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Rigid fixation of facial fractures in children.

This article presents a retrospective analysis of a selective use of rigid fixation among 62 children with facial fractures, treated at a Level I trauma center over a 5-year period (1986-1991). There were 21 mandible fractures, 11 orbital fractures, 11 zygomaticomalar complex fractures, 7 nasal fractures, 5 maxillary fractures, 3 pan-facial fractures, 2 nasal-orbital-ethmoidal complex fractures, and 2 frontal sinus fractures. Only 18 children had rigid fixation of their injuries. Complications of Le Fort upper facial fractures repaired with rigid fixation involved perioperative sinusitis; one case required oral antibiotics, the other ethmoidectomy and maxillary antrostomy. One child with a Le Fort fracture had delayed exposure of a zygomaticomalar buttress plate, which required surgical removal. Permanent enophthalmos occurred in two children with Le Fort fractures. The authors conclude that traditional conservative management is appropriate in most cases. However, in children aged 13 and older with mandible fractures and children with complex mid- and upper facial fractures, a judicious use of rigid fixation has advantages over the traditional techniques.

Adolescent↗

[Rigid ureteroscopy in the case of suspected tumor of the upper urinary tract: report of 63 cases].

OBJECTIVE: This retrospective study was designed to determine the place of rigid ureteroscopy in the diagnosis of upper urinary tract tumours. MATERIAL AND METHODS: 63 patients (45 males and 18 females) with a mean age of 60 years, were investigated by rigid ureteroscopy for suspected upper urinary tract tumour. The Wolf 8-9.8 F ureteroscope was used in the case of suspected upper urinary tract tumour in a context of ureteric obstruction on the IVU in 29 cases, haematuria in 23 cases, a defect on retrograde ureteropyelography in 5 cases, suspicious CT scan in 5 cases and positive cytology with normal cystoscopy in 2 cases. RESULTS: The ureteroscope was able to be advanced as far as the suspicious zone in 89% of cases. The mean operating time was 48 minutes and the mean hospital stay was 3.2 days. Diagnostic rigid ureteroscopy has a Sensitivity of 58% (95% confidence interval CI95: +/- 28), a Specificity of 100%, a Positive Predictive Value of 100%, a Negative Predictive Value of 91% (+/- 7) and a low morbidity (3%). CONCLUSION: Rigid ureteroscopy does not appear to be the examination of choice for the diagnosis of upper urinary tract tumours, as it cannot investigate the renal pelvis or calices and the ureteroscope cannot always be advanced to the suspicious zone. The flexible ureteroscope now appears to be a more reliable diagnostic tool.

Female↗

[Stability analysis of an enhanced load sharing dynamic pedicle screw fixation device and its equivalent rigid device].

OBJECTIVES: To compare the stability of an enhanced load sharing dynamic pedicle screw fixation device with its equivalent rigid device and to evaluate biomechanical roles of the dynamic fixation. METHODS: A model of L(1) body fracture was produced on seven specimens of fresh adult cadaver spine from T(10) to L(4). Both dynamic and rigid devices were applied in the specimens to strength the injured level. Ranges of three dimensional movements and stiffness under flexion-compression were measured in intact, injured and stabilized specimens. RESULTS: Both dynamic and rigid devices were found to provide significant stability for injured segment in flexion-extension and lateral bending. In axial rotation, the devices could restore the stability to levels similar to those in an intact spine. Results indicated 40% increase in range of motion in flexion-extension and 24.1 Nmm reduction in stiffness of flexion-compression for dynamic device, compared with the rigid device. CONCLUSION: The dynamic device offers a design that may enhance load sharing without sacrificing the stability and will decrease stress-shielding and stress concentration.

Biomechanical Phenomena↗

Rigid ring fixation of the mitral annulus does not impair left ventricular systolic function in the normal canine heart.

