1-4. DIAGNOSTIC ASSESSMENT

a. Radiography is the most widely used procedure for evaluating patients with musculoskeletal disorders. X-rays of a joint may show spur formation, changes in joint structure, or the presence of fluid. X-rays of bone may show bone texture, density, and erosion or other bone changes. Special X-ray techniques include the following:

(1) Tomography, or body section roentgenography, is the recording of internal body structures in a specific plane of tissue. Computerized Axial Tomography, or CAT scan, uses both X-rays and computers to create three-dimensional images that appear on a screen in cross-sectional view.

 

(2) Myelography outlines the subarachnoid space and may show spinal cord distortions, herniated intervertebral discs, or the presence of lesions. A contrast medium (radiopaque dye, oxygen) is injected into the spinal subarachnoid space by lumbar puncture and X-ray films are taken.

 

(3) Arthrography involves the injection of radiopaque substance or air into the joint cavity in order to outline the soft tissue structures and joint contour.

b. Arthrocentesis is the insertion of a needle into a joint and the aspiration of synovial fluid for examination.

c. Electromyography (EMG) is the recording of the electrical properties of skeletal muscles in order to study aspects of neuromuscular function and conduction. This test helps determine any abnormal physiology.

d. Thermography is a technique using infrared cameras to photographically portray the degree of heat radiating from the skin surfaces. It is used to investigate underlying pathologic processes.

e. Arthroscopy is visual examination of the interior of a joint by using a small fiberoptic instrument called an arthroscope.

f. Scintiscan is a procedure that provides a two-dimensional representation of the gamma rays emitted by a radioactive isotope, revealing its concentration in specific body tissues. In bone scanning, the patient is given

an intravenous injection of bone-seeking radioactive isotope and the body is "scanned" for increased isotope uptake. Increased concentrations of isotope uptake are associated with primary skeletal disease, metastatic bone disease, osteomyelitis, and some types of fractures.

g. Magnetic resonance imaging (MRI) is an imaging process that makes rapid, detailed pictures of body tissue. The patient is placed in a giant, horizontal cylinder and exposed to a magnetic field 15,000 times greater than the earth's natural magnetic field. No discomfort is experienced with this procedure.