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PubMed1983

Daily repeated traction in developing osteoarthritis. An experimental study in rabbits.

The effect of repeated traction on rabbit knee joint was studied during the development of experimental osteoarthritis. The traction (10 N to the immobilized leg) was administered one hour daily during seven weeks of immobilization of the knee and eight weeks of follow-up. The control group consisted of rabbits similarly immobilized and followed but without traction. The degree of osteoarthritis was measured from joint mobility, the evaluation of radiographs and the histological picture. Traction did not statistically significantly increase the mobility range of the knee joint in the treatment group in comparison with that of the control group, and the differences were small between the histological assessments of the two groups. At the end of immobilization the radiographic changes were less marked in the traction group than in the control group, but at the end of the follow-up the difference between the two groups was not as clear. Repeated traction did not, therefore, permanently prevent degenerative changes produced by the immobilization of the rabbit knee.

Animals↗
PubMed1982

Home cervical traction: evaluation of alternate equipment.

Overhead intermittent cervical traction is often utilized to control the symptoms of cervical radiculopathy associated with osteoarthritis. The long-term home use of presently available counterweight systems has often presented problems including: (1) lack of patient compliance, (2) difficulty with application by elderly or debilitated patients, (3) tensing of both the cervical paraspinalis and upper extremity muscles while maneuvering the counterweights, and (4) discomfort while using the device. A prototype home pneumatic traction device was developed, which has many of the advantages of the expensive hydraulic units in common use in physical therapy departments. The initial favorable responses of 17 patients led to the development of a prototype commercial unit in cooperation with the Jobst Company. Of 36 patients who used the pneumatic traction device at home, 29 (81%) preferred it to the conventional counterweight system. Typical reasons were that it was easier to use, more "workable" and provided a steadier pull with more gradual onset of traction. Disadvantages most commonly mentioned were minor air pressure loss in the hand pump model and the complexity of the unit. The most rational approach to the use of these new pneumatic devices would be to initiate a home traction program using conventional counterweight units and then to switch to the pneumatic unit for long-term patients or those who are unable to apply conventional traction systems unassisted.

Adult↗
PubMed1994

Simple intraoperative traction system for acetabular fracture surgery.

The open reduction and internal fixation of complex acetabular fractures generally require some amount of sustained intraoperative traction. This traction can be provided by either specialized traction tables or scrubbed assistants. Both methods have their advantages and disadvantages. Specialized traction tables provide excellent controlled traction but are costly. Interested assistants are less costly, but at many institutions an adequate number of them are unavailable. We describe the design, construction, and use of a simple intraoperative traction device to aid in the open reduction and internal fixation of acetabular fractures.

Acetabulum↗
PubMed1994

[Biomechanics of traction for treatment of lumber disc prolapse].

The intervertebral distance in 31 prolapsed discs under traction increased on the average by 1.34 mm, but in normal discs 0.87 mm. Of 47 prolapsed discs without traction, 29 had negative intradisc pressure, 10 zero, and 8 positive. The total average value of the pressure before traction was -1.3 kPa. Under lumber traction, the pressure decreased in 30 discs, unchanged in 8, and increased in 9, with the average value being -3.2 kPa. The intradisc pressure in 7 normal discs was contrary to the pressure in the prolapsed disc. The difference between the two groups was highly significant (P < 0.01). The pressure unchanged when the intervertebral distance of prolapsed disc unchanged under traction, but the pressure decreased as the distance increased in most cases under traction.

Adolescent↗
PubMed1994

Traction reduction of acute and acute-on-chronic slipped capital femoral epiphysis.

Gentle reduction of acute or the acute portion of acute-on-chronic severe slipped capital femoral epiphyses (SCFE) is generally recommended. Reports of the use of longitudinal traction with medial rotation traction, although few, are uniform in describing a high rate of success with rare complications. Of 30 acute or acute-on-chronic SCFEs examined at the author's institution between 1970 and 1990, 13 underwent attempted traction reduction with longitudinal traction and medial rotation. Only five of these 13 hips had discernible reduction. One of these five hips developed aseptic necrosis; however, this hip was clearly distracted from the acetabulum by excessive longitudinal traction that may have contributed to the development of osteonecrosis. One of the seven hips that failed traction reduction developed aseptic necrosis, and one of the 17 acute SCFEs pinned in situ developed aseptic necrosis. All three hips developing necrosis were in a group of 14 hips with moderate to severe SCFEs and complete inability to bear weight with severe pain.