BACKGROUND: Previous studies suggest that rigid fixation of the mitral annulus with an annuloplasty ring may impair left ventricular (LV) systolic performance. We used load-insensitive indexes of global and regional LV contractile mechanics to test the hypothesis that rigid fixation of the mitral annulus alters LV systolic function. METHODS AND RESULTS: Global and regional LV systolic mechanics were compared in 10 dogs during two mitral annular conditions: rigidly fixed and freely mobile. Carpentier-Edwards annuloplasty rings (20-24 mm) were inserted using a special buttressing suture technique that permitted alternate cinching of the ring down onto the annulus and subsequent removal away from the annulus. Aortic flow was measured with an electromagnetic flow probe, LV pressure by a micromanometer, and LV wall thickness and three near-orthogonal LV endocardial chamber dimensions using piezoelectric crystals during four sequential ring conditions: 1) down, 2) away, 3) down, and 4) away. The following parameters were analyzed during each ring condition to assess global LV systolic function: end-systolic chamber elastance (end-systolic pressure-volume relation), fiber elastance (end-systolic stress-volume relation), preload recruitable stroke work, and myocardial stress-strain relation. Additionally, regional LV systolic performance was assessed using the end-systolic pressure-diameter relation and a regional analog of preload recruitable stroke work. No significant differences in any of these measurements of LV systolic mechanics were observed between the two mitral annular conditions. CONCLUSIONS: Rigid fixation of the mitral annulus alters neither global nor regional LV systolic function in anesthetized, open-chest dogs with normal ventricles.

Animals↗

Rigid rectosigmoidoscopy: still a well-tolerated diagnostic tool.

BACKGROUND: Although rigid rectosigmoidoscopy has been gradually replaced by the use of flexible rectosigmoidoscopy in recent years, it remains an effective, economic and widely available diagnostic tool. The aim of this study was to determine the type and magnitude of symptoms during rigid rectosigmodoscopy. METHODS: Prospective evaluation of patients who underwent diagnostic rigid rectosigmoidoscopy. The main complaints were recorded, and their magnitude quantified using a visual analogue scale. RESULTS: A total of 134 patients (mean age = 48 years) were examined. The prone jackknife position was used in 54% of them and left lateral decubitus in 46%. A complete (full length) examination was achieved in 68%. There were no complications. Sixty percent of patients referred complaints: pain (33%), discomfort by rectal preparation (13%), uncomfortable defecation desire (8%), and discomfort by the position (4%). Median values determined by visual analogue scale for pain, discomfort by rectal preparation, uncomfortable positioning and overall discomfort were graded as 3.3, 3.3, 2.1 and 2, respectively. There was an association between higher magnitude of pain and overall discomfort with female gender, left lateral decubitus position, and full-length exploration (p < 0.05). CONCLUSION: A high percentage of patients have symptoms during rigid rectosigmoidoscopy but the study is usually well tolerated due the low magnitude of pain and discomfort and remains a very cost-effective study.

Female↗

[A comparative analysis of the inclination angle of rigid and soft IOLs with intracapsular fixation].

Eighty-four eye were examined in 67 patients after phacoemulsification with intracapsular IOL implantation. The patients were shared, with respect to IOL rigidity, between 2 groups: group 1--rigid PMMA lenses and group 2--soft hydrogel and acryl lenses. The inclination angle was evaluated for different lens types by using an elaborated mathematical formula. The lenses had capsular fixation in all cases. The deviation angle ranged from 0.58 to 1.22 degrees. The difference between the inclination angle and ocular visual axis for rigid and soft lenses was statistically reliable (p < 0.05). The inclination angle of the optic axis in case of soft lenses versus rigid lenses was to a greater extent pronounced after 2 months of observation. However, the conclusion is not final due to continuous fibrosis of the capsular sac, which affects dynamically the IOL positioning. Therefore, similar studies will be made after 12-14 months to enable final conclusions.

Adult↗

[A 65-year-old man with rigid-bradykinetic parkinsonism, vertical gaze palsy, difficulty of eye-lid opening, and marked pseudo-bulbar palsy].

