Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CONTRACTURE”

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 325 records · Page 18Linked to original sources
PubMedDate not supplied

Differential blockade of potassium and carbachol contractures of toad isolated rectus abdominis muscle by calcium entry blockers, ketamine and hydrallazine.

Contractures of the rectus abdominis muscle of Buffo regularis evoked by carbachol were inhibited in concentration-dependent fashion by verapamil, nifedipine, hydrallazine and ketamine, whereas KCI-induced contractures were relatively resistant to blockade by these compounds. The order of potency in blocking carbachol-induced responses was: verapamil greater than nifedipine greater than hydrallazine greater than ketamine, verapamil being over 10 times more potent than nifedipine. In high K+-depolarized muscles, carbachol elicited contractural responses which were inhibited by verapamil, nifedipine, hydrallazine and ketamine; these compounds exhibited similar blocking potencies against carbachol responses in high K+-depolarized muscles as in the polarized muscles. In Ca2+-free EGTA-Ringer's solution, both KCl and carbachol contractures were abolished, but were restored on readmission of Ca2+. d-Tubocurarine competitively antagonized carbachol, but not KCl contractures. It is suggested that (i) extracellular Ca2+-influx occurs during contractures of the toad rectus abdominis muscle induced by carbachol and KCl; (ii) there probably exists more than one pathway for Ca2+-entry into this muscle--one pathway is stimulated by high K+-depolarization, and another which is linked to the activation of nicotinic cholinoceptors. Verapamil, nifedipine, hydrallazine and ketamine appear to preferentially inhibit Ca2+-influx stimulated via a pathway linked to nicotinic cholinoceptors.

Animals↗
PubMed1985

The etiology of arthrogryposis (multiple congenital contracture).

In laboratory animals, prenatal contractures have been induced by viruses, neuromuscular blocking agents, toxins, insecticides, hyperthermia, and limb immobilization. In agricultural animals, prenatal contractures are related to pregnant animals foraging on plants containing toxic alkaloids. Epizootics of prenatal contractures in cattle have been related to Akabane viral infections, which can now be prevented by vaccination. Human arthrogryposis (multiple congenital contracture) may occur in any synovial joint in a large variety of combinations. Several lethal syndromes commonly associated with prenatal contractures (Pena Shokeir 1 and 11, Potter's) provide supportive evidence for the following concept of prenatal contracture etiology. Evidence is provided that indicates that the following multiple etiologic factors are related to production of human arthrogryposis: mutagenic agents, mitotic abnormalities, toxic chemicals or drugs, hyperthermia, neuromuscular blocking agents, and mechanical immobilization. These multiple factors mediate their effect via the central nervous system (craniospinal motor neuraxis), motor end-plates, or by primary degeneration of muscle. The resultant effect is loss of muscle mass with imbalance of muscle power at the joints, which provokes a collagenic response (Law of the Connective Tissue). The collagenic response consists of partial replacement of muscle volume and collagenous thickening of the joint capsules. The latter process leads to joint fixation.

Abnormalities, Drug-Induced↗
PubMed1985

Inhibition of potassium-induced contracture of the isolated rat aorta by amiloride.

Potassium contractures of helically cut strips of rat aorta were recorded isometrically. Contractures induced by KCl 40 mmol/l were decreased dose-dependently by amiloride (1.7 X 10(-5) to 1.4 X 10(-4) mol/l) added to the bath 10 min before the depolarization. Ouabain (10(-3) mol/l) antagonized this effect. Contractures induced by using, instead of normal Krebs solution, a solution in which potassium was replaced by sodium (Krebs potassium) were also decreased dose-dependently by amiloride, but the slope of the linear log dose-effect curve line was steeper. When arteries were incubated in a solution deprived of sodium and calcium (isotonicity maintained by choline), the intensity of consecutive contractures by Krebs potassium decreased progressively. Incubation in a normal Krebs solution restored the normal contractures; amiloride added at the same time prevented this restoration. These findings are in agreement with the assumption that sodium-calcium exchange plays an important part in the contracture of vascular smooth muscles.

Amiloride↗
PubMed1982

Effects of hypertonicity on frog muscle contractures induced by quinine.

