INTRODUCTION: Gait disturbance is a characteristic difficulty for patients with degenerative lumbar spinal disorder. Objective evaluation of the gait will help to fully understand how the spinal pathology results in disability. Three-dimensional (3D) gait analysis can obtain real-time information without any known risks to the patients. There is little information about the assessment of gait ability and comparison with radiographic parameters in patients with degenerative lumbar scoliosis (DLS). The purpose of this study was to measure pre-and postoperative gait characteristics in patients with DLS using 3D gait analysis and to analyze the correlation between the gait parameters and the radiographic spinopelvic parameters.

METHODS: Subjects: Twenty-two patients (4 men and 18 women; avg. age: 68.9 years) who received lumbar spinal surgery in our institutions were included. Ten patients with DLS (10 women; 66.4 years) and twelve patients with lumbar spinal stenosis (LSS: 4 men, 8 women; 70.9 years) were evaluated before spinal surgery and after 6 months.

Gait analysis: Sixteen reflective markers were attached to the surface of the body. Gait data were collected using six infrared cameras. Each subject performed a series of over-ground gait trials at a comfortable self-selected speed. The gait parameters (gait speed, stride length, step width, and cadence) and gait cycle (swing phase, stance phase, double support, and single support phase) were measured.

Radiographic measurements of spinopelvic parameter: Full-length free-standing lateral radiographs were taken. Radiographic measures included sagittal vertical axis (SVA), pelvic incidence (PI), sacral slope (SS), pelvic tilt (PT), and lumbar lordosis (LL).

Statistical analysis: Student t-test was used to determine differences in gait parameters and gait cycle between DLS and LSS groups. Correlations between radiographic parameters and gait characteristics were analyzed using the Pearson coefficient.

RESULTS: Subject characteristics: There were no significant differences in age, gender, body weight, and body height between DLS and LSS groups.

Gait parameters: There were no significant differences in gait speed, stride length, step width, and cadence between DLS and LSS groups before surgery. The gait speed and stride length in the DLS group after surgery were significantly higher than those before surgery. However, there were no significant differences in cadence and step width between DLS and LSS groups before surgery and after 6 months.

Gait cycle: The swing phase in the DLS group after surgery was significantly higher than that before surgery.

Correlations between radiographic parameters and gait characteristics: Correlation coefficient analyses identified significant correlations between the gait speed/stride length and SVA, LL, and PI-LL before surgery. (P<0.05; correlation coefficient 0.51 to 0.64). Correlation coefficient analyses identified significant correlations between the gait speed/stride length and SVA after surgery (P<0.05; correlation coefficient 0.65 to 0.77).

DISCUSSION: We have evaluated the gait characteristics of patients with spinal disorders using 3D gait analysis and compared the data between the patients with DLS and LSS. Our study showed that gait parameters/cycle were improved after corrective spinal surgery and gait speed/stride length had a significant correlation with SVA before and after surgery.