Acute Disease↗
PubMed1994

An innovative model of system-linked community care: home-based traction as an alternative to institutional treatment.

Home-based traction is an alternative treatment to conventional hospital-based traction for children with orthopedic conditions such as congenital dislocated hip and Legg-Perthes disease. The application of a proposed theoretical model is used to describe the process of the home-based traction innovation. Creativity and innovation occasions a reconceptualization of stresses. The reconceptualization of stress, plus the operational support of coordinated in-home services, can help families and nurses in the community and in the hospital develop, implement, and evaluate this kind of innovative care. In applying the home-based traction professionals empower and legitimize parents as resourceful co-providers of care. The legitimizing of the alternative in-home service affords parents a more optimistic appraisal of their situation as manageable. Parents are free to develop a coordinated response to their overall circumstance, including the treatment of their one child's illness. The evaluation of this home-based traction example found the alternative to be acceptable, safe, effective in accomplishing treatment goals, and less expensive than conventional hospital-based traction.

Adult↗
PubMed1998

[Leg length inequality and rotational deformity after traction treatment of femoral shaft fractures in children].

87 patients who experienced femoral shaft fracture at the age of two to 14 years were reviewed, on average, seven (three to 12) years after the injury occurred. Three methods of treatment had been used: Bryant skin traction, and skeletal traction using either the Weber table or the Braun frame. Patients two to three years of age at the time of injury had significantly less leg length inequality than those aged four to ten years. The reason was that in the youngest group, where which 16 out of 21 patients had been treated with skin traction, the effect of traction was less efficient and there was therefore a larger overlap of the fragments at fracture healing than in the older group, where all patients had had skeletal traction. Among ten to 14 year olds there was also less leg length inequality than among four to ten year olds. This was because of lack of growth stimulation in the oldest patients after fracture healing. The results indicate that an initial overlap of approximately 10 mm should be aimed at in patients under 11 years of age, whereas overlap should be avoided in older patients. Rotational deformity, defined as side difference in anteversion angle of 15 degrees or more, occurred in seven patients (8%), but none of them had any complaints. We conclude that traction treatment gives good results, with few complications. Over-growth remains a significant problem in children under 11 years of age.

Adolescent↗
PubMed2004

Molecular dissection of the fibroblast-traction machinery.

Motile fibroblasts generate forces that can be expressed as cell migration or as traction, the drawing-in of extracellular matrix. Traction by cultured fibroblasts can induce a rapid concerted reorganization of collagen gel, creating a pattern of collagen alignment similar to that seen in tendons and ligaments. In such fibrous connective tissues, after pattern morphogenesis is complete, ongoing traction may be responsible for the maintenance of proper form and function. The molecules that generate and transmit forces have been catalogued; however, how these nanometer-scale molecules contribute to millimeter-scale patterns has not been directly tested. Here, we placed pairs of explants of human periodontal ligament fibroblasts in collagen gels, where ligament-like straps of anisotropic collagen formed on the axes between them. We scrutinized the traction apparatus using electron microscopy, video microscopy, and computer-based pattern analysis, augmented with pharmacologic inhibitors of cytoskeletal function. Patterning was marked by the co-alignment of collagen, fibroblasts, and their actin cytoskeletons, all parallel to the axis between explants. The pattern was diminished by depolymerizing actin filaments or by blocking myosin activity, but was accentuated by depolymerizing microtubules. The plasma membrane also seems to contribute to the traction force. These molecular components combine to exert a sub-maximal traction force on the matrix, suggesting that the force may be regulated to ensure tissue tensional homeostasis.

Actin Cytoskeleton↗
PubMed2002

A novel implantable collagen gel assay for fibroblast traction and proliferation during wound healing.

BACKGROUND: A novel implantable assay for studying cellular behavior in the wound environment was developed. The assay is unique in that it combines the more quantitative nature of in vitro assays with the greater physiological relevance of in vivo wound healing models. MATERIALS AND METHODS: Cells were seeded in a physiologically relevant biological matrix, a collagen gel, contained within a semipermeable tube, and then exposed to soluble factors of the wound environment at different stages of the wound healing response. Gels were harvested at prescribed time points, and cell proliferation rates and gel compaction were measured. These data were combined with our theory for cell-matrix mechanical interactions to estimate the cell traction exerted by the cells leading to gel compaction. Cell morphology and alpha-smooth muscle actin expression were also characterized. RESULTS: The proliferation of and traction exerted by fibroblasts exposed to the soluble wound environment were different from those in similar collagen gels maintained in culture in complete medium. Proliferation and traction also varied over the course of the wound healing response. Traction was higher and proliferation lower in day 1-5 wounds compared to day 7-11 wounds. Recovered cells no longer stained for alpha-smooth muscle actin, in contrast to cells maintained in culture. CONCLUSIONS: Changes in the soluble wound environment that occur as the wound healing response proceeds alter fibroblast traction and migration. We have developed a new assay that employs a physiologically relevant biological matrix and allows the effects of the dynamic soluble wound environment on cellular traction, proliferation, and other phenomena such as protein expression to be quantified.