We report a 65-year-old man with rigid-bradykinetic parkinsonism, vertical gaze palsy, difficulty in eye-lid opening, and marked pseudo-bulbar palsy. He felt difficulty of it, hand movement at 59 years old. When he was 60 years old, monotonous speech and slowness of movement appeared. He visited a neurologist who noted vertical gaze palsy, neck rigidity, and bradykinesia. He was diagnosed as progressive supranuclear palsy (PSP) and given 300 mg L-Dopa/Benserazide by the neurologist. This medication improved his rigidity and bradykinesia. At 62 years of the age, his eye-lids closed involuntary and it was difficult to open. In addition, he began to complain of wearing-off, autonomic symptoms, and dysphagia. Anti-parkinsonian drugs were increased, but his bradykinesia progressed. At 64 years of the age, he was admitted to the Neurology Service of Juntendo Hospital. On admission, he was alert and not demented. No aphasia, apraxia, or agnosia was noted. In the cranial nerves, upward and downward gaze were markedly restricted. His face was hypomimic and seborrhoic. It was difficult to swallow liquid or solid for him. No weakness was noted, but he walked in small steps with freezing and falling tendency to backward. Rigidity was noted on his extremities and stronger on his left side than right. Tremor was absent. Bradykinesia of his body and extremities was marked. No cerebellar ataxia was noted. Deep tendon reflexes were within normal range. Planter response was flexor bilaterally. Myerson's sign was noted. Sensory and autonomic function were normal. He was treated with L-Dopa, Pergolide, and Bromocriptine. However, these medications improved his bradykinesia and gait disturbance only slightly, dysphagia became progressively worse. He developed aspiration pneumonia when he was 65 years old and admitted to Juntendo Hospital. A large amount of sputum was aspirated from his trachea. Two days after from admission, he was found dead on his bed. He was discussed in a neurological CPC and the chief discussant arrived at a conclusion that the patient had progressive supranuclear palsy (PSP). Other differential diagnoses included Parkinson's disease, pallido-nigroluysian atrophy (PNLA), multiple system atrophy (MSA), and corticobasal degeneration(CBD). Many participants considered that PSP or PNLA was most likely. Post-mortem exmination revealed marked nigral neuronal loss and gliosis. The globus pallidus and the luysian body changed mildly. However, the frontal cortex was relatively spared, there were many ballooned neurons in the cortical layer. Other parts were spared. With sliver (Bodian and Gallyas-Braak) and anti-phsphorylated tau stain, abundant astrocytic plaques, neurofibrillary tangles, and argyrophilic threads on the frontal cortex, striatum, and substantia nigra were seen. There was no tufted astrocyte which was hallmark of diagnosis of PSP. In addition, several Lewy bodies were seen in the brainstem. Because astrocyte plaque was considered specific for pathology of CBD, the pathologist revealed that the pathological diagnosis of this patient was CBD. Nevertheless, discussion was focused on the relatively mild degeneration of the frontal cortex for CBD.

Aged↗

[Evaluation of rigid internal fixation in mandibular reconstruction with autogenous bone].

OBJECTIVE: To investigate the application of rigid internal fixation in mandibular reconstruction with autogenous bone and to evaluate its efficacy. METHODS: From January 1994 to May 2004, 98 patients with mandibular defect received mandibular reconstruction with autogenous bone by using rigid internal fixation. Seventy-two cases of benign tumor and 26 cases of malignant tumor were included. Four hundred and ono rigid fixation plates were inserted. The clinical results and X-ray films were analyzed and the healing processes were evaluated. The functional and aesthetic results of the mandibular reconstruction were also evaluated according to Lopez assessment system. RESULTS: After a follow-up of 1 to 3 years, 95 patients (96.9%)achieved successful effect. The forms and function of the mandibles were resumed. Eighty-one (82.7%) patients were satisfied with the results of operations. Thirteen patients (13.3%) achieved acceptable results. Four patients (4.1%) were dissatisfied with the results of operations. CONCLUSION: The rigid internal fixation is conductive to healing and remodeling of the transplant bone in mandibular reconstruction.

Adolescent↗

Concentric isokinetic trunk extension/flexion testing of rigid and semirigid lumbar/sacral supports.

Using a Cybex(R) trunk extension/flexion device, we measured the effects of rigid and semirigid lumbar/sacral supports on peak muscular torque, total work, and average power. Ten well-conditioned men, aged 21 to 35, performed three testing sessions each at 7-day intervals (one session with a rigid support, one session with a semirigid support, and one with no support). We selected four isokinetic testing speeds (30 degrees /s, 60 degrees /s, 90 degrees /s, and 120 degrees /s), complying with a standard Cybex trunk extension/flexion protocol. Differences between lumbar/sacral supports were analyzed using an analysis of variance (ANOVA) and Scheffé post hoc tests. Peak torque, total work, and average power were significantly different (p<.05) during trunk flexion at various isokinetic velocities. Trunk extension movements did not appear to be affected by the use of supports, but trunk flexion was significantly greater with the semirigid device and with no device than with the rigid support. We concluded that a rigid lumbar/sacral support decreases strength during movement tasks involving trunk flexion with resistance.

Journal Article↗

A three-year audit of rigid oesophagoscopy at Lady Reading Hospital Peshawar.

