Use of lumbar vertebral body antero-posterior ratio to detect vertebral fractures among Sri Lankan patients with low backache

Abstract

OBJECTIVE: To determine an antero-posterior (A/P) ratio value for lumbar vertebral bodies to detect vertebral fractures among Sri Lankans presenting with low backache. DESIGN, SETTING AND METHODS: A case control study conducted at Teaching Hospital, Ragama and Rehabilitation Hospital, Ragama. In lateral radiographs of lumbar spine, the anterior and posterior vertebral body heights of fourth and fifth lumbar vertebrae were measured in 130 patients with low backache and 133 without low backache. Vertebral body heights were measured using a vernier caliper. After measuring the heights of the vertebrae, the antero- posterior (A/P) ratio was calculated. Reduction in anterior, middle, posterior or total height of the vertebral body was classified as a vertebral fracture. Cases and controls were matched for age and sex. Results were analysed using EPI6 statistical package. RESULTS: The age range of study subjects were 38- 82 years (mean age of cases 49.3 years, SD 15; mean age of controls 51.4 years, SD 17). 81 (62.5%) of the patients and 82 (61.7%) of the controls were females. 67% of cases and 6% of controls had an A/P ratio value of less than 0.9 in at least one of the fourth and fifth lumbar vertebrae. This difference was statistically significant (P <0.00i). CONCLUSION: A/P ratio value of iess than 0.9 can be used to detect vertebral fractures among Sri Lankan patients with low backache