Prediction of surgical outcome for proximal-type cervical spondylotic amyotrophy novel mode of assessment using compound action potentials of deltoid and biceps brachii and central motor conduction time

Surgical Outcomes of Full Endoscopic Posterior Cervical Foraminotomy for Proximal Cervical Spondylotic Amyotrophy

STUDY DESIGN

Retrospective analysis of case series.

PURPOSE

This study aimed to clarify the effects of full endoscopic posterior cervical foraminotomy (FPCF) on cervical spondylotic amyotrophy (CSA).

OVERVIEW OF LITERATURE

The method for decompressing the ventral nerve root and anterior horn (AH) in CSA is controversial.

METHODS

Patients without myelopathy who underwent FPCF for proximal CSA between 2017 and 2022 were analyzed. The outcome measure was the results of the manual muscle testing (MMT) of the deltoid and biceps. Preoperative nerve root and AH compression were evaluated by magnetic resonance imaging. The intervertebral foramen morphology and bony decompression extent were evaluated by computed tomography.

RESULTS

FPCF was performed at the C4/5 level and at the C4/5 and C5/6 levels in 14 and 11 patients, respectively. The width of the narrowest intervertebral foramen was significantly narrower on the affected side than on the healthy side at the C4/5 (2.5 mm vs. 3.6 mm) and operated C5/6 (1.9 mm vs. 3.1 mm) levels. AH compression occurred at the C4/5 and C5/6 levels in 28% and 21% of the patients, respectively. Bony decompression was performed laterally beyond the narrowest foramen at the C4/5 and C5/6 levels in 96% and 91% of the patients, respectively. Compared with patients without AH compression, in those with AH compression, the lamina was resected medially by an average of >1.7 mm and >3.6 mm at the C4/5 and C5/6 levels, respectively. Furthermore, 76% and 81% of the facet joint surfaces were preserved at the C4/5 and C5/6 levels, respectively. Postoperative MMT grade improvement was excellent, good, and fair in 64%, 20%, and 16% of the patients, respectively.

CONCLUSIONS

FPCF was effective for treating proximal CSA.

Resting-state functional magnetic resonance imaging indices are related to electrophysiological dysfunction in degenerative cervical myelopathy

The age-related degenerative pathologies of the cervical spinal column that comprise degenerative cervical myelopathy (DCM) cause myelopathy due spinal cord compression. Functional neurological assessment of DCM can potentially reveal the severity and pathological mechanism of DCM. However, functional assessment by conventional MRI remains difficult. This study used resting-state functional MRI (rs-fMRI) to investigate the relationship between functional connectivity (FC) strength and neurophysiological indices and examined the feasibility of functional assessment by FC for DCM. Preoperatively, 34 patients with DCM underwent rs-fMRI scans. Preoperative central motor conduction time (CMCT) reflecting motor functional disability and intraoperative somatosensory evoked potentials (SEP) reflecting sensory functional disability were recorded as electrophysiological indices of severity of the cervical spinal cord impairment. We performed seed-to-voxel FC analysis and correlation analyses between FC strength and the two electrophysiological indices. We found that FC strength between the primary motor cortex and the precuneus correlated significantly positively with CMCT, and that between the lateral part of the sensorimotor cortex and the lateral occipital cortex also showed a significantly positive correlation with SEP amplitudes. These results suggest that we can evaluate neurological and electrophysiological severity in patients with DCM by analyzing FC strengths between certain brain regions.

Efficacy of Intraoperative Neuromonitoring Using Transcranial Motor-Evoked Potentials for Degenerative Cervical Myelopathy: A Prospective Multicenter Study by the Monitoring Committee of the Japanese Society for Spine Surgery and Related Research

STUDY DESIGN

A prospective multicenter observational study.

OBJECTIVE

To elucidate the efficacy of transcranial motor-evoked potentials (Tc(E)-MEPs) in degenerative cervical myelopathy (DCM) surgery by comparing cervical spondylotic myelopathy (CSM) to cervical ossification of the posterior longitudinal ligament (OPLL) and investigate the timing of Tc(E)-MEPs alerts and types of interventions affecting surgical outcomes.

SUMMARY OF BACKGROUND DATA

Although CSM and OPLL are the most commonly encountered diseases of DCM, the benefits of Tc(E)-MEPs for DCM remain unclear and comparisons of these two diseases have not yet been conducted.

