CHAPTER XII.
SPECIAL REGIONAL EXAMINATION.
I. METHODS OF EXAMINATION.
1. Bones and Bone-Marrow. The methods employed will depend wholly upon the indications in any given case, the anatomic relations and the aim of the examination. Anatomic knowledge should be applied in the removal of any bone. In the case of the extremities adequate incisions should be made in the skin extending the entire length of the bone which is to be removed, and the soft parts dissected from the bone before the latter is disarticulated or cut out. When the bone is examined in situ it may be opened with hammer and chisel or cut with a saw, either transversely or longitudinally, so as to give the most instructive picture of the condition present. The spinal column may be cut longitudinally. The symphysis pubis is first cut through, a block of wood is placed beneath the lumbar vertebræ, and the vertebral bodies are sawed through in the median line, from below upward, moving the block toward the head as the sawing proceeds. The cut-surfaces of the vertebræ are then inspected. The pelvis may be removed whole in connection with the lumbar vertebræ and the upper halves of the femurs. The spinal column and the pelvis may also be removed entire by sawing the ribs on each side of the spine, cutting the occipito-atloid ligaments above, and disarticulating the femurs or sawing them at their upper half or third and removing them with the pelvis. Of the long bones the femur is the one most frequently examined. An incision is made in the skin from the groin in the direction of the large vessels extending to the middle of the leg. The ligamentum patellæ is cut through and the skin and muscles turned back at the knee until the joint is laid bare; the capsule of the joint is opened and the femur disarticulated. The skin and muscles are then separated from the upper part of the femur, the hip-joint opened, and the femur disarticulated and removed. When held in a vise it may be opened longitudinally by sawing. Other bones are removed as indicated; the chief points to be observed in their removal are the anatomic considerations and the making of the incisions in such a way as to cause the least possible disfigurement. For the examination of the bone-marrow the tibia or femur, sternum, a rib and the body of one of the vertebræ are usually opened by means of the saw or chisel.
2. Joints. The joints are opened for examination with attention to the same considerations given above for the examination of the bones. Approved surgical incisions may be used. If fistulous openings into the joint are present these should not be cut until the joint is open. When bacteriologic examinations are to be made the joint should be opened with a sterile knife, or the capsule seared and punctured with a sterile pipette through which the contents of the joint-cavity are secured. The articular surfaces, epiphyses and diaphyses should be examined by transverse or vertical incisions.
3. Lymph-glands. The cervical, axillary and inguinal lymphnodes can be secured for examination by carrying the skin-flaps of the main-incision far enough back to make these regions accessible. For the examination of other glands, such as the cubital, popliteal, interscapular, posterior cervical, etc., the cadaver should be placed in a convenient position, and the skin-incisions should be made so as to expose sufficiently the part to be examined, without unnecessary mutilation.
4. Peripheral Blood-vessels and Nerves. Skin-incisions are made along the course of the vessels and nerves, and these are then exposed by careful dissection. In the case of the upper extremity the clavicle is removed when the entire course of the nerves and vessels of the arm is to be exposed.
5. Sympathetic System. The cervical, thoracic and abdominal sympathetic systems are examined either at the close of the examination of each one of these regions or at the end of the autopsy. Careful anatomic dissections are necessary for the demonstration of the sympathetic ganglia and nerves.
6. Organs of Special Sense. These may be examined at the close of the autopsy, according to the methods given above, if they have not been examined at the close of the section of the brain.
II. POINTS TO BE NOTED IN SPECIAL REGIONAL EXAMINATION.
1. Bones and Bone-marrow. Note size, form, color of surface, consistence (diminished in necrosis, osteomalacia, rachitis, senile osteoporosis, etc.; increased in sclerosis), fragility, fractures, separation of epiphyses, fissures, dislocations, elevation or separation of periosteum, periosteal defects, changes in periosteum (thickened, indurated, and showing hard white elevations in chronic inflammation; swollen and easily stripped from the bone in acute inflammation; hæmorrhages and collections of pus beneath periosteum cause separation of periosteum; in chronic inflammation the periosteum may become more firmly adherent to the bone and contain spongy, compact, cartilaginous or osteoid osteophytes that vary in color according to the degree of calcification [bluish-red, yellowish, dirty-white, shining-white]; the normal periosteum is grayish-white in color; it is reddened in hyperæmia and hæmorrhage). The surface of bones normally is smooth and grayish-yellow in color; it becomes red with an increase in the number and size of the medullary spaces, and paler, grayish-white or white in necrosis; a dull, rough, uneven surface indicates lacunar absorption. Note localized or general thickening (exostoses, hyperostosis). On section note thickening of the bone (osteomyelitis ossificans), thinning (osteoporosis, excentric atrophy), enlargement of medullary spaces, obliteration of spaces by newly-formed bone (osteosclerosis; bone becomes heavy and solid like ivory), and caries (pyogenic infection, tuberculosis, syphilis, actinomycosis, neoplasm). Caries occurs in both spongy and compact bone, but more often in the former. The necrotic bone appears as soft, friable granules (molecular necrosis) or sequestra, between which living bone or granulation-tissue may be found. The necrotic granules feel like fine grains of sand when the finger is rubbed over the cut-surface. The color depends essentially upon the amount of granulation-tissue present (gray, grayish-red or deep bluish-red). Purulent areas are cloudy, opaque and yellowish. Tubercles appear as round, grayish, semitranslucent areas, with opaque yellowish centers when calcification has occurred. In young subjects the developing portions of the bone (epiphyses, cartilages) should receive especial examination. Note amount, color and consistence of bone-marrow. In the young individual the marrow is red; after puberty the red marrow gradually becomes restricted to the flat bones and the short spongy bones, while in the long bones there develops a yellow, fatty marrow. In old age the marrow of the long bones may become brownish, transparent, myxomatous or soft like colloid, or contain large cystoid spaces filled with a thin mucoid fluid or liquid fat. Red lymphoid marrow is found in the long bones in severe anæmias; it is grayish-red or deep red according to its blood-content. In leukæmia the marrow may be red, violet, pink, grayish or grayish-yellow (pyoid); in chloroma the marrow may be greenish. In cachexias the marrow may become gelatinous as in old age. A hyperæmic fatty marrow should not be mistaken for lymphoid marrow; the fatty shine serves to distinguish the former. Cloudy yellowish areas in the marrow point to purulent infiltration. Firm sulphur-yellow masses are gummata.