Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TENDONS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources
PubMed2003

Spontaneous rupture of the Achilles tendon is preceded by widespread and bilateral tendon damage and ipsilateral inflammation: a clinical and histopathologic study of 60 patients.

60 consecutive patients with spontaneous rupture of the Achilles tendon (AT) underwent surgery. Biopsies were taken at the operations from the site of the rupture, the proximal part, the calcaneal insertion, and the peritendium of the injured tendon. A percutaneous needle biopsy was taken from the contralateral (uninjured) AT. On histological examination, collagen degeneration, tenocyte necrosis, and acute inflammation were found at the rupture site in all cases. In the proximal part and at the insertion, degeneration was present in 56/56 and 51/55 of the cases, necrosis in 55/56 and 50/55, and acute inflammation in 49/56 and 35/55, respectively. The severity of the histological changes decreased from the rupture site to the proximal part to the site of insertion, and showed no relation to the age of the patients or the time from the rupture to the operation. Peritendineal vascular changes were minor. In the contralateral AT, degeneration and necrosis were present in 47/50 and 42/50 of the cases, respectively, but the severity of the changes was less than in the injured tendon. Acute inflammation was present in only 1 case. Spontaneous rupture of AT seems to be preceded by widespread, bilateral damage of the tendon and widespread ipsilateral acute inflammation.

Achilles Tendon↗
PubMed2003

Antisense oligonucleotides reduce synthesis of procollagen alpha1 (V) chain in human patellar tendon fibroblasts: potential application in healing ligaments and tendons.

Many ligaments and tendons will heal after injury. However, they heal with poor mechanical properties when compared with the native tissue and show no improvement of these properties with time. Although the mechanisms that lead to this process are poorly understood, the presence of uniformly smaller collagen fibrils is believed to play a major role. Quantitatively minor when compared with type I collagen, type V collagen was found to be significantly elevated in healing medial collateral ligament of the rabbit knee. Previous studies have shown that type V collagen plays a role in regulating the diameter of type I collagen fibrils and reducing its level may lead to the formation of larger collagen fibrils in healing ligaments. Hence, type V collagen antisense gene therapy may be an approach to obtain this goal. In this study, our objective was to find specific antisense oligonucleotide sequences for type V procollagen alpha1 chain to elucidate the feasibility of type V collagen antisense gene therapy in ligaments or tendons. We hypothesized that antisense oligonucleotides that selectively target the type V procollagen alpha1 chain mRNA could partially reduce the synthesis of type V procollagen alpha1 chain in human tendon fibroblasts. Western blotting analysis showed that antisense oligonucleotides (AS-V1 and AS-V2) significantly reduced synthesis of type V procollagen alpha1 chain. In addition, reverse transcription polymerase chain reaction revealed that both antisense oligonucleotides partially reduced type V procollagen alpha1 chain mRNA expression. This experiment identified two sequences within the type V procollagen coding region that are susceptible to antisense suppression, and thus provide the basis to explore the effects of antisense oligonucleotides on type V collagen synthesis, collagen fibril diameter, and mechanical properties of healing tendons and ligaments.

Base Sequence↗
PubMedDate not supplied

Anatomical reconstruction of the patellar tendon: a new technique with hamstring tendons and iliotibial tract.

A new technique of patellar tendon reconstruction was performed in a patient who lost tendon and tibial tuberosity during wide excision surgery for a malignancy. In this procedure, the tendon was anatomically replaced by a graft composed of ipsilateral hamstring tendons and iliotibial tract, with the biomechanical conditions considered. Both ends of the graft were secured in the size-matched bone tunnels in the patella and tibia by screw post fixation, which is a technique established in ligament reconstruction surgery in the knee joint. At the twenty-month follow-up, the result was deemed successful.

Bone Neoplasms↗
PubMed1994

Effect of ageing on ultrastructure of slow and fast skeletal muscle tendon in rabbit Achilles tendons.

This reports presents the changing morphological characteristics of collagen and fibroblasts in the soleus and gastrocnemius muscle tendon of female Japanese white rabbits with ageing. The fibroblasts decreased in number per 37 microns 2 with ageing in each group, and their morphology became longer and more slender through ageing. The mean fibril area and diameter of the collagen fibrils of soleus muscle tendon (SMT) and lateral gastrocnemius muscle tendon (GMT) in 8- to 10-month old rabbits were significantly higher than those of 3-wk-old rabbits during growth (P < 0.01). The mean area and diameter of collagen fibrils of SMT and GMT decreased during senescence: the values for 4- to 5-yr-old rabbits were lower than those for 8- to 10-month-old rabbits, but the difference was not significant. Statistically significant differences in fibril area and diameter between the SMT and GMT were not found during ageing. The number of thick fibrils increased during growth, but decreased in senescence. There were more thin fibrils (30-60 nm) in the 3-wk-old rabbits than in the 8- to 10-month old and 4 to 5-yr-old groups, and the large-diameter collagen (300-360 nm) was more abundant in the 8- to 10-month-old group than in the 3-wk-old and 4- to 5-yr-old groups. Differences in fibril size between slow and fast muscle tendons were not observed during ageing.

