On examination, the knee-joint was found distended with purulent matter. The syno vial membrane was covered in patches by a vascular pulpy membrane ; the cartilages were removed in several places. An opening was found in the inner condyle the tibia, which per:lin-Wed the spongy substance of this bone, and thus established a communication between the interior of the knee-joint and a large abscess as it were which had formed under the periosteum of the tibia. The shaft of the tibia was detached from the epiphysis and the periosteum, and was surrounded by matter. The periosteum was thickened, vascular, rough, and gritty from minute particles of bone depo sited in it. The ankle-joint was free.—The boy recovered his health.
Acute arthritis of the knee may be com bined with acute osteitis of the bones of this articulation, and without any discoverable com munication between the cavity of the arti culation and the interior of the bones. On the 21st March, 1840, Mr. Smith presented to the Pathological Society the following case. Susan Christie, wt. 56, an inmate of the House of In dustry, and for a long period disabled by the affection of the knee-joints which we have described as chronic rheumatic arthritis, was removed to the Whitworth Hospital, where she died of a most acute attack of inflammation of the right knee-joint. On the post-mortem exa mination old adhesions were observed in the chest. The right knee-joint presented the ex ternal appearances noticed as belonging to the chronic rheumatic arthritis in a somewhat ad vanced stage ; moreover, it was greatly swollen, and when the synovial membrane was opened purulent matter escaped; organizable lymph lined this membrane and the cartilages generally. These structures, however, were in some places removed altogether, their place being supplied by a porcelainous deposit, grooved in the line of flexion and extension. From the condyles of the tibia the cartilage was raised up from the bone, apparently stretched out, and converted into a thin, flexible, and soft yellow membrane, difficult to be distinguished, except by its si tuation, from a deposit of lymph the produce of recent inflammation.
But the interior of the head of the tibia, its cancellated structure, the medullary mem brane lining these cancelli, and the membrane of the medullary canal itself, all presented evi dences of their having been the seat of acute inflammation. The purulent matter was dif fused through the cancelli of the tibia, from the knee-joint, for one-third of its extent, but was nowhere collected into any isolated cavity or abscess, nor was there any communication between the purulent matter which occupied the synovial sac of the knee-joint, and that which pervaded the medullary structure and cancellated tissue of the tibia. In a word, the anatomical characters of a true acute osteitis of the bones entering into the formation of the knee-joint coexisted in an advanced stage with those of acute inflammation of all the other structures of the articulation.
The osteitis of the lower extremity of the femur or upper portion of the tibia sometimes presents more of a chronic character. The in
flammation of the interior of the bone may proceed to cause the death of a portion, which is converted into a sequestrum, the presence of which becomes a source of irritation and in flammation of the surrounding bone and the formation of an abscess. The following case came under the writer's observation while under the care of his colleague Dr. Hutton in the Richmond Hospital. Thomas Conolly, wt. 43, was admitted in May, 1838, for a disease in the lower extremity of the left femur, of many years' duration. Ile had long suffered from a deep boring pain in the interior of the bone. At length an abscess formed, matter made its way to the surface and was evacuated, and two small fistulous openings remained, through which a probe could be passed deep into the interior of the enlarged femur. The man was greatly exhausted by the quantity of the dis charge, by confinement, and hectic fever, and amputation was performed in the femur just above the diseased part. The femur was found much enlarged near the knee-joint, and covered by wasted muscles, which had undergone a considerable degree of fatty degeneration. When these were removed, the periosteum was found thickened. A vertical cut from before back wards was made through the femur, knee joint, and tibia, by which section the cavity of an abscess capable of containing a hen's egg was exposed, which was placed transversely between the condyles, having two open fistu lous orifices, one on the inner, the other on the external condyle. This abscess was lined by a thick membrane which by a fine injection was proved to have been highly vascular ; villous flocculi hung from it into the interior of the ca vity; a dark-looking sequestrum of a cylin drical form, an inch and a half long and half au inch thick, occupied the superior half of the cavity; one end of the sequestrum was fixed into the bony tissue of the femur, as if it were on its way to present itself at the outer fistulous orifice ; the remainder of it lay dia gonally across the cavity of the abscess, the front wall of which was principally constituted of soft parts, the femur having been absorbed in this situation. In the vicinity of the ab scess, particularly above it, the bone was greatly thickened, its cancellated structure solidified, and rendered apparently as dense as ivory. The interior of the joint was quite unconnected with the cavity of the abscess, but the joint it self presented evidence of its having been at one time the seat of some form of inflam matory action, because the shape of the con dyles of the femur was somewhat altered, and at the same time the tibia was partially displaced backwards, and ligamentous anchylosis had taken place. The cartilage had been removed somewhat from the ends of the bones, and its place supplied in patches by a membrane like periosteum, and in other situations by a dense polished enamel. It was to be inferred from the appearances which the bones and conti guous structures presented, that the knee-joint had latterly been quite useless.