Three-dimensional CT Improves the Reproducibility of Stability Evaluation for Intertrochanteric Fractures

Femoral intertrochanteric fractures are among the most common fractures in the elderly. There are various classification systems in intertrochanteric fractures. The aim of these classification systems is to help surgeons choose an appropriate treatment. The treatment of femoral intertrochanteric fractures depends on the results of a stability evaluation using imaging studies. However, it is difficult to evaluate the true fracture line using plain X-ray films, especially on the sagittal plane and for intertrochanteric fractures with complex morphologies. The aim of the current study was to determine whether three-dimensional CT (3DCT) improves the reproducibility of stability evaluation for femoral intertrochanteric fractures.

This was a single-center observational study of intertrochanteric fractures. We retrospectively collected patients in our hospital with intertrochanteric fractures that underwent plain X-ray (anteroposterior, lateral view) CT scans with axial images (2DCT) and 3DCT for an injured hip between 1 December 2011 and 30 November 2015. The exclusion criteria were pathological fractures (due to metastasis or primary bone tumors) and previous intertrochanteric surgery. During this period, 61 patients were enrolled. Two patients were excluded because lateral view X-rays were not available. A total of 59 patients (27 women, 32 men) with an average age of 77 years (range, 55-96 years) were included in our final analysis. The stability evaluation (i.e. stable or unstable) and implant choices (i.e. dynamic hip screws or Gamma nail) were recorded independently by four observers (two attending physicians and two residents). All images were reviewed and classified using the AO/OTA and Evans modified by Jensen (EVJE) classification systems. The session was repeated after a 3-month wash-out period. The inter-observer agreement was evaluated using the Kappa test.

The inter-observer agreements, measured by the mean weighted kappa values (expressed as X-ray vs 3DCT) were as follows: For stability evaluation, the mean kappa values for attending physicians and residents were 0.68 versus 0.76 and 0.55 versus 0.56. For implant choices, the mean kappa values for attending physicians and residents were 0.68 versus 0.76 and 0.57 versus 0.65. For AO/OTA classification, the values for attending physicians and residents were 0.67 versus 0.65 and 0.70 versus 0.81. For EVJE classification, the values for attending physicians and residents were 0.66 versus 0.63 and 0.56 versus 0.55.

Three-dimensional CT improved the reproducibility of stability evaluation for femoral intertrochanteric fractures. Preoperative CT scanning may provide a diagnostic benefit for evaluating the stability of intertrochanteric fractures.