Contracture Bands Research Articles

Biomechanical properties of normal tendons, normal palmar aponeuroses, and tissues from patients with Dupuytren's disease subjected to elastase and chondroitinase treatment

Normal tendons, normal palmar aponeuroses and palmar aponeuroses from patients with Dupuytren's disease were subjected to elastase or chondroitinase treatment. Young's modulus was derived from the linear portion of stress-strain graph. It showed the lowest value for the apparently normal palmar aponeuroses and the highest value for tendon samples. Elastase treatment caused an increase of extensibility and a reduction of Young's modulus of normal palmar aponeuroses and tendons, but not of contracture bands. In normal tendons, normal palmar aponeuroses and apparently normal palmar aponeuroses residual strain and hysteresis loop increased significantly as a linear function of the amount of digested elastin. In contrast these biomechanical parameters were not affected significantly in contracture bands. In normal and apparently normal areas incubation with chondroitinase ABC resulted in a significant increase of residual strain and, as opposed to elastase, a decrease of normalized hysteresis loop. In contracture bands, however, these biomechanical parameters remained unchanged.

Halothane Protects the Isolated Rat Myocardium Against Excessive Total Intracellular Calcium and Structural Damage During Ischemia and Reperfusion

A recent study from our laboratory demonstrated halothane to be a powerful protectant of the isolated rat heart during reperfusion after normothermic cardioplegic arrest. It was speculated that this protective effect might be due to prevention of excessive intracellular calcium. The aim of the present study was to evaluate the effect of halothane on the total intracellular calcium (Ca2+) content and on myocardial structure both at the end of normothermic cardioplegic arrest and at the end of reperfusion. Isolated perfused rat hearts were perfused for a control period of 30 min, followed by 40 min of normothermic cardioplegic arrest with or without reperfusion for 30 min. Halothane (1.5%) was administered continuously before and after arrest. Halothane caused a significant decrease of intracellular Ca2+ at the end of normothermic cardioplegic arrest and after reperfusion. Myocardial morphology was assessed by extensive light microscopy and ultrastructure was evaluated by electron microscopy. Grading of ischemic damage showed that exposure to normothermic cardioplegia resulted in marked ischemic injury, regardless of whether the hearts were treated with halothane. Reperfusion in the presence of halothane caused a significant reversal of ischemic damage and almost complete ultrastructural repair, whereas untreated hearts still exhibited severe edema, contracture, and contracture bands. Our results indicate that the beneficial effects of halothane on myocardial structural recovery during reperfusion is associated with a reduction in excessive intracellular Ca2+. The exact mechanism of this protective action is under investigation.

Paired Five-Flap Z-Plasty

Web-like contractures may occur along both the outer borders of joints, creating double-parallel contracture bands that turn into webs during movements. A combination of two "five-flap z-plasties" lying in confrontation to each other was used to release such contractures. The two Vs face each other and meet at their upper ends, forming a rhomboid (Fig. 1, a and b) or hexagon (Fig. 1, c and d) whose position remains unchanged after the contractures have been released and all the flaps transferred or advanced. This method has been used to release a total of seven double-parallel web-like linear contractures with very satisfactory results. Paired five-flap z-plasty seems to be superior when release of double web-like contractures, with the presence of sufficient spared skin, is contemplated.

Historical notes on the use of pressure in the treatment of hypertrophic scars or keloids

Despite the frequent description of skin diseases that can be found in the ancient literature, those describing deforming scars and contractures did not begin to appear in the medical literature until the works of Pare in the sixteenth century (Johnson, 1678). This lack of early information on abnormal scarring might be a consequence of short or inadequate descriptions, or the terminology used by the fathers of medicine may not be comprehended in terms of contemporary discussions of these entities (Banejee and Dutta, 1968). Among the cases described in the Smith Papyrus (Breasted, x930), case number 45 describes the ‘existence of swelling on his breast, large, spreading, and hard. Touching them is like touching a ball of wrappings’ which may have been the description of hypertrophic healing. Literature from the Yoruba people, around the tenth century and beyond, indicates that the Yorubas not only knew about keloids but understood some of the specifics of their character and presentation (Omo-Dare, 1973). The first full medical description, however, was probably the reference by Retz (1790) in his book Treatise on Skin Diseases ad Things of the Mind, to a ‘dartre de graisse’ (fatty hernia) where he describes the case of a woman with hypertrophic scars and a thick contracture band on her left arm. But it was Alibert (1806, 1816, 1817) who gave the name of ‘Cancroid’, ‘Cheloide’ or ‘Keloide’ to these lesions. Also Alibert introduced the differentiation between keloids arising spontaneously (true keloids) and those arising after trauma (false keloids). This differentiation lead to the controversy about keloids and hypertrophic scars that still continues, almost 200 years later. Currently, a general agreement exists that both keloids and hypertrophic scars originate from a previous lesion of the skin. However, we support the concept that keloids are morbid variations of hypertrophic scars and that they constitute similar abnormalities within the spectrum of human wound healing and scar maturation. In our opinion, the differences are only quantitative, with keloids representing the most severe degree of hypertrophic scarring (Linares, 1988). For the purpose of this paper, the words keloid, hypertrophic scar, or hypertrophic keloid scar will be used without distinction. To our knowledge, the first medical reference to the use of pressure upon deforming scars and contractures appeared in

