[Clinical and radiographic factors associated with failure of the dynamic hip screw system]

The most widely used fixation system for transtrochanteric fractures is the dynamic hip screw system, which has a failure prevalence of 10 to 17% and it is associated with the presence of clinical and radiographic factors.

To evaluate the association of clinical and radiographic factors with the failure of the screw system in post-operative patients for transtrochanteric hip fracture.

A case-control study was carried out. The inclusion criteria were: patients > 18 years, who underwent surgery due to transtrochanteric fracture, were treated with the hip screw system, and who attended the Trauma Service. The patient with failure of the hip screw system was selected as the case and the patient without failure of the system as control. The variables analyzed in these groups were: age, gender, body mass index and radiographic variables. Statistical analysis was performed with chi-squared and Mann-Whitney U.

163 patients (median 73 years), 20 cases and 143 controls, were included. The radiographic factors with a significant association with hip screw system failure were the AO classification of fractures (p < 0.001), the tip apex distance (p = 0.03), the calcar-referenced tip apex (p = 0.02), the position of the screw (p < 0.001), and quality of reduction (p < 0.003). Clinical factors did not show a significant association.

Radiographic factors are associated with failure in the hip screw system in patients in post-operative care due to transtrochanteric fracture.