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Biomedical subjects

Z Mikić

Publications and source records attributed to Z Mikić.

At least 19 recordsLinked to original sources

[Morphologic characteristics and static resistance of transplanted patellar ligaments after replacement of the cruciate ligaments in the knee--an experimental study in a dog].

An experimental study on transplantation validity of patella's ligament, when transplanting front crossed ligament, was performed on 106 knees in 53 grown-up dogs. The investigation had three stages. Three months after the transplantation of the front crossed ligament with the medial third part of the patella's ligament animals were sacrificed and in one group the static resistance and the resistance to elongation, by using special tweezers (Alfred Amsler Co., Schafhausen, Switzerland), was investigated. The results showed that the patella's ligament is very suitable for transplantation because its resistance and strength were almost identical with the same parameters of intact front crossed ligament. Revascularization of the new ligament using Spaltenholz's technique was done in the second group, and three months after the operation, complete revascularization of transplants took place. The synovial membrane which covers the new ligament represents the main source of fresh blood vessels on one side, while similar process takes place along the bone tunnels where the new ligament was fixed. The new ligament histologic analysis carried out in the third group of experimental animals showed that after three months the transplant acquires the structure which is very similar to the front crossed ligament. The obtained results of the investigation show that the patella's ligament is a very good biologic material for transplantation of the crossed ligament.

Animals

[Patellar height in patients with chondromalacia].

A radiogrametric assessment of the patellar height performed by three measurement methods, in the lateral views of radiograms of 136 patients with chondromalacia of the patella was aimed at the establishment of certain parameter values in the studied population and the assessment of the influence the altered patellofemoral ratio has upon the onset of the disease. The results of the study verified the remarkable advantages of the method by Insall and Salvati for the measurement of the patellar height and showed a significant involvement of patellofemoral incongruity in the development of chondromalacia, since in 15-16% of the cases the patella was not properly placed.

Adult

The blood supply of the human distal radioulnar joint and the microvasculature of its articular disk.

The arterial blood supply of the distal radioulnar joint was investigated in 35 upper extremities taken from 22 fresh cadavers (11 newborns and 11 adults using the India ink injection and tissue-clearing techniques according to Spalteholz). Microvasculature of the articular disk of the distal radioulnar joint was also performed in 35 articular disks taken from 22 fresh human cadavers, 11 newborn and 11 adults using the same technique. It was found that the general blood supply to the joint is received mainly from the palmar and dorsal branches of the anterior interosseous artery. These branches, after dividing at the proximal border of the pronator quadratus, arborize in a fanlike fashion around the joint and their small ramifications penetrate and vascularize the capsule and the articular disk from the palmar, dorsal, and medial sides. The terminal branches of the anterior interosseous artery reinforced by the posterior interosseous artery and a small branch of the ulnar artery give the direct peridiscal vessels to the palmar, medial, and dorsal margins of the articular disk, which arborize and anastomose with one another and form the terminal capillary networks that end at the peripheral segments of the disk in a series of terminal capillary loops, leaving the inner segments devoid of blood vessels. The posterior interosseous artery anastomoses at the distal part of the forearm with one of the terminal rami of the dorsal branch of the anterior interosseous artery and, in that way, contribute to the vascularization of the dorsal capsule of the distal radioulnar joint. The ulnar artery gives off a small branch that anastomoses with one of the terminal ramifications of the palmar branch of the anterior interosseous artery and contributes to the formation of a small arterial arch on the anteromedial side of the distal ulna, supplying the anteromedial capsule and the basistyloid area of the ulna. Both ulnar and radial arteries contribute to the vascularity of the joint through the collateral network of the palmar and dorsal carpal arches. In the articular disk, the major central portion of the disk is avascular and only its peripheral, palmar, medial, and dorsal margins are vascularized. The proportion of vascularized zone to avascular zone depends on the age of the subject and, in newborns, is approximately 33%. In adults, only 25% of the peripheral segments are vascularized.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult

Histologic structure of the articular disk of the human distal radioulnar joint.