1. Frog sartorius and extensor longus digiti ("toe") muscles were used to investigate the effects of solutions of two (2T) and three (3T) times normal tonicity on the contractures elicited by quinine or by high-[K]O media, and on twitch and tetanic tension. 2. Solution 2T had no effect on the peak amplitude of quinine-induced contractures (PQ) of toe muscle but increased the PQ of sartorius muscle. Toe muscle PQ was significantly reduced by 3T. The quinine-induced contractures of sartorii bathed in 3T were slower than, but reached peak values not significantly different from, those obtained with control Ringer solution (1T). 3. The twitch and tetanic contractions of both sartorius and toe muscles were partially or totally blocked by 2T and were always abolished by solution 3T. 4. The maximal amplitude of K+-induced contractures (PK) of toe muscle was significantly reduced, but not abolished, by solutions 2T and 3T. The PK of sartorius muscle was greater at 2T than at 1T, but, in contrast to the transient tension recorded for 1T, the K+-induced contracture in solution 2T had a prolonged plateau. 5. The results suggest that hypertonicity affects the contractile apparatus as well as the excitation-contraction coupling process. The enhancement of quinine- and K+-induced contractures is ascribed to inhibitory effects of hypertonicity on Ca2+-sequestration by the sarcoplasmic reticulum.

Action Potentials↗
PubMed1980

[Effect of homologous n-alkanoic acids on the function of isolated skeletal muscles. V. Relations between twitch, tetanus and contracture].

Twitch, tetanus, and contractures induced by potassium ions (K+) or caffeine were investigated on isolated bundles of frog muscles. Using supramaximal stimuli the twitch amplitude amounts to about 50% of the tetanic tension (22 degrees C). Usually the contracture in 190 mM K+ is smaller than the tetanic tension, in 20 mM caffeine the contracture maximum corresponds to the tetanus amplitude. All of the mechanical answers are diminished if the fibres were bathed in solutions containing 2.5 to 10 mM Na-octanoate or 0.5 mM decanoic acid. Twitch and tetanic tensions decrease nearly in the same degree. A sequence of tetanic stimulations in a distance of 2 s induces a depression of the amplitudes. Fatty acids increase this depression and delay restoration between the series. Contractures in 190 mM K+ are diminished by a preceding bath in 10 mM Na-octanoate. Contractures with submaximum concentrations of K+ were decreased by lower concentrations of octanoate. The caffeine induced contractures are delayed by fatty acids, but the maximum tension is not reduced. It is supposed that the mobilisation of calcium ions is alterated by fatty acids. The decreasing effect of fatty acids on the mechanical activity, induced by different ways of the muscles' stimulation suggests that the main action may take place in the process of mechanical coupling, probably during the activation of calcium ions.

Animals↗
PubMed1964

SELECTIVE INHIBITION OF POTASSIUM CONTRACTURE IN PRESENCE OF INTACT TWITCH.

If a sartorius muscle of frog is pretreated for 30 min. with a hyposmotic Ringer's (called "hyposmotic potassium chloride") in which all sodium chloride is replaced by 23 mM potassium chloride, and then is immersed in normal Ringer's for about 40 min., a twitch of normal size can be elicited although the potassium contracture is almost completely abolished. During the time that this selective inhibition of potassium contracture occurs, the action potential and both the size and the speed of depolarization due to potassium are almost the same as in a control muscle that is pretreated for 30 min. with 23 mM potassium chloride under isosmotic conditions and that can give a normal potassium contracture. If a muscle is pretreated not with hyposmotic potassium chloride but with a hyposmotic Ringer's in which the concentration of sodium chloride is reduced to 22 mM, the evoked potassium contracture is inhibited, but to a much smaller degree. The partial replacement of chloride by nitrate in hyposmotic potassium chloride has no influence on the degree of the selective inhibition. If after the pretreatment with hyposmotic potassium chloride the muscle is left in normal Ringer's for about 3 hours, there is considerable recovery of ability to undergo contracture. The mechanism of the selective inhibition is briefly discussed.

Animals↗
PubMed1989

Limited joint mobility, Dupuytren's contracture and retinopathy in type 1 diabetes: association with cigarette smoking.

