The Permeability of the Synovial Membranes

Abstract

Little is known of the physiology of the synovial membranes, particularly regarding their permeability. As a consequence, it is difficult to understand the effusions occurring in joint cavities, or the accumulations of fluid in tendon sheaths and in bursae, consequent to trauma or disease. The knee joint is usually studied since it is easily accessible. In addition, it possesses the most extensive synovial membrane in the body. Diffusible constituents pass readily from the blood into the synovial fluid. In fact Crouter, Cajori and Pemberton 1 have shown that their concentration in synovial fluid can be readily changed by inducing corresponding changes in the blood. Fisher 2 observed that potassium iodide, Berlin Blue, and colloidal silver were absorbed from the knee joints of rabbits. He demonstrated iodide in the urine but did not determine in this manner its rate of absorption from the synovial cavity.

Using the method of Dandy and Rowntree, 3 we have studied the permeability of the synovial membrane to phenolsulphonepththalein in 5 male patients with effusion in the knee joint. In 4 this was traumatic in origin; in one it was due to chronic infection. With the patient at rest during the entire procedure, a soft rubber catheter a demeure was first introduced into the bladder. Under strict asepsis and local anesthesia, a large bored needle was then inserted into the joint cavity through the upper and outer portion of the joint capsule. As much as possible of the effusion fluid was aspirated without undue manipulation. This was cultured, injected into guinea pigs and analyzed chemically. The usual amount, 6 mg. in 1 cc, of P.S.P. was then injected into the joint cavity through the aspirating needle.