METHODS

We examined the results of Tc(E)-MEPs from 1176 DCM cases (840 CSM /336 OPLL) and compared patients background by disease, preoperative motor deficits, and the type of surgical procedure. We also assessed the efficacy of interventions based on Tc(E)-MEPs alerts. Tc(E)-MEPs alerts were defined as an amplitude reduction of more than 70% below the control waveform. Rescue cases were defined as those in which waveform recovery was achieved after interventions in response to alerts and no postoperative paralysis.

RESULTS

Overall sensitivity was 57.1%, and sensitivity was higher with OPLL (71.4%) than with CSM (42.9%). The sensitivity of acute onset segmental palsy including C5 palsy was 40% (OPLL/CSM: 66.7%/0%) whereas that of lower limb palsy was 100%. The most common timing of Tc(E)-MEPs alerts was during decompression (63.16%), followed by screw insertion (15.79%). The overall rescue rate was 57.9% (OPLL/CSM: 58.3%/57.1%).

CONCLUSION

Since Tc(E)-MEPs are excellent for detecting long tract injuries, surgeons need to consider appropriate interventions in response to alerts. The detection of acute onset segmental palsy by Tc(E)-MEPs was partially possible with OPLL, but may still be difficult with CSM. The rescue rate was higher than 50% and appropriate interventions may have prevented postoperative neurological complications.Level of Evidence: 3.

Factors associated with an excellent outcome after conservative treatment for patients with proximal cervical spondylotic amyotrophy using electrophysiological, neurological and radiological findings

Objective: To investigate factors associated with excellent outcomes after conservative treatment in patients with proximal cervical spondylotic amyotrophy (CSA) using electrophysiological, radiological, and neurological findings. Design: Retrospective study. Setting: Yamaguchi University Hospital. Participants: Seventy-seven patients. Interventions: Erb-point-stimulated compound muscle action potentials (CMAP) were recorded in deltoid and biceps. The percentages of CMAP amplitudes on the affected side compared to the normal side in deltoid (PD) and biceps brachii (PB) were calculated. Central motor conduction time was calculated by subtracting peripheral motor conduction time from the onset latency of motor evoked potentials. Cervical lordotic angles, the diameter of C5 canal, and the intervertebral range at C4-C5 and C5-C6 levels were assessed on plain radiographs. Magnetic resonance imaging was used to assess the width of the intervertebral foramen (WIF) at C4-C5 and C5-C6 levels in the axial views. First visit and final follow-up strengths of most atrophic muscles were evaluated using manual muscle testing (MMT). Improvements in strength were classified as excellent (five grades recovered), good (more than one grade recovered), unchanged (no improvement), or poor (worsened). Results: The outcomes were excellent in 27 patients (35.1%), good in 22 (28.6%), unchanged in 26 (33.8%), and poor in two (2.5%). Factors associated with excellent outcomes were WIF at C4-C5 and C5-C6 on the normal side, PB, and CMAP amplitudes of the deltoid on the normal side. Conclusions: Patients with excellent outcomes originally had wide WIF at C4-C5 and C5-C6 levels and the absence of symptomatic spinal cord compression at C3-C4 and C4-C5 levels.

Evaluation of Anterior Decompression Surgical Outcomes of Proximal-Type Cervical Spondylotic Amyotrophy: A Retrospective Study

OBJECTIVE

To investigate the efficiency of anterior decompression on the proximal-type cervical spondylotic amyotrophy patients.

METHODS

This was a retrospective analysis. From January 2014 to November 2017, 21 patients with proximal-type cervical spondylotic amyotrophy (CSA) underwent anterior decompression. There were 15 males and 6 females, aged 35-73 years with an average of 51.62 years. All the patients underwent surgery of anterior decompression (ACDF or ACCF). Among them, 12 patients underwent C_4/5 single level ACDF, eight patients underwent C_4/5 and C_5/6 double level ACDF, and one patient underwent C5 anterior cervical corpectomy decompression and fusion surgery. Preoperative and postoperative clinical and radiologic parameters were assessed. The clinical examinations were reviewed, including muscle strength, neck disability index (NDI) score, cervical Japanese Orthopaedic Association (JOA) score, and improvement rate of manual muscle test (MMT) at the last follow-up. Preoperative spinal cord or nerve impingement was assessed by magnetic resonance imaging (MRI) or computed tomography (CT) myelography. Postoperative lateral X-ray radiographs were performed every 3 months after the surgery.

