Quantitative changes in gait parameters after central corpectomy for cervical spondylotic myelopathy

Gait function assessed using 3D gait analysis in patients with cervical spinal myelopathy before and after surgical decompression: a systematic review and meta-analysis

BACKGROUND

Degenerative cervical myelopathy (DCM) is the most common cause of cervical spinal cord dysfunction in adults and the result of chronic degenerative changes of the cervical spine. The compression of the spinal cord can lead to ischemia, inflammation, and neuronal apoptosis with a consequent impairment of the neurological function. Gait impairment is one of the most frequent signs of DCM.

PURPOSE

To investigate the changes in spatio-temporal gait parameters assessed using 3D gait analysis in patients affected by DCM compared with healthy controls and the effect of surgical decompression on these parameters.

STUDY DESIGN/SETTING

Systematic review and meta-analysis.

PATIENT SAMPLE

The meta-analysis included 267 patients with DCM and 276 healthy controls.

OUTCOME MEASURES

Spatio-temporal parameters of gait were assessed. The primary outcome was gait speed; the secondary outcomes were cadence, stride length, step width, stride time, single-limb support time, and double-limb support time.

METHODS

Studies reporting spatial and/or temporal gait parameters measured using 3D gait analysis in patients with DCM were included. Data sources were Embase, Medline, and the Core Collection of Web of Science. Meta-analyses were performed to investigate the influence of surgical decompression in patients measured before and after surgery as well as to compare gait parameters of patients with DCM with controls.

RESULTS

Thirteen studies reporting on 267 patients with DCM and 276 healthy controls met the inclusion criteria. Seven studies compared patients with DCM with healthy controls, three studies compared gait in patients with DCM before and after surgical decompression, and three studies performed both comparisons. Compared with healthy controls, patients with DCM had slower gait speed (Standardized Mean Difference (SMD), -1.49; 95% confidence interval (CI) [-1.86; -1.13]; p<.001), lower cadence (SMD, -0.78; 95%CI [-1.00; -0.56]; p<.001), shorter stride length (SMD, -1.27; 95%CI [-1.53, -1.01]; p<.001), greater step width (SMD, 0.98; 95%CI [0.42, 1.54]; p=.003), longer stride time (SMD, 0.77; 95%CI [0.37, 1.16]; p=.009), single-limb support phase (SMD, -0.68; 95%CI [-1.06; -0.29]; p=.011), and double-limb support phase (SMD 0.84; 95%CI [0.35, 1.32]; p=.012). After surgical decompression, patients with DCM showed an improvement in gait speed (SMD, 0.57 (95%CI [0.29; 0.85]; p=.003) and no significant differences in other spatio-temporal parameters.

CONCLUSIONS

Patients with DCM have clearly different spatio-temporal gait parameters than healthy controls. Gait speed is the only spatio-temporal gait parameter that improves significantly after surgical decompression suggesting that gait speed may be an important clinical outcome parameter in patients with DCM.

Kinematic movement and balance parameter analysis in neurological gait disorders

BACKGROUND

Neurological gait disorders are mainly classified based on clinical observation, and therefore difficult to objectify or quantify. Movement analysis systems provide objective parameters, which may increase diagnostic accuracy and may aid in monitoring the disease course. Despite the increasing wealth of kinematic movement and balance parameter data, the discriminative value for the differentiation of neurological gait disorders is still unclear. We hypothesized that kinematic motion and balance parameter metrics would be differently altered across neurological gait disorders when compared to healthy controls.

METHODS

Thirty one patients (9 normal pressure hydrocephalus < NPH > , 16 cervical myelopathy < CM > , 6 lumbar stenosis < LST >) and 14 healthy participants were investigated preoperatively in an outpatient setting using an inertial measurement system (MyoMotion) during 3 different walking tasks (normal walking, dual-task walking with simultaneous backward counting, fast walking). In addition, the natural postural sway of participants was measured by pedobarography, with the eyes opened and closed. The range of motion (ROM) in different joint angles, stride time, as well as sway were compared between different groups (between-subject factor), and different task conditions (within-subject factor) by a mixed model ANOVA.

RESULTS

Kinematic metrics and balance parameters were differently altered across different gait disorders compared to healthy controls. Overall, NPH patients significantly differed from controls in all movement parameters except for stride time, while they differed in balance parameters only with regard to AP movement. LST patients had significantly reduced ROMs of the shoulders, hips, and ankles, with significantly altered balance parameters regarding AP movement and passed center-of-pressure (COP) distance. CM patients differed from controls only in the ROM of the hip and ankle, but were affected in nearly all balance parameters, except for force distribution.

