Clinical, physical, and radiographic analyses of lumbar degenerative kyphosis and spondylolisthesis among community-based cohort.

PURPOSE: To investigate longitudinal radiographic changes, and physical characteristics of lumbar degenerative kyphosis (LDK) and spondylolisthesis (DS). METHODS: Two-hundred eighty nine community-based female subjects were recruited from population register and studied longitudinally for a mean 12.3 years. Upright entire spine radiographs were used to evaluate spinopelvic parameters, including lumbar lordosis (LL), pelvic incidence (PI), and vertebral slip (% slip). Physical measurements included lumbar range of motion (ROM), isometric trunk muscle strength, and photometric gait posture using change in trunk inclination angle (dTIA). RESULTS: Subjects' mean age (standard deviation: SD) was 56.9 (10.0) years at baseline and 68.5 (9.2) years at the final follow-up. Among 202 subjects who could perform instructed physical measurements, DS, defined as more than 5 % slip, was found in 50 subjects (24.8 %), and LDK, defined as LL of less than 1SD of mean value (<24.4°), was found in 24 subjects (11.9 %). DS subjects showed a significant weakness in trunk flexor strength (normal 282.5 ± 73.0 N vs. DS 245.5 ± 75.5 N, p = 0.0219), and LDK subjects showed significant differences in: trunk extensor strength (normal 493.4 ± 172.8 N vs. LDK 386.3 ± 167.6 N, p = 0.0066), ROM, and dTIA (normal 3.5° ± 2.7° vs. LDK 7.6° ± 4.8°, p < 0.0001). PI was significantly larger in DS and smaller in LDK than normal subjects (normal 53.8° ± 9.9° vs. DS 58.2° ± 10.6°, p = 0.0111; normal vs. LDK 48.4° ± 9.2°, p = 0.0191). CONCLUSIONS: Current study showed that DS was associated with reduced trunk flexor strength, which might increase pelvic anteversion, and LDK was associated with reduced extensor strength, ROM, and ambulatory kyphosis. Physical characteristics should be evaluated for the successful management of adult spinal deformity