Factors determining failure of intertrochanteric fracture fixation with a dynamic hip screw: a retrospective analysis

Abstract

Background: The intertrochanteric fractures are extra capsular fractures of proximal femur in the trochanteric region. Different fixation techniques were tried for intertrochanteric fractures, with variety of implants but the dynamic hip screw fixation is most widely accepted treatment. However, several authors have concluded that sliding compression screws may be associated with several complications such as perforation of the femoral head, loss of reduction caused by excessive sliding of the lag screw, non-union, shortening of the affected limb and pain. This study was carried out to ascertain the factors that contributed to mechanical failure at our institute. Methods: We retrospectively reviewed 92 patients with unilateral intertrochanteric fracture treated with a sliding hip screw between July 2015 and April 2017. Postoperative radiographs were studied for any loss of reduction, which was defined as a varus deformity greater than 10°, perforation of the femoral head, extrusion of the lag screw of more than 20 mm, or metal failure. The Pearson chi-square test was used to assess the relationship between failure and osteoporosis. A p value of less than 0.05 was considered to be significant. Results: Results revealed a significant relationship between failure and osteoporosis. A possible relationship between the stability of the fracture on Evans’ classification and osteoporosis on Singh’s index was investigated which revealed a high positive correlation between the failure rates of unstable fractures with osteoporosis. Conclusions: An unstable fracture combined with osteoporosis, has higher percentage of fixation failure leading to other methods of treatment like hemiarthroplasty.