Vol 1, No 4 (1994)

On the basis of the analysis of home and foreign experience, the author discusses the certain most actual problems of total joint replacement and the ways of their solution, i.e. search of new sufficiently strong and, in the same time, biologically inert materials for the production of joint implants; modification of the implant components surface in order to ensure their maximum biological compatibility and optimum conditions for the bone tissue ingrowth; improvement of the tribologic characteristics of the friction couple in the mobility unit; elaboration of bone cement. High social and economic significance of joint replacement is emphasized.

One of the main reasons for endoprosthesis instability (loosening) is a high friction coefficient in the mobility point. The tribological studies made at the Laboratory of Polymers, Central Institute of Traumatology and Orthopedics, have indicated that greasing the prosthesis mobility angle with bone marrow shows a 2-3-fold reduction in the friction coefficient. On this basis, a new type of the Movshovich-Gavryushenko hip joint endoprosthesis having a reserve friction mechanism was designed. In the prosthetic crus, neck, and head, a canal was formed, along which bone marrow drops entered the mobility node throughout the endoprosthetic functioning period. The endoprosthesis is also noted for its changeable cervical diaphysial angle due to the fact that there are three replaceable necks. This enables a surgeon to make the head have its varus or vagus position, as well as to place it in the ante- or retroversion position. Endoprosthesis by mean of the model was successfully performed in 146 patients, as shown by a 5-year follow-up.

The paper discusses the problem in replacing extensive bone defects after adequate resections in patients with locomotor system tumors, defines a concept of an adequate operation, and provides an original classification of osteotumors by the extent of a tumorous process. After extirpation of the clavicle (including resection of the manubrium sterni and the first rib), scapulectomy, inter-scapulothoracic, pelvic, and proximal fibular resections, the author does not replace bone defects, without deteriorating the surgical functional outcomes. In 135 patients, defects were replaced by variously designed endoprostheses (in 23 of them this was done after total removal of the femur or humerus). Postendoprosthetic complications developed in 14 patients: early suppuration (n = 3), metallosis and late suppuration (n = 3), endoprosthetic fracture (n = 5), and intraoperative bone fracture (n = 3). Bone fracture occurred while mastering the procedure and failed to affect therapeutical functional results. In extensive long bone diaphysial defects and combined bone and soft tissue defects, the author used autografting on micro-vascular anastomoses in 34 patients or defect replacement in the Ilizarov apparatus in 8 patients.

Attention is concentrated on the basically varying nature of early and late suppurative complications after implanting and hence on different approaches to treating deep suppurative processes. In early deep suppurations, timely intensive care permitted the authors to eliminate suppurative complications in 67.8%, by preserving the implant. In late suppurations associated with metallosis, the implant cannot be preserved, it is necessary to treat not only a deep suppuration, but also metallosis.

The artificial and natural joints are biomechanically adequate due to their similar technical characteristics. The tribological characteristics are responsible for joint mobility. With high material abrasion resistance, a low friction coefficient cannot be achieved without greasing. If the friction coefficient can be reduced to the level typical of a healthy joint (0.008—0.04), one can expect a relevant decrease in breaking forces resulting in the friction point from slip resistance. In this case the safety margin generated on cement fixation will be sufficient for the service life of an implant to be 2—3 times higher than the currently available (the Chanley joint implants serve as many as 30 years). With these occurring events, the demand will decrease for a small number of cementless fixation joint implants and their application will be associated only with contraindications for cement use.

The paper deals with results of conservative treatment of 96 patients with Paget’s disease with the national drugs, such as calcitrin and xidiphone which affect osseous metabolism. Positive results were achieved in the clinical, X-ray, biochemical pattern of the disease in most patients. This makes it possible to recommend the drugs for treatment. The advantages and disadvantages of the agents are determined. The efficiency of xidiphone therapy is regarded to be the most beneficial. It is suggested that complications may develop and progress in some cases even when there are marked positive shifts, which dictates the necessity of continuous monitoring of patients.

The paper provides evidence for the fact that conservative therapy for femur head dislocation fractures is ineffective. It considers surgical techniques used in 12 patients, such as removal of small fragments (n=4), osteosynthesis of a large fragment on a pedicle (n=5), total joint implanting (n=3). Contraindications for each technique are defined. Despite many months’ postoperative joint unloading, 3 of the 7 patients examined in late periods developed aseptic femur head necrosis.

The authors elaborated the method of preservation of 2 doses of autoerythrocytic mass prior to the planned surgical interventions with the expected massive blood loss. During autoblood storing and preservation of 2 doses of erythrocytic mass the reinfusion of plasma to the patient was carried out thereby the circulating blood volume was restored in the volume up to 1000 ml. It provided the reduction of the requirement in donor blood by 89,2%. The method was effective at such surgical interventions as the total joint replacement (4), hip joint arthrodesis (7), subtrochanteric and intertrochanteric corrective osteotome (5), osteosynthesis of acetabulum fragments (50).

The device proposed is notable for its simplicity and compactness. It prevents mechanical stenosis of the vessel in the suture zone, considerably improves the convenience of the suturing (even when rotation of the vessel is not possible) and enables to make a vascular suture without any assistance.

Attempts to avoid limb amputation upon detection of a malignant bone or soft tissue tumor were made by surgeons as early as the beginning of our century. One of them was related to plasty according to F. Sauerbruch: after resection of the femur, the tibia was moved upwards and placed in the musculocutaneous bed, resulting in a stump suitable for prosthetics. Tikhov and Linberg performed an extensive resection of the scapula and the proximal end of the humerus, preserving an "elongated" and unstable, but mobile upper extremity. Preservation of stability of the lower extremity by implanting tumor prostheses seemed to be the most reasonable. The first operation of this type was performed in the late 1930s by A. Moore for a gigantoclavicular tumor of the proximal femur. In the late 50s and early 60s, with the development of hip arthroplasty, the tendency to develop and implant special prostheses for patients with tumor diseases also intensified.