To examine the associations between cigarette smoking, connective tissue changes, and diabetic retinopathy, a detailed smoking history was elicited from 150 normotensive non-diabetic subjects, and from 266 randomly selected adult patients with Type 1 diabetes, after examination for limited joint mobility, Dupuytren's contracture, and diabetic retinopathy. Mean insulin dose and current glycosylated haemoglobin concentrations were comparable in diabetic smokers and non-smokers. The historical duration of smoking correlated with the duration of diabetes (r = 0.72, p less than 0.001). In diabetic patients limited joint mobility was positively associated with retinopathy, being found in 73/147 (50%) patients with retinopathy compared with 20/114 (18%) without retinopathy (chi 2 = 28.9, p less than 0.001), and also with Dupuytren's contracture, 19/34 (56%) of patients with limited joint mobility having Dupuytren's contracture, compared with 76/232 (33%) of patients without Dupuytren's contracture (chi 2 = 7.05, p less than 0.01). Limited joint mobility was observed in 50% of diabetic smokers compared with 25% of non-smokers (odds ratio = 2.87 (corrected for diabetes duration), 95% confidence interval 1.64-5.01). Diabetic retinopathy was weakly associated with smoking (odds ratio 1.09; 95% confidence interval 0.60-1.96). There was however an increased prevalence of background retinopathy among male smokers (50% vs 29%; chi 2 = 6.88, p less than 0.01). In non-diabetic males limited joint mobility was observed in 37% of smokers but only in 11% of non-smokers (NS), while 33% of smokers and 8% of non-smokers had Dupuytren's contracture (p = 0.012). These results suggest that cigarette smoking contributes to the development of extra-articular connective tissue changes in both diabetic patients and non-diabetic subjects, and possibly to the development of diabetic retinopathy.

Adult↗
PubMed2005

A classification system for postburn mentosternal contractures.

HYPOTHESIS: Postburn mentosternal contractures can be clinically classified into 4 major groups based on the location of the contracting band(s) and extent of flexion or extension away from the anatomical position of the neck and jaws. Each group can be further subclassified depending on the width of the contracting segment(s) and availability of surrounding supple skin. DESIGN: Case series. SETTING: Nigerian subregional apex hospital specializing in plastic surgery, orthopedic surgery, and traumatology. PATIENTS: A consecutive sample of 41 patients with postburn mentosternal contractures who underwent surgery between 1997 and 2002 and 4 patients who had not yet had surgery, seen between January and March 2003. Data were obtained from operative records, photographic records, and interview of teams who treated the patients. During data collection, a classification system was devised in which mild, moderate, and severe anteriorly located contractures were designated types 1, 2, and 3, and posteriorly located contractures were considered type 4. Subtypes a through d were included to denote characteristics affecting reconstruction. RESULTS: The classification system was successfully used to classify postburn mentosternal contractures as a guide to management. Sufficient data were available to classify 32 of the 45 patients. The observers were not blinded. CONCLUSION: The classification system is useful in describing severity and guiding reconstructive options, but further study is required before it is used in choice of airway management for anesthesia.

Burns↗
PubMed1988

The diagnostic management of newborns with congenital contractures: a nosologic study of 75 cases.

A prospective clinical study is presented of 75 patients with multiple congenital contractures. With the data from medical history, child neurologic examinations, laboratory tests including chromosome and dermatoglyphic analysis, and neuropathology in 23 cases with perinatal death, a nosological or syndromal diagnosis was made in 61 cases. These cases were classified by localization of causal pathology in the categories "cerebral dysgenesis", spinal cord defects, neuromuscular disorders and miscellaneous disorders without muscle weakness. Following this concept, the various modes of inheritance of specific disorders presenting with congenital contractures, as well as possibilities for prenatal diagnosis by ultrasonography are discussed. A guideline for the child neurologic evaluation of infants with congenital contractures is proposed. It is concluded that: 1) specification of the causal lesion and proper classification of disorders with congenital contractures is crucial for genetic counseling, (prenatal) diagnosis and management; 2) the analysis of dermatoglyphics in differential diagnosis of congenital contractures should be restudied; and 3) more study and experience is required in the observation of abnormal or decreased fetal movements by ultrasonography.

Brain↗
PubMedDate not supplied

MR assessment of posttraumatic flexion contracture of the elbow.

Preoperative assessment of posttraumatic flexion contracture of the elbow includes plain radiographs and tomograms, which are difficult to obtain in the coronal plane due to the contracture. We conducted this study to determine the usefulness of MR imaging in the work-up of these patients. Twelve patients with flexion contracture of the elbow were studied. In addition to standard spin-echo sequences, a sagittally acquired spoiled gradient-recalled echo 3D data set of the flexed elbow was obtained and reformatted coronally using a curved plane of reconstruction. The MR findings were compared to the plain films, tomograms and surgical results. MRI allowed identification of loose bodies that were sometimes poorly visualized, or not seen, on plain films, and demonstrated degenerative changes equally as well as tomograms. MR showed soft tissue abnormalities including capsular and collateral ligament thickening. Curvilinear reconstructions were helpful in the assessment of collateral ligaments in patients with severe contractures. We conclude that MR is useful in the evaluation of elbow flexion contractures, particularly in assessing soft tissue causes.

