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PubMed1984

Abduction-traction injury of the knee.

Disruption of the major ligaments of the knee was seen in six young men, five parachutists and a house painter, after what we have termed abduction-traction injury. This unusual complaint results from the application of a sudden block to the ankle while falling head first, leading to traction and abduction of the knee. All the patients underwent operations, generally with unsatisfactory results. At operation tears of the anterior cruciate ligament, medial collateral ligament and posterior oblique ligament were seen in each case; in four patients the posterior capsule and in three the posterior cruciate ligament also were torn. In one patient the lateral collateral ligament was torn and the lateral meniscotibial ligament was avulsed. The compression component is absent in this type of injury and consequently the menisci and the osteochondral surfaces of the tibia and femur remained intact in each case.

Accidents, Occupational↗
PubMed1985

Fragmentation of the proximal pole of the patella. Another manifestation of juvenile traction osteochondritis?

Six boys with fragmentation of the proximal pole of the patella are reported; the condition was bilateral in one. Four of the six presented with symptoms of Osgood-Schlatter's disease or Larsen-Johansson disease of the same or of the contralateral knee, but they had no symptoms or signs relating to the proximal pole of the patella; one also had features suggesting minimal chondromalacia patellae. Two boys had no objective abnormality in either knee. It is suggested that the fragmentation may be a further form of traction osteochondritis of the attachments of the quadriceps mechanism. Attention is drawn to its characteristic radiographic appearance, its association with other forms of juvenile traction osteochondritis (which are commonly symptomatic), and to its occurrence in boys aged 10 or 11 years.

Child↗
PubMed2007

Neutrophil traction stresses are concentrated in the uropod during migration.

We find that in contrast to strongly adherent, slow moving cells such as fibroblasts, neutrophils exert contractile stresses largely in the rear of the cell (uropod) relative to the direction of motion. Rather than the leading edge pulling the cell, the rear is both anchoring the cell and the area in which the contractile forces are concentrated. These tractions rapidly reorient themselves during a turn, on a timescale of seconds to minutes, and their repositioning precedes and sets the direction of motion during a turn. We find the total average root mean-squared traction force to be 28+/-10 nN during chemokinesis, and 67+/-10 nN during chemotaxis. We hypothesize that the contraction forces in the back of the neutrophil not only break uropodial adhesive contacts but also create a rearward squeezing contractility, as seen in amoeboid or amoeboidlike cells and the formation of blebs in cells, causing a flow of intracellular material to the fluidlike lamellipod. Our findings suggest an entirely new model of neutrophil locomotion.

Cell Adhesion↗
PubMed2006

Study of the traction resistance of mitral valve chordae tendineae.

OBJECTIVE: To determinate the extension and the resistance of the primary mitral valve chordae tendineae when submitted to traction. The importance of keeping the integrity of papillary muscle, chordae tendineae, and mitral valve cuspid when the replacement of this valve occurs is clear, but the knowledge of the maximum resistance that a primary tendinea chorda can withstand is not known. METHODS: Eight hearts were dissected, and one hundred and thirty two primary human chordae tendineae were measured (length and thickness) and submitted to traction under controlled conditions so that the absolute resistance, resistance relative to thickness (relative resistance), and elongation could be measured. RESULTS: The correlation between the elongation at the moment of rupture and the thickness was equal to 1.54 + 17.02 x thickness (P = 0.026); and to absolute resistance was equal to 0.95 + 1.42 x resistance (P < 0.001); and to the resistance relative to thickness (relative resistance) was equal to 1.95 + 0.08 x relative resistance (P = 0.009). The correlation between the absolute resistance and the thickness was equal to 0.26 + 14.53 x thickness (P < 0.001). CONCLUSION: The resistance of primary mitral valve chordae tendineae is associated with its thickness and elongation at the moment of rupture, but is not associated with the length. The elongation at the moment of rupture shows a relationship with the resistance relative to thickness (relative resistance) and with the thickness of the primary chordae tendineae, but not with the length of the chordae tendineae.

Adult↗
PubMed2002

Simultaneous, real-time imaging of intracellular calcium and cellular traction force production.

Cells can sense and respond to different types of mechanical stimuli that can lead to changes in rate of cell division, cell orientation, cell motility, and gene expression. There is rapidly growing interest in understanding how these processes are regulated by mechano-chemical signaling mechanisms. The movement offish epithelial keratocytes is regulated by the activation of stretch-activated calcium channels, which allow cells to trigger retraction of the rear cell margin, when forward movement is impeded. We have developed a new assay that permits imaging of intracellular calcium concentration simultaneously with the detection of traction forces generated by moving keratocytes. The assay consists of a thin sheet of gelatin embedded with a surface layer of small fluorescent marker beads, on which cells can move. The elastic properties of the gelatin substrata can be reproducibly varied over a wide range and are stable for long periods, while submerged beneath culture medium. Gelatin substrata are thin, transparent, and highly elastic, allowing real-time detection of changes in traction force production that are associated with transient increases in intracellular calcium and that occur in response to mechanical stretching.

