Objective: To investigate the usefulness of multi-detector computed tomography (MDCT) in three-part intertrochanteric fractures of proximal femur.
Materials and methods: Twenty-six patients with Boyd-Griffin type 2 intertrochanteric fractures with MDCT (group 1) and 36 patients of the same type fracture without MDCT (group 2) were compared. Lesser trochanter (LT)/greater trochanter (GT) volume ratio above 0.5 or the volumetric proportion of GT in total volume of proximal femur below 25% was considered an unstable fracture. The fractures were fixed with dynamic compression hip screws (DCS). Additional greater trochanter stabilizing (GTS) plate or bone cement augmentation of the femoral head was performed in unstable fractures. Clinical outcome between the two groups by fixation failure and radiological results was compared.
Results: The volume ratio of the LT/GT was 0.33 (range, 0.13-0.73). The volume of the LT was inversely correlated with that of the GT (p < 0.001). The volume of the GT was significantly correlated with the LT/GT ratio or the head and neck (HN)/GT ratio (p < 0.001). Seven cases were regarded as unstable fractures in group 1. Fixation failures happened in one case in group 1 and five cases in group 2. There was significantly lower failure rate in group 1 than group 2 (p = 0.03). Neck-shaft angle at last follow-up was 134.8 degrees +/- 5.3 in group 1 and 131.3 degrees +/- 5.1 in group 2 (p = 0.01). The sliding length of lag screws were 5.6 degrees +/- 2.9 mm in group 1 and 8.3 degrees +/- 3.2 in group 2 (p = 0.03).
Conclusion: Preoperative use of MDCT provides useful information about the fracture pattern and the geometry of the proximal femur in unstable intertrochanteric fractures and helps surgical planning. The ratio of the LT to the GT is inversely correlated with fracture stability.