BACKGROUND: The number of oesophagoscopies performed annually provides an indication of the extent of oesophageal disorders in any particular setting. The present study aimed to provide such data for rigid oesophagoscopy at the only referral centre for this procedure in Peshawar. METHODOLOGY: An audit of all available records of patients undergoing rigid oesophagoscopies from January 2002 to December 2004, at the Lady Reading Hospital Peshawar was performed. RESULTS: A total of 200 cases of rigid oesophagoscopies were performed during this three-year period of study. The ages of patients ranged from I to 90 years, with a two fold male preponderance. The main indication was dysphagia. with major causes being oesophageal carcinoma (115, 57.5%), reflux oesophagitis (56, 28%), strictures of various aetiologies (19, 9.5%) and foreign bodies (10, 5%). Successful dilatation was possible in 70% of cases: the morbidity rate was 4.5% due to perforation observed in 9 cases. The mortality rate was 1.5% due to septicemia in 3 cases. CONCLUSION: A high rate of rigid oesophagoscopies was observed indicating an increased frequency of oesophageal disorders in this setting. The morbidity and mortality rates observed are within acceptable ranges for this procedure.

Adolescent↗

Rigid ventilation bronchoscopy under general anesthesia for treatment of pediatric pulmonary atelectasis caused by pneumonia: A review of 33 cases.

Pediatric pulmonary atelectasis caused by pneumonia is a common disease. If the mucus plugs or secretions occlude the bronchial trees and cannot be cleaned by coughing, suctioning, or vigorous respiratory and physical therapy, is rigid ventilation bronchoscopy (V-B) effective and safe as a therapeutic procedure in such patients? We collected 33 cases of pediatric pulmonary atelectasis that were treated by rigid V-B under general anesthesia for removal of the mucus plugs or foreign bodies. During the rigid V-B with lung lavage performed by experienced bronchoscopists, the oxygen saturation was maintained in good condition. No disastrous complications were noted. Sixty-four percent (21/33) of those with pediatric pulmonary atelectasis had significant improvement in either oxygen saturation or chest radiography within 72 hours. We conclude that when the traditional treatment in pediatric pulmonary atelectasis was ineffective, rigid V-B might be an adequate and safe procedure to remove the mucus plugs and restore pulmonary function.

Anesthesia, General↗

[The comparison of visual acuity and contrast sensitivity in patients with cataract and age-related macular degeneration implanted with foldable or rigid intraocular lenses].

OBJECTIVE: To evaluate the maximally corrected visual acuity and contrast sensitivity under photopic and mesopic conditions with or without glare in pseudophakic patients implanted with either foldable or rigid intraocular lenses. MATERIAL AND METHODS: A total of 83 patients after cataract surgery were examined at baseline and 8-12 weeks later: 47 patients with age-related macular degeneration (Group 1) and 36 patients without ocular comorbidities (Group 2). Contrast sensitivity was measured using a Ginsburg Box, VSCR-CST-6500. RESULTS: Using logistic regression analysis it was revealed that probability of clinically significant improvement of contrast sensitivity under photopic conditions with and without glare in the patients with implanted foldable lenses increased by 3.1 times (95% PI 1.6-5.9, P<0.001) compared with the patients with rigid lenses. In mesopic conditions with and without glare, it increased by 3.9 and 3.0 times (95% PI 1.9-7.8 and 1.6-5.9, respectively, P<0.001) in the patients with foldable lenses as compared with the patients with rigid lenses. CONCLUSIONS: The foldable intraocular lenses have shown better contrast sensitivity than rigid lenses under both mesopic and photopic conditions with or without glare. Postoperatively, there was no significant difference in visual acuity concerning the types of the implanted intraocular lenses.

Contrast Sensitivity↗

Reticulocyte rigidity and passage through endothelial-like pores.

The importance of cell rigidity in regulating the release of reticulocytes from the bone marrow has been investigated in a model system. Reticulocytes were obtained from phlebotomized rabbits and separated from whole blood by discontinuous density gradient centrifugation. The mechanical properties of the cells were tested. Using single-cell micromechanical techniques, the membrane elastic rigidity and the viscoelastic response of reticulocyte and mature cell populations were measured. The reticulocyte membranes were more rigid than the mature membranes, but the reticulocyte properties were heterogeneous, and some cells exhibited behavior indistinguishable from the mature cells. The mean time constant for viscoelastic recovery was the same for reticulocytes as for mature cells, but the variability within the reticulocyte population was greater. The possible influence of this increased rigidity on cell egress from the bone marrow was tested using an in vitro model of the thin endothelial pores found within the marrow. A silicon wafer approximately 0.1 microns in thickness and containing a small (1.2-microns diameter) pore in its center was cemented over the tip of a large (15.0-microns ID) micropipette. The passage of cells through the pore was observed as a function of the pressure across the pore. Consistent with the difference in mechanical properties, the reticulocytes required greater pressures (as great as 4.0 mm Hg compared with less than 1.0 mm Hg) and took longer to traverse the pore. These measurements support the postulate that deformability is important in the regulation of the release of cells from bone marrow.

