Hoffa fracture--a radiologic diagnostic approach.

Hoffa fracture is a rare injury consisting of unicondylar tangential posterior fracture of the distal femur. On plain radiographs the fracture line is clearly seen. However, some fractures and musculotendinous injuries may display subtle features and may be difficult to detect even with optimal images. We explain the mechanism of injury, discuss the diagnostic work-up and the operative and nonoperative management.

Preoperative CT and MR imaging of inferior vena cava leiomyosarcoma.

We investigated the radiological findings of five patients with primary leiomyosarcoma of the inferior vena cava (IVC) comparing cavography, computed tomography (CT), and magnetic resonance imaging (MRI). The radiographic presentation ranged from an intraluminal lesion with obstruction of the IVC to a tumor mass extending from the media musculature into the surrounding perivascular tissue with only slight protrusion into the lumen. The lesions were associated with late or few symptoms. Pathognomonic radiological findings could not be established. In cases with an extraluminal growth a lobulated, well-defined, encapsulated tumor with an inhomogeneous contrast uptake is characteristic in CT studies. Additional information was provided by MRI. Leiomyosarcomas with extraluminal involvement showed homogeneous intermediate signal intensity (SI) on T1-, and mixed intermediate/high SI on T2-weighted images. In cases with predominantly intraluminal growth, both CT and MRI demonstrated the IVC to be dilatated and allowed to differentiate between tumor extent and obliterating thrombosis. Modern imaging modalities allow an early and accurate pre-operative diagnosis resulting in a higher rate of surgical resection and improvement of survival.