• PURPOSE
    • To assess the Dorr proximal femoral types and the cortical thickness index for predicting peri-operative complications during hemiarthroplasty.
  • METHODS
    • Records of 53 male and 147 female elderly who underwent cemented or uncemented monopolar hemiarthroplasty for displaced intracapsular femoral neck fractures were reviewed. Any intra-operative fracture and postoperative dislocation within 30 days was recorded. The cortical thickness index was defined as the ratio of cortical width minus endosteal width to cortical width at a level of 100 mm below the tip of the lesser trochanter. Higher values indicated thicker cortices. The Dorr proximal femur morphology was classified into types A, B, and C.
  • RESULTS
    • 28 patients were excluded. The proximal femurs of the remaining 172 patients (mean age, 85 years) were categorised as Dorr type A (n=29), type B (n=75), and type C (n=68). The respective mean cortical thickness indices were 1.10, 0.79, and 0.65. Lower cortical thickness indices correlated with worse Dorr types (p<0.05). There were 18 intra-operative fractures; 8 and 10 occurred in Dorr types B and C femurs versus none in Dorr type A femurs (p=0.046). There were 5 postoperative dislocations; 3 and 2 occurred in Dorr types B and C femurs versus none in Dorr type A femurs (p=0.591). The mean cortical thickness index was significantly lower in those with a fracture (n=18) than those without a fracture (n=154) [0.59 vs. 0.81, p=0.0003].
  • CONCLUSION
    • Dorr types B and C proximal femurs were at greater risk of intra-operative fracture.