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Biomedical subjects

A Reffy

Publications and source records attributed to A Reffy.

10 recordsLinked to original sources
PubMed1991

Three-dimensional ultrastructure of human tendons.

The three-dimensional ultrastructure of human tendons has been studied. Epitenon and peritenon consist of a dense network of longitudinal, oblique and transversal collagen fibrils crossing the tendon fibres. The internal structure of tendon fibres is also complex. The collagen fibrils are oriented not only longitudinally but also transversely and horizontally. The longitudinal fibrils do not run only parallel but also cross each other forming spirals (plaits). These fibril bundles are bound together by a three-dimensional collagen fibril network of endotenon. In the myotendinous junction the surface of the muscle cells form processes. A network of tendineal collagen fibrils fills the recesses between the muscle cell processes penetrating the basement membrane of these processes. This complex ultrastructure of human tendons most likely offers a good buffer system against longitudinal, transversal, horizontal as well as rotational forces during movement and activity.

Adolescent↗
PubMed1991

Changes in muscle structure following tenotomy. A scanning electron microscopical study in the rat.

The alterations caused by Achilles tenotomy in the calf muscles of the rat were studied one, two and three weeks postoperatively by scanning electron microscopy (SEM). One week after tenotomy connective tissue had accumulated in endomyseal and perimyseal structures, which continued to increase even more after two and three weeks. The normal muscle architecture was markedly disturbed and in individual muscle cells hypercontracted segments, longitudinal splitting as well as destruction of myofilaments were found. Apparently due to the loss of muscle tension some muscle cells were reversed on their long axis and fixed with the adjacent collagen fibres. Some muscle cells were spiral in shape or crossing over each other. Formation of myotubes indicated onset of regenerative processes. According to the SEM-analyses tenotomy has many severe deleterious effects on muscle structure. In clinical practice tendon ruptures should therefore be repaired as soon as possible to avoid degenerative--potentially irreversible--changes in the muscular tissue.

Animals↗
PubMed1990

The effect of tenotomy and immobilisation on intramuscular connective tissue. A morphometric and microscopic study in rat calf muscles.

The effect of tenotomy and of immobilisation in lengthened and shortened positions on the intramuscular connective tissue of the calf muscles of the rat was studied morphometrically and with a scanning electron microscope. Both tenotomy and immobilisation produced a marked increase in both the endomysial and the perimysial collagen networks, with a simultaneous decrease in intramuscular capillary density. The increase in connective tissue volume was more pronounced and occurred more rapidly in the soleus, which consists mainly of type I, slow-twitch fibres than in the gastrocnemius, which is mainly of type II, fast-twitch fibres. The relative volume of connective tissue increased in parallel with the duration of immobilisation or after tenotomy. There was slightly more increase after immobilisation in a shortened rather than in a lengthened position.

Animals↗
PubMed1990

Fibronectin in the ruptured human Achilles tendon and its paratenon. An immunoperoxidase study.

The purpose of the present study was to examine the role and distribution of fibronectin--a major connective tissue protein--in normal and ruptured Achilles tendon and its paratenon using peroxidase antiperoxidase (PAP) method and conventional histology. Samples were taken intraoperatively 6 to 48 hours after rupture from 30 patients, and 4 male cadavers served as controls. In controls fibronectin could not be detected in the tendinous connective tissue or in the areolar tissue of the paratenon. In the ruptured tendons fibronectin was detected around the tenocytes and in the collagen fibres in the necrotic and mucinous degenerated areas, but also in the macroscopically healthy areas of the tendon. In the oedematous paratenon vascular walls were rich in fibronectin and fat cells were outlined by fibronectin. Areas of homogenous deposition of fibronectin were also frequently seen in the paratenon. A vast amount of fibronectin was observed also at the site of rupture. The present results indicate that there are striking changes in the composition of connective tissue in degenerated tendon and paratenon. These changes seem to have increased susceptibility of the tendon to rupture.

Achilles Tendon↗
PubMed1989

Foreign bodies in tendons.

