Search

Six patients were retrospectively identified as having undergone lateral ligament reconstruction surgery. The surgical procedures were categorized into four groups: direct lateral ligament repair, peroneus brevis tendon rerouting, peroneus brevis tendon loop, and peroneus brevis tendon split and rerouting. At radiography and magnetic resonance (MR) imaging, the presence of one or more suture anchors in the region of the anterior talofibular ligament indicates direct ligament repair, whereas a fibular tunnel indicates peroneus brevis tendon rerouting or loop. Both ultrasonography (US) and MR imaging demonstrate rerouted tendons as part of lateral ankle reconstruction; however, MR imaging can also depict the rerouted tendon within an osseous tunnel if present, especially if T1-weighted sequences are used. Artifact from suture material may obscure the tendon at MR imaging but not at US. With both modalities, the integrity of the rerouted peroneus brevis tendon is best evaluated by following the tendon proximally from its distal attachment site, which typically remains unchanged. The rerouted tendon or portion of the tendon can then be traced proximally to its reattachment site. Familiarity with the surgical procedures most commonly used for lateral ankle ligament reconstruction, and with the imaging features of these procedures, is essential for avoiding diagnostic pitfalls and ensuring accurate assessment of the ligament reconstruction.

The bone marrow edema (BME) pattern of signal intensity changes on magnetic resonance (MR) images (decreased on T1-weighted and increased on T2-weighted) is a nonspecific finding encountered with several entities, including transient osteoporosis of the hip, transient BME syndrome, osteonecrosis, trauma, infection, and infiltrative neoplasm. Transient osteoporosis, an unusual but distinct syndrome characterized by self-limited pain and radiographically evident osteopenia, can be distinguished from other causes of the BME pattern, particularly osteonecrosis, on the basis of clinical findings and the development of radiographically evident focal osteopenia within 8 weeks after the onset of pain. This is an important distinction, since all patients with transient osteoporosis recover completely, without intervention. The term transient BME syndrome can be used to describe any patient in whom a reversible BME pattern is seen on MR images. Although the transient BME syndrome is also self-limited and quite likely related to transient osteoporosis, the authors believe that to avoid confusion, this nonspecific term should be reserved only for patients who do not develop radiographically evident osteopenia.

The seat belt syndrome consists of skeletal, soft-tissue, and visceral injuries associated with use of two- and three-point restraints in patients involved in motor vehicle accidents. Skin abrasions of the neck, chest, and abdomen--the classic seat belt sign--indicate internal injury in 30% of cases. Neck abrasions are associated with injuries to the carotid artery, larynx, and cervical spine; chest abrasions, with fractures of the sternum, ribs, and clavicles and injuries to the heart and thoracic aorta; and abdominal abrasions, with mesenteric tears, bowel perforation and hematoma, Chance fractures, and injuries to the abdominal aorta. The seat belt sign should prompt a diligent search for related injuries.

Calcium hydroxyapatite crystal deposition disease is characterized by the presence of basic calcium phosphate crystals--predominantly hydroxyapatite--in the periarticular soft tissues, especially the tendons. The entity is best recognized as "calcific tendinitis" at its most frequent site about the shoulder, but the disease involves numerous other sites and may be more appropriately termed calcific periarthritis. This article illustrates typical and atypical radiographic features of hydroxyapatite deposition, as well as some unusual manifestations of the disease. A brief review of various theories on the pathogenesis of the disease and a section on differential diagnosis is included.