Subject(s)
Acetabulum/surgery , Hip Prosthesis , Polyethylenes/therapeutic use , Acetabulum/diagnostic imaging , Adult , Aged , Female , Humans , Male , Middle Aged , Prosthesis Design , Radiography , ReoperationABSTRACT
Survey of methods. In first part new classification of prostheses. Discussion of some biomechanical problems, mainly on hinge-prosthesis which can only be compromises for various periods. Replacement to be considered only for elderly or very old patients, when conservative treatment offers no chances, other operations are not promising or have failed, arthrodeses cannot be done and pain and loss of function are severe. Indications for hinge- and slide-prostheses are given. In the second part two statistics of results from the literature are discussed and experience with 130 own cases using own model is described. Infection occurred in 3 cases where removal of prosthesis had to be done. Examples of the need for reversal operations are given.
Subject(s)
Joint Prosthesis , Knee Joint/surgery , Adult , Age Factors , Aged , Arthritis, Rheumatoid/surgery , Arthrodesis , Biomechanical Phenomena , Female , Follow-Up Studies , Humans , Male , Middle Aged , Osteoarthritis/surgery , Postoperative Complications , Surgical Wound InfectionABSTRACT
The introduction explains the general problems of knee joint replacement by artificial hinge-type prostheses, due to the reduction of the physiological "degrees of freedom" to only rotational movements around a horizontal axis. These problems are compared with the advantages of this type of prosthesis. Subsequently a description of some significant constructional characteristics of the hinge-type prosthesis, 13 given as there are placement of the joint, size of the contact surface, safety of the rotational device, design of the hinge-mechanism, the patella shield and the prosthetic stems as well as the breaking of dynamic forces, which all are subsequently compared in their values. Finally a hinge-type prosthesis is described with characteristics judged optimal according to our present scientific knowledge. We statistically evaluated our material of hinge-type prostheses with regard to final results and frequency of serious complications.