Acrylic Resins↗
PubMed1975

Genu recurvatum: a late complication of tibial wire traction in fractures of the femur in children.

Seven cases of genu recurvatum following wire traction through the proximal end of the tibia in children treated for fractures of the femur are reported. A premature closure of the anterior part of the growth plate was most probably caused by too close a proximity of the wire to the tibial tuberosity. Where tibial wire traction is used in children it is advisable to insert the wire distal to the tuberosity.

Adolescent↗
PubMed2006

Vitreopapillary traction: cost-effective diagnosis by optical coherence tomography.

CASE REPORTS: A prospective, noncomparative, observational case series. Three patients, aged 76 to 81, all referred to subspecialty services for evaluation of optic disc elevation, and all were found to have optic disc (vitreopapillary) traction as verified by optical coherence tomography. COMMENTS: Vitreopapillary traction is a recently recognized syndrome characterized by incomplete posterior vitreous detachment. The use of optical coherence tomography is helpful in the diagnosis of this syndrome, preventing many costly, unwarranted evaluations.

Aged↗
PubMed2004

Evaluation of suprascapular nerve neurotization after nerve graft or transfer in the treatment of brachial plexus traction lesions.

OBJECT: The aim of this retrospective study was to evaluate the restoration of shoulder function by means of suprascapular nerve neurotization in adult patients with proximal C-5 and C-6 lesions due to a severe brachial plexus traction injury. The primary goal of brachial plexus reconstructive surgery was to restore biceps muscle function and, secondarily, to reanimate shoulder function. METHODS: Suprascapular nerve neurotization was performed by grafting the C-5 nerve in 24 patients and by accessory or hypoglossal nerve transfer in 29 patients. Additional neurotization involving the axillary nerve was performed in 18 patients. Postoperative needle electromyography studies of the supraspinatus, infraspinatus, and deltoid muscles showed signs of reinnervation in most patients; however, active glenohumeral shoulder function recovery was poor. In nine (17%) of 53 patients supraspinatus muscle strength was Medical Research Council (MRC) Grade 3 or 4 and in four patients (8%) infraspinatus muscle power was MRC Grade 3 or 4. In 18 patients in whom deltoid muscle reinnervation was attempted, MRC Grade 3 or 4 function was demonstrated in two (11%). In the overall group, eight patients (15%) exhibited glenohumeral abduction with a mean of 44 +/- 17 degrees (standard deviation [SD]; median 45 degrees) and four patients (8%) exhibited glenohumeral exorotation with a mean of 48 +/- 24 degrees (SD; median 53 degrees). In only three patients (6%) were both functions regained. CONCLUSIONS: The reanimation of shoulder function in patients with proximal C-5 and C-6 brachial plexus traction injuries following suprascapular nerve neurotization is disappointingly low.

Adolescent↗
PubMedDate not supplied

Traction testing in superior oblique palsy.

This report describes the use of superior oblique traction testing in the evaluation of superior oblique palsy. Four consecutive children presenting with signs and symptoms of superior oblique palsy were found to have markedly abnormal tendon laxity with traction testing. Surgical exploration revealed anomalies including three with elongated lax tendons, one of which had an anomalous insertion, and one absent tendon. This tendon laxity is not typically found in acquired superior oblique palsy. It is proposed that, in addition to the well known neurogenic paresis/paralysis, a second type of "palsy" due to anatomic abnormalities of the tendon may exist and be responsible for a number of congenital superior oblique palsies. The mechanical disadvantage of these markedly long tendons may explain why inferior oblique weakening procedures alone frequently fail to correct head tilts due to superior oblique palsy in infancy.

Child, Preschool↗
PubMedDate not supplied

Medial tibial stress syndrome (tibial fasciitis): a proposed pathomechanical model involving fascial traction.

