title: Degenerative retrolisthesis: is it a compensatory mechanism for sagittal imbalance?
abstract: We investigated the spinopelvic morphology and global sagittal balance of patients with a degenerative retrolisthesis or anterolisthesis. A total of 269 consecutive patients with a degenerative spondylolisthesis were included in this study. There were 95 men and 174 women with a mean age of 64.3 years (sd 10.5; 40 to 88). A total of 106 patients had a pure retrolisthesis (R group), 130 had a pure anterolisthesis (A group), and 33 had both (R+A group). A backward slip was found in the upper lumbar levels (mostly L2 or L3) with an almost equal gender distribution in both the R and R+A groups. The pelvic incidence and sacral slope of the R group were significantly lower than those of the A (both p < 0.001) and R+A groups (both p < 0.001). The lumbar lordosis of the R+A group was significantly greater than that of the R (p = 0.025) and A groups (p = 0.014). The C7 plumb line of the R group was located more posteriorly than that of the A group (p = 0.023), but was no different from than that of the R+A group (p = 0.422). The location of C7 plumb line did not differ between the three groups (p = 0.068). The spinosacral angle of the R group was significantly smaller than that of the A group (p < 0.001) and R+A group (p < 0.001). Our findings imply that there are two types of degenerative retrolisthesis: one occurs primarily as a result of degeneration in patients with low pelvic incidence, and the other occurs secondarily as a compensatory mechanism in patients with an anterolisthesis and high pelvic incidence.
authors.affiliation: Ajou University School of Medicine, Department of Orthopaedic Surgery, San 5 Wonchon-dong, Youngtong-gu, Suwon, Kyounggi-do Suwon, Korea.
authors.forename: C-H
authors.initials: CH
authors.lastname: Jeon
authors.forename: J-U
authors.initials: JU
authors.lastname: Park
authors.forename: N-S
authors.initials: NS
authors.lastname: Chung
authors.forename: K-H
authors.initials: KH
authors.lastname: Son
authors.forename: Y-S
authors.initials: YS
authors.lastname: Lee
authors.forename: J-J
authors.initials: JJ
authors.lastname: Kim
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D006801:Humans; D007738:Kyphosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D008141:Lordosis / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology; D008159:Lumbar Vertebrae / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D010388:Pelvis / Q000473:pathology*; D011446:Prospective Studies; D011859:Radiography; D013168:Spondylolisthesis / Q000000981:diagnostic imaging / Q000209:etiology / Q000473:pathology*
keywords: Degenerative; Pelvic parameter; Retrolisthesis; Sagittal balance; Spine; Spondylolisthesis