Change characteristics of standing-sitting spinopelvic sagittal parameters in patients with diffuse idiopathic skeletal hyperostosis

English Keywords:Diffuse idiopathic skeletal hyperostosis  Bone hyperplasia  Spinopelvic sagittal parameters  Spinopelvic mobility

English Abstract:

  【Abstract】 Objectives: To investigate the impact of bone hyperplasia in the thoracolumbar spine caused by diffuse idiopathic skeletal hyperostosis(DISH) on the changes of spinopelvic sagittal parameters between standing and sitting positions. Methods: A total of 61 DISH patients[DISH group, 42 males and 19 females, 50-76(65.1±6.3) years] who underwent surgical treatment for lumbar spinal stenosis in our hospital between January 2019 and December 2023 were retrospectively analyzed. 100 age- and sex-matched non-DISH patients undergone the same surgical procedure during the same period were included as control[N-DISH group, 63 males and 37 females, 54-77(67.5±7.2) years]. According to the distribution of osteophytes, the patients in the DISH group with ectopic ossification limited to the thoracic spine were categorized into the T-DISH group, while those with involvement of both thoracic and lumbar spines were divided in the L-DISH group. Preoperatively, full-spine anteroposterior and lateral X-rays were taken in both standing and sitting positions. All patients were measured for spinopelvic sagittal parameters in standing and sitting positions, including sagittal vertical axis(SVA), pelvic tilt(PT), sacral slope(SS), pelvic incidence(PI), thoracic kyphosis(TK), lumbar lordosis(LL), and proximal femoral angle(PFA). The differences in standing and sitting positions and changes between DISH and N-DISH groups, T-DISH and L-DISH groups were compared. Results: In the standing position, the SVA(P=0.008) and TK(P=0.028) in the DISH group were significantly higher than those in the N-DISH group, while no significant differences were observed in PI, PT, SS, LL, and PFA(P>0.05). In the sitting position, the TK(P=0.003) and LL(P=0.007) in the DISH group were significantly higher than those in the N-DISH group, whereas no significant differences were noted inSVA, PT, PI, SS, and PFA(P>0.05). When transitioning from standing to sitting, the changes in SVA(P=0.021), PT(P=0.008), SS(P=0.001), TK(P=0.002), and LL(P<0.001) in DISH group of patients were significantly smaller than those in N-DISH group of patients. Among DISH patients, the L-DISH group had significantly lower PI(P=0.016), SS(P=0.011), and LL(P=0.006) in the standing position compared to the T-DISH group, while no significant differences were observed in SVA, PT, TK, and PFA(P>0.05). In the sitting position, the PI(P=0.008) and SS(P=0.007) of the L-DISH group were significantly lower than those of the T-DISH group, while no significant differences were observed in SVA, PT, TK, LL, and PFA(P>0.05). The changes in LL when transitioning from standing to sitting were significantly lower in the L-DISH group compared to the T-DISH group(P=0.033), while the changes of other sagittal parameters showed no significant difference(P>0.05). Conclusions: Bone hyperplasia in DISH patients significantly limits spinal mobility, and the restriction is more pronounced in patients with osteophytes extending to the lumbar spine compared to those with isolated thoracic involvement.