RESULTS

Severe preoperative muscle atrophy of the deltoid or biceps muscles occurred in 21 patients included in the study. All of them involve impingements of the ventral nerve root and/or the anterior horn according to MRI and CT myelography. The preoperative duration of symptoms averaged 8.4 months. The average follow-up for all patients was 13.2 months. At the final follow-up, all patients showed statistically significant improvements in muscle strength and NDI scores (P < 0.05, P < 0.05). For the deltoid muscles force and C-JOA scores, the average improvement rates were 66.49% ± 10.04% and 62.23% ± 9.23%, respectively. With respect to MMT, 12 proximal-type patients were graded excellent, six were good, and three were fair, and the overall improvement rate was 85.7%.

CONCLUSIONS

For proximal-type CSA patients with cervical radiculopathy, earlier anterior decompression surgery can achieve satisfactory results by significantly improving a patient's muscle strength and relieving compression symptoms.

Preoperative factors that predict fair outcomes following surgery in patients with proximal cervical spondylotic amyotrophy. A retrospective study

STUDY DESIGN

Observational cohort study OBJECTIVES: To investigate preoperative factors that predict fair outcomes following surgery in patients with proximal cervical spondylotic amyotrophy (CSA) using electrophysiological and neurological findings.

SETTING

Yamaguchi University METHODS: 54 patients with proximal CSA who underwent surgical treatment of the cervical spine were enrolled. Erb-point stimulated compound muscle action potentials (CMAP) were recorded from the deltoid and biceps brachii muscles. We computed the ratio of affected to normal side CMAP amplitudes in two muscles (deltoid and biceps brachii) and regarded the mean ratio (CMAP-R) as representing the severity of neural involvement. Pre- and postoperative strengths of the most atrophic muscles were evaluated using manual muscle testing. Improvements in strength were classified as excellent (5 grades recovered), good (more than one grade recovered), fair (no improvement), or poor (worsened).

RESULTS

Surgical outcomes were excellent in 26 patients, good in five, fair in 16, poor in seven. Patients with fair outcomes had lower CMAP-R than those patients with excellent and good outcomes [P = 0.0099, odds ratio = 0.89 (95% confidence interval, 0.81-0.97; for a change of 10%)]. Eight patients (15%) had a C5 palsy.

CONCLUSIONS

CMAP-R could be used as a reliable predictive factor related to a fair surgical outcome. We must pay attention to the incidence of C5 palsy after surgery.

Cervical Spondylotic Amyotrophy: Case Series and Review of the Literature

OBJECTIVE

Cervical spondylotic amyotrophy (CSA) is a relatively rare entity caused by cervical degenerative spinal diseases and characterized by motor weakness accompanied by remarkable muscle atrophy in the upper extremities without significant sensory deficits or spastic paraparesis in the lower extremities. Postoperative outcomes and predictive prognostic factors vary among previous reports. In the present report, we describe the surgical results in patients who were surgically treated for CSA and present a literature review.

METHODS

In total, 33 patients with CSA were retrospectively analyzed. Correlations between the surgical outcome and the following factors were statistically analyzed: age, sex, type of impaired muscle, preoperative severity of motor weakness, number of levels of cord or root compression, presence of a T2 high-intensity area in the spinal cord, cervical kyphosis, and methods of surgical procedure.

RESULTS

On postoperative neurological evaluation, 25 patients (75.8%) had favorable outcomes and 8 had unfavorable outcomes (proximal type, 72.2%; distal type, 78.6%). Patients with favorable outcomes were significantly younger than those with unfavorable outcomes (p=0.013). Patient's characteristics except for age and radiological factors were not correlated to surgical outcome.

CONCLUSION

The present study focused on the surgical results in patients who were surgically treated for CSA along with updated information from a literature review. Improvement of motor weakness is expected with acceptable prevalence although higher age can be a negative factor. Surgical outcomes and predictive factors related to a poor prognosis were determined and compared with those of previous articles.

Cervical spondylotic amyotrophy: a systematic review

PURPOSE

Cervical spondylotic amyotrophy (CSA) is characterized by upper limb muscle weakness and atrophy, without sensory deficits. The pathophysiology of CSA has been attributed to selective injury to the ventral nerve root and/or anterior horn of the spinal cord. This review aimed to delineate the history of CSA and to describe the epidemiology, etiology, pathophysiology, classification, clinical features, radiological and electrophysiological assessment, diagnosis, differential diagnosis, natural history and treatment of CSA.