A histologic study of the structure of the articular disk of the distal radioulnar joint in humans was performed on 57 disks from 37 fresh cadavers that included fetuses and individuals up to age 65 years. The specimens were stained with hematoxylin and eosin, orcein, and Mallory and Mann-Dominici's methods, and studied with the light microscopy. It was found that the disks of adults were basically formed of the so-called fibrocartilagenous tissue composed of an intercellular substance in which there were interwoven wavelike collagen fiber bundles and between them three specific types of cells: (1) rather sparse fibrocytes mostly situated in dorsal and palmar margins, (2) predominant and constant chondroid cells dispersed throughout the disk, and (3) less-frequent real chondocytes distributed mostly in the central parts. This basic tissue is modified according to the age of the subjects and functional requirements. In fetuses and newborns, it is almost completely fibrous and very cellular, while in adults, it is more cartilaginous with significantly reduced cellularity. The structure of various parts of disks is adapted to the functional stresses exerted on them. In central parts exposed to pressure, the tissue is more cartilaginous, while peripheral, massive margins, subjected mostly to traction, are built in a ligamentlike pattern. The ulnar and carpal surfaces are adapted to the gliding movements of the ulna and carpus. It is concluded that the articular disk in humans, which is basically of fibrocartilagineous nature, is a dynamic structure biomechanically, predetermined and changing with aging.

Adolescent

[Early functional and anatomic results after total condylar knee prosthesis implantation].

The results of total knee replacement in 30 patients have been analyzed. Total knees were implanted during 1990, and the shortest follow-up time after the operations amounted to 6 months. All 30 total condylar prosthesis were of Insall-Burstein posterior stabilized design. The average age of the operated patients was 61 years. Osteoarthritis caused serious knee damage in 21 patients and was the indication for the operation; in 7 patients it was rheumatoid arthritis; in 1 patient synovitis villonodularis; and severe posttraumatic osteoarthrosis in 1 patient. In 18 patients axial knee deformity was noted prior to operation in the sense of valgus or varus. The continuous passive motion machine was used in the postoperative treatment of all patients. Clinically acceptable results were obtained in 90%. Wound healing complications were noted in 2 patients. Full axial deformity correction was achieved in all the patients with a full extension and flexion of over 90 degrees in the operated knees. Preliminary results after the implantation of this type of prosthesis are very encouraging and justify it's further routine use.

Adult

[The size and suitability of blood vessels for transplantation into the knee of the dog].

An investigation of the size and suitability for the transplantation procedures of the knee blood vessels was made in 20 adult dogs with 40 extremities using the technique of injection of the arterial network through the femoral artery with the mixture of the methacrylic resin (SIGMAL R "Galenika", Belgrade) and the red ink. When the polymerisation of injected methacrylic resin was completed the specimens were exposed to either chemical or biological maceration of the tissues. Thirty-five specimens were chemically macerated using either 30% solution of hydrochloride acid or 40% potassium hydroxide. With this method bones were also destroyed and only the methacrylic vascular cast remained unaffected. Five specimens were exposed to the biological maceration using the insects (Dermestes vulpinus). This method proved to be better as the bones elements were not destroyed which allowed more precise study of vessel relations and topography. Calibre of the arteries was measured using the micromethod MEBA (Zagreb) with the accuracy of 0.01 mm. The main arterial vessels of the knee joint on the medial side are aa. saphena, genus descendes (branches of the femoral artery, then a. genus descendens (branches of the femoral artery, then a. genus medialis (branch of the popliteal artery), and on the lateral side are a. caudalis femoris distalis, (branch of the femoral artery), a genus lateralis (branch of the popliteal artery) and recurrent branches of the a. tibialis cranialis. Calibre of the femoral and popliteal arteries was over 2 mm which means that they are suitable for macrosurgical sutures, while the calibre of all other arteries was under 2 mm, and it is concluded that they are suitable only for microsurgical sutures.

