A new study has found that after cervical decompression surgery, cervical spondylotic myelopathy (CSM) patients exhibited improved gait pattern, spatiotemporal parameters, spine and lower extremity range of motion (ROM), and patient reported outcomes. The study was carried out by Ram Haddas (Texas Back Institute, Plano, USA) and colleagues, and won the First Place Clinical Research Award at the 46th annual meeting of the Cervical Spine Research Society (CSRS; 6–8 December 2018, Scottsdale, USA). The study was partially sponsored by CSRS and Haddas won the grant seed award for the project in 2017.
Difficulties with balance and gait are two of the most common manifestations of CSM, the authors write. They mention that patients with CSM have a slower gait speed, prolonged double support duration, and reduced cadence compared to healthy controls.
According to the authors, surgical decompression has been found to improve clinical outcomes, but conflicting results are apparent when examining function. “To our knowledge,” they write, “there is no literature regarding spinal and lower extremity kinematics, with very limited literature on the spatiotemporal gait parameters of patients having CSM before and after surgical intervention.”
The main purpose of the study was to explore the level of functional compromise, both objectively and subjectively with patient-reported outcome measures, in patients with CSM. Secondarily, the authors sought to quantify the potential benefit of cervical decompression surgery on the biomechanics of the spine and lower extremities as evaluated by gait analysis.
Haddas and colleagues note that pre-operatively, CSM patients clearly demonstrated altered gait parameters compared to controls. Specifically, they found that CSM patients demonstrated slower walking speed (p=0.006) and reduced cadence (p=0.001), longer step time (p=0.013) and double support time, shorter step length and wider step width (p=0.001) pre-operatively in comparison to controls. Furthermore, CSM patients had significantly greater ankle ROM (p=0.019), less hip ROM (p=0.050), increased pelvis (p=0.001) and lumbar spine (p=0.049) ROM in the sagittal plane when compared to the control group.
They found that postoperatively, CSM patients demonstrated a faster walking speed (p=0.002), increased cadence (p=0.029), longer step length (p=0.015), and narrower step width (p=0.004). They also exhibited 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 (NDI, ODI, and VAS; p=0.001) compared to their pre-operative values. When comparing clinical outcomes, the NDI (p=0.001), ODI (p=0.001), VAS neck (p=0.001), and VAS arm (p=0.001) scores were significantly improved following surgery.
Following cervical decompression surgery, CSM patients not only exhibited improved gait pattern, but also improved spatiotemporal parameters, spine and lower extremity ROM, and patient-reported outcomes. The authors found that three months after surgery, CSM patients did not present with any differences compared to controls beside pelvis ROM, which had a p-value of 0.019.
Haddas and colleagues describe the study as a non-randomised, prospective, concurrent control cohort study of patients with CSM before and after cervical decompression compared to a matched asymptomatic control group. Twenty-five patients with symptomatic CSM underwent clinical gait analysis a week before and three months after surgery. Clinical gait was performed on 30 matched asymptomatic controls as well. Each subject performed a series of over-ground gait trials at a self-selected speed. Spine and lower extremity kinematics, spatiotemporal parameters, and clinical outcome were measured. A repeated measurement and one-way ANOVA were used for the statistical analysis.
According to the investigators, this is the first study, both objectively and with patient-reported outcome measures, to quantify the benefits of cervical decompression surgery on the biomechanics and function of the spine and lower extremities before and after surgical intervention in a population of CSM patients.
Talking to Spinal News International, Haddas mentioned that “the results of this study conflict with those of Malone and colleagues who did not find any significant change in spatiotemporal or kinematic parameters but did find improvement in kinetic and neuromuscular parameters when they examined 13 CSM patients pre- and 12 months postoperatively.” He commented that the smaller sample size and different follow up time of the Malone study may offer a “possible explanation” for the difference.
On potential limitations of the study, Haddas told Spinal News International that that “as with any gait study, the data collected will have large inter-subject variability.” Furthermore, he added that “for the purpose of the study, we only analysed the right lower extremity of the patient, but there could be asymmetries between the right and left sides of the body.”
Haddas and colleagues suggest that this study “not only provided a richer understanding of the gait pathology in cervical myelopathy, but uniquely showed that surgical intervention improves gait and function as measured by spatiotemporal parameters, spine and lower extremity ROM, and patient reported outcome measures.”