Reverse obliquity fractures of the intertrochanteric region of the femur

Background: The reverse obliquity fracture of the proximal part of the femu r is a distinct fracture pattern that is mechanically different from most i ntertrochanteric fractures. The purpose of this retrospective study was to determine the prevalence of these fractures and the results and complicatio ns of different types of internal fixation used in their treatment. Methods: Between 1988 and 1998, 2472 consecutive patients with a hip fractu re were treated at our Level-One Trauma Center; 1035 of the fractures were classified as intertrochanteric or subtrochanteric. Clinical and radiograph ic records were retrospectively reviewed, and fifty-five fractures with a r everse obliquity pattern were identified. Forty-nine patients were followed until the fracture united or a revision operation was performed. The durat ion of clinical follow-up averaged eighteen months (range, three to sixty-s even months), and the duration of radiographic follow-up averaged fifteen m onths (range, three to sixty months). Fractures were classified with the Or thopaedic Trauma Association scheme. Results were analyzed according to the fracture pattern, type of implant, quality of the reduction, position of t he implant, and use of bone graft at the index operation. Function was asse ssed on the basis of pain, living situation, need for walking aids, need fo r analgesics, and walking capacity. Results: Thirty-two (68%) of forty-seven hips treated with internal fixatio n healed without an additional operation. Fifteen (32%) of the forty-seven failed to heal or had a failure of fixation. The failure rate was nine of s ixteen for the sliding hip screws, two of fifteen for the blade-plates, thr ee of ten for the dynamic condylar screws, one of three for the cephalomedu llary nails, and zero of three for the intramedullary hip screws. Use of th e fixed-angle devices (the blade-plate and the dynamic condylar screw) resu lted in fewer failures than did use of the sliding hip screw (p = 0.023). E leven (46%) of twenty-four nonanatomically reduced fractures and four (17%) of twenty-three anatomically reduced fractures had a failure of treatment (p = 0.060). Eleven (26%) of forty-two fractures with an ideally placed imp lant and four (80%) of five fractures with a non-ideally placed implant had a failure of treatment (p = 0.023). Of the fifteen fractures that failed t o heal or had a failure of fixation, five were treated with revision to a c alcar-replacement prosthesis, seven were treated with revision open reducti on and internal fixation with bone-grafting, and one was treated with bone- grafting without revision of the fixation. Two patients refused additional surgery because they had limited functional demands. The two-year mortality rate was 33%. Functional results were poor, with many patients requiring w alking aids and losing the capacity for independent walking and self-care. Conclusions: In this series, reverse obliquity fractures accounted for 2% o f all hip fractures and 5% of all intertrochanteric and subtrochanteric fra ctures. Ninety-five-degree fixed-angle internal fixation devices performed significantly better than did sliding hip screws. Results were also worse f or fractures with poor reduction and those with a poorly placed implant.