Unilateral and Bilateral Lumbosacral Transitional Vertebrae: Comparison of the Incidence of Combined Diseases

Park, Jin Yong; Kwon, Soon Tae; Han, Tae Il; Lee, Se Hyo; Han, Ki Tae; Kim, Hyun Jeong; An, Jae Sung; Yang, Jun Young; Lee, Jun Kyu

Abstract

PURPOSE: The purpose of this study was to evaluate the radiologic findings of lumbosacral transitional verte-brae (LSTV), as seen on plain radiographs and MRI, and to compare the incidence of combined diseases be-tween unilateral and bilateral groups.
MATERIALS AND METHODS
We retrospectively evaluated the plain radiographs and MR images of 63 patients with LSTV, classifying its type according to Castellvi 's criteria, and evaluated disc herniations, facet joint os-teoarthritic change, scoliosis, and spondylolisthesis. We then compared the incidence of each combined diseases between unilateral and bilateral groups, and as a control group, 63 patients without LSTV were also eval-uated. RESULTS: Forty of 63 cases of LSTV (63.5%) were bilateral, and 23 (36.5%) unilateral. According to Castellvi 's criteria, the incidence of type I was 41.3% (unilateral 7 cases, bilateral 19), type III30.2% (unilateral 8 cases, bilateral 11), type II23.8% (unilateral 8 cases, bilateral 7), and type IV 4.8% (unilateral 0 cases, bilateral 3).With combined diseases, the incidence of disc herniation was 66.7% (unilateral 15 cases, bilateral 27), moderate to severe facet joint osteoarthritic change 28.6% (unilateral 11 cases, bilateral 7), scoliosis 27.0% (unilateral 9 cases, bilateral 8), and spondylolisthesis 9.5% (unilateral 2 cases, bilateral 4). The incidence of facet joint os-teoarthritic change was significantly higher in the unilateral group (47.8%) than in the bilateral group (17.5%) (p=0.02), and scoliosis occurred at a higher rate in the unilateral group (39.1%) than in the bilateral group (20.0%) (p=0.18). There was, however, no significant difference in the incidence of disc herniation and spondylolisthesis between the two groups (unilateral group: 65.2% and 8.7%; bilateral group: 67.5% and 10.0%, respectively). CONCLUSION: With LSTV, the incidence of facet joint osteoarthritic change was significantly higher in the unilat-eral group than in the bilateral group, and scoliosis also showed a higher rate of occurrence in the unilateral group.