METHODS

A comprehensive search of PubMed, EMBASE, Cochrane library and Web of Science databases was conducted, from their inception to April 3, 2018.

RESULTS

Clinically, CSA is classified into three types: a proximal-type (involving the scapular muscles, deltoid and biceps), a distal-type (involving the triceps and muscles of the forearm and hand) and a diffuse-type (involving features of both the distal- and proximal-type). Diagnosis requires documentation of muscle atrophy, without significant sensory deficits, supported by careful neurological, radiological and neurophysiological assessments, with amyotrophic lateral sclerosis, Parsonage-Turner syndrome, rotator cuff tear and Hirayama disease being the principle differential diagnoses. Conservative management of CSA includes cervical traction, neck immobilization and physical therapy, with vitamin B12 or E administration being useful in some patients. Surgical treatment, including anterior decompression and fusion or laminoplasty, with or without foraminotomy, is indicated after conservative treatment failure. Factors associated with a poor outcome include the distal-type CSA, long symptom duration, older age and greater preoperative muscle weakness.

CONCLUSION

Although the disease process of CSA is self-limited, treatment remains challenging, leaving scope for future studies. These slides can be retrieved under Electronic Supplementary Material.

Clinical Features and Long-Term Surgical Outcomes of Patients with Cervical Spondylotic Amyotrophy

BACKGROUND

Cervical spondylotic amyotrophy (CSA) is not common. The clinical features and long-term surgical outcomes of patients with CSA are also unclear. We sought to summarize clinical features, assess long-term surgical outcomes, and determine the prognostic factors relevant for patients with CSA.

METHODS

A total of 136 patients with CSA who underwent anterior or posterior decompression during January 2001 to December 2012 were included. Their clinical and radiologic data were collected. The surgical outcome was evaluated using manual muscle test and improvements in the muscle strength. Correlations between the surgical outcome and various factors also were analyzed.

RESULTS

In total, 128 patients underwent anterior decompression and 8 patients underwent posterior decompression. At the final follow-up, the surgical outcome was significantly better after anterior decompression compared with that after posterior decompression. Statistical analyses showed the type of CSA, duration of symptoms, and association with ossification of the posterior longitudinal ligament were associated with a poor outcome after anterior surgery (P < 0.05).

CONCLUSIONS

Besides significant muscular atrophy in one upper extremity, CSA also occasionally presents with mild atrophy in the other upper extremity, sensory disturbance in the upper extremities, or hyperflexia in the lower extremities. Anterior decompression is generally effective in the treatment of patients with CSA. Preoperative duration of symptoms, type of CSA, and ossification of the posterior longitudinal ligament are important predictors for the surgical outcome.

Treatment of Cervical Spondylotic Amyotrophy With Nerve Transfers

Cervical spondylotic amyotrophy is characterized by severe, proximal upper extremity weakness including an inability to abduct the shoulder and flex the elbow. Treatment using both medical and surgical decompression approaches has produced variable results. This paper reports the use of nerve transfers (spinal accessory to suprascapular, flexor carpi ulnaris fascicle of ulnar to biceps motor branch, radial nerve branch to triceps to axillary) to restore shoulder and elbow function in a case of unilateral cervical spondylotic amyotrophy involving C5 and C6 myotomes. Evidence of regeneration was observed on electromyography as well as clinically at 5 months postoperatively. At 3 years after surgery, recovery of elbow flexion and shoulder abduction was Medical Research Council grade 4/5 with improved external rotation and considerably improved patient-rated Disabilities of the Arm, Shoulder and Hand scores. We propose that nerve transfers be considered along with other reconstruction modalities in the treatment of cervical spondylotic amyotrophy.

Influence of placement sites of the active recording electrode on CMAP configuration in the trapezius muscle

•

The active recording electrode site influences the CMAP waveform of the trapezius muscle (TM).

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CMAP becomes high by placement of the active recording electrode 2 cm behind the belly of the TM.

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Volume conduction from the supraspinatus muscle affects the CMAP waveform of the TM.

Objective

We investigated how the active electrode placement site influences compound muscle action potential (CMAP) configuration of the upper trapezius muscle (TM).

Methods

A nerve conduction study of the accessory nerve was performed, and the CMAPs obtained with two different placement sites, i.e., placement of the active recording electrode on the belly of the upper TM (CMAP-A) and placement of the electrode 2 cm behind the belly (CMAP-B), were compared. CMAPs were also obtained with the active recording electrode placed in the supraspinous fossa (CMAP-C).