CONCLUSION

The application of inertial measurement systems and pedobarography is feasible in an outpatient setting in patients with different neurological gait disorders. Rather than defining singular discriminative values, kinematic gait and balance metrics may provide characteristic profiles of movement parameter alterations in the sense of specific ´gait signatures´ for different pathologies, which could improve diagnostic accuracy by defining objective and quantifiable measures for the discrimination of different neurological gait disorders.

TRIAL REGISTRATION

The study was retrospectively registered on the 27th of March 2023 in the 'Deutsches Register für Klinische Studien' under the number DRKS00031555.

The Effects of Surgery on Postural Instability in Patients With Cervical Compressive Myelopathy: Evaluating Subjective Perceptions and Objective Measurements

STUDY DESIGN

A retrospective study.

OBJECTIVE

To investigate the effects of surgery on the subjective perception of bodily unsteadiness and the objective measurements of postural instability in patients with cervical compressive myelopathy (CCM).

SUMMARY OF BACKGROUND DATA

Several studies have demonstrated that CCM patients have impaired postural stability and investigated its surgical outcomes. However, these studies have only objectively measured postural stability by using a stabilometer or three-dimensional motion capture system. There have been no studies examining the subjective perception of postural instability in CCM patients.

MATERIALS AND METHODS

We retrospectively reviewed patients who underwent decompressive surgery for CCM. The Fall Efficacy Scale-International (FES-I) and a self-prepared questionnaire were used to evaluate subjective perception of bodily unsteadiness. To objectively assess postural instability, a stabilometric analysis was performed with the following parameters: sway area (SwA, cm2), sway velocity (SwV, cm/s), and sway density (SwD, /cm). The evaluations were performed preoperatively, during the early postoperative period (3-6 mo postoperatively), and at 1-year postoperatively in patients with CCM. The evaluation results were compared with age-matched, sex-matched, and body mass index-matched healthy subjects.

RESULTS

We included 70 CCM patients and 36 healthy subjects in this study. In both the FES-I and self-prepared questionnaire, CCM patients reported significantly milder postoperative bodily unsteadiness. The stabilometric parameters were significantly improved during the postoperative period when compared with preoperative values. Nevertheless, neither the self-reported outcome measures nor stabilometric parameters of CCM patients reached the levels of those in healthy controls in the postoperative period.

CONCLUSION

This was the first study to examine CCM surgical outcomes in terms of both subjective perception and objective postural instability. While both objective postural stability and subjective perception improved following decompressive surgery, they did not reach the levels seen in healthy participants.

LEVEL OF EVIDENCE

Level III.

Subclinical gait disturbance and postoperative gait improvement in patients with degenerative cervical myelopathy

This study aimed to evaluate the subclinical gait abnormalities and the postoperative gait improvements in patients with degenerative cervical myelopathy using three-dimensional gait analysis. We reviewed the gait analysis of 62 patients who underwent surgical treatment for degenerative cervical myelopathy. The asymptomatic gait group included 30 patients and the gait disturbance group included 32 patients who can walk on their own slowly or need assistive device on stairs. The step width (17.2 cm vs. 15.9 cm, P = 0.003), stride length (105.2 cm vs. 109.1 cm, P = 0.015), and double-limb support duration (13.4% vs. 11.7%, P = 0.027) improved only in the asymptomatic gait group. Preoperatively, the asymptomatic gait group exhibited better maximum knee flexion angle (60.5° vs. 54.8°, P = 0.001) and ankle plantarflexion angle at push-off (− 12.2° vs. − 6.5°, P = 0.001) compared to the gait disturbance group. Postoperatively, maximum knee flexion angle (62.3° vs. 58.2°, P = 0.004) and ankle plantarflexion angle at push-off (− 12.8° vs. − 8.3°, P = 0.002) were still better in the asymptomatic gait group, although both parameters improved in the gait disturbance group (P = 0.005, 0.039, respectively). Kinematic parameters could improve in patients with gait disturbance. However, temporospatial parameters improvement may be expected when the operative treatment is performed before apparent gait disturbance.