Achilles Tendon↗
PubMed1999

Treadmill exercise-induced tendon hypertrophy: assessment of tendons with different mechanical functions.

The equine superficial digital flexor tendon (SDFT) functions as an energy store during high-speed gaits reducing the energetic cost of locomotion. To enable the SDFT to function effectively, the appropriate mechanical properties are essential. We tested the hypothesis that the SDFT does not undergo gross hypertrophy in response to high-intensity exercise whereas tendons not involved in energy storage undergo adaptive hypertrophy. Two groups (n = 6) of Thoroughbred fillies were trained at high-intensity on a high-speed equine treadmill for 5 months (short-term study) or 18 months (long-term study). Age-matched groups (n = 6) of horses undertook low-intensity exercise only for the same time period. Throughout the short-term study the SDFT and deep digital flexor tendon (DDFT) were ultrasonograpically scanned at mid-metacarpal level and cross-sectional area (CSA) calculated. At the end of the short-term study (horse age = 2 years) and long-term study (horse age = 3 years) the left SDFT, DDFT, suspensory ligament (SL) and common digital extensor tendon (CDET) were harvested and CSA calculated. Comparison of the DDFT from 2- and 3-year-old horses revealed an age-related increase in CSA which was confirmed by ultrasonographs. Post mortem analysis showed a significant hypertrophy of the CDET with high-intensity training in the short-term study (younger horses). CSA did not differ significantly between training groups for any of the structures following long-term training. These results suggest a structure specific hypertrophic response to the imposed training regime.

Animals↗
PubMed2003

Motor unit properties in the soleus muscle after its distal tendon transfer to the plantaris muscle tendon in the rat.

The aim of this study was to evaluate how a modification in the mechanical conditions under which a muscle is used could induce changes in the characteristics and the spinal drive of its motor units (MU). The distal tendon of the soleus muscle of Wistar rats was transferred to the distal stump of the plantaris muscle tendon. The EMG activity of the soleus was chronically recorded for 8 weeks, every other day, during a 1-min treadmill walk. After spinal ventral root splitting, individual MU contractile properties were measured in control soleus (102 MUs) or in transposed soleus muscles after 4 weeks (41 MUs) or 8 weeks (28 MUs). Muscle/body weight ratio did not vary after transposition, nor did MU tetanic forces. A decrease in MU twitch contraction times and in their half relaxation times was observed at weeks 4 and 8. MU tension-frequency curves varied significantly after tendon transfer, becoming closer to the curves of the fast MUs of the control group. During locomotion, we observed no change in the amplitude of rectified-filtered electromyographic activity, but a significant decrease in mean burst duration and an increase in the median frequency of the power density spectrum. Tendon transposition of the soleus muscle brought about adaptations in MU contractile properties and soleus spinal control.

Animals↗
PubMed1998

Pathology of the posterior tibial tendon in posterior tibial tendon insufficiency.

Gross and histologic examinations of 15 normal cadaver and 15 surgical posterior tibial tendons from patients with posterior tibial tendon insufficiency were performed. All surgical specimens were abnormal with enlargement distal to the medial malleolus and a dull white appearance. At histologic examination, 12 of 15 cadaver tendons displayed normal tendon structure characterized by linear orientation of collagen bundles, normal fibroblast cellularity, low vascular density, and insertional chondroid metaplasia. The surgical specimens displayed a degenerative tendinosis characterized by increased mucin content, fibroblast hypercellularity, chondroid metaplasia, and neovascularization. This resulted in marked disruption of the linear orientation of the collagen bundles.

Adult↗
PubMed2006

Synovial sarcoma of the tendon and tendon sheath in a dog.