Actins↗
PubMed2002

Restoration of upper arm function in traction injuries to the brachial plexus.

BACKGROUND: Restoration of upper arm function presents the main priority in nerve repair of brachial plexus traction injuries. The results are predominantly influenced by the level and extent of injury, and the type of surgical procedure. The purpose of this study is to evaluate influence of these factors on final outcome. METHODS: Study included 91 surgically treated patients, including 71 patients with avulsions of one or more spinal nerve roots and 20 with peripheral traction injuries. We performed 120 nerve transfers, 25 nerve graftings and 29 neurolyses on different nerve elements depending on the type of nerve damage. Analysis of motor recovery for elbow flexion and arm abduction, isolated or in combination, was done. FINDINGS: Recovery of elbow flexion was obtained in 75% nerve transfers, and in 68,7% nerve graftings in peripheral traction injuries. Recovery of arm abduction was obtained in 78,5% nerve transfers, and in 44,4% nerve graftings in peripheral traction injuries. Neurolysis was successful in all cases. Generally, the quality of recovery was better for the musculocutaneous nerve. Useful global upper arm function was obtained in 49,3% of patients with avulsion of spinal nerve roots, and in 55% of patients with peripheral traction injuries. INTERPRETATION: Regarding upper arm function the prognosis of surgically treated patients with traction injuries to the brachial plexus is generally similar in cases with central or peripheral level of injury. However, nerve transfers of collateral branches seem to be superior to nerve grafting and may be another possibility for repair in cases with extensive nerve gaps.

Adolescent↗
PubMed1997

Neodymium:YLF picosecond laser segmentation for retinal traction associated with proliferative diabetic retinopathy.

PURPOSE: To determine the applicability of laser segmentation for severing fibrovascular tissue and hyaloid interfaces in the treatment of tractional complications of proliferative diabetic retinopathy. METHODS: A prototype neodymium:yttrium-lithium-fluoride (Nd:YLF) picosecond pulse photodisruptive laser was used in eight eyes (seven patients) with proliferative diabetic retinopathy as part of a Food and Drug Administration-approved phase 1 protocol. There were three indications for treatment: type I: distortion and shallow elevation of the macular caused by taut, adherent, posterior hyaloid interface (two eyes); type II: traction retinal detachment involving the fovea (two eyes); and type III: fovea-threatened, traction retinal detachment (four eyes). Traction release was accomplished by laser segmentation of the detached hyaloid interfaces and fibrotic, contracted proliferative tissue. The Nd:YLF uses low pulse energy (0.10 mJ, 1,000 pulses per second for 10 consecutive seconds) that allows tissue cutting near the retinal surface. RESULTS: Both type I eyes had relief of traction forces; visual acuity improved from 20/400 to 20/50 in one eye; the other remained stable. Of the two type II eyes, one had anatomic reattachment of the fovea with improvement in visual acuity (hand movements to 20/50); the second required vitrectomy. Of the four type III eyes, all had anatomic improvement; three maintained pretreatment acuity; the fourth eye developed vitreous hemorrhage at 6 months and underwent vitrectomy. Three treatments (two eyes) caused vitreous hemorrhage that resulted in a transient drop in acuity (1 to 2 lines). No patient developed a retinal break or choroidal hemorrhage. CONCLUSION: In a small pilot study, the Nd:YLF laser segmented proliferative tissue near the retinal surface and elevated hyaloid interfaces. In selected cases, this may enable flattening of traction retinal detachment or release of retinal distortion.

Adult↗
PubMed1985

Pulsion intubation versus traction intubation for obstructing carcinomas of the esophagus.