Walk and Run Test in Patients with Degenerative Compression of the Cervical Spinal Cord

Impaired gait is one of the cardinal symptoms of degenerative cervical myelopathy (DCM) and frequently its initial presentation. Quantitative gait analysis is therefore a promising objective tool in the disclosure of early cervical cord impairment in patients with degenerative cervical compression. The aim of this cross-sectional observational cohort study was to verify whether an objective and easily-used walk and run test is capable of detecting early gait impairment in a practical proportion of non-myelopathic degenerative cervical cord compression (NMDCC) patients and of revealing any correlation with severity of disability in DCM. The study group consisted of 45 DCM patients (median age 58 years), 126 NMDCC subjects (59 years), and 100 healthy controls (HC) (55.5 years), all of whom performed a standardized 10-m walk and run test. Walking/running time/velocity, number of steps and cadence of walking/running were recorded; analysis disclosed abnormalities in 66.7% of NMDCC subjects. The DCM group exhibited significantly more pronounced abnormalities in all walk/run parameters when compared with the NMDCC group. These were apparent in 84.4% of the DCM group and correlated closely with disability as quantified by the modified Japanese Orthopaedic Association scale. A standardized 10-m walk/run test has the capacity to disclose locomotion abnormalities in NMDCC subjects who lack other clear myelopathic signs and may provide a means of classifying DCM patients according to their degree of disability.

Kinematic, kinetic, and musculoskeletal modeling analysis of gait in patients with cervical myelopathy using a severity classification

BACKGROUND CONTEXT

Although a few reports have shown a change in gait motion in cervical myelopathy (CM) patients using a three-dimensional (3D) gait analysis system, there has been no detailed quantitative investigation of their gait including musculoskeletal modeling parameters. Also, 3D gait analysis using a classification of severity has not been substantiated.

PURPOSE

This study aimed to investigate kinematic, kinetic, and musculoskeletal modeling parameters of gait motion in CM patients using a severity classification.

STUDY DESIGN

Prospective cohort and cross-sectional study.

PATIENT SAMPLE

Forty-two patients with CM and 40 healthy, age-matched volunteers.

OUTCOME MEASURES

Lower extremity spatiotemporal, kinematic, kinetic, and musculoskeletal modeling parameters.

METHODS

Subjects were classified as to its severity using the Japan Orthopaedic Association score excluding the upper extremity items: group 1 (>10 points); group 2 (7-9 points); and group 3 (<6 points). A 3D motion analysis system and musculoskeletal modeling software were used to obtain the spatiotemporal, kinematic (the lower extremity joints angles in the sagittal plane), kinetic (the lower extremity joints moment and power in the sagittal plane), and musculoskeletal modeling parameters (the muscle-tendon length and velocity).

RESULTS

Genu recurvatum, deteriorated lower-extremity joint motion, and muscle-tendon velocity were observed in severe CM patients (group 3). Muscle-tendon velocities of the long head of the biceps femoris in controls and mild CM patients (groups 1 and 2) showed a bimodal waveform in the negative direction during the initial contact and preswing phases, whereas these characteristics were not present in severe CM patients (group 3).

CONCLUSIONS

The strategies of the knee joint moment during gait motion in severe CM patients were different from those of the normal gait pattern. The imbalance between agonist and antagonist muscle tissue during gait could be involved in the occurrence of genu recurvatum. It might be important for CM patients to consider improving the contraction or extension velocity of the biceps femoris muscle during each gait phase from the early stages of symptoms.

A Diagnostic Approach to Myelopathy Based on Prognostic Factors in Patients With Lower Extremity Symptoms

STUDY DESIGN

Case-control study.

OBJECTIVE

We aimed to identify predictors for latent myelopathy and to develop a diagnostic protocol based on these factors.

SUMMARY OF BACKGROUND DATA

There is no diagnostic protocol for latent myelopathy to avoid misdiagnosis in patients complaining only of lower extremity symptoms.

METHODS

This case-control study identified 791 patients discussed at conferences from April 2006 to August 2012. Overall, 460 patients complaining only of lower extremity symptoms and who underwent spine surgery were included as participants; 54 underwent surgery involving the cervical and thoracic vertebrae and were assigned to the cervical-thoracic group (C-T group); 406 underwent lumbar surgery and were assigned to the lumbar group (L group).

RESULTS

By univariate analysis, age ≥67 years, patellar tendon (PT) hyperreflexia, Achilles tendon (AT) hyperreflexia, spastic gait, and gait inability were more common in the C-T group than in the L group. By multivariate analysis, age ≥67 years (OR, 8; P = 0.001), AT hyperreflexia (OR, 20.5; P < 0.001), spastic gait (OR, 225; P < 0.001), and gait inability (OR, 64; P < 0.001) were significant predictive factors. In patients with age ≥67 years, PT hyperreflexia, and/or AT hyperreflexia, the sensitivity for myelopathy diagnosis was 98%. In patients with spastic gait or gait inability, the specificity of myelopathy diagnosis was 96%.

