Search

Study Design: A prospective cohort study., Objective: Quantify the extent of change in dynamic balance and stability in a group of patients with cervical spondylotic myelopathy (CSM) after cervical decompression surgery and to compare them with matched healthy controls., Summary of Background Data: CSM is a naturally progressive degenerative condition that commonly results in loss of fine motor control in the hands and upper extremities and in gait imbalance. Whereas this was previously thought of as an irreversible condition, more recent studies are demonstrating postoperative improvements in balance and stability., Materials and Methods: Thirty subjects with symptomatic CSM and 25 matched asymptomatic controls between the ages of 45 and 75 years underwent functional balance testing using a 3D motion capture system to gather kinematic and spatiotemporal parameters. CSM subjects underwent testing 1 week before surgery and again 3 months postoperatively., Results: Patients with CSM exhibited markedly diminished balance as indicated by increased sway on a Romberg test and requiring significantly more time and a wider stance to complete tandem gait tests. The surgical intervention resulted in improved balance at the 3-month postoperative time point; however, kinematic and spatiotemporal parameters did not completely normalize to the levels observed in asymptomatic controls., Conclusions: Human motion video capture can be used to robustly quantify balance parameters in the setting of CSM. Compared with healthy controls, such patients exhibited increased standing sway and poorer performance on a tandem gait task. The surgical intervention resulted in significant improvement in many of the measures of functional balance, but overall profiles had not completely returned to normal when measured 3 months after surgery. These data reinforce the importance of operative intervention in the treatment of symptomatic CSM with the goal of halting disease progress but the expectation that balance may actually improve postoperatively.

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., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Study Design: A prospective cohort study., Objective: The aim of this study was to quantify the amount of sway associated with maintaining a balanced posture in a group of untreated cervical spondylotic myelopathy (CSM) patients., Summary of Background Data: Balance is defined as the ability of the human body to maintain its center of mass (COM) within the base of support with minimal postural sway. Sway is the movement of the COM in the horizontal plane when a person is standing in a static position. CSM patients have impaired body balance and proprioceptive loss., Methods: Thirty-two CSM patients performed a series of functional balance tests a week before surgery. Sixteen healthy controls (HCs) performed a similar balance test. Patients are instructed to stand erect with feet together and eyes opened in their self-perceived balanced and natural position for a full minute. All test subjects were fitted to a full-body reflective markers set and surface electromyography (EMG)., Results: CSM patients had more COM sway in the anterior-posterior (CSM: 2.87 cm vs. C: 0.74 cm; P = 0.023), right-left (CSM: 5.16 cm vs. C: 2.51 cm; P = 0.003) directions as well as head sway (anterior-posterior - CSM: 2.17 cm vs. C: 0.82 cm; P = 0.010 and right-left - CSM: 3.66 cm vs. C: 1.69 cm; P = 0.044), more COM (CSM: 44.72 cm vs. HC: 19.26 cm, p = 0.001), and head (Pre: 37.87 cm vs. C: 19.93 cm, P = 0.001) total sway in comparison to controls. CSM patients utilized significantly more muscle activity to maintain static standing, evidenced by the increased trunk and lower extremity muscle activity (multifidus, erector spinae, rectus femoris, and tibialis anterior, P < 0.050) during 1-minute standing., Conclusion: In symptomatic CSM patients, COM and head total sway were significantly greater than controls. Individuals with CSM exhibit more trunk and lower extremity muscle activity, and thus expend more neuromuscular energy to maintain a balanced, static standing posture. This study is the first effort to evaluate global balance as a dynamic process in this patient population., Level of Evidence: 3.

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.

Study Design: Retrospective review., Objective: Our objective was to examine the prevalence, clinical significance, ramifications, and possible etiology of postoperative bone formation at the index level after cervical disc replacement (CDR) with a minimum of 5 years of follow-up., Summary of Background Data: CDR can be complicated by postoperative ossification and unwanted ankylosis at the index level, which some authors have termed "heterotopic ossification." This terminology may be inaccurate as it assumes the postoperative bone formation is unnatural and a consequence of the CDR surgery. We advocate that this phenomenon has more to do with individual patient factors rather than the surgery., Methods: Patients who underwent Bryan CDR for cervical myelopathy or radiculopathy between 12/2003 and 8/2008 with a minimum of 5-years follow-up were analyzed. They were divided into two groups, those with and without postoperative bone formation. Patient-reported outcomes (Japanese Orthopaedic Association score, Neck Disability Index, Visual Analogue Scale for neck and arm pain) and radiographic parameters were collected pre- and postoperatively and compared between groups., Results: Sixty-one patients (76 levels) were identified (mean follow-up 94.2 mo). The overall incidence of postoperative ossification was 50%. Both groups had sustained significant improvements across all patient-reported outcome measures at final follow-up. Notably, patients with more severe preoperative cervical spondylosis had higher rates of postoperative ossification (P = 0.036) and adjacent segment degeneration (P = 0.010)., Conclusion: Although the long-term incidence of postoperative bone formation after CDR was relatively high, this did not adversely affect patient outcomes. Patients with more severe preoperative spondylosis had higher rates of postoperative ossification, suggesting that postoperative ossification at the CDR segment is likely one of progressive bone formation in individuals already predisposed to forming bone rather than one of alleged heterotopic ossification as a consequence of the surgery., Level of Evidence: 3.