A 19.5-year-old male mongrel dog developed a progressive lameness and swelling around the right carpus. A tumor (6 x 3 x 3 cm) was found in the caudal of distal antebrachium of the right forelimb, including tendons of the superficial digital flexor muscle and deep digital flexor muscle. No joint destruction was observed. The tumor consisted of round and spindle cells arranged in a compact sheet. There were occasional slit-like spaces or lumina, and areas rich in collagen fibers giving an appearance of tendon tissues. Neoplastic cells gave a positive immunoreaction to vimentin, but negative reactions to antibodies against S-100 protein, cytokeratin and myoglobin. Based on these findings, this tumor was diagnosed as a synovial sarcoma generating from the tendon and tendon sheath, which is very uncommon in dogs.

Animals↗
PubMed1977

The vascularization and structure of the human digital tendon sheath as related to flexor tendon function. An angiographic and histological study.

The gliding surfaces of the flexor tendons and the tendon sheath are delicate structures of the complex digital flexor system. Beside the fibrous parts, the tendon sheath also exhibits membranous synovial components, which represent a dialysing membrane producing a plasma ultrafiltrate--the synovial fluid. In this study, interest was focused on the vascularization of the synovial sheath. By a microangiographic method it was demonstrated that this membrane is richly vascularized and that the vascular plexus is in continuity on the outside of the fibrous pulleys. The friction surfaces of the system--the inside of the pulleys and the surface of the flexor tendons--are devoid of vessels, and here a differentiation into chondrocyte-like cells is observed. It is suggested that these tissue areas, in analogy to joint cartilage, are nourished by diffusion from the synovial fluid, and that the flexor system can be regarded as a specialized joint, sliding longitudinally and exhibiting an extremely large range of motion.

Angiography↗
PubMed1996

Division of flexor tendons causes progressive degradation of tendon matrix in rabbits.

Deep flexor tendons of 30 rabbits were divided at the ankle level. The effects of unloading on the synthesis and content of matrix components, the synthesis of DNA, and dry weight were investigated. The ability of the tendons to synthesize collagen during short-term culture and the contents of matrix components decreased inversely to the time of unloading. 12 weeks following division, the fibrocartilagnious segments had lost 2/5 of their dry weight, 2/3 of proteoglycan and 1/3 of collagen and non-collagen protein content. Less pronounced losses were observed in the non-fibrocartilaginous segments. A transient increase in cell proliferation in both types of segments was found. These findings indicate that divided flexor tendons undergo a progressive degradation, degradation, which may have implications for delayed suture of deep flexor tendon injuries.

Animals↗
PubMed2000

Fibroma of tendon sheath involving the patellar tendon.

Fibroma of tendon sheath is a benign soft-tissue tumor that usually arises in association with tendons or ligamentous structures. We describe, what is, to the best of our knowledge, the first reported case of fibroma of tendon sheath involving the patellar tendon.

Adult↗
PubMed1982

Giant cell tumor of tendon sheath developing at the site of tendon laceration.

A 32-year-old man suffered sharp trauma to the volar aspect of the wrist. A lacerated tendon found on exploration had been left unrepaired and the skin closed primarily. A few months later the patient presented with a nodule at the same site. Reoperation demonstrated a 2 X 1 cm nodule bridging the gap between the stumps of the previously severed palmaris longus tendon. Pathologic examination of the nodule revealed the typical microscopic appearance of giant cell tumor of tendon sheath (GCTTS) in continuity with the lacerated tendon. The literature regarding the relationship of trauma to the development of GCTTS presents interesting controversy about whether this lesion is reparative or neoplastic.

Adult↗
PubMed1980

[Studies on regeneration and adhesion of the tendon. Part 7: Influence of the vincula on regeneration of the tendon (author's transl)].

Repair of the flexor digitorum profundus (FDP) of the chicken was studied by light microscopic and microangiographic examination. The effects of altered circulation in the vincula breve were related to repair processes of tendon. Sixty young-adult chickens weighing 2 to 3 kg were used. The FDP tendons of the third toes were incised and sutured without anesthesia, then the vincula breve was cut and ligated. In the control group, no procedure was performed to the vincula breve. Samples were obtained at the fixed time intervals up to 8 weeks after the operation. For microangiography, Micropaque solution was injected into the femoral artery after perfusion of physiological saline. The amputated legs were fixed in 10% formalin, subcutaneous tissues removed, then soft X-ray examination performed using Softex-CMB. Histological specimens were stained with hematoxylin-eosin. The results were as follows: 1) In the group with ligated vincula, delay of cellular reaction in the repair process was histologically evident in the early stages. There were little granulation and proliferation of the dorsal epitenon, which formed adhesion with surrounding tissues in the later stages. 2) In the angiographic examination, the sutured site of the tendon was not avascular, and compensatory proliferation of the periosteal and capsular vessels was found around the suture although the vincula breve had been ligated. However, there was a somewhat impaired circulatory pattern in the group with ligated vincula during the early stages. Later, normalization of the circulation was delayed compared to the control samples. 3) Damage of the vincula was thought to delay regeneration in tendon injuries. Poor circulation, if present, may also influence the healing process by inducing adhesion of the surrounding tissues.