Eighty-eight patients were intubated to relieve the dysphagia of malignant esophageal obstruction. Because of advanced metastatic disease or poor general condition, 49 patients could not be operated on and were intubated endoscopically. Under radiographic control, the Nottingham Introducer was used to position Atkinson or modified Celestin tubes. In 39 other patients, palliative resection could not be done or liver metastasis was found at preliminary exploration with a view to esophagectomy. In these patients, Celestin tubes were inserted by the traction technique. The pulsion intubation group was older than the traction intubation group but comparable in other respects. Hospital stay was significantly shorter for the pulsion intubation group (8.4 versus 18.6 days). Hospital mortality rates were comparable (14.3% in the pulsion intubation group versus 23.1% in the traction intubation group), and survival did not differ (93 days in the pulsion intubation group versus 137 days in the traction intubation group). Overall complication rates were similar, but there were two significant differences: (1) wound infection or dehiscence was a major problem in the traction intubation group, occurring in 23% of the patients; and (2) tube obstruction or displacement occurred more frequently in the pulsion intubation group (18.3% versus 5.1%) but did not constitute a serious problem. Perforation occurred in 4 patients (8.2%) in the pulsion intubation group but was fatal in only 1. Pulsion intubation offers distinct advantages over traction intubation in that hospital stay is decreased and morbidity reduced.

Adenocarcinoma↗
PubMed2001

Traction force microscopy of migrating normal and H-ras transformed 3T3 fibroblasts.

Mechanical interactions between cell and substrate are involved in vital cellular functions from migration to signal transduction. A newly developed technique, traction force microscopy, makes it possible to visualize the dynamic characteristics of mechanical forces exerted by fibroblasts, including the magnitude, direction, and shear. In the present study such analysis is applied to migrating normal and transformed 3T3 cells. For normal cells, the lamellipodium provides almost all the forces for forward locomotion. A zone of high shear separates the lamellipodium from the cell body, suggesting that they are mechanically distinct entities. Timing and distribution of tractions at the leading edge bear no apparent relationship to local protrusive activities. However, changes in the pattern of traction forces often precede changes in the direction of migration. These observations suggest a frontal towing mechanism for cell migration, where dynamic traction forces at the leading edge actively pull the cell body forward. For H-ras transformed cells, pockets of weak, transient traction scatter among small pseudopods and appear to act against one another. The shear pattern suggests multiple disorganized mechanical domains. The weak, poorly coordinated traction forces, coupled with weak cell-substrate adhesions, are likely responsible for the abnormal motile behavior of H-ras transformed cells.

3T3 Cells↗
PubMed2003

Experimental studies about the impact of traction sand on urban road dust composition.

Traffic causes enhanced PM(10) resuspension especially during spring in the US, Japan, Norway, Sweden and Finland, among other countries. The springtime PM(10) consists primarily of mineral matter from tyre-induced paved road surface wear and traction sand. In some countries, the majority of vehicles are equipped with studded tyres to enhance traction, which additionally increases road surface wear. Because the traction sand and the mineral matter from the pavement aggregate can have a similar mineralogical composition, it has been difficult to determine the source of the mineral fraction in the PM(10). In this study, homogenous traction sand and pavement aggregate with different mineralogical compositions were chosen to determine the sources of PM(10) particles by single particle analysis (SEM/EDX). This study was conducted in a test facility, which made it possible to rule out dust contributions from other sources. The ambient PM(10) concentrations were higher when traction sand was used, regardless of whether the tyres were studded or not. Surprisingly, the use of traction sand greatly increased the number of the particles originating from the pavement. It was concluded that sand must contribute to pavement wear. This phenomenon is called the sandpaper effect. An understanding of this is important to reduce harmful effects of springtime road dust in practical winter maintenance of urban roads

Journal Article↗
PubMed1999

Traction on the mesentery as a model of visceral nociception.