CONCLUSIONS

We analyzed factors that predict latent myelopathy in patients complaining only of lower extremity symptoms. We believe a diagnostic protocol based on the predictors shown in this study would contribute to the accurate diagnosis of latent myelopathy.

LEVEL OF EVIDENCE

4.

Characterizing gait abnormalities in patients with cervical spondylotic myelopathy: a neuromuscular analysis

BACKGROUND CONTEXT

Gait impairment is a hallmark of cervical spondylotic myelopathy (CSM). It has been shown to affect quality of life but has not been well defined. Further electromyographic (EMG) characterization of the gait cycle may help elucidate the true neuromuscular pathology with implications on prognosis and rehabilitation techniques.

PURPOSE

This study compares neuromuscular activity in patients with CSM to that of healthy age-matched controls.

STUDY DESIGN

Nonrandomized, prospective, concurrent control cohort study.

METHODS

Neuromuscular activity was measured in 40 patients with symptomatic CSM during a series of over-ground gait trials at a self-selected speed before surgical intervention. External oblique, multifidus, erector spinae, rectus femoris, semitendinosus, tibialis anterior, medial gastrocnemius, and medial deltoid were assessed. Identical measurements were taken in 25 healthy control patients. Differences in time of muscle onset, peak EMG, time to peak EMG, and integrated electromyography (iEMG) were assessed using one-way ANOVA.

RESULTS

There were no significant differences between patients with CSM and healthy controls with respect to time of muscle contraction onset. Peak EMG muscle activity was significantly higher in the medial deltoid of patients with CSM (39.3% vs. 23.3% sMVC, p=.042), but no other differences were seen in the remaining muscles tested. They also demonstrated significantly longer time to peak EMG muscle activity compared with controls in 5 of the 8 muscles tested, including the multifidus (20.2 vs. 16.8 ms, p=.050), erector spinae (18.2 vs. 8.9 ms, p<.001), semitendinosis (26.3 vs. 22.4 ms, p=.037), tibialis anterior (14.7 vs. 11.0 ms, p=.050), and medial deltoid (24.2 vs. 9.2 ms, p<.001). Compared with controls, patients with CSM demonstrated significantly higher iEMG activity in the semitendinosis (586.5% vs. 272.5 sMVC, p=.047) and medial deltoid (87.62% vs. 22.5% sMVC, p=.008).

CONCLUSIONS

The onset of muscle activity is not delayed in CSM patients, but many key muscles take longer to fully contract. This produces a situation in which patients with CSM are unable to fully fire their muscles with sufficient speed to maintain a normal gait. The core and lower extremity muscles do not contract with increased peak amplitude in response, but the deltoid and hamstring muscles are more active, suggesting compensatory activity as patients attempt to maintain balance. The end result is less efficient ambulation. These findings provide a more nuanced understanding of gait in individuals suffering from CSM and may have implications on rehabilitation protocols.

Gait Alteration in Cervical Spondylotic Myelopathy Elucidated by Ground Reaction Forces

STUDY DESIGN

.: Prospective cohort study.

OBJECTIVE

.: Analyze GRF parameters in cervical spondylotic myelopathy (CSM) patients to elucidate gait alterations as compared with healthy controls.

SUMMARY OF BACKGROUND DATA

.: During the human gait cycle, the magnitude and direction of the force each foot imparts on the ground varies in a controlled fashion to propel the body's center of mass forward. Alterations in GRF patterns can both point to subtle gait disturbances and explain altered gait patterns such as that seen in CSM.

METHODS

.: Thirty-two patients with symptomatic CSM who have been scheduled for surgery, along with 30 healthy controls (HC), underwent clinical gait analysis a week before surgery. Vertical GRF parameters and force magnitude and timing at various points of the gait cycle (i.e., heel contact, maximum weight acceptance, mid-stance, and push off) were analyzed and compared between groups.

