Oral Posters: Adult Spinal Deformity
Presented by: I. Lieberman - View Audio/Video Presentation (Members Only)
R. Haddas(1), S. Aghyarian(1), I. Lieberman(2)
(1) Texas Back Institute, Research Foundation, Plano, TX, United States
(2) Texas Back Institute, Plano, TX, United States
Introduction: Age related changes such as progressive and asymmetric degeneration of the disc and facet joints are associated with degenerative adult scoliosis and lead to segmental instability, deformity and stenosis. Narrowing of the spinal canal as a result of this degeneration can also lead to back pain, as well as leg pain, weakness, and numbness. Degenerative adult scoliosis does directly affect a patient's gait pattern. Changes in gait can include decreased step length and reduced range of motion in the upper and lower extremities, asymmetry of trunk rotation as well as ground reaction forces and a decrease in the muscular mechanical work. The purpose of this study was to evaluate the biomechanics of the lower extremities and the spine during gait in adult degenerative scoliosis patients before surgical intervention.
Methods: Twenty subjects with symptomatic degenerative scoliosis who were deemed appropriate surgical candidates were compared to 20 healthy volunteers. Clinical gait analysis was performed the week before surgery for the scoliosis patients. Clinical gait analysis was likewise performed on a group of healthy subjects for comparison. Fifty-one reflective markers (9.5 mm diameter) were incorporated to collect full body three-dimensional kinematics using 10 cameras (VICON, Denver, CO) at a sampling rate of 100 Hz. Ground reaction forces (GRFs) were measured at 2000 Hz using three parallel force plates (AMTI, Watertown, MA). The patients walked barefoot at his/her self-selected speed along a 10 m walkway. Spine and lower extremity kinematic were measured and recorded. The data was analyzed with one way ANOVA to determine differences between group walking patterns.
Results: A significantly slower walking speed (S: 0.72 vs 1.04 m/s p< 0.001), cadence (S: 87.76 vs H: 105.91 steps/min p< 0.008), shorter step (S: 0.48 vs H: 0.61 m p< 0.041) and stride length (0.96 vs 1.18 m p< 0.037) was measured in the degenerative scoliosis patients in comparison to the controls. Furthermore, the scoliosis´ patients exhibited a significantly smaller knee flexion angle at initial contact (5° p< 0.019), larger lumbar spine flexion (14° p< 0.021), larger head extension position (19° p< 0.001), less range of motion (ROM) in pelvis obliquity (4° p< 0.001), and less lumbar spine side flexion ROM (4° p< 0.050). Larger GRFs (Right S: 631 vs H: 501 N p>0.032; Left S: 714 vs H: 509 N p>0.015) were found in the scoliosis´ patients when compared to the healthy control group.
Discussion: Adult degenerative scoliosis patients have an altered gait pattern in comparison to healthy controls. Scoliosis patients walk slower with reduced trunk and lower extremity function and efficiency. Due to these changes in gait, compensation can occur in the form of increased trunk flexion, head extension along with other less obvious biomechnical deficiencies. Tracking the gait parameters and observing posture can give insight into the effectiveness of treatments. Formal gait and motion analysis can provide a true and consistent objective method to assess the impact of spinal deformity on function and help assess the therapeutic benefits after treatment.