Awareness of tip-apex distance reduces failure of fixation of trochanteric fractures of the hip

We compared the results of the surgical treatment of trochanteric hip fractures before and after surgeons had been introduced to the tip-apex distance (TAD) as a method of evaluating screw position. There were 198 fractures evaluated retrospectively and 118 after instruction. The TAD is the sum of the distance from the tip of the screw to the apex of the femoral head on anteroposterior and lateral views. This decreased from a mean of 25 mm in the control group to 20 mm in the study group (p = 0.0001). The number of mechanical failures by cut-out of the screw from the head decreased from 16 (8%) in the control group at a mean of 13 months to none in the study group at a mean of eight months (p = 0.0015). There were significantly fewer poor reductions in the study group. Our study confirms the importance of good surgical technique in the treatment of trochanteric fractures and supports the concept of the TAD as a clinically useful way of describing the position of the screw.