RESULTS

.: Increased heel contact (CSM: 60.13% vs. HC: 27.82% of body weight, BW,P = 0.011), maximum weight acceptance (CSM: 120.13% vs. HC: 100.97% of BW, P = 0.016), and diminished push off (CSM: 91.35% vs. HC: 106.54% of BW, P = 0.001) forces were discovered in CSM patients compared with HC. Compared with controls CSM patients had delayed heel contact (CSM: 9.32% vs. HC: 5.12% of gait cycle, P = 0.050) and earlier push off (CSM: 54.96% vs. HC: 59.0% of gait cycle, P = 0.050), resulting in a shorter stance phase.

CONCLUSION

.: This study reinforces how CSM patients commonly exhibit altered gait patterns, but also uniquely demonstrates the increased heel-contract and maximum weight acceptance forces, diminished toe-off forces, and the shorter stance phase to absorb the BW load. When examined from a global perspective, these altered GRF parameters reflect the difficulty CSM patients have with catching their center of mass during heel-contact to avoid falling and with subsequently propelling themselves forward.

LEVEL OF EVIDENCE

3.

Effect of Cervical Decompression Surgery on Gait in Adult Cervical Spondylotic Myelopathy Patients

STUDY DESIGN

This is a prospective cohort study.

OBJECTIVE

To evaluate the effect of cervical decompression surgery on the biomechanics of the spine and lower extremities in cervical spondylotic myelopathy (CSM) patients and compare with asymptomatic controls.

SUMMARY OF BACKGROUND DATA

Difficulties with balance and gait are one of the most common manifestations of CSM. Patients with CSM have a slower gait speed, prolonged double support duration, and reduced cadence compared with healthy controls. Surgical decompression was found to improve clinical outcomes, but conflicting results are noted when examining function.

MATERIALS AND METHODS

In total, 25 subjects with symptomatic CSM underwent clinical gait analysis performed a week before (pre) and 3 months after the surgery (post). Clinical gait analysis was performed on 30 matched asymptomatic controls as well. Spine and lower extremity kinematics, spatiotemporal parameters, and clinical outcome were measured.

RESULTS

CSM patients demonstrated slower walking speed (P=0.006), reduced cadence (P=0.001), longer step time (P=0.013) wider step width (P=0.001), greater ankle range of motion (ROM) (P=0.019), less hip ROM (P=0.050), increased pelvis (P=0.001), and lumbar spine (P=0.049) ROM compared with controls. Postoperatively CSM patients demonstrated a faster walking speed (P=0.002), increased cadence (P=0.029), longer step length (P=0.015), narrower step width (P=0.004), greater knee (P=0.043), and hip ROM (P=0.007), less pelvis (P=0.002), lumbar spine (P=0.035), and cervical spine (P=0.044) ROM, and improved clinical outcomes (neck pain disability index questionnaire, oswestry disability index, and visual analog scale; P=0.001) compared with their preoperative values. Postsurgical CSM patients did not present with any differences compared with controls, beside pelvis ROM (P=0.019).

CONCLUSIONS

Preoperatively, CSM patients clearly showed altered gait parameters compared with controls. However, after cervical decompression surgery, CSM patients exhibited improved gait pattern, spatiotemporal parameters, spine and lower extremity ROM, as well as patient-reported outcomes. Postoperatively, CSM patients did not show major differences in gait when compared with matched asymptomatic controls.

Spine and lower extremity kinematics during gait in patients with cervical spondylotic myelopathy

BACKGROUND CONTEXT

Cervical spondylotic myelopathy (CSM) typically manifests with a slow, progressive stepwise decline in neurologic function, including hand clumsiness and balance difficulties. Gait disturbances are frequently seen in patients with CSM, with more advanced cases exhibiting a stiff, spastic gait.

PURPOSE

To evaluate the spatiotemporal parameters and spine and lower extremity kinematics during the gait cycle of adult patients with CSM before surgical intervention.

STUDY DESIGN

Prospective cohort study.

PATIENT SAMPLE

Twenty-eight subjects with symptomatic CSM who have been scheduled for surgery and 30 healthy controls (HC).

OUTCOME MEASURES

Spine and lower extremity kinematics and spatiotemporal parameters.

METHODS

Clinical gait analysis was performed for patients with CSM and HC. The data were analyzed with a one-way analysis of variance.