Although medial tibial stress syndrome is one of the most common lower-extremity overuse injuries, its pathomechanics remain controversial. Two popular theories have been proposed to account for this condition: tibial bending and fascial traction. This article evaluates the role of fascial traction in medial tibial stress pathomechanics. We hypothesized that with contraction of the deep leg flexors tension would be imparted to the tibial fascial attachment at the medial tibial crest. We also speculated that circumferential straps would dampen tension directed to the medial tibial crest. The amount of strain present in the tibial fascia adjacent to its distal medial tibial crest insertion during loading of the leg was investigated as a descriptive laboratory pilot study using three fresh cadaver specimens. Strain in the distal tibial fascia was measured using strain gauges placed in the fascia at its medial tibial crest insertion. As tension on the posterior tibial, flexor digitorum longus, and soleus tendons increased, strain in the tibial fascia increased in a consistent linear manner (P < .0001). We conclude that fascial tension may play a role in the pathomechanics of medial tibial stress syndrome. The tenting effect of the posterior tibial, flexor digitorum longus, and soleus tendons caused by muscle contraction exerts a force on the distal tibial fascia that is directed to its tibial crest insertion. Circumferential straps provided no dampening effect on tension directed to the medial tibial crest.

Cumulative Trauma Disorders↗
PubMed1999

Hoffmann-reflex is delayed during 6 degree head-down tilt with balanced traction.

BACKGROUND: Increased spinal height due to the lack of of axial compression on spinal structures in microgravity may stretch the spinal cord, cauda equina, nerve roots, and paraspinal tissues. HYPOTHESIS: Exposure to simulated microgravity causes dysfunction of nerve roots so that the synaptic portion of the Achilles tendon reflex is delayed. METHODS: Six healthy male subjects were randomly divided into two groups with three in each group. The subjects in the first group underwent horizontal bed rest (HBR) for three days. After a two week interval they underwent bed rest in a position of head-down tilt with balanced traction (HDT). So that each subject could serve as his own control, the second group was treated identically but in opposite order. Bilateral F waves and H-reflexes were measured daily (18:30-20:30) on all subjects placed in a prone position. RESULTS: By means of ANOVA, differences between HDT and HBR were observed only in M-latency and F-ratio, not in F-latency, central latency, and H-latency. Differences during the course of the bed rest were observed in M-latency and H-latency only. Tibial H latency was significantly lengthened in HDT group on day 2 and 3, although no significant difference between HDT and HBR was observed. CONCLUSION: The monosynaptic reflex assessed by H-reflex was delayed during 6 degree HDT with traction. The exact mechanism of this delay and whether the change was due to lengthening of the lower part of the vertebrae remain to be clarified.

Action Potentials↗
PubMed1999

[Vitreoretinal tomography and foveolar traction in macular hole development and macular pseudohole].

OBJECT: To clarify the morphologic features and foveolar traction in macular hole development and macular pseudohole. METHODS: The vitreoretinal tomography of idiopathic macular holes and macular pseudoholes was observed with optical coherence tomography (OCT). RESULTS: In stage 1 and 2, foveolar intraretinal splitting was evident. The posterior hyaloid membrane was detected in 7 of 10 eyes with stage 1 and 2 holes. Dome-shaped vitreoretinal separation was seen in 6 of 7 eyes in which the posterior hyaloid membranes were detected. A complete posterior vitreous detachment was seen around a stage 3 hole. In the macular pseudohole with preretinal membrane, there was anterior and central displacement of the inner retina in the perifoveal region, resulting in a U-shaped deformation of the macular lesion. In contrast, the structure of the central fovea was virtually intact. CONCLUSIONS: On the basis of the OCT findings, the intraretinal splitting and the cyst formation are important features in the development of a macular hole. The dome-shaped vitreoretinal separation in the early stages of macular holes suggests that the posterior hyaloid membrane may not be taut but slack, and would not cause a tractional force continuously even in early-stage macular holes.

Aged↗
PubMed2000

[Ultrastructural findings of epimacular membrane and detached posterior hyaloid in vitreomacular traction syndrome].

PURPOSE: Vitreomacular traction syndrome is characterized by an incomplete posterior vitreous detachment and by the cortical vitreous remaining attached to the macula. In certain case epimacular membrane is clinically well defined. We studied the electron microscopic features of epiretinal tissue and posterior hyaloid removed from the posterior pole. MATERIAL AND METHODS: [corrected] Six epimacular membranes were removed during a pars plana vitrectomy, placed in 2.5% glutaraldehyde solution, embedded in Epoxy resin, and examined in a transmission electron microscope. The detached posterior hyaloid was removed and analyzed separately in two cases. RESULTS: The analysis disclosed five morphologically cell types. Fibrous astrocytes were predominant in five cases. Other cell types were less frequent and were identified as fibroblasts, macrophages and myofibroblasts. In one case epithelial-like cell type was predominant. The stroma was mainly composed of a thin layer of 15-nm diameter collagen evoking a vitreous origin. Internal limiting membrane was present in one case only. Detached posterior hyaloid was constituted by the same cellular constituents on thin layer of vitreous collagen. DISCUSSION: The cellular proliferation is principally constituted by fibrous astrocyte and occurs on the inner surface of cortical vitreous. Some glial cells seem to present an epithelial differentiation. CONCLUSION: The attached and detached posterior hyaloid in vitreomacular traction syndrome is the place of glial cells migration and proliferation.

