Frequency of Hypoplasia of the Vertebral Body at L5, and Its Relationship with Degeneration in Patients with Low Back Pain.

AIM: To explain the association between vertebral body hypoplasia and degenerative changes in the discovertebral complex and facet joints, and to assess the incidence of hypoplasia of the vertebral body at the L5 level. MATERIAL AND METHODS: A retrospective analysis was made of 3,100 patients aged 20?50 years who underwent lumbar MRI with a complaint of back pain, of which 55 were identified with vertebral body hypoplasia. Intervertebral disc degeneration was evaluated in the study using the Pfirrmann and Modified Pfirrmann classification systems, while degenerative changes in the vertebrae endplate were assessed using the Modic classification system. Osteoarthritis of the facet joint was graded at the L4-5 level, and spondylolysis and spondylolisthesis rates were compared between the control group and the hypoplasic group. RESULTS: The incidence of hypoplasia of the vertebral body at the L5 level was found to be 1.8% in the population with back pain in the 20?50-year age group. In the hypoplasia group, disc degeneration was detected at a higher rate than in the control group (p < 0.001). The distribution of Modic signal changes in the superior and inferior endplates of the vertebrae differed significantly between the hypoplasia and control groups (p < 0.001).The rate of spondylolysis was 7.7% in the control group and 65.5% in the hypoplasia group (p < 0.001), and spondylolisthesis was significantly more common in the hypoplasia group (18.4%, p < 0.001). In addition, facet joint degeneration was identified more frequently in the hypoplasia group. Degenerative findings were detected in 74.5% of the right posterior intervertebral joints, and in 70.9% of the left posterior intervertebral joints in the hypoplasia group. CONCLUSION: Vertebral body hypoplasia is a predisposing factor for disc degeneration, facet osteoarthritis and degeneration in the vertebral endplates, and has also been associated with spondylolysis and spondylolisthesis.