RESULTS

Patients with CSM have significantly more anterior pelvis tilt (CSM: 13.97°, HC: 5.56°), larger lumbar lordosis (CSM: 8.59°, HC: 2.7°), smaller cervical lordosis (CSM: 6.02°, HC: 11.35°), and less head flexion (CSM: 0.69°, HC: 8.66°) at the beginning of the gait cycle. There was a decrease in knee range of motion in patients with CSM compared with controls (CSM: 36.31°, HC: 50.17°). Furthermore, patients with CSM presented with slower walking speed (CSM: 0.81 m/s, HC: 1.05 m/s), decreased cadence (CSM: 95.57 step/m, HC: 107.64 step/m), increased double support time (CSM: 0.40 s, HC: 0.28 s) and stride time (CSM:1.28 s, HC: 1.13 s), shorter stride length (CSM: 1.04 m, HC: 1.18 m) and step length (CSM:0.51 m, HC: 0.58 m), and wider width (CSM: 0.14 m, HC:0.11 m).

CONCLUSIONS

Our study shows that patients with CSM enter the gait cycle with a larger anterior pelvic tilt and lumbar lordosis as well as less cervical lordosis and head flexion. As a consequence of these abnormal spinal parameters at the onset of the gait cycle, lower extremity biomechanics are also altered. Our study is the first to demonstrate the relationship between aberrant spinal alignment and lower extremity function. Identification of this interrelationship as well as the specific gait and biomechanical disturbances seen in myelopathic patients can both inform our understanding of the disease and tailor rehabilitation protocols.

Analysis of spastic gait in cervical myelopathy: Linking compression ratio to spatiotemporal and pedobarographic parameters

BACKGROUND

Gait dysfunction associated with spasticity and hyperreflexia is a primary symptom in patients with compression of cervical spinal cord. The objective of this study was to link maximum compression ratio (CR) to spatiotemporal/pedobarographic parameters.

METHODS

Quantitative gait analysis was performed by using a pedobarograph in 75 elderly males with a wide range of cervical compression severity. CR values were characterized on T1-weighted magnetic resonance imaging (MRI). Statistical significances in gait analysis parameters (speed, cadence, stride length, step with, and toe-out angle) were evaluated among different CR groups by the non-parametric Kruskal-Wallis test followed by the Mann-Whitney U test using Bonferroni correction. The Spearman test was performed to verify correlations between CR and gait parameters.

RESULTS

The Kruskal-Wallis test revealed significant decline in gait speed and stride length and significant increase in toe-out angle with progression of cervical compression myelopathy. The post-hoc Mann-Whitney U test showed significant differences in these parameters between the control group (0.45<CR) and the worst myelopathy group (CR≤0.25). Cadence and step width did not significantly change with CR. On the other hand, the Spearman test revealed that CR was significantly correlated with speed, cadence, stride length, and toe-out angle.

CONCLUSION

Gait speed, stride length, and toe-out angle can serve as useful indexes for evaluating progressive gait abnormality in cervical myelopathy. Our findings suggest that CR≤0.25 is associated with significantly poorer gait performance. Nevertheless, future prospective studies are needed to determine a potential benefit from decompressive surgery in such severe compression patients.

The Role of Gait Analysis in the Evaluation of Patients with Cervical Myelopathy: A Literature Review Study

BACKGROUND

Gait analysis represents one of the newest methodologies used in the clinical evaluation of patients with cervical myelopathy (CM).

OBJECTIVE

To describe the role of gait analysis in the clinical evaluation of patients with CM, as well as its potential role in the evaluation of the functional outcome of any surgical intervention.

METHODS

A literature review was performed in the PubMed, OVID, and Google Scholar medical databases, from January 1995 to August 2016, using the terms "analysis," "anterior," "cervical myelopathy," "gait," "posterior," and "surgery." Clinical series comparing the gait patterns of patients with CM with healthy controls, as well as series evaluating gait and walk changes before and after surgical decompression, were reviewed. Case studies were excluded.

RESULTS

Nine prospective and 3 retrospective studies were found. Most of the retrieved studies showed the presence of characteristic, abnormal gait patterns among patients with CM, consisting of decreased gait speed, cadence, step length, stride length, and single-limb support time. In addition, patients with CM routinely present increased step and stride time, double-limb support time, and step width, and they have altered knee and ankle joint range of motion, compared with healthy controls. Moreover, gait and walk analysis may provide accurate functional assessment of the functional outcome of patients with CM undergoing surgical decompression.

CONCLUSIONS

Gait analysis may well be a valuable and objective tool along with other parameters in the evaluation of functionality in patients with CM, as well as in the assessment of the outcome of any surgical intervention in these patients.

Gait Analysis in Cervical Spondylotic Myelopathy

STUDY DESIGN

Gait analysis of patients with cervical spondylotic myelopathy (CSM) by using a sheet-type gait analysis system.