At the National Institute of Traumatology in Budapest, a search has been made for foreign bodies in tendons over the last 15 years. 53 foreign bodies have been found in 931 tendons removed at operation and 45 foreign bodies in 950 tendon samples at autopsy. The foreign material was found to be organic in 29 cases, metal in 20 cases and plastic in six cases. In the others, glass, sand, mineral grease and textiles could be detected. In 33 cases the material could not be identified. The foreign bodies were found in the tendons of the upper extremities in 51 cases and the lower extremities in 47 cases. Foreign bodies in the tendons were more likely to cause problems in the upper limbs than in the lower limbs: these problems were purulent tendonitis, necrosis, foreign body granuloma, fibrosis and peritendonitis and calcification.

Foreign Bodies↗
PubMed1989

Alterations in dry mass content of collagen fibers in degenerative tendinopathy and tendon-rupture.

The dry mass concentration and collagen fiber morphology of intact, as well as of degenerated and ruptured human Achilles, biceps brachii, extensor pollicis longus and quadriceps tendons, were determined by using the interference microscopical technique. The variation in the collagen fiber thickness was demonstrated in different intact tendons, the fibers being largest in the Achilles and smallest in the extensor pollicis longus tendons. However, the intact tendons exhibited only thick collagen fibers. In the degenerative tendinopathies an increase of the dry mass content was observed, being especially marked in calcifying tendinopathy. In the degenerated tendons the average collagen fiber diameter had decreased, and two clearly distinct populations of thick and thin fibers were observed. The dry mass content of the thick fibers was significantly greater than that of the thin fibers. The present results demonstrate striking changes in the collagen and its dry mass content in degenerative tendinopathy, thus also increasing the susceptibility to ruptures.

Collagen↗
PubMed1989

Distribution of blood groups in patients with tendon rupture. An analysis of 832 cases.

We aimed to determine the distribution of the ABO and Rh blood groups in 832 patients with a tendon rupture. Among these, the frequency of blood group O (52.8%) was significantly higher than in the general population of Hungary (31.1%) and the frequency of group A was significantly lower. Of the 83 cases of multiple ruptures or re-rupture, 57 patients (68.7%) had group O blood. The dominance of group O was found for all sites of tendon rupture, but there was no significant association with the Rh groups. Individuals with blood group O appear to have an increased risk of tendon rupture.

ABO Blood-Group System↗
PubMed1989

Fibronectin and laminin in Achilles tendon.

Ten intact and 22 ruptured Achilles tendons were studied by immunohistochemical techniques. In intact tendons, both fibronectin and laminin were found in vascular walls, myotendineal junction, and endomysium, but not in the connective tissue of the tendons. In ruptured tendons the distribution of laminin was not changed. Fibronectin deposits, on the contrary, could be detected on the tear surface and in the collagen fibers of the ruptured tendons.

Achilles Tendon↗
PubMedDate not supplied

The role of recreational sport activity in Achilles tendon rupture. A clinical, pathoanatomical, and sociological study of 292 cases.

During the last few decades, the incidence of tendon ruptures has increased in civilized countries. Our material comprises 749 patients who had 832 tendon ruptures treated surgically between 1972 and 1985. There were no competitive athletes among the patients studied. There were 292 single ruptures of the Achilles tendon, 274 of the proximal biceps brachii, 113 of the extensor pollicis longus, and 70 of other tendons. Forty-eight patients had multiple ruptures and 35 patients had reruptures. Achilles tendon ruptures often occurred in recreational sports activities (59%), in contrast to other tendon ruptures (2%; P less than 0.001). The mean age for patients who had Achilles tendon rupture was 35.2 years and for patients with other ruptures, 50.7 years (P less than 0.001). There was a connection between the high incidence of blood group O and tendon ruptures (P less than 0.001). In cases of multiple ruptures and reruptures, the frequency of blood group O was 71%. Sixty-two point three percent of the patients with Achilles tendon rupture were professionals or white collar workers, which is markedly more than in the Hungarian population (12.7%; P less than 0.001). Two hundred and six Achilles tendon ruptures were studied histologically, and all cases displayed pathological alterations. The results indicate that complete rupture of the Achilles tendon is usually a sequel to a sedentary life-style and participation in sports activities.

Achilles Tendon↗