Animals↗
PubMed2006

Adult acquired flexible flatfoot, treated by calcaneocuboid distraction arthrodesis, posterior tibial tendon augmentation, and percutaneous Achilles tendon lengthening: a prospective outcome study of 20 patients.

BACKGROUND: Several methods for the treatment of acquired flexible flatfoot have been described. PATIENTS AND METHODS: We followed the outcome of calcaneocuboid distraction arthrodesis with lengthening of the lateral column prospectively in 20 patients (20 feet). The mean age of the patients was 55 (30-66) years and 16 were women. The lateral column lengthening was combined with percutaneous lengthening of the Achilles tendon and augmentation of the posterior tibial tendon in all patients. Fixed forefoot supination, hallux valgus, and/or symptomatic arthrosis, were corrected with arthrodesis of the first cuneiform-metatarsal joint (n = 8) and arthrodesis of the naviculocuneiform joint (n = 2). The Foot Function Index (FFI) and American Orthopedic Foot and Ankle Society (AOFAS) Clinical Rating Index hindfoot score (CRI) were completed preoperatively and at follow-up. Follow-up time was 25 (13-39) months. All patients were physically examined at follow-up at the outpatient clinic, and the overall satisfaction rate was registered. Standardized weight-bearing radiographs were taken preoperatively and at follow-up. The lateral and dorsoplantar talometatarsal angle was measured, together with the ground-navicular distance. RESULTS: At follow-up, 17/20 feet had complete relief of pain or only minor symptoms. The overall patient satisfaction rate was excellent or good in 15 patients and 17 patients reported an increase in daily and/or recreational activities. 3 patients complained of pain at the distraction site and/or cuboid-MT5 joint, without signs of arthrosis. All but 1 patient would have chosen to undergo the same procedure given the same circumstances. The improvement in both the FFI and CRI was statistically significant. On radiographic examination, the lateral and dorsoplantar talometatarsal angle and the ground-navicular distance improved significantly. Nonunion developed in 2 patients and united after bone grafting. 3 patients had either paresthesia or anesthesia in the distribution area of the sural nerve. INTERPRETATION: We found good short-term results after calcaneocuboid distraction arthrodesis, percutaneous tendon Achilles lengthening, and medial soft tissue augmentation for the treatment of degenerative/acquired flexible flatfoot. Pain or discomfort along the lateral aspect of the foot is the most common and worrying postoperative complaint.

Achilles Tendon↗
PubMed1975

A fine structural study of the development of the chick flexor digital tendon: a model for synovial sheathed tendon healing.

The development of the synovial sheathed flexor digital tendon in the chick was studied by light and electron microscopy in 12-day embryos to 22-day post-hatched chickens. Areas of specialized connective tissue differentiation were identified in this complex structure consisting of a lubricated synovial sheath, elastic vincula and fibrocartilaginous adaptations on the surface of the tendon. The presence of some of these specialized adaptations may be related to the specific types of mechanical forces and stresses applied to the developing connective tissue system. This model system appears to be appropriate for the experimental study of tendon injuries related to the human hand.

Animals↗
PubMed2006

Reconstruction of the superior peroneal retinaculum using an autologous gracilis tendon graft for chronic dislocation of the peroneal tendons accompanied by lateral instability of the ankle: technical note.

This is a technical note on reconstructive surgery for the combination of chronic dislocation of the peroneal tendons and lateral instability of the ankle. The traditional surgery for this condition consists of direct repairs of the lateral ligaments of the ankle and the superior peroneal retinaculum, if possible. However, repair surgery is difficult in cases with insufficient structural remnants. We describe here a technique of simultaneous reconstruction of the anterior talofibular ligament and superior peroneal retinaculum with an autologous gracilis tendon graft for the combination of chronic dislocation of the peroneal tendons and lateral instability of the ankle.

Ankle Injuries↗
PubMed1976

Experimental flexor tendon healing without adhesion formation--a new concept of tendon nutrition and intrinsic healing mechanisms. A preliminary report.

An experimental model is presented enabling an analysis of the healing process of completely cut and re-sutured free segments of rabbit flexor tendons, kept avascular in a synovial milieu and completely isolated from adhesion formation. Under these conditions the cut tendons heal within a few weeks. It can be shown that this healing process is a result of intrinsic tendon cell activity only.

Animals↗