No abstract

A contracture of the elbow joint is a challenge for diagnostic radiology. Radiographs remain the method of choice for primary diagnosis, however, diagnostic confidence can be limited if periarticular ossifications or contracture do not permit evaluation of the whole joint. In these cases, CT or MRI can be used for specific diagnostic problems. Additional multiplanar or three-dimensional reformations can be used by the orthopedic surgeon for planning the surgical procedure. MRI has a great advantage in allowing visualization of muscles, capsula-ligamentous complex and articular cartilage. The main disadvantages are duration of examination time and artifacts. CT is superior in terms of spatial resolution and visualization of bony structures. MRI and CT examinations of the elbow will increase with the number of minimal invasive surgical procedures. Protocols must therefore be optimized with attention to positioning, sequence selection and image processing. This article reviews the current standards of high resolution imaging with CT and MRI, including arthrographic techniques. The pros and cons of both methods are discussed in the setting of a contracture of the elbow joint.

Fibrous cortical defect and non-ossifying fibromas can be classified together as fibrous metaphyseal defects (FMD) since they have the same pathological substrate, with a tendency to the same localisation around the knee, and occurring at the same age. They have a tendency to spontaneous healing, are clinically silent and are usually discovered accidentally during radiological examination. A radiological survey of 5.674 metaphyseal regions in the upper and lower extremities of 2.065 unselected patients aged one to 20 years revealed an incidence of 1.8%; exclusive examination of the distal femur showed an incidence of 2.7%. 96% of all lesions were in the lower extremities and only 4% in the upper. The marked discrepancy in the incidence rate between American and German publications is discussed.

Anticonvulsant therapy can lead to severe rachitic changes in the skeleton which closely resemble renal osteopathy. In addition to apparent widening of the epiphyseal plate, there are changes in the cortex of the long bones. Within four to six weeks of the commencement of vitamin D therapy, recalcification of the poorly recognised. Since the changes are best seen in the hand, further examinations of the skeleton are only indicated if there are positive findings in the hand.

The measured lower limit of visualisation of cancellous bone structures is clearly worse than expected from the measurements of spatial resolution with standard phantoms used for HR-CT (0.6 versus 0.4 mm). True and exact imaging of normal cancellous bone cannot be achieved even by modern HR-CT. Noise creates structures mimicking cancellous bone.