures noted in this series.

CONCLUSION

Enlarged laminectomy with fixation for the management of multilevel CDM is demonstrated to be an effective strategy for improving neurological function, restoring the normal cervical lordosis, and decreasing the incidence of axial symptoms and C5 root palsy, but there is a need for randomized controlled studies with long-term follow-up to confirm and clarify these results.

Syndromic versus nonsyndromic atlantoaxial dislocation: do clinico-radiological differences have a bearing on management?

BACKGROUND

This prospective study attempts to study the clinico-radiological differences between patients with syndromic AAD (SAAD), non-syndromic AAD (NSAAD), and AAD with Klippel-Feil anomaly (AADKFA) that may impact management.

METHODS

In 46 patients with AAD [SAAD (including Morquio, Down, Larson and Marshall syndrome and achondroplasia; n = 6); NSAAD(n = 20); and, AADKFS (n = 20)], myelopathy was graded as mild (n = 17, 37 %), moderate (15, 32.5 %) or severe (14, 30.5 %) based on Japanese Orthopaedic Association Score modified for Indian patients (mJOAS). Basilar invagination (BI), basal angle, odontoid hypoplasia, facet-joint angle, effective canal diameter, Ishihara curvature index, and angle of retroversion of odontoid and vertebral artery (VA) variations were also studied.

STATISTICS

Clinico-radiological differences were assessed by Fisher's exact test, and mean craniometric values by Kruskal-Wallis test (p value ≤ 0.05 significant)

RESULTS

Incidence of irreducible AAD in SAAD (n = 0), NSA AD (11.55 %) and AADKFS (n = 18.90 %) showed significant difference (p = 0.01). High incidence of kyphoscoliosis (83 %) and odontoid hypoplasia (83 %) in SAAD, and assimilated atlas and BI in NSAAD and AADKFA groups were found. In AADKFA, effective canal diameter was significantly reduced(p = 0.017) with increased Ishihara index and increased angle of odontoid retroversion; 61 % patients had VA variations. Thirty-five patients underwent single-stage transoral decompression with posterior fusion (for irreducible AAD) or direct posterior stabilization (for reducible AAD). Postoperative mJOAS evaluation often revealed persistent residual myelopathy despite clinical improvement.

CONCLUSIONS

Myelopathy is induced by recurrent cord trauma due to reducible AAD in SAAD, and compromised cervicomedullary canal diameter in NSAAD and AADKFA. SAAD in children may be missed due to incomplete odontoid ossification or coexisting angular deformities. In AADKFA, decisions regarding vertebral levels to be included in posterior stabilization should take into consideration intact intervening motion segments and compensatory cervical hyperlordosis. Following VA injury, endovascular primary vessel occlusion/stenting across pseudoaneurysm preempts delayed rehemorrhage.

Long-term impacts of different posterior operations on curvature, neurological recovery and axial symptoms for multilevel cervical degenerative myelopathy

Purpose

To investigate the long-term impacts of different posterior operations on curvature, neurological improvement and axial symptoms for multilevel cervical degenerative myelopathy (CDM), and to study the relationship among loss of cervical lordosis, recovery rate and axial symptom severity.

Methods

We retrospectively reviewed 98 patients with multilevel CDM who had undergone laminoplasty (Group LP, 36 patients), laminectomy (Group LC, 30 patients), or laminectomy with lateral mass screw fixation (Group LCS, 32 patients) between January 2000 and January 2005. Loss of curvature index (CI) was measured according to the preoperative and final follow-up radiographic parameters. The recovery rate was calculated based on the Japanese Orthopedic Association (JOA) score. Axial symptom severity was quantified by Neck Disability Index (NDI).

Results

Analysis of final follow-up data showed significant differences among the three groups regarding loss of CI (F = 41.46, P < 0.001) between preoperative and final follow-up JOA scores (P < 0.001), final follow-up JOA score (F = 7.81, P < 0.001), recovery rate (F = 12.98, P < 0.001) and axial symptom severity (χ² = 18.04, P < 0.001). Loss of CI showed negative association with neurological recovery (r = −0.555, P < 0.001) and positive correlation with axial symptom severity (r = 0.696, P < 0.001).

Conclusions

Excellent neurological improvement was obtained by LP and LCS for patients with multilevel CDM, while loss of CI in groups LP and LC caused a high incidence of axial symptoms. Loss of CI was correlated with poor neurological recovery and axial symptom severity. Lateral mass screw fixation can effectively prevent loss of postoperative cervical curvature and reduce incidence of axial symptoms.

Quantifying cervical-spine curvature using Bézier splines

Knowledge of the distributions of cervical-spine curvature is needed for computational studies of cervical-spine injury in motor-vehicle crashes. Many methods of specifying spinal curvature have been proposed, but they often involve qualitative assessment or a large number of parameters. The objective of this study was to develop a quantitative method of characterizing cervical-spine curvature using a small number of parameters. 180 sagittal X-rays of subjects seated in automotive posture with their necks in neutral, flexed, and extended postures were collected in the early 1970s. Subjects were selected to represent a range of statures and ages for each gender. X-rays were reanalyzed using advanced technology and statistical methods. Coordinates of the posterior margins of the vertebral bodies and dens were digitized. Bézier splines were fit through the coordinates of these points. The interior control points that define the spline curvature were parameterized as a vector angle and length. By defining the length as a function of the angle, cervical-spine curvature was defined with just two parameters: superior and inferior Bézier angles. A classification scheme was derived to sort each curvature by magnitude and type of curvature (lordosis versus S-shaped versus kyphosis; inferior or superior location). Cervical-spine curvature in an automotive seated posture varies with gender and age but not stature. Average values of superior and inferior Bézier angles for cervical spines in flexion, neutral, and extension automotive postures are presented for each gender and age group. Use of Bézier splines fit through posterior margins offers a quantitative method of characterizing cervical-spine curvature using two parameters: superior and inferior Bézier angles.