Calculation of the entire synovial surface area in the major joints of the human body and the percentage of synovectomized tissue area in an entire synovium of the knee, the ankle, the elbow and the wrist joints.

Abstract

Articular index or in another words joint index first introduced 1956 by J. Lansbury is obviously an indicator rapidly able to show the spread of joint inflammation throughout the body in the patient of R. A.. It also is one of the 3 main components of what we call “Rheumatoid Activity Index”for evaluating general rheumatic condition. This index was obtained by the anatomical measurement of the area of bone ends-(cartilage surface area)- which together form the individual joint;a value 24 is given to the knee,24 to the hip,8 to the ankle,12 to the shoulder,12 to the elbow,4 to the wrist. By using this index it is possible to rapidly calculate the percentage of total possible joint involvement in a given case of rheumatoid arthritis. From the view point of joint pathology, however, it seems more scientific to determine this type of joint index by measuring the total surface area of intra-articular synovial tissue than by measuring the opposing articular surface areas, because rheumatoid joint inflammation is entirely synovial. For this reason, the author, using human cadavers, developed a new joint index by measuring the entire surface area of the synovial membrane of major joints such as hip, knee, ankle, shoulder, elbow and wrist, and the following values were obtained: 159.18cm² for the knee,59.48cm² for the hip,25.89cm²for the ankle,50.05cm² for the shoulder,39.86cm² for the elbow,9.86cm² for the wrist. If the synovial surface of the knee joint is supposed to have just the same index value of 24, as the joint index of Lansbury in the knee joint it is selfevident from the above findings that an index value 9 is to be given for the hip,4 for the ankle,8 for the shoulder,6 for the elbow,1 for the wrist joint. In the 2nd part of his article the author using the same human cadavers as a specimen measured the area of synovial tissue which is surgically removed in his clinic from the knee, the ankle, the elbow and the wrist joint. These areas are proved 66% from the knee,73% from the ankle,80% from the elbow and 60% from the wrist. From these findings it is concluded that postoperative results following synovectomy could not be successful unless more than two thirds of the entire synovial tissue is removed from a given joint of the patient of R. A..