On the pathological basis of the treatment of joint diseases / by Henry G. Davis, M.D.

  • Davis, Henry G. (Henry Gassett), 1807-1896.
Date:
1862
Catalogue details

Licence: Public Domain Mark

Credit: On the pathological basis of the treatment of joint diseases / by Henry G. Davis, M.D. Source: Wellcome Collection.

Provider: This material has been provided by the National Library of Medicine (U.S.), through the Medical Heritage Library. The original may be consulted at the National Library of Medicine (U.S.)

    6/20
    fixated by disease or artiScially, the pressure, whether it be a portion of the weight of the body, or only the contractile power of the mus- cles, (as exerted in fixing the joint,) falls entirely upon a small por- tion of each condyle, and a corresponding portion of the head of the tibia in contact with it. If it is admitted that only a small portion of the articular surfaces of the condyles and the tibia are in contact at any given time, in the normal condition, we are prepared for the inquiry, What will be the result of continual pressure, effected by the contractile force of the muscles while fixing the joint; a compression from which there may be no relief for weeks or months in succession ? The effect of continued, unremitting pressure upon other portions of the body is well understood. Every practitioner cautions his pupils not to allow the heel to rest upon the bed while treating a case of fracture of the lower limb, warning him that, if he does so, the parts will slough; this result takes place, not because of the severity of the pressure, but from its persistency; from its not allowing, by change of position, the circula- tion, and consequently nutrition, to proceed uninterruptedly. The liability to this casualty increases the less sensibility there resides in the structure affected. It is also promoted by diminished vitality. We can hence easily understand why it so readily takes place in the heel. I would call attention to this fact, as I shall have occasion to notice the importance of its consideration when applied to the effect of pressure upon cartilages. There are two reasons why diminished sensibility and nutritive en- dowment should render parts liable to destruction by pressure. First, the sensibility being slight, death of the parts occurs with very little suffering. Secondly, the vitality being low, less pressure is required to interrupt the vital functions, and thus cause death. I trust that I shall be able to show conclusively, that in inflamma- tions external to the capsules of the joints, sufficient to render them motionless, absorption, if not death, results to those portions of artic- ular cartilage in contact and pressing upon each other; that this occurs when the external disease has not extended to the articular surfaces, and that it is owing chiefly, if not entirely, to continued pressure; this pressure being limited to that portion of the articu- lating surfaces that are held in contact for a period of time, without intermission or change, by the muscles which control the motions of the joint affecting the parts, precisely as pressure does when applied to the surface of the body, viz., producing absorption, when not suffi- cient entirely to arrest the nutrition of the parts, and when going be-