Animals

[Transplantation of the meniscus in dogs--preliminary report].

A preliminary investigation of the allogenic transplantation of the meniscus without the vascular bundle was carried out in 4 adult dogs with 8 knees. In one operation session on 2 dogs at 2 operative tables and with two operative teams an identical surgical procedure in general anaesthesia was done. A medial parapatellar incision of the knee was used, the medial capsule and the collateral ligament near its proximal insertion were severed. Explanted medial menisci were exchanged and the meniscus from the other dog was put in position of the explanted one and fixed with 3 tangentially placed sutures (posterior, medial and anterior) which were taken out through the capsule and teid extra-articularly; there was no immobilisation, and after 3 weeks the identical operation was done on the other knee. The animals were sacrificed 4-5 months after the operation, the knees were dissected and observed. In all 8 knees transplanted menisci were completely healed around their periphery, however their appearance was rather changed. They were narrower, thinner, and of different colour and consistency. The transplanted menisci were removed and conserved in 10% (formalin) for the further investigation. It is concluded that the allogenic meniscal transplantation without the vascular bundle is possible and that the further investigation of this problem is justified.

Animals

[Histologic changes in fascia lata transplants in the replacement of the anterior cruciate ligament of the knee in dogs].

Lesions of the anterior cruciate ligament of the knee are very frequent misfortune and the results of their suture being insufficient yet, made us to explore the possibility to replace the damaged ligament with the fascia lata as an autologous transplant. Surgical operation was performed on dogs. Instead of the anterior cruciate ligament removed, we used a piece of a rolled fascia lata. Six months after transplantation being performed, samples of the fascia lata were extracted for histological analysis to assess their structure and to evaluate the transplant as a neoligament, on the basis of its similarity with the normal structure of the ligament. After degeneration of a part of transplant because of the insufficient supply of nutrients, the invasion of the synovial blood vessels into the fascia lata was established and the young granulation tissue formed on the account of the nondifferentiated adventitial cells. In the mosaic of the transplant structure there were present parts of a more mature, dense connective tissue with longitudinal orientation of the cells, the fibers and the vascular elements, which partially made structure similar to that in ligaments. In the attachment region fibrocartilage was noticed, gradually passing into the hyaline one, to merge with the hyaline cartilage of the joint surface. After the histological analysis follows the conclusion that fascia lata functionally could replace the anterior cruciate ligament if a role was supplied with sufficient collagenic fibers on the cross-section. Time is of a high importance, too.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals

[Humeral fractures complicated by radial nerve lesions].

In the period of 1966-1975 the authors treated 228 patients with a fractures of diaphysis of humerus, 103 of whom underwent surgery; in 36 of them a paralysis of the radial nerve occurred. These 36 patients were divided into two groups: primary lesions (22 cases) which were discovered during hospitalization, and secondary lesions which occurred in postoperative course. The aim of clinical research with the primary lesion (respectively 22 patients) was to ascertain which method would have the best effect. In 77,2% of these patients, a radial nerve was not interrupted, while in 13.6% its continuity was partially preserved, and only in 9.09% a complete interruption occurred. Complete recovery of the nerve was in 50% of patients, 22.7% had a small conduction deficit, while its paralysis was further present in 18.8% of cases. Accordingly to this, the authors attained an excellent and very good results in 59% of patients, while in the remaining 41% of cases the results was satisfactory. It has been established that primary lesions of radial nerve has been occurring in 7.64% of cases (similar date do exist in reviewed reports), and in the majority of patients a spontaneously recovery will occur in the course of 2-3 months. Therefore the authors are not for a primary exploration of n.radialis if it is a question of closed fractures. In rare cases with interruption of the radial nerve with extensive contusions of both simultaneously interrupted nervous stumps a primary suture is not indicated. Therefore an eventual surgical exploration to establish whether an interruption of the nerve exists, does not contribute to attain recovery.

Adolescent