Symptomatology.—­A difference in the character of symptoms is evidenced when dissimilar causes exist.  Small penetrant wounds which infect the synovial membranes cause infectious arthritis in some cases, whereas a wound of sufficient size to produce evacuation of all synovia will, in many instances, cause no serious distress to the subject, even when not treated for several days.  If it is not evident that an open joint exists and the articular cavity is not exposed to view a positive diagnosis may be early established by carefully probing the wound.  In some cases where a small wound has perforated the joint capsule, swelling and slight change of relation of the overlying tissues may preclude all successful exploratory probing.  In such instances it is necessary to await development of symptoms.  Twenty-four hours after injury has been inflicted, there is noticeable discharge of synovia which coagulates about the margin of the orifice, where synovial discharge is possible.  Particularly evident is this accumulation of coagulated synovia where wounds have been bandaged—­there is no mistaking the characteristic straw-colored coagulum which, in such cases, is somewhat tenacious.

No difference exists between other symptoms in infectious arthritis caused by punctures, and non-infectious arthritis, excepting the intensity of the pain occasioned, the rise in temperature, circulatory disturbances, etc.; all of which have been previously mentioned.

Treatment.—­Just as has been stated in discussions on the subject of open joint, probing or other instrumentation is to be avoided until the exterior of the wound and a liberal area surrounding has been thoroughly cleansed—­too much importance can not be placed on this preliminary measure.  In cases of open joint where ragged wound margins exist and the interior of the joint capsule is contaminated, much time is required to thoroughly cleanse all soiled parts.  In some instances an hour’s time is required for this cleansing process after the subject has been restrained and prepared.  In order to thoroughly cleanse these delicate structures without doing them serious injury, one ought to be skillful and careful in all manipulations of the exposed parts of the joint capsule.

The general plan of treatment, after preliminary cleansing has been accomplished, has been outlined on page 66 in the consideration of scapulohumeral joint affections.  The injection of undiluted tincture of iodin in ounce quantities, it must be remembered, is not to be done unless there is provision for its free exit.  Where good drainage from the joint cavity exists all infected wounds should be thus treated, and this treatment may be repeated as conditions seem to require—­until infection is checked.

If daily injections are necessary, dilution of the tincture of iodin with an equal amount of alcohol is advisable in order to avoid doing irreparable damage to the articular cartilages and synovial membranes.