Adult↗
PubMed1989

Effects of electrical stimulation on joint contracture in a rat model.

This study was intended to delineate whether electrical stimulation could significantly reduce the amount of joint contracture in a rat model. Rat knees were surgically immobilized in 150 degrees of flexion. Two groups of rats had sham electrodes, and two groups were electrically stimulated. All rats were killed 14 days after surgery. The degree of joint contracture was assessed by measuring the femorotibial angles with a 0.015-Nm extension moment applied. When the electrical current was applied in a transverse manner, there was a statistically significant reduction in the amount of posterior capsule (p less than 0.005) and anterior cruciate ligament (ACL) (p less than 0.05) contracture. When the electrical current was applied longitudinally, no significant difference in the amount of joint contracture was found. These findings support the hypothesis that electrical stimulation can inhibit joint contracture. These findings also suggest that the effect occurs when the electrical current is applied transversely as opposed to longitudinally.

Animals↗
PubMed1995

Effect of cocaine on the contracture response to 1% halothane in patients undergoing diagnostic muscle biopsy for malignant hyperthermia.

Two case reports have cited the recreational use of cocaine as possible trigger of a malignant hyperthermia (MH) crisis. We evaluated whether toxic concentrations of cocaine altered the in vitro muscle response to halothane during contracture tests for MH. Twenty-two patients were studied. Muscle biopsies were obtained and first tested for MH susceptibility with 3% halothane and caffeine contracture testing. Ten patients were diagnosed as MH-susceptible and 12 as MH non-susceptible, in accordance with the North American Malignant Hyperthermia Group protocol. Then, muscle strips were exposed to 1% halothane in the presence and absence of 0.1 mmol.L-1 cocaine. Cocaine alone did not affect baseline muscle tension in either group. With 1% halothane, MH non-susceptible muscle showed no contracture with or without cocaine. In contrast, in the presence of 1% halothane, MH-susceptible muscle showed either no change in contracture (six patients), an increase (two patients), or a decrease (two patients) when exposed to cocaine. However, the overall effect of cocaine on muscle contracture in the presence of 1% halothane was insignificant in both groups. We conclude that cocaine, even at toxic levels, does not have a direct effect on skeletal muscle contractility and thus is safe for MH-susceptible patients.

Adult↗
PubMed2003

Congenital contracture of the quadriceps muscle: a case report with magnetic resonance imaging.

INTRODUCTION: Case report of a rare form of congenital contracture of the quadriceps muscle. Congenital contracture of the quadriceps muscle is encountered very rarely in daily orthopaedic practice. A few cases have been reported, but unfortunately these did not detail the MRI findings of congenital contracture. MATERIALS AND METHODS: A 34-year-old woman presented with difficulty in sitting with full flexion of the bilateral knee joints. She had no history of intramuscular injection, and her brother had a similar abnormality. A physical and radiographical review of the case was conducted. RESULTS: A palpable corded induration was detected in the quadriceps muscle which prevented further flexion of the bilateral knee joints. Magnetic resonance imaging of both thighs demonstrated marked atrophy of the rectus femoris muscle and dark signal intensity of the muscle on both T1-weighted and T2-weighted images. It was suggested that the muscles had been replaced by fibrosis. CONCLUSION: This appears to be the first report to include MRI findings of congenital contracture. Clinical awareness of congenital contracture with unique clinical symptoms and radiographic findings may aid the correct diagnosis.

Adult↗
PubMed1999

Limb contractures in levodopa-responsive parkinsonism: a clinical and investigational study of seven new cases.

We describe six patients with classical levodopa-responsive Parkinson's disease (PD) and one case of levodopa-responsive familial juvenile dystonia-parkinsonism with fixed contractures of the hands, feet or legs. In most patients contractures became established over a short period (2 months-2 years) but a considerable time after onset of parkinsonism (mean 13 years). Mean disease duration was 17 years, and all patients had severe levodopa-induced dyskinesias, either biphasic or peak dose, in the affected limb prior to onset of the contracture. Nerve conduction studies excluded peripheral ulnar nerve lesions in all patients with one exception, who was found to have a mild bilateral ulnar entrapment neuropathy. Transcranial magnetic stimulation performed in five of the seven patients showed shorter mean central motor conduction time in the affected than in the unaffected limb. Results of magnetic resonance imaging of the brain performed in a subgroup of patients were normal, with no evidence to suggest multiple system atrophy, cerebral infarction or focal abnormalities of the basal ganglia. We conclude that hand and feet contractures are not necessarily restricted to parkinson plus syndromes and may complicate otherwise typical PD in the absence of a structural or peripheral nervous cause. Striatal dopaminergic deficiency, particularly long-standing, may have a role in the pathogenesis of limb contractures in PD.

