Destructive joint changes in rheumatoid arthritis (RA) are thought to be mediated in part by the neutral proteinases collagenase and stromelysin. Collagenase messenger RNA (mRNA) has been previously localized to the synovial lining layer. In this study, synovial tissue from 8 patients with RA and 2 patients with osteoarthritis was examined for proteinase production by in situ hybridization. Stromelysin mRNA localized predominantly to the synovial lining layer cells. In serial sections, collagenase mRNA was shown to be localized to the same tissue areas as those producing stromelysin mRNA, and grain counts revealed a direct correlation between production of stromelysin mRNA and production of collagenase mRNA. All patients with RA were producing collagenase and stromelysin mRNA in detectable amounts. One of 2 osteoarthritis patients was producing these metalloproteinases, but in levels below those found in the RA patients. These data support the identity of the synovial lining cells as the major synovial cells producing collagenase and stromelysin in RA and provide new evidence for the coordinate production of collagenase and stromelysin in RA in vivo.

S as to which ligaments are most important. We hypothesized that a comparative macroscopic and microscopic analysis of the ligaments of the thumb carpometacarpal joint would further define their role in joint stability. Methods: Thirty cadaveric hands (ten fresh-frozen and twenty embalmed) from nineteen cadavers (eight female and eleven male; average age at the time of death, seventy-six years) were dissected, and the supporting ligaments of the thumb carpometacarpal joint were identified. Ligament width, length, and thickness were recorded for morphometric analysis and were compared with use of the Student t test. The dorsal and volar ligaments were excised from the fresh-frozen specimens and were stained with use of a triple-staining immunofluorescent technique and underwent semiquantitative analysis of sensory innervation; half of these specimens were additionally analyzed for histomorphometric data. Mixed-effects linear regression was used to estimate differences between ligaments. Results: Seven principal ligaments of the thumb carpometacarpal joint were identified: three dorsal deltoid-shaped ligaments (dorsal radial, dorsal central, posterior oblique), two volar ligaments (anterior oblique and ulnar collateral), and two ulnar ligaments (dorsal trapeziometacarpal and intermetacarpal). The dorsal ligaments were significantly thicker (p < 0.001) than the volar ligaments, with a significantly greater cellularity and greater sensory innervation compared with the anterior oblique ligament (p < 0.001). The anterior oblique ligament was consistently a thin structure with a histologic appearance of capsular tissue with low cellularity. Conclusions: The dorsal deltoid ligament complex is uniformly stout and robust; this ligament complex is the thickest morphometrically, has the highest cellularity histologically, and shows the greatest degree of sensory nerve endings. The hypocellular anterior oblique ligament is thin, is variable in its location, and is more structurally consistent with a capsular structure than a proper ligament. Clinical Relevance: Delineation of the structural and microscopic anatomy of the ligaments of the thumb carpometacarpal joint provides further evidence regarding the stability and mobility of this joint that is often affected by osteoarthritis....

The purpose of the study was to evaluate the feasibility of Norian SRS bone cement injected percutaneously into a distal radius following reduction in both preventing loss of reduction as well as safety. The study was a prospective clinical study with an established protocol. The study was conducted at the Massachusetts General Hospital following approval of the institutions Investigational Review Board. All patients were required to read and approve an informed consent document. While twenty patients' radiographs fulfilled the requirement of a dorsally displaced extraarticular fracture to have occurred within 72 hours of presentation, only five consented to participate fully and one voluntarily withdrew after a six-month follow-up. All fractures were reduced under regional or general anesthesia, and the Norian SRS was introduced via a catheter system into the metaphyseal defect of the fracture. A short arm cast was applied and remained in place for six weeks. Radiographic parameters of fracture reduction were measured prospectively by an independent radiologist throughout the 12 months of the study. Clinical parameters of hand and wrist function were measured prospectively by an independent occupational therapist. At 12-month follow-up, radial length was a mean 9.9 mm with an average loss of < 1 mm; radial angle maintained at a mean 25.4 degrees; volar angle was within normal range (0-21 degrees) in 4; and 1 patient had a dorsal angle of 7 degrees. Wrist motion improved 50 percent between 6 weeks and 3 months and improved further by 12 months when grip strength reached a mean of 88 percent of the contralateral side. Dorsal and volar extrusion of injected Norian SRS in 4 patients resorbed over time. There were no clinically significant adverse effects or complications. Norian SRS proved to be clinically safe and effective as a cancellous bone cement to maintain fracture reduction of unstable extraarticular distal radius fractures.