The association between supracondylar-intercondylar distal femoral fractures and coronal plane fractures.

BACKGROUND Isolated coronal plane fractures of the distal femoral condyles (Hoffa fractures) occur uncommonly, are difficult to diagnose, and may be challenging to treat. The combination of supracondylar distal femoral fractures and these coronal plane fractures is thought to occur rarely. The purposes of the present study were to identify the frequency of the association between supracondylar-intercondylar distal femoral fractures and coronal fractures of the femoral condyle and to describe the radiographic evaluation of these injuries. METHODS One hundred and eighty-nine patients with 202 supracondylar-intercondylar distal femoral fractures were retrospectively evaluated clinically and radiographically. RESULTS Coronal plane fractures were diagnosed in association with seventy-seven (38.1%) of the 202 supracondylar-intercondylar distal femoral fractures. Fifty-nine (76.6%) of these coronal fractures involved a single condyle, and eighteen involved both the medial and lateral femoral condyles. Eighty-five percent of the coronal fractures involving a single condyle were located laterally. Patients with an open distal femoral fracture were 2.8 times more likely to have a coronal plane fracture than patients with a closed fracture were (95% confidence interval, 1.54 to 5.25). Coronal plane fractures were diagnosed in 47% of the 102 knees that were evaluated with computerized tomography, compared with 29% of the 100 knees that were not (p = 0.008). Ten coronal plane fractures that had been unrecognized preoperatively were identified only at the time of operative fixation of the distal femoral fracture; none of these fractures occurred in patients who had been evaluated with computerized tomographic scanning preoperatively. CONCLUSIONS Coronal plane fractures frequently occurred in association with high-energy supracondylar-intercondylar distal femoral fractures; in the present study, the prevalence of associated coronal plane fractures was 38%. The lateral condyle was involved more frequently than the medial condyle was. Coronal plane fractures of both condyles were observed commonly, and the majority of coronal plane fractures were associated with open wounds. Since the surgical tactic for the treatment of a supracondylar-intercondylar distal femoral fracture may be altered by the additional diagnosis of a coronal plane fracture component, preoperative computerized tomographic scanning of the injured distal part of the femur, particularly when there is an associated open wound, is strongly recommended.