Articular cartilage changes seen with magnetic resonance imaging-detected bone bruises associated with acute anterior cruciate ligament rupture.

Occult osteochondral lesions (bone bruises) have been documented on magnetic resonance images in more than 80% of patients sustaining acute anterior cruciate ligament ruptures. Despite the high prevalence of these lesions, little is known about the histologic changes in the adjacent articular cartilage. Ten patients with acute anterior cruciate ligament ruptures who had a preoperatively documented (by magnetic resonance imaging) geographic bone bruise at the sulcus terminalis on the lateral femoral condyle underwent a 3-mm diameter trephine biopsy of the articular cartilage and subchondral bone overlying the bone bruise at the time of anterior cruciate ligament reconstruction.

Unrecognized foreign body in the hip joint.

A 40-year-old woman involved in a motor vehicle accident sustained a left acetabular fracture and a dislocated left hip with a large ipsilateral traumatic hip wound. Multiple plain radiographic films of the pelvis and a pelvic computed tomographic scan were obtained. None of these images showed a 25 x 20 x 12-mm piece of the gearshift that was found in the hip joint at the time of the surgery.

Type 4 acromion: a new classification.

The three types of acromial processes previously described in the literature include type 1, in which the undersurface is straight, and types 2 and 3, in which the undersurface is concave. In this report, a fourth type of acromion is described in which the undersurface is convex near its distal end. The frequency of a type 4 acromion in the normal population is discussed based on a retrospective review of the MR examinations of 30 patients that originally were read as normal.

MR diagnosis of superior labral anterior posterior (SLAP) injuries of the glenoid labrum: value of routine imaging without intraarticular injection of contrast material.

Objective: Superior labral anterior posterior (SLAP) lesions are peculiar types of tears that involve the superior and anterior aspects of the glenoid labrum and extend posteriorly. The biceps tendon may also be involved in the injury. There have been conflicting reports in the literature about the value of MR imaging in depicting these injuries.