CLANDESTINE FEMORAL-NECK FRACTURES WITH IPSILATERAL DIAPHYSEAL FRACTURES

We present a protocol for diagnosis of all femoral neck fractures asso ciated with ipsilateral femoral diaphyseal fractures. A 30% incidence of delayed diagnosis has been reported by other investigators. Between 1982 and 1990, we have treated 32 patients with ipsilateral femoral n eck and shaft fractures due to blunt trauma. Only 22 femoral neck frac tures were diagnosed on prediaphyseal fixation radiographs. This left the 10 patients in this study who had normal prediaphyseal fixation ra diographs and were subsequently found to have femoral neck fractures. The ipsilateral femoral neck fractures were found through a retrospect ive chart and radiographic review of all 555 femoral diaphyseal fractu res identified through our trauma and fracture registries. The clinica l and radiologic techniques for diagnosing the femoral neck fractures were presented. The time to union of the femoral shaft and neck was de termined, and a preliminary radiologic assessment of the vascularity o f the femoral head was made. Ten femoral neck fractures (31%) with nor mal preoperative radiographs were diagnosed after femoral diaphyseal f ixation. One patient did not have a post-diaphyseal fixation radiograp h. An incidental radiograph at 6 weeks showed a mildly displaced femor al neck fracture in an asymptomatic patient. At 16 weeks the patient b ecame symptomatic, and a repeat, radiograph showed the fracture. Five fractures were diagnosed in asymptomatic patients on routine post-femo ral fixation radiographs. Two patients had normal post-femoral fixatio n radiographs, became symptomatic, and had their femoral neck fracture s diagnosed on repeat radiographs at 3 and 7 days. One patient had nor mal pre- and postfixation radiographs, and on a 25-day routine femoral radiograph, the femoral neck fracture was diagnosed. In one patient, a femoral neck fracture was diagnosed during insertion of an intramedu llary nail. Nine of the femoral diaphyseal fractures were plated becau se these were blunt polytrauma patients. All fractures were Pauwel's c lassification III. Our study demonstrates that routine preoperative ra diographs of the hip are inadequate to diagnose all femoral neck fract ures associated with ipsilateral femoral diaphyseal fractures. We sugg est (a) routine postoperative radiographs, (b) routine 2- to 4-week po stinjury radiographs, and (c) radiographs any time a patient becomes s ymptomatic. Our incidence of delayed diagnosis of femoral neck fractur es is similar to that reported in the literature. It is possible to ha ve a mildly displaced femoral neck fracture and to be asymptomatic. Fe moral neck fractures seen after intramedullary nailing are not due to improper technique.