PURPOSE

The aim of this study was to compare the gait patterns of patients with CSM, evaluated by the Nurick grades, and to determine the threshold values of gait parameters predicting the occurrence of a fall by using a gait recorder.

OVERVIEW OF LITERATURE

Gait disorder due to CSM may progress to severe paraplegia, following even a minor trauma such as a fall. The indications for the surgery of CSM without severe paralysis remain controversial. The quantitative gait analysis and the decision for decompressive surgery in patients with CSM are important in order to prevent severe paraplegia from a fall.

METHODS

One hundred thirty-two subjects (normal, 34; CSM, 98) underwent gait analysis by using a sensor sheet. Measurements of gait cycle parameters included the step and stride length, step width, foot angle, swing phase, and stance phase. CSM was assessed by Nurick grade.

RESULTS

Although the clinical symptoms were lacking, Nurick grade 1 had significant abnormalities in the parameters of velocity, step length, and step angle (p<0.05). Regarding the Nurick grade and walking phase, the length of the stance phase was increased to more than 70% of the entire walking cycle in Nurick grade 4.

CONCLUSIONS

Gait analysis was an objective tool for evaluating the gait stability. Our results suggested that when the percentage of the stance phase in the gait cycle increases to above 70%, the CSM patients have an increased fall risk.

Electromyographic characteristics of gait impairment in cervical spondylotic myelopathy

AIM

Gait impairment in cervical spondylotic myelopathy (CSM) is characterised by a number of kinematic and kinetic abnormalities. Surface electromyography (EMG) can evaluate the contributions of individual muscles to a movement pattern and provide insight into the underlying impairments that characterise an abnormal gait. This study aimed to analyse EMG signals from major lower limb muscles in people with CSM and healthy controls during gait.

METHODS

Sixteen people with radiologically confirmed CSM and 16 matched healthy controls participated in gait analysis. Surface EMG was recorded during walking from four lower limb muscles bilaterally. The timing of muscle activation, relative amplitudes of each burst of activity and baseline activation during gait, and the muscles' responses to lengthening as a measure of spasticity were compared using previously validated methods of EMG analysis.

RESULTS

Compared to healthy controls, people with CSM had prolonged duration of activation of biceps femoris (12.5% longer) and tibialis anterior (12.4%), prolonged co-activation of rectus femoris and biceps femoris (5.14%), and impaired scaling of the amplitude of rectus femoris and biceps femoris. Muscle activation in response to lengthening was similar between groups.

CONCLUSION

The results provide evidence for paresis as a contributory factor to gait impairment in CSM, indicated by impaired amplitude and the need for proximal co-activation to compensate for lack of distal power generation. Poor proprioception may have contributed to prolonged activation of tibialis anterior. Analysis of muscle responses to lengthening suggested that spasticity was not an important contributor. These findings have implications for the assessment and rehabilitation of gait impairment in CSM.

Gait impairment in cervical spondylotic myelopathy: comparison with age- and gender-matched healthy controls

INTRODUCTION

Gait impairment is a primary symptom of cervical spondylotic myelopathy (CSM); however, little is known about specific kinetic and kinematic gait parameters. The objectives of the study were: (1) to compare gait patterns of people with untreated CSM to those of age- and gender-matched healthy controls; (2) to examine the effect of gait speed on kinematic and kinetic parameters.

MATERIALS AND METHODS

Sixteen patients with CSM were recruited consecutively from a neurosurgery clinic, and 16 healthy controls, matched to age (± 5 years) and gender, were recruited for comparison. Patients and controls underwent three-dimensional gait analysis using a Vicon(®) motion analysis system, at self-selected speed over a 10-m track. Controls were also assessed at the speed of their CSM match.

RESULTS

At self-selected speed, the CSM group walked significantly more slowly, with shorter stride lengths and longer double support duration. They showed significant decreases in several kinematic and kinetic parameters, including sagittal range of motion at the hip and knee, ankle plantarflexion, anteroposterior ground reaction force (GRF) at toe-off, power absorption at the knee in loading response and terminal stance, and power generation at the ankle. At matched speed, the CSM group showed significant decreases in knee flexion during swing, total sagittal knee range of motion, peak ankle plantarflexion and anteroposterior GRF.

CONCLUSION AND IMPLICATIONS

The findings suggested that people with CSM have significant gait abnormalities that have not been previously reported. In particular, there are key differences in the motor strategies used in the terminal stance phase of gait that cannot be explained by speed alone.

