Evaluation of loose bodies in the elbow with MR imaging.

The evaluation of loose bodies in the elbow is usually done by means of clinical examination, radiography, and postarthrographic computed tomography (CT). The authors review their experience with magnetic resonance (MR) imaging in place of post-arthrographic CT for the evaluation of loose bodies in the elbow. The prospective interpretation of MR studies of the elbow in 20 patients was compared with arthroscopic findings. All elbows were imaged in multiple planes with thin sections, surface coils, and combinations of T1, T2, and proton-density weighting. The sensitivity for showing loose bodies with MR imaging was 100%, and the specificity was 67%. Because this was a nonblinded study, the results are biased and caution must be used when extrapolating these results to the general population. In this limited experience, MR imaging has reliably shown loose bodies in the elbow, and in the authors' institutions has replaced postarthrographic CT for that purpose.

Fatigue fracture of the sacrum: a case report.

We report a patient with a stress fracture in the sacrum. This may be a cause of hip or back pain. In contrast to typically bilateral insufficiency fractures, fatigue fractures are usually unilateral and the appearances are not diagnostic on scintigraphy. As the plain film findings may be subtle and overlooked, computed tomography is more specific in delineating a sclerotic vertical fracture parallel to the sacroiliac joint. Recognition of the characteristic radiographic pattern in sacral fatigue fractures can avoid incorrect diagnosis and unnecessary tests or treatment.

Reactive perineurial fibroblastic proliferation of the median nerve: MR characteristics.

We report a case of fibroblastic proliferation of the median nerve presenting as a focal mass. This report discusses the pathological and magnetic resonance correlations and reviews the differential diagnosis for median nerve masses.

Magnetic resonance images of chronic patellar tendinitis.

Chronic patellar tendinitis can be a frustrating diagnostic and therapeutic problem. This report evaluates seven tendons in five patients with chronic patellar tendinitis. The etiologies included "jumper's knee" and Osgood-Schlatter disease. In all cases magnetic resonance images (MRI) showed thickening of the tendon. Some of the tendons had focal areas of thickening which helped establish the etiology. All cases had intratendinous areas of increased signal which, in four cases, proved to be chronic tendon tears. MRI is useful in evaluating chronic patellar tendinitis because it establishes the diagnosis, detects associated chronic tears, and may help determine appropriate rehabilitation.

Achilles tendon: MR imaging at 1.5 T.

Thirty magnetic resonance (MR) examinations of the Achilles tendon were performed: 20 from patients without suspected tendon abnormalities; ten from patients with suspected tendon abnormalities. The appearance of the normal Achilles tendon is hypointense and flattened. Partial tears appeared as high-signal intratendinous collections, complete acute ruptures appeared as tendinous discontinuity, and uncomplicated surgical repairs appeared as areas of tendinous continuity with inhomogeneous signal in the operative site. Chronic tendinitis appeared as a diffuse thickening of the tendon. MR imaging of the Achilles tendon at 1.5 T enabled the determination of the degree of tendinous continuity, which may help with diagnosis, treatment, and the pacing of rehabilitation.

Finger arthrography.

The use of arthrography in patients with chronic finger complaints is discussed. Magnification arthrography was performed to assist the clinical evaluation of 15 patients with pain in the metacarpal-phalangeal or proximal interphalangeal joints. Conditions detected include collateral ligament laxity, extravasation around the volar plate, and fibrous ankylosis. Demonstration of normal articular cartilage was important for clinical management in some patients. Direct radiographic magnification was considered useful for best visualization, but tomography was not helpful.

Stressing the knee joint for arthrography.

A restraining device for arthrography of the knee, made from an automobile safety belt, is described. Contrary to usual practice, the authors place the strap below the knee joint. There is less tendency for the knee to flex when compared with placement above the knee, resulting in improved demonstration ot the meniscus.

Fracture of the hook of the hamate.

Three patients with hamate hook fractures were evaluated. These fractures were difficult to diagnose clinically and radiographically. Mechanisms of injury reported in the literature include blunt trauma to the hamulus or pisiform, forceful swinging of a grasped object, or a forceful muscular contraction. Delayed diagnosis may result in late complications including carpal tunnel syndrome, flexor tendon rupture, ulnar nerve palsy, or ulnar artery compromise. Pain when grasping or swinging an object is often a clue to the correct diagnosis. Normal standard and carpal tunnel views do not exclude this injury. Tomography may be necessary for radiographic detection and permits detailed evaluation of fracture margins. Pertinent carpal anatomy is reviewed.

Iron content of pigmented villonodular synovitis detected by computed tomography.

Pigmented villonodular synovitis is a rare lesion in which iron is accumulated. A CT scan performed on one such lesion demonstrated significantly increased attenuation values. We have calculated the amount of iron which would have to be added to muscle tissue in order to produce this increase in density. We have also measured the iron content directly. The close agreement of these two figures suggests that the observed density increase is due to the iron content of the lesion.