Results

All CMAPs were recorded from 21 healthy volunteers. The mean peak-to-peak amplitude of CMAP-B was 3.4 mV higher than that of CMAP-A (11.0 ± 4.0 mV vs. 14.4 ± 4.9 mV; P < 0.01). The mean peak-to-peak amplitude of CMAP-C was 10.3 ± 5.0 mV.

Conclusions

CMAP of the upper TM was always higher when the active recording electrode was placed 2 cm behind the belly of the muscle.

Significance

When stimulating the accessory nerve, a current spread occurs to the C5 spinal nerve root and another CMAP originating from the supraspinatus muscle occurs in the supraspinous fossa. The volume conduction from the supraspinatus muscle affects the active recording electrode on the TM, resulting in an increase in CMAP amplitude.

A Novel Scoring System Associated With Surgical Outcome of Distal-type Cervical Spondylotic Amyotrophy

STUDY DESIGN

A single-center retrospective study.

OBJECTIVE

To elucidate the pathology of distal-type cervical spondylotic amyotrophy (CSA) and to assess predictive factors and a novel scoring system associated with surgical outcome.

SUMMARY AND BACKGROUND

Because of its rarity, the pathophysiology and surgical outcome of distal-type CSA are less well understood compared with proximal-type CSA.

METHOD

Surgical procedures were performed in 13 patients with distal-type CSA. Patients were classified into 2 groups: those with good recovery of muscle power (group 1, n=4) and those with fair recovery (group 2, n=9). All patients underwent magnetic resonance imaging. Central motor conduction time was recorded in abductor digit minim and compound muscle action potentials (CMAPs) were recorded in extensor carpi dig. Predictive factors associated with surgical outcome and a scoring system based on clinical, radiologic, and electrophysiological findings were evaluated. Twelve of 13 patients were scored for the following features: (1) duration of symptoms ≥13 months, (2) initial manual muscle testing ≤1, (3) multiple compressions in magnetic resonance imaging, (4) CMAPs amplitudes on affected side <1 mV, (5) CMAPs amplitudes on normal side <7.2 mV, (6) central motor conduction time longer than 7.4 ms, (7) the ratio of CMAPs amplitudes comparison with the normal side <50%.

RESULT

At final follow-up, 2 patients were graded excellent, 2 good, 9 fair, and 0 poor. None of the predictive factors was significantly different between groups 1 and 2. The mean score in group 2 (5.12±1.12) was significantly higher than for group 1 (2±1.15; P=0.006). Although all 8 patients in group 2 scored ≥4 points, all 4 patients in group 1 scored ≤3.

CONCLUSIONS

Comprehensive assessment using a scoring system is useful for predicting the surgical outcome of distal-type CSA. Surgeons should be aware that a score of ≥4 points correlates with poor surgical outcome on motor function.

Use of Central Motor Conduction Time and Spinal Cord Evoked Potentials in the Electrophysiological Assessment of Compressive Cervical Myelopathy

STUDY DESIGN

A retrospective study.

OBJECTIVE

This study investigated the pathophysiology of compressive cervical myelopathy (CCM) with prolonged central motor conduction time (CMCT) in the upper limbs (ULs) rather than lower limbs (LLs) and prolonged CMCT at the thoracic level (TL).

SUMMARY OF BACKGROUND DATA

Earlier reports indicated the usefulness of CMCT to assess preoperative CCM severity. However, little information exists on patients with prolonged CMCT-UL rather than CMCT-LL and prolonged CMCT-TL.

METHODS

Ninety-four patients (61 men, 33 women; age 28-87 years) with CCM who underwent cervical laminoplasty participated. Fifty-three volunteers provided normal data on CMCT-UL and LL. CMCT-TL was calculated as CMCT-LL - CMCT-UL. We defined three groups: group U, prolonged CMCT-UL rather than CMCT-LL (n = 14); group E, prolonged CMCT-UL and CMCT-LL equality (n = 43); and group L, prolonged CMCT-TL (n = 37). We evaluated intraoperative recording of spinal cord evoked potentials (SCEPs), neurological findings, and surgical outcomes.