Adult↗
PubMed2000

Rapid cooling-induced contractures in rat skinned skeletal muscle fibres originate from sarcoplasmic reticulum Ca2+ release through ryanodine and inositol trisphosphate receptors.

Previous reports have shown that cooling striated muscles induces contractile responses that are related to Ca2+ release from the sarcoplasmic reticulum. However, the effect of cooling has generally been studied in the presence of pharmacological agents that potentiate rapid cooling-induced contractures. The present study shows that in saponin-skinned rat skeletal muscle preparations, a drop in temperature from 22 degrees C to 2 degrees C per se induces a contracture which relaxes on return to 22 degrees C. In fast-twitch fibres, rapid cooling-induced contractures are fully blocked by ryanodine, an inhibitor of ryanodine receptors. By contrast, in slow-twitch fibres, ryanodine partially inhibits the rapid cooling-induced contractile response, leaving a residual tension that dissipates after application of inositol 1,4,5-trisphosphate (InsP3). At low concentrations, heparin, an inhibitor of InsP3 receptors, decreases rapid cooling-induced contractures in both types of muscle. The present results suggest that in skeletal muscle, rapid cooling-induced contractures are due to both ryanodine-sensitive and InsP3-sensitive Ca2+ release from the sarcoplasmic reticulum.

Animals↗
PubMed1983

A bipedicle flap in the correction of burn contractures.

The principle of the bipedicle flap has been employed in the correction of contractures using some of the skin and scar at the site of the contracture. The contracture is released by making two parallel transverse incisions one above and the other below outlining a bipedicle flap at the level of the joint crease. The scar above and below this transverse pedicle is excised to release the contracture and the raw areas are skin grafted. This manoeuvre combines the advantages of a flap (in the critical area) with those of skin grafting. With proper care and planning the "flap" invariably survives. It has been employed in the release of 38 contractures of various joints.

Adolescent↗
PubMed1989

Capsular contracture after breast reconstruction with tissue expansion.

Tissue expansion before placement of an implant for breast reconstruction is said to lessen the chance of capsular contracture. Forty-nine patients who had undergone post-mastectomy breast reconstruction using tissue expansion were reviewed. Capsular contracture was assessed using the Baker scale and compared with the speed of expansion, the degree of over-expansion and the interval between full expansion and placement of the definitive prosthesis. The overall incidence of capsular contracture (Baker III or worse) was 29%. Only one patient, however, has required capsulotomy for capsular contracture alone. Neither the speed of expansion nor the degree of over-expansion influenced the onset of contracture. Those patients with breasts assessed in Baker group I had a significantly longer interval between full expansion and reconstruction than those in Baker group III (p = 0.05). A modification of Baker's scale is suggested for the assessment of reconstructed breasts. Prospective studies are required to define the optimum timing for tissue expansion procedures.

Adult↗
PubMed2005

Treatment of axillary burn scar contracture using opposite running Y-V-plasty.

Burn scar contractures are frequently observed following full-thickness burns of the axillary area. Such contractures are traditionally reconstructed sometime within the first year after injury with therapeutic methods including skin grafting, Z-plasty, local/regional flap, island flap, perforator flap, free flap or combination thereof. Flap methods have many advantages over split skin grafting, including less likelihood of recurrence of contracture as well as making prolonged splinting unnecessary. However these flaps are cumbersome, unattractive, and apparently distort the axillary hair. Moreover, they have a risk of flap necrosis or marginal vascular compromise. A new opposite running Y-V-plasty presented here is designed to overcome those dilemmas. This procedure was performed in eight cases with good functional recovery and cosmetic appearance. It is also a simple, adaptable, and reliable method. The range of motion of shoulder joint was also satisfactorily achieved since axillary contracture scars were almost completely released. Most of all the procedure can be repeated if the release is not enough. In short, the opposite running Y-V-plasty is a good alternative method when we consider the reconstruction of axillary burn contracture.

Adolescent↗