Certain rather definite findings are to be noted. First:—contraction of the quadriceps without adhesions will produce a loss of function of the knee.
Second:—contraction and adhesion between the muscles themselves, or between muscle and bone, will produce loss of flexion of the knee.
Third:—the capsular changes are not as constant a finding as the muscular changes. Knee joints that cannot be forcibly flexed before the releasing of the tendon can be easily flexed afterwards.
Fourth:—contraction of the muscular tissue following long immobilization for inflammatory knee joint disease, probably is present, but it is rot advisable to operate in the presence of a sensitive joint.
Time is an important factor. It is better to operate on a patient who has walked for five years with ten degrees of motion, than on one who has walked for five months with thirty degrees of motion. In the former, joint and muscle tissue are in good tone: therefore, they lend themselves better to operation and they return to function much more rapidly.