RESULTS

Control mean CMCT-UL was 5.2 ± 0.7 ms, CMCT-LL was 11.8 ± 1.1 ms, and CMCT-TL was 6.6 ± 1.2 ms. SCEPs results were significantly different between CCM patients in group U and L (P < 0.01). Almost all patients in three groups showed hyperreflexia of the patellar tendon reflex, but great toe position sense was abnormal in most patients in group L only. Japanese Orthopedics Association (JOA) scores improved postoperatively in all patients. There was a significant difference in recovery rate of the JOA score between group L and other groups (both P < 0.05).

CONCLUSION

Multimodal SCEPs, clinical findings, and surgical outcomes showed that patients with CCM and prolonged CMCT-TL had substantial disorders of the gray matter, lateral corticospinal tract, and posterior funiculus. Spine surgeons should be aware that prognosis may be poor even after surgery in patients with severe myelopathy such as prolonged CMCT-TL.

LEVEL OF EVIDENCE

4.

Reconstruction of shoulder and elbow function using multiple muscle transfers for cervical spondylotic amyotrophy

STUDY DESIGN

This was a retrospective study of 8 patients with cervical spondylotic amyotrophy who underwent multiple muscle transfers.

OBJECTIVE

The purpose of this study was to evaluate results of multiple muscle transfers about the shoulder and elbow in patients with cervical spondylotic amyotrophy.

SUMMARY OF BACKGROUND DATA

Cervical spondylotic amyotrophy is characterized by severe muscle atrophy of the shoulder girdle and elbow. Even after cervical spine surgery, many patients have poor shoulder and elbow function.

METHODS

Multiple muscle transfer procedures including the transfer of trapezius, pectoralis major, latissimus dorsi muscles, and the Steindler procedure for reconstruction of shoulder and elbow function were performed in 8 patients with cervical spondylotic amyotrophy. Patients were evaluated at a mean of 18.2 months (range, 5-75 mo).

RESULTS

All 8 patients obtained satisfactory functional recovery with improvement of active range of motion without any systemic and local complications within 3 to 6 months postoperatively. Patients at the last follow-up had obtained a mean of 91° of shoulder abduction, 111° of shoulder flexion, 23° of external rotation and 110° of elbow flexion. Disability scores (Japanese version) of the arm, shoulder, and hand improved by a mean of 28 points.

CONCLUSION

Multiple muscle transfers can improve shoulder and elbow function in cervical spondylotic amyotrophy, in cases of not only poor outcome after cervical surgery, but also in advanced paralysis. It is a useful set of procedures even in old patients, and provides definitive functional improvement of shoulder and elbow function from 3 to 6 months.

LEVEL OF EVIDENCE

4.

Evaluation of characteristics and surgical outcomes in cervical spondylotic amyotrophy

BACKGROUND

Cervical spondylotic amyotrophy (CSA) is a rare clinical syndrome resulting from cervical spondylosis. Surgical treatment includes anterior cervical decompression and fusion (ACDF), and laminoplasty with or without foraminotomy. Some studies indicate that ACDF is an effective method for treating CSA because anterior decompression with or without medial foraminotomy can completely eliminate anterior and/or anterolateral lesions. We retrospectively evaluated outcome of surgical outcome by anterior cervical decompression and fusion (ACDF).

MATERIALS AND METHODS

28 CSA patients, among whom 12 had proximal type CSA and 16 had distal type CSA, treated by ACDF, were evaluated clinicoradiologically. The improvement in atrophic muscle power was assessed by manual muscle testing (MMT) and the recovery rate of the patients was determined on the basis of the Japanese Orthopedic Association (JOA) scores. Patient satisfaction was also examined.

RESULTS

The percentage of patients, who gained 1 or more grades of muscle power improvement, as determined by MMT, was 91.7% for those with proximal type CSA and 37.5% for those with distal type CSA (P < 0.01). The JOA score-based recovery rates of patients with proximal type and distal type CSA were 60.8% and 41.8%, respectively (P < 0.05). Patient satisfaction was 8.2 for those with proximal type CSA and 6.9 for those with distal type CSA (P < 0.01). A correlation was observed among the levels of improvement in muscle power, JOA score based recovery rate, patient satisfaction and course of disease (P < 0.05).

CONCLUSION

ACDF can effectively improve the clinical function of patients with CSA and result in good patient satisfaction despite the surgical outcomes for distal type CSA being inferior to those for proximal type CSA. Course of disease is the fundamental factor that affects the surgical outcomes for CSA. We recommend that patients with CSA undergo surgical intervention as early as possible.