Joint Recesses Research Articles

Histopathological study of human TMJ perforated discs with emphasis on synovial membrane response

Fifteen perforated TMJ discs from human cadavers were studied histologically to examine the synovial membranes and to compare the findings with previous experimental results in monkeys. There were four with perforations in the bilaminar zone (these four discs were displaced anteriorly), three in the medial third of the disc, and eight in the lateral third of the disc. Histopathologically, there was an increase in vascularity and strong methyl pyronine-positive cellularity around the margins of the perforations. A young, loose, collagenous tissue lined the lateral margins of the perforated discs. Increased fibrous tissue content of the synovial subintimal territorial matrix and osteochondroid metaplasia were also seen. Severe synovial hyperplasia was visible in all joint recesses, but was greatest within those associated with displaced discs. There was patchy distribution of acidic glycoproteins, especially in the lateral parts of the perforated discs. As in the animal studies, human TMJ disc perforation was associated with a vigorous synovial reaction that was seen to form lateral bridges along the margins.

Synovial chondromatosis associated with experimental osteoarthritis in adult monkeys

This report describes the synovial response to temporomandibular joint disc perforation in an experimental animal model. Histologic examination revealed the presence of marked synovial membrane hypertrophy in all experimental joint recesses. Gradual transformation of synovial islands from a cellular to a metaplastic stage, with chondroid or even osteochondroid-containing tissue also was seen. The cartilage was arranged in a lobular pattern with intervening fibrous septae within the synovial islands. These synovial islands were observed in the anterior recess of three joints and in the posterior recess of another joint. The experimental findings suggest a relation between synovial chondromatosis and osteoarthritis.

Facet joint arthrography in lumbar spondylolysis: anatomic basis for spread of contrast medium.

Facet arthrograms in patients with lumbar spondylolyses show spread of contrast medium through pars interarticularis defects into the adjacent ipsilateral facet joint space and across the midline into the contralateral joint space. Transverse and sagittal sections of facet joints from 141 postmortem lumbar spines were studied. Five examples of spondylolysis were found. Anatomic studies of the relationship of the joint recesses to the pars interarticularis demonstrated the basis for the patterns of spread of contrast medium observed radiographically in this and previous series. The pars interarticularis forms the only boundary between the inferior recess of one facet joint and the superior recess of the adjacent joint. Fracture through the pars interarticularis establishes communication between adjacent ipsilateral joints and opens a communication to the retrodural space, through which contrast medium can track to the contralateral joint.

IMMUNOHISTOCHEMICAL DEMONSTRATION OF NOCICEPTORS IN THE CAPSULE AND SYNOVIAL FOLDS OF HUMAN ZYGAPOPHYSEAL JOINTS

Substance P, a physiologically potent neuropeptide, is considered to participate in nociceptive transmission of nerve impulses. Substance P immunofluorescent nerves are demonstrated in the inferior joint recess capsule and its synovial folds in human lumbosacral zygapophyseal joints. This may have clinical significance in spinal pain.

Etiopathogenesis of the rheumatoid arthritis-like disease in MRL/l mice. I. The histomorphologic basis of joint destruction.

MRL/l mice spontaneously develop a hindlimb arthropathy, as well as a number of immunologic abnormalities, including circulating rheumatoid factors. Although previous studies have suggested that this arthropathy is primarily an inflammatory process, we performed a comprehensive histomorphologic study which indicated that inflammation is a late manifestation of MRL/l arthritis. The pathologic changes that occur in the joints of these mice can be divided into 3 stages. The first stage develops between the ages of 7 and 13 weeks and consists of synovial cell proliferation in the joint recesses. The second stage is characterized by continued proliferation of synovial cells which take on an appearance similar to that of transformed mesenchymal cells. The earliest destructive changes occur in the second stage and include marginal erosions, followed soon after by progressive destruction of articular and meniscal cartilage. The final stage is characterized by a diminution of synovial cel proliferation, extensive cartilage destruction, formation of scar tissue and fibrocartilage, and a very moderate infiltration of the synovial stroma by mononuclear and polymorphonuclear inflammatory cells. Throughout the disease progression there is a striking dissociation between inflammatory cell infiltration or exudation and tissue destruction. The histomorphologic similarities between human rheumatoid synovitis and the arthritis of MRL/l mice, as well as the presence of rheumatoid factors, make this mouse strain an excellent model for studying human rheumatoid arthritis.

Septic shoulders in children.

A review was carried out on nine children who were diagnosed and treated for septic arthritis of the glenohumeral joint at the University of California, San Diego affiliated hospitals. Eight of the nine patients were under 18 months of age at the time of diagnosis. Three patients had a history of antecedent trauma, and four had a previous or concurrent source of infection. The longest delay between the onset of symptoms and diagnosis was 30 days with the majority being diagnosed within 4 days of onset. Laboratory findings revealed a mean white blood cell count of 17,400 and a mean temperature of 39.3 degrees C. The sedimentation rate was always greater than 30 mm and averaged nearly 60 mm in these nine patients. Joint cultures were positive for a variety of organisms. Early radiographic findings often demonstrated widening of the joint space. Associated osteomyelitis of the proximal humerus was present in five of nine patients. Once the diagnosis has been established by aspiration, we recommend arthrotomy. Important aspects of the surgery include drainage of the joint and bicipital recess, and drilling of the proximal humeral metaphysis to rule out osteomyelitis or to more adequately decompress the bone.

Restoration of superficially damaged flexor tendons in synovial environment. An experimental ultrastructural study in rabbits.

Flexor tendon from the synovial sheath region of rabbits was resected and placed as a free body in a synovial knee joint recess. Structural changes of the surface of the graft caused by the instruments used to handle the tendon during the surgery (jewellers microforceps), was analysed by electron microscopy at various time intervals up to 6 weeks. The superficial coat of amorphous material, i.e. ground substance, on the surface of the tendon was dishevelled by the instruments. The injured areas were crowded with monocytes and macrophages during the first days. An increasing number of fibroblasts and mesothelial-like cells covered the damaged area in less than two weeks. The superficial coat of ground substance was not completely restored until after 3 weeks or more. The results obtained are discussed in relation to functional aspects.