[Experimental and clinical studies on the Jikei total knee prosthesis (author's transl)]

Total knee prostheses for a dog were developed and were inserted into knee joints of seven adult dogs to study the mobility of the artificial joint, the degree of fixation to bone and the durability of the prosthesis, to examine the reactions in the surrounding tissues and the internal organs in the JIKEI total knee prosthesis in clinical use. As a result of surgery, it was proved that the length in the hinged part of the prosthesis needed to be seventy percent of the length of the excised area of the joint to gain good mobility and supportability of the knee joint after surgery. As a result of findings based on necropsy, wear at the hinged part of the prosthesis was mild and debris caused in wear was not harmful for the living body if breakage does not occur there. Histopathological findings revealed that collagenous fibrous tissue with new bone formation was observed on the inner wall of the bone around the stem of the prosthesis four months after surgery. Then it was proved that the fixation of the prosthesis to the bone was sufficient. Therefore the author would like to mention that bone cement is not necessary for the fixation between bone and prostheses. The JIKEI total knee prosthesis (universal type) based on the results of these experimental studies has been developed and was used to the clinical cases. The clinical results until four years after surgery have been most satisfactory with loss of pain, good supportability and movement of joints in almost all of the cases.