Measurement of Lumbosacral Angle in Normal Radiographs: A Retrospective Study in Southeast Nigeria

BACKGROUND A retrospective study of lumbosacral angle (LSA) in normal lateral supine lumbosacral radiographs of 274 Nigerians (aged 15-74 years) of Southeast region. A supine lateral lumbar spine radiograph is a very accurate means of measuring lordotic angles. The LSA is one of such angles, and can be used in the investigation, treatment and follow-up of low back disorders. Little is known about what the normal value for our population is and therefore, what constitutes hypo-/hyper-lordosis; most of the data in use in medical practice are based on studies on other races. AIM To quantify the normal LSA in our population. MATERIALS AND METHODS LSA was measured by the Ferguson's technique and the data analyzed with SPSS Statistics version 17.0 (Chicago IL, USA). RESULTS LSA varied between 18° and 71°. With a 95.0 confidence interval of 43.3-45.6°, the mean (standard deviation) was 44.5 (9.9)° and showed no significant variation with sex and between various age groups; it compared favorably (though with small difference) with some of the literature values currently in use. CONCLUSION This study had established the normal lordosis and the possible values at which to consider hypo-lordosis (below 15°), and hyper-lordosis (above 75°) in our population. Also established is that the development of lumbar lordosis ceases at spinal maturity, and that in normal lumbar lordosis measurement, the retrospective approach is a credible alternative to the prospective method.