Reliability of surface electromyography timing parameters in gait in cervical spondylotic myelopathy

The aims of this study were to validate a computerised method to detect muscle activity from surface electromyography (SEMG) signals in gait in patients with cervical spondylotic myelopathy (CSM), and to evaluate the test-retest reliability of the activation times designated by this method. SEMG signals were recorded from rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA), and medial gastrocnemius (MG), during gait in 12 participants with CSM on two separate test days. Four computerised activity detection methods, based on the Teager-Kaiser Energy Operator (TKEO), were applied to a subset of signals and compared to visual interpretation of muscle activation. The most accurate method was then applied to all signals for evaluation of test-retest reliability. A detection method based on a combined slope and amplitude threshold showed the highest agreement (87.5%) with visual interpretation. With respect to reliability, the standard error of measurement (SEM) of the timing of RF, TA and MG between test days was 5.5% stride duration or less, while the SEM of BF was 9.4%. The timing parameters of RF, TA and MG designated by this method were considered sufficiently reliable for use in clinical practice, however the reliability of BF was questionable.

Functional outcomes assessment for cervical degenerative disease

Object

The objective of this systematic review was to use evidence-based medicine to identify valid, reliable, and responsive measures of functional outcome after treatment for cervical degenerative disease.

Methods

The National Library of Medicine and Cochrane Database were queried using MeSH headings and key words relevant to functional outcomes. Abstracts were reviewed after which studies meeting inclusion criteria were selected. The guidelines group assembled an evidentiary table summarizing the quality of evidence (Classes I–III). Disagreements regarding the level of evidence were resolved through an expert consensus conference. The group formulated recommendations that contained the degree of strength based on the Scottish Intercollegiate Guidelines network. Validation was done through peer review by the Joint Guidelines Committee of the American Association of Neurological Surgeons/Congress of Neurological Surgeons.

Results

Myelopathy Disability Index, Japanese Orthopaedic Association scale, 36-Item Short Form Health Survey, and gait analysis were found to be valid and reliable measures (Class II) for assessing cervical spondylotic myelopathy. The Patient-Specific Functional Scale, the North American Spine Society scale, and the Neck Disability Index were found to be reliable, valid, and responsive (Class II) for assessing radiculopathy for nonoperative therapy. The Cervical Spine Outcomes Questionnaire was a reliable and valid method (Class II) to assess operative therapy for cervical radiculopathy.

Conclusions

Several functional outcome measures are available to assess cervical spondylotic myelopathy and cervical radiculopathy.

Patient perceived outcome after central corpectomy for cervical spondylotic myelopathy

BACKGROUND

Patient perception of outcome after decompressive surgery for CSM is infrequently reported. We evaluated a simple, quantitative patient-reported assessment of outcome after CC for CSM by comparing it with the NGRR.

METHODS

In a prospective study between 1994 and 2004, patients who underwent CC for CSM were asked to quantify the outcome (relative to their preoperative status) on a scale of 0 to 100. Patient perceived outcome score was compared with the NGRR (preoperative grade - postoperative grade / preoperative grade x 100) at the same follow-up.

RESULTS

A total of 208 patients with a follow-up ranging from 6 to 72 months (mean, 16.3 months) were evaluated. There was a good positive correlation between PPOS and NGRR for the whole group (Pearson correlation coefficient, 0.62; P < .001), good-grade patients (preoperative Nurick grade of 1-3) (Pearson correlation coefficient, 0.52; P < .001), and poor-grade patients (Pearson correlation coefficient, 0.79; P < .001); the correlation was strongest in the poor-grade group of patients. kappa statistic revealed moderate agreement between the 2 scores in the whole group (kappa = 0.45), substantial agreement in the poor-grade patients (kappa = 0.61), and fair agreement in the good-grade patients (kappa = 0.34). In 28 of the 208 patients (13.5%), there was no agreement between the 2 scores with a significantly greater proportion (24/28), reporting an improvement in spite of no change in their Nurick grade (McNemar chi(2) test, P = .0002).

CONCLUSIONS

Although there was good agreement and a positive correlation between PPOS and NGRR, the disagreement in 13.5% of patients suggests that the 2 scores are evaluating some dissimilar functional domains; therefore, PPOS provides additional independent data in the assessment of the results of decompressive surgery for CSM. Patient-reported outcome should be included in reporting outcome of decompressive surgery for CSM.