Humans↗
PubMed2000

[A novel instrument for off-pump coronary artery bypass grafting: traction-type coronary artery stabilizer].

A new instrument for heart stabilization during beating coronary bypass grafting without cardiopulmonary bypass and a clinical experience of off-pump LITA-to-LAD bypass using this mechanical stabilizer are described. This device provide optimal motionless field by traction mechanism in which traction sutures placed proximal and distal to the target coronary artery are tied to the U-shaped foot plate with multiple small holes. The advantages of this stabilizer are as follows; no need of heart compression, ability to displace the target lesion to facilitate anastomosis, reusable, compact size and easy handling. We believe this novel instrument will improve the anastomosis quality in patient undergoing coronary artery bypass without cardiopulmonary bypass.

Aged↗
PubMedDate not supplied

Perifoveal traction retinal detachment following successful optic disc pit surgery.

A 25-year-old male presented 8 years after a successful vitreoretinal operation for a left optic disc pit (ODP). On presentation his visual acuity had reduced from 6/5 (20/15) to 6/12 (20/40) in his operated eye. On examination an annular serous retinal detachment possibly secondary to tangential traction by either the internal limiting membrane (ILM) or residual lamellar vitreous cortex or both around the peripheral macular area was seen. The central fovea was flat. Following an uncomplicated vitrectomy and ILM peel, visual acuity improved to 6/6 (20/20) postoperatively. The author suggests that traction forces are responsible for the development of the serous detachment in eyes with ODP. Epiretinal membranes together with the ILM should be removed in all patients undergoing therapy for a retinal detachment associated with ODP in an effort to initially achieve a further relief of all forces and to try to avoid the late retinal detachment associated with epiretinal membrane or ILM contraction.

Adult↗
PubMed1976

Continuous trans-physeal traction: a simple method of bone lengthening.

Leg length increments utilizing continuous traction across the epiphyseal plate of growing puppies produces a cleavage fracture at the level of the primary metaphyseal trabeculae which neither anatomically nor physiologically alters the growth plate. These fractures heal readily and growth resumes following removal of the traction device. This method is relatively atraumatic to the extremity. It does not require an open operation and the controlled distraction rate has not caused neurological or vascular complications. The study was designed to determine the anatomic site of fracture; no attempt was made to achieve maximal leg length increments.

Bone Lengthening↗
PubMed1992

Acute onset of rubeosis iridis after diabetic vitrectomy can indicate peripheral traction retinal detachment.

Acute onset or exacerbation of rubeosis iridis associated with peripheral retinal detachment after vitrectomy represents a rare but serious complication of advanced diabetic retinopathy that indicates a poor prognosis. The clinical features, surgical procedures, and anatomical and functional results for a series of 13 eyes presenting with this complication are reported. In addition to rubeosis iridis and peripheral retinal detachment, anterior hyaloidal fibrovascular proliferation (APH) was also present in 10 eyes. All eyes had undergone one or more previous vitrectomies for diabetic complications such as nonclearing vitreous hemorrhage and traction retinal detachment. Treatment modalities for iris neovascularization and peripheral retinal detachment included reattachment procedures with an encircling band, peripheral membrane peeling, and, if necessary, peripheral retinectomy. Peripheral coagulation therapy was performed in all eyes. Eight eyes received an intraocular silicone-oil tamponade. Early results (4 weeks post-surgery) showed regression or stabilization of rubeosis iridis in all eyes. Later results (mean, 9 months post-surgery) revealed nine eyes with stabilized anterior ocular neovascularization and reattachment of the retina. Four eyes were anatomic failures due to recurrent rubeosis iridis/AHP or traction retinal detachment, and three of them also developed ocular hypotony. None of the eyes has thus far been lost as a result of neovascular glaucoma or painful phthisis. Ambulatory vision was retained in ten eyes, but function was limited to a low level as a result of the underlying ischemic disease. Immediate reattachment surgery in combination with anterior/peripheral coagulation therapy was shown to be an effective measure for controlling iris neovascular activity in eyes afflicted with acute anterior ocular neovascularization.

Acute Disease↗