Effect of electrical stunning or sticking without stunning on the microstructure of zousoon, a Chinese semi-dry pork product

The microstructure of muscle fibers from pigs killed following electrical stunning was compared to that from pigs killed after tying-resting and sticking. Examination of the muscle fibers demonstrated that electrical stunning resulted in contracture bands that caused tearing and fragmentation of the myofibers/myofibrils. On the other hand, tying-resting and sticking was not accompanied by microstructural fragmentation of the muscle fibers. Results indicate that electrical stunning of hogs causes fragmentation and breakage of the muscle fibers so that the meat is not suitable for production of Zousoon—a semi-dry shredded Chinese pork product and other similar items prepared from prerigor pig muscle. Heating and drying intensify the deteachment of the myofibrils from the muscle fiber bundles, which is caused mainly by electrical stunning or stimulation and improper conditioning following slaughter. The combined effects of electrical stunning and heating—drying appear to be responsible for the fragmentation of the muscle fibers/myofibrils and contribute to the unsuitability of prerigor muscle from electrically stunned pigs for use in the production of Zousoon. Since sticking of pigs without stunning does not meet humane slaughter standards, alternative animal welfare slaughter procedures should be examined from the standpoint of their usefulness in producing Zousoon.

Surgical correction of burn scar contractures of the foot in children

The results of reconstructive procedures for the treatment of burn scar contractures of the feet in 55 children undergoing 90 operations were reviewed. The patients were treated in all but one case by release of the contracture band with placement of a skin graft in the resulting defect. There was an overall recurrence rate of 15 per cent that was not affected by the use of split-thickness versus full-thickness grafts. The time delay from the thermal injury to the reconstructive procedure was also found not to affect the outcome. Postoperative immobilization by the use of either a dynamic or an adynamic splint was found to be important both for preventing graft loss and for decreasing the rate of contracture recurrence.

A functional and ultrastructural analysis of experimental diabetic rat myocardium. Manifestation of a cardiomyopathy.

The effects of experimental diabetes on cardiac function and ultrastructure were studied in rats that had been diabetic for 6-24 wk. Experimental diabetes was produced by the intravenous (i.v.) injection of 65 mg/kg streptozocin (STZ) into rats 42-43 days old. Diabetic rat hearts perfused at 15 cm H2O on the working heart apparatus demonstrated depressed cardiac function (i.e., lower left ventricular pressure and +/- dP/dt) at 6, 12, and 24 wk of diabetes. Electron microscopic analysis of ventricular myocardium revealed increased lipid deposition from 6 to 24 wk of diabetes and progressive deterioration of the myocardial cell integrity at 12 and 24 wk of diabetes. This deterioration was characterized by loss of contractile protein, vacuolization (swollen sarcoplasmic reticulum), myelin formations, myocytolysis, and contracture bands. These alterations paralleled the depression of cardiac function at 12 and 24 wk of diabetes. There was, however, depressed function at 6 wk of diabetes but no observable alterations in myocardial ultrastructure. Therefore, experimental diabetes produced ultrastructural alterations in the rat heart that manifested themselves only after a demonstrable depression in cardiac function.

