To determine the optimum foot position and imaging plane at magnetic resonance (MR) imaging of each ankle ligament, 10 cadaver ankles were dissected to visualize the orientation, precise attachment sites, and relationships of each ligament. Then eight cadaver ankles were studied with MR imaging and were cryosectioned in the optimum imaging planes. The ankles of 12 healthy volunteers were imaged to ensure consistency in identifying the normal ligaments. With the foot taped into full dorsiflexion of 10 degrees-20 degrees, axial imaging provided optimum views of the anterior, posterior, and inferior tibiofibular ligaments and of the anterior and posterior fibulotalar ligaments and provided an overview of the deltoid ligament. Coronal images provided full-length views of the tibiospring, tibiocalcaneal, and posterior tibiotalar parts of the deltoid ligament. With the foot taped into full plantar flexion of 40 degrees-50 degrees, axial imaging optimized visualization of the fibulocalcaneal ligament and of the tibionavicular and anterior tibiotalar parts of the deltoid ligament. Sagittal images provided the best full-length views of the spring ligament.

Isolated avulsion fractures of the lesser tuberosity of the humerus are exceptionally rare. Two cases are reported here, each involving a 12-year-old boy. The mechanism of injury appears to be a strong external rotatory force applied while the arm is at maximum external rotation and approximately 60 degrees of abduction. In children and adolescents the fracture most likely occurs through the apophyseal plate of the lesser tuberosity (traction epiphysis). In adults, clinical differentiation from the far more common calcific peritendinitis of the rotator cuff can be difficult. Whereas large, displaced fractures can be easily demonstrated on anteroposterior radiographs with internal and external rotation of the humerus, the axillary view is often necessary to detect smaller fragments with little displacement.

Two new cases of popliteal venous aneurysm, confirmed with findings from venography, are added to seven previously reported cases revealed in the authors' search of the English-language literature. This rare anomaly usually shows as recurrent pulmonary emboli in patients with no underlying predisposition to deep venous thrombosis. Physical examination is usually not helpful in the diagnosis. Results of combined real-time and Doppler ultrasound should indicate the diagnosis, but venography is necessary for confirmation and further anatomic detail. Surgical treatment has been fraught with complications. Eight patients, including these two new cases, have undergone surgery, and none have had a recurrence of pulmonary embolism following surgery.

The MR findings in transient osteoporosis of the knee have been described as showing a diffuse area of decreased signal intensity (relative to normal bone marrow) on T1-weighted images and increased signal intensity on T2-weighted images. We report a case of transient osteoporosis, in which MRI showed a crescentic area of abnormal signal intensity in the posterior portion of the lateral femoral condyle, which was bordered by a rim of low signal intensity, best seen on the T2-weighted images. This abnormality was shown to resolve on follow-up MR scans.

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