The Proximal Femoral Bone Geometry in Plain Radiographs

Background: Osteoporosis represents the most common bone disease and has to be respected in planning total hip replacement, especially against the background of increasing uncemented total hip replacement. In this context, the radiographic geometry of the proximal femur got into focus and is controversially discussed. The aim of the presented study was to find any difference regarding known indices for proximal femur bone geometry between patients with high-grade osteoarthritis and patients suffering from a femoral neck fracture caused by low impact trauma. Methods: Retrospective matched-paired analysis of 100 plane pelvic radiographs from 50 patients who suffered from high-grade hip osteoarthritis and 50 patients who suffered from femoral neck fracture was performed. Measurement of Canal-Bone Ratio (CBR), Canal-Calcar Ratio (CCR), Mineral Cortical Index (MCI) and Canal Flare Index (CFI) were performed. Results: CBR was significantly higher in the fracture-group (0.45 +/- 0.06 vs. 0.41 +/- 0.08) (P-value= 0.008). Moreover, the femoral thickness 10 cm below the trochanter minor [F] was significantly higher in the osteoarthritis-group (34.68 +/- 4.14 vs 32.11 +/- 3.43) (P-value 0.001). Conclusion: In conclusion, patients with a femoral neck fracture demonstrated a higher CBR, which indicates a poorer bone quality. In case of planning a THA, the CBR is an index which can easily be measured and can be seen as one decision criterion in THA regarding fixation technique.