Structural Changes in Beef Longissimus dorsi Induced by Postmortem Low Voltage Electrical Stimulation

ABSTRACTAdvanced myofibrillar degeneration with changes of I‐bands and Z‐discs was noted in electrically stimulated samples as early as the day of slaughter. Occurrence of the proteolytic changes observed paralleled rate of depletion of muscle energy stores during electrical stimulation and subsequent improvements in tenderness. Localized supercontractions have been implicated as one cause of improved tenderness of electrically stimulated bovine carcasses, as has enhancement of autolytic proteolysis. Contracture bands occurred in both nonstimulated and electrically stimulated samples in the early postmortem period. Contracture bands are a common artefact in improperly prepared tissue preparations, therefore they are not a specific effect of electrical stimulation. Improved tenderness of ES samples could more easily be explained by an accelerated autolytic proteolysis.

Brief or new: measuring cone for thumb abduction/extension.

Contracture bands and adduc­ tion deformities in the first web space of the burn injured hand are not always preventable. Burned hands often require re­ construction procedures to deep­ en and increase the breadth of the first web space and to im­ prove hand function and grasp. It is important to record joint motion of the thumb both before and

Dupuytren's Contracture and Microvessels

Dupuytren's Contracture is a nodular proliferation of the longitudinal fiber bundles of palmar fascia with its attendant contraction. The factors attributed to its etiology have included trauma, diabetes, alcoholism, arthritis, and auto-immune disease. The tissue has been observed by electron microscopy and found to contain myofibroblasts.Dupuytren's Contracture constitutes a scar, and as such, excessive collagen can be observed, along with an active form of fibroblast.Previous studies of the hypertrophic scar have led us to propose that integral in the initiation and sustenance of scar tissue is a profusion of microvascular regeneration, much of which becomes and remains occluded producing a hypoxia which stimulates fibroblast synthesis. Thus, when considering a study of Dupuytren's Contracture, we predicted finding occluded microvessels at or near the fascial scarring focus.Three cases of Dupuytren's Contracture yielded similar specimens, which were fixed in Karnovskys fluid for 2 to 20 days. Upon removal of the contracture bands care was taken to include the contiguous fatty and areolar tissue which contain the vascular supply and to identify the junctional area between old and new fascia.

Electrical Stimulation of Intact or Split Steer or Cow Carcasses

Fifteen carcasses, 10 from steers and 5 from cows, were used for the present study. Five steer carcasses (group A) were electrically stimulated as intact, unsplit carcasses. The left sides of 5 steer carcasses (group B) and of 5 cow carcasses (group C) were electrically stimulated; the right sides of the same 5 steer carcasses (group D) and of the same 5 cow carcasses (group E) were used as controls and were not electrically stimulated. Electrically stimulated carcasses and sides (groups A and B) had brighter, more youthful colored lean, less “heat-ring” and produced more tender and more palatable rib steaks than did control sides (group D). Electrical stimulation did not (P > .05) affect ultimate pH or sarcomere length in steers or cows. Light and electron micrographs revealed increased (P < .05) structural damage (more severe contracture bands) in steer or cow muscles from electrically stimulated sides than in muscles from control sides; however, structural damage was not (P >.05) increased when intact steer carcasses were electrically stimulated and compared to unstimulated sides. Troponin-T was reduced in SDS gels of muscle from electrically stimulated, as compared to control, sides of cow carcasses (group C versus group E); no differences in percentage of protein subunits were observed between electrically stimulated and control sides of steer carcasses (group B versus group D). Electrical stimulation can be done on intact carcasses or sides of young beef to improve USDA lean maturity and lean color scores, to reduce “heat-ring” incidence and to improve tenderness.

STRUCTURAL CHANGES IN ELECTRICALLY STIMULATED BEEF MUSCLE

ABSTRACTThe right sides of five steers were electrically stimulated with 50 impulses of 0.5‐1.0 set duration, 100 volts (machine setting), 5 amps, 50‐60 cycles per set, producing an approximate 440 volt potential difference between electrodes; the left sides were used as untreated controls. Longissimus muscle samples were removed 20‐24 hr postmortem from both sides of each carcass for palatability, cookery and sarcomere length determination as well as for light and electron microscopy. Steaks from electrically stimulated sides were less juicy, more tender and more flavorful, had less organoleptically detectable connective tissue and lower shear force values, and sustained greater cooking losses than did samples from control sides. Mean sarcomere length did not differ significantly between control and electrically stimulated samples. Light micrographs of electrically stimulated samples revealed contracture bands throughout the myofibers along with stretched areas on either side of the contracture bands. Electron micrographs also showed contracture bands along with physical disruption of the myofibrils on either side of the bands. These data suggest that electrical stimulation (performed in the manner described here) may improve tenderness by physical disruption and the formation of contracture bands and not by prevention of cold shortening.

