Abdominal changes in patients with degenerative spinal deformity: A comparative study

The incidence of degenerative spinal deformity (DSD) is increasing with the age while the effect of DSD on the abdominal cavity parameters is unclear.To identify the characteristics of abdominal change in DSD and to explore the correlation between the abdominal cavity volume (ACV) and various types of DSD.The retrospective study included 95 patients with DSD and 100 subjects without deformity as control group. The Cobb angle, thoracic kyphosis angle, thoracolumbar kyphosis (TLK) angle, and lumbar kyphosis angle were obtained through full-length X-ray. The ACV was calculated by measuring the longitudinal, transversal, and coronal diameters of the abdominal cavity on magnetic resonance imaging (MRI). The rotation of the diaphragm (DR) were measured in the sagittal plane. DSD ones were divided into degenerative lumbar scoliosis (DLS group), degenerative kyphosis (DK group), and degenerative lumbar scoliokyphosis (DKS group).Compared to control group, ACV of the DLS and DKS group was smaller. The distance between the xiphoid process and spine in DLS group was shorter and DR in DK group and DKS group was smaller. The inter-group analysis showed ACV and the shortest distance between xiphoid process and spine in DLS and DKS group were significantly lower than those in DK group. The degree of DR in DK group and DKS group was higher than that in the DLS group. Multiple linear regression analysis showed Cobb angle and weight were influencing factors of ACV with ACV = 0.67 × weight - 0.19 × Cobb angle + 2231.8. The DR was affected by TLK with DR = 25.82 - 0.42 × TLK.DLS can cause the decrease of ACV. DK will not cause changes of ACV but is related to the degree of kyphosis. DKS will impact both ACV and DR.