Animals↗

Ineffective ventilation during conscious sedation due to chest wall rigidity after intravenous midazolam and fentanyl.

Chest wall rigidity has been reported after the administration of high-dose intravenous fentanyl. This case report supports the observation that low-dose intravenous fentanyl may also cause chest wall rigidity. The treatment of chest wall rigidity with naloxone or neuromuscular blocking agents is controversial. A discussion of the management of fentanyl-induced chest wall rigidity is presented.

Adult↗

Comparison of relapse in bilateral sagittal split osteotomies for mandibular advancement: rigid internal fixation (screws) versus inferior border wiring with anterior skeletal fixation.

A retrospective study of 28 patients treated by bilateral sagittal split ramus osteotomies for mandibular advancement and stabilized by two different methods of fixation was performed. Fourteen patients received rigid fixation, and 14 patients had inferior border wiring with anterior skeletal fixation. The postoperative and long-term cephalograms (greater than 6 months) were analyzed in a horizontal and vertical direction for relapse. In the horizontal direction, the rigid group experienced a 1.5% relapse in point B and a 3.2% relapse in pogonion. In the vertical direction, the rigid group experienced a 4% relapse in point B and a 9% relapse in pogonion, while the wire osteosynthesis group had a 13% relapse in point B and a 6% relapse in pogonion. These results support the belief that rigid fixation is more stable than is wire osteosynthesis and that it helps prevent relapse in the long-term results.

Bone Screws↗

Comparison of rigid and flexible rings for annuloplasty of the porcine mitral valve.

Seven rigid (Carpentier) and six flexible (Duran) annuloplasty rings were implanted in healthy pigs. First, in the intact pig, cinefluoroscopy was used to record movements of the anulus. Results were compared with data from three pigs instrumented with a continuous radiopaque marker on the anulus. Pump function of all hearts with annuloplasty rings and function of the mitral valve were studied 4-6 weeks after the operation, first in the exposed heart and then subsequently in the isolated heart in a perfusion chamber at maximal filling pressure and normal or low arterial pressure. Separation of the blood-perfused coronary circulation from the crystalline solution pumped by the left heart allowed videoendoscopy of the working valve. Flexible rings interfered less with normal movements of the mitral anulus than rigid rings and caused less impairment of filling of the basal part of the ventricle, and the unloaded stroke volume was 16% larger. For normal arterial pressures, the differences were smaller and will be difficult to detect in clinical situations. A stiff anulus was seen to be pushed underneath the aortic valve during systole, which caused a mild subvalvular obstruction. The mean diastolic pressure gradient across rigid annuloplasty rings was slightly larger than across flexible rings of the same or slightly smaller diastolic size. Rigid rings change the pattern of movement of the leaflets; the mural leaflet remains immobile throughout diastole. Although Duran rings interfere less with valvular function and filling of the basal part of the ventricle than do Carpentier rings, the differences are small and probably only of limited clinical importance.

Animals↗

Open-mindedness, rigidity, and the tendency to change inferences among psychiatric nursing staff: a pilot study.

To test the relationship between open- and closed-mindedness, between rigidity and nonrigidity, and the tendency of psychiatric nursing staff to alter inferences when given additional information about a patient, the Dogmatism Scale, Form E, And the Gough-Sanford Rigidity Scale were presented to 120 psychiatric nursing staff members, all employed and working directly with patients. Low-dogmatic subjects changed their inferences regarding patient behavior significantly more than high-dogmatic subjects. Although high-rigid subjects changed their inferences about patient behaviour more than low-rigid subjects, the relationship was not significant.

Attitude of Health Personnel↗

The effect of rigidity on fracture healing in external fixation.

Knowledge of the basic biomechanics of external fixation is necessary to obtain the full benefits of the technique for bone fracture treatment. The rigidity of external fixation, including pin-bone interface stresses, is discussed and bone healing and remodeling under different fixation stiffnesses and fracture gap conditions are described. The rigidity of fixation ultimately depends on the biomechanical characteristics of the fracture, the accuracy of reduction, and the amount of physiologic loading. Comparative experiments using a canine tibial fracture model have suggested that fixation rigidity is important in early bone healing and in the prevention of pin loosening. Bone union can be achieved under external fixation through different pathways, ranging from callus-free gap healing under a rigid neutralization configuration to direct-contact healing with periosteal new bone formation under axially dynamized stable fixation. Cortical reconstruction by secondary osteons seems to be important for the ultimate strength of the bone union.

Animals↗