Femoral nerve stretch test predicts radiological features of lumbar spondylosis in Nigerians with low back pain

Abstract

Background: Lumbar spondylosis is one of the most common cause of low back pain. The diagnosis of lumbar spondylosis often depends on  radiodiagnostic evaluations which are not readily available in primary healthcare centers. This study examined the ability of clinical test to diagnose  radiographic lumbar spondylosis compared to x-rays in subjects with low back pain.

Methods: This was a secondary analysis of data from the 2016 Jos COPCORD study. The data on subjects with low back pain who had complete  clinical and radiological examinations were analyzed to determine clinical factors that were independently associated with radographic lumbar  spondylosis. A P value of <0.05 was considered significant for all statistical test.

Results: The data of 187 subjects with a mean age of 46±15 years were analyzed. There were 38.5% males and 61.5% 2 2 females. Age (X² =75.91, P  <0.001), marital status (X² 29.85,  <0.001), education (X² 11.34, P = 0.01), occupation (X²=18.44,  P <0.001) BMI (X² =10.79, P = 0.02) hypertension (X²  =9.20, P  = 0.002), SLR (X² =9.37, P=0.002) and FNST (X² =50.49, P<0.001) were statistically correlated with radiographic lumbar spondylosis. On  logistic regression, age > 45years, marital status, education, occupation, hypertension, SLR and FNST remained significantly associated with  radiographic lumbar spondylosis. A positive SLR had a sensitivity of 26.32%, specificity of 91.78% and an ROC Area of 0.59, while a positive FNST had  a sensitivity of 85.96%, specificity of 64.38% and ROC Area of 0.75 in predicting radiographic lumbar spondylosis.

Conclusion: A positive FNST was more discriminatory in predicting the occurrence of radiographic lumbar spondylosis compared to SLR. Therefore,  it can be used acceptably in the diagnosis of Lumbar spondylosis in centers where there are no X-ray facilities.