Intra-articular pressures

Jason, M.I.V. and Dixon, A. St. J. (1970a). Intra-articular pressures in rheumatoid arthritis of the knee. I. Pressure changes during passive joint distention. Ann. Rheum. Dis. 29, 261-265. 

Unsworth, J., Outhwaithe, J., Blake, D.R., Morris, C.J., Freeman, J. and Lunec, J. (1988). Dynamic studies of the relationship between intra-articular pressure, synovial fluid oxygen tension, and lipid peroxidation in the inflamed knee an example of reperfusion injury. Ann. Clin. Biochem. 25, 8S-11S. 

Recently, we have provided evidence that hypoxic reperfusion injury occurs in the inflamed human joint [2,12,13]. Joint movement in patients with RA produces intra-articular pressures in excess of the synovial capillary perfusion pressure. This phenomenon does not occur in normal joints, where the pressure remains subatmospheric throughout a movement cycle. During exercise of the inflamed joint, the intra-articular pressure is transmitted directly to the synovial membrane vasculature, producing occlusion of the superficial synovial capillary bed and ischaemia. Reperfusion of the synovial membrane occurs when exercise is stopped. Recently, electron spin resonance spectroscopy with spin trapping was employed to demonstrate that synovial tissue from a patient with RA generated ROI following a transient hypoxic... 

In normal conditions, the iliopsoas bursa cannot be visualized with US because its cavity contains only a thin film of synovial fluid. When communicating with the joint cavity, hip joint fluid can enter the bursa (Fig. 12.34a). In cases of abundant joint effusions, the bursa acts primarily as a reservoir thus limiting the damage to the intra-articular structures related to a high intra-articular pressure. Intra-... 

Betamethasone is hardly ever used orally. It has a long duration of activity and can therefore also be used for alternate-day therapy. The parenteral formulation is also the sodium phosphate salt which when given IV or IM has a rapid onset of action. There are many similarities with dexamethasone such as their metabolic pathways and the indications for which both steroids are used, like the prevention of neonatal RDS and reduction of raised intracranial pressure. Combinations of betamethasone acetate and sodium phosphate have, when used for intra-articular and intra-lesional injections, the dual advantage of a rapid onset of action together with the long duration of action of a depot preparation. 

Anmarkmd, N., Bergaust, B. and Bulle, T., The effect of Healon and Timolol on early postop>erative intraocular pressure after extracapsular cataract extraction with implantation of posterior chamber lens, Acta. Ophthalmol., 70,96,1992. Punzi, L., Schiavon, F., Ramonda, R., Malatesta, V. and Bambari, P., Intra-articular hyaliuxrnic acid in the treatment of inflammatory and non-inflamma-tory knee effusions, Curr. Ther. Res., 43, 643,1988. 

Fractures involving the epiphysis and physis of the finger metacarpals are uncommon (Mahabir et al. 2001). Epiphyseal fractures are rare, and non displaced fractures may heal well (Fig. 19.19). Displaced split fractures of the epiphysis may need open reduction to restore articular congruity (Graham and Waters 2001). Intra-articular fractures of the epiphysis are important to identify as they are associated with joint effusions. If these effusions are under enough pressure, blood flow to the epiphysis maybe sufficiently compromised to cause avascular necrosis. Preventative joint aspiration may be considered (McElfresh and Dobyns 1983). 

Plain radiographs can be normal or show intra-articular effusion, an ill-defined para-articular soft-tissue mass and, in longstanding disease, juxta-articular bone erosions and subchondral cysts caused by pressure and hypertrophied synovium. CT shows hemosiderin and fat deposits, and is able to detect bone erosions that are not manifest on radiographs. 

Quadriceps tendinopathy is far less conunon than patellar tendinopathy and usually relates to sporting activities or strenuous exercise. Clinically, this condition is characterized by focal pain over the distal portion of the tendon, exacerbated by resisted extension of the knee or firm pressure over it. The skin is normal and there is no evidence of intra-articular effusion at physical examination. Similar to other tendinopathies, the involvement of the quadriceps tendon mainly relates to degeneration and fibro-myxoid changes. In this setting, the main value of... 

---