Reliablity of Singh index in grading of osteoporosis using digital radiographs in elderly patients with proximal femoral fractures

Even though dual energy X-ray absorptiometry is the gold standard for measuring the osteoporosis, many institutes in India doesn't have the facility. Singh index for osteoporosis in plain radiographs have low reliability. So in this retrospective study, we used digital radiographs to analyze the relationship between the Singh index with age, gender, fracture site, laterality, along with intra and inter-observer reliability in elderly patients having proximal femoral fractures due to simple fall.
Materials and Method: Records and digital radiographs of 87 consecutive patients (41 women, 46 men), who were older than 50 years of age and with proximal femoral fracture were retrospectively analyzed.
Results: The grade of osteoporosis was not related to age, gender and laterality in the osteoporotic patients with proximal femur fractures (p>0.05). Over all mean intra-observer, agreement was 0.49±0.1 and inter-observer agreement was 0.21±0.2 (kappa value). Fracture neck femur was mostly seen in grade 2 and 3 of Singh index and intertrochanteric fractures were seen in grade 4 and 5 Singh index.
Conclusion: Even in digital radiographs, there is poor to fair inter-observer reliability, but good intra-observer reliability. Reliability is good in severe osteoporosis than mild to moderate osteoporosis. Older patients with borderline or mild osteoporosis are more prone to intertrochanteric fractures in the hip region.
The risk of femoral neck fractures increases in patients with advanced osteoporosis.