Traction of the mesentery is known to induce strong autonomic reactions in patients undergoing abdominal surgery. An experimental model using this stimulus in anaesthetized rats has been developed, which allows the comparison of noxious mechanical and chemical stimulation of the mesentery. Graded traction on a bundle of jejunal vessels with 2-30 g led to reflex changes in blood pressure and intragastric pressure, the size of which correlated with the strength of the stimulus. Comparable responses were elicited by clamping the same vessels either at their distal or proximal end or by applying 100 microl 0.6% acetic acid or 0. microM bradykinin. These reflexes are fairly insensitive towards impairment of the autonomic system. Only the combination of phentolamine and propranolol reduced the cardiovascular responses to all stimuli but at the same time, significantly lowered basal blood pressure. The adrenoceptor antagonists affected the gastric response to acid only. Atropine on its own was ineffective. Administered together with the combination of adrenoceptor blockers it had no further influence on the cardiovascular reflexes but significantly reduced the gastric responses to stretch, proximal clamping and acid. Acute desensitization of small diameter afferents with capsaicin almost abolished the reflex responses to acid. The cardiovascular, but not the gastric, response to traction was reduced by capsaicin. Morphine led to dose-dependent reductions of the reflex responses in a naloxone-reversible manner, whereas indomethacin was inactive. The bradykinin B2-antagonist icatibant abolished the reflex in response to the application of bradykinin but not to acid or traction. It is concluded that the measurement of the cardiovascular and gastric responses of anaesthetized rats to traction on the mesentery is a suitable method to investigate acute visceral nociception. Chemical stimuli to the mesentery are transmitted by capsaicin-sensitive afferents, but there is a dichotomy regarding capsaicin's influence on visceral mechanonociception. Opioid mechanisms are always involved, whereas prostaglandins or bradykinin have no role in the reflexes evoked by acid or traction. Intact alpha- or beta-adrenergic (as tested with unselective receptor antagonists) or muscarinic mechanisms are required for the reaction of the end organs in the reflex but they have no role in the afferent or central processing.

Anesthesia↗
PubMed2005

Size and composition of airborne particles from pavement wear, tires, and traction sanding.

Mineral matter is an important component of airborne particles in urban areas. In northern cities of the world, mineral matter dominates PM10 during spring because of enhanced road abrasion caused by the use of antiskid methods, including studded tires and traction sanding. In this study, factors that affect formation of abrasion components of springtime road dust were assessed. Effects of traction sanding and tires on concentrations, mass size distribution, and composition of the particles were studied in a test facility. Lowest particle concentrations were observed in tests without traction sanding. The concentrations increased when traction sand was introduced and continued to increase as a function of the amount of aggregate dispersed. Emissions were additionally affected by type of tire, properties of traction sand aggregate, and driving speed. Aggregates with high fragmentation resistance and coarse grain size distribution had the lowest emissions. Over 90% of PM10 was mineral particles. Mineralogy of the dust and source apportionment showed that they originated from both traction sand and pavement aggregates. The remaining portion was mostly carbonaceous and originated from tires and road bitumen. Mass size distributions were dominated by coarse particles. Contribution of fine and submicron size ranges were approximately 15 and 10% in PM10, respectively.

Cities↗
PubMed1981

Fibroblast traction as a mechanism for collagen morphogenesis.

To make visible the traction forces exerted by individuals cells, we have previously developed a method of culturing them on thin distortable sheets of silicone rubber. We have now used this method to compare the forces exerted by various differentiated cell types and have examined the effects of cellular traction on re-precipitated collagen-matrices. We find that the strength of cellular traction differs greatly between cell types and this traction is paradoxically weakest in the most mobile and invasive cells (leukocytes and nerve growth cones). Untransformed fibroblasts exert forces very much larger than those actually needed for locomotion. This strong traction distorts collagen gels dramatically, creating patterns similar to tendons and organ capsules. We propose that this morphogenetic rearrangement of extracellular matrices is the primary function of fibroblast traction and explains its excessive strength.

Animals↗
PubMed2006

Visualization of vitreomacular tractions with en face optical coherence tomography.

BACKGROUND: In vitreomacular traction syndrome, an incomplete vitreous detachment with persistent vitreous traction on the macula is present. This condition may determine formation of epiretinal membranes, macular puckering, macular oedema, and traction macular detachment. Recently introduced en face optical coherence tomography (OCT) provides not only longitudinal B-scan but also coronal C-scan images of the retina. METHODS: Fifteen eyes of 11 non-diabetic patients presenting vitreomacular traction syndrome have been evaluated with en face OCT (OTI, Toronto, Ontario, Canada). RESULTS: In 12 eyes, cystoid macular oedema was detectable at fundus examination and was associated with a broad-based adherence of the posterior hyaloid to the macula. In three eyes, foveal detachment appeared to be associated with focal foveal vitreoretinal traction. In all eyes, the lateral extent of the hyaloidal tractions on the macula was clearly detectable at coronal C-scan. They appeared as sigmoid hyper-reflective bands in the hyporeflective vitreous chamber. Overlay of C-scans on red-free confocal images allowed the visualization of the edges of the adherences in relation to the structures of the posterior pole. CONCLUSIONS: The C-scan images allowed clear visualization of the total extension of the posterior vitreomacular adherences and their relationships with the vascular arcades, the optic disc, and the fovea.

Adult↗