Localization by autoradiography of tritiated isoproterenol in “infarct-like lesions of rat myocardium

A number of physiopathogenic mechanisms have been outlined to explain the "infarct-like" lesions produced by isoproterenol (ISP) in the hearts of various animals: Excess of oxygen consumption and inotropic effect, coronary vasoconstriction, deleterious action on glucose and lipid metabolism, direct cardiotoxic effect, platelet aggregation in the small cardiac vessels and formation of microclots, excessive mobilization of fatty acids, fluid and electrolytic imbalances, loss of high-energy intracellular coupling, and inadequate activation of the "calcium pump." For this reason, localization of the tritiated ISP in the normal myocardial fibers and in the induced lesions was studied. The first control group (G-1), consisted of 40 Wistar rats, weighing from 180 to 200 grams; they were injected intraperitoneally with ISP sulfate (10 mg. per kilogram) and were killed under ether anesthesia after periods of 5, 30, and 120 minutes, and 12 and 24 hours. A similar group (G-2) was injected intraperitoneally with an equal dose of ISP plus 5 muCi of tritiated ISP sulfate (3H). In this group animals were killed at the same periods as above. In rats treated with ISP-3H an abundant amount of the labeled drug was observed on the sarcolemma surface and a smaller quantity was noted inside the myocardial fibers. This observation was noted in the autoradiographs obtained 5 minutes after the injection and persisted in all subsequent observation times. In those animals which were killed 5 and 30 minutes after injection, the deposit was noted in "grooves" along the edge of the sarcolemma, strongly suggesting a primary action on the cellular membrane. These findings and the peculiar topography suggest that (1) myocardial necrosis induced by ISP is probably due to an increased activation of the "calcium pump"; the early presence of contracture bands and the positivity of the ischemia test further emphasize this statement; (2) the ISP effect is rapid; (3) the morphologic alterations are similar to those recently described as "coagulation myocytolysis" and present in human infarctions or following sudden death.

The effect of a cardiotoxic component of the venom of the Indian cobra ( Naja nigricollis) on the subcellular structure and function of heart muscle

The effect of the purified cardiotoxic component of the venom from the Indian cobra snake ( Naja nigricollis) on the subcellular function and structure of heart muscle cells was investigated. The concentration of toxin used ranged between 10 and 50 μg/ml. When added to microsomal fractions rich in sarcoplasmic reticulum 10 to 50 μg toxin/ml interfered with ability of these fractions to accumulate Ca 2+ from an oxalatecontaining reaction mixture. This effect was accompanied by an inhibition of the Ca 2+-activated ATPase enzyme. Ten, 25 and 50 μg toxin/ml caused the microsomes to release their previously bound Ca 2+ at a relatively rapid rate, and accelerated the onset of this release process. Ten μg toxin/ml reduced the ability of isolated mitochondria to accumulate Ca 2+ by approximately 50%; the ability of isolated fragments of the plasma membrane to accumulate Ca 2+ was also reduced but to a lesser extent. When added to either isolated papillary muscle immersed in Krebs-Henseleit solution or Langendorff-perfused hearts the cardiotoxin caused extensive ultrastructural damage. The plasma membranes were disrupted and particulate matter appeared in the extracellular space. The mitochondria were damaged and contracture bands developed.

Alterations in the Contracture Band Patterns of Unfrozen and Prerigor Frozen Ovine Muscle Due to Variations in Post‐Mortem Incubation Temperature

SUMMARYSamples of unfrozen and prerigor frozen ovine semitendinosus muscle were incubated for 24 hr post‐mortem at six temperature levels between 0 and 4O°C. Examination of electron‐micrographs showed that variations in temperature caused muscle fibers to be in various states of contraction. The variations in sarco‐mere length of unfrozen and prerigor muscle did not follow any specific course in relation to temperature. All the observed transverse striations were definable components of the sarcomere.Prerigor frozen muscle incubated at 30 and 40°C showed severe disruption of the Z lines. However, Z‐line material was observed to be present in a disoriented state. H zones and M lines were observed in all samples, and their boundaries were clearly defined. The lengths of the H zones and M lines were constant among all treatments.