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PubMed1998

A comparison of rigid -v- video thoracoscopy in the management of chest trauma.

Between December 1, 1994 and April 1,1998, 44 thoracoscopic procedures were performed in 42 patients following chest injuries. Indications included exploration in 15, retained haemothorax in 10, continued bleeding after chest tube placement in 3, air leak in 5 and empyema in 11. Video thoracoscopy was used in 24 cases and rigid thoracoscopy in 20, including 14 patients in whom video thoracoscopy was contraindicated. There was no difference in the operative times, length of stay or incidence of complications. Two formal and 3 "mini" thoracotomies were used in the video thoracoscopy group. Three "mini" thoracotomies were required in the rigid thoracoscopy group. Rigid thoracoscopy is an effective tool that, in selected cases, increases the utility of thoracoscopy in the management of chest trauma and its complications.

Contraindications↗

PubMed1983

Nocturnal penile rigidity measured by the snap-gauge band.

Nocturnal penile tumescence is used commonly to evaluate erectile dysfunction. However, this test is not equivalent to erection since it measures circumferential change only rather than the crucial variable of penile rigidity. We present a new concept in the measurement of penile rigidity--the capability of a patient during sleep to break a band furnished with pre-set snap-gauges with different release-force constants applied around the penile shaft. The snap-gauge band was tested simultaneously with the recording of nocturnal penile tumescence measuring penile rigidity rather than tumescence.

Adult↗

PubMed2003

Intrapalpebral migration of a rigid gas-permeable contact lens resulting in an eyelid mass.

PURPOSE: To report a case of an eyelid mass that was found to be a rigid gas-permeable contact lens that had migrated into the intrapalpebral tissue and to provide a brief review of the literature on intrapalpebral migration of contact lenses. DESIGN: Interventional case report and review of the literature. METHODS: The case is described, and the literature is reviewed. MAIN OUTCOME MEASURES: Clinical presentations and mechanisms of intrapalpebral contact lens migration are discussed. RESULTS: A patient had a mass on the left upper lid 3 years after she stopped wearing gas-permeable contact lenses. Orbital magnetic resonance imaging (MRI) showed a curvilinear signal in the area of the mass. Surgical exploration revealed a rigid gas-permeable contact lens entrapped within a fibrous capsule located within the eyelid tissue. A review of the literature revealed several reports of intrapalpebral migration of hard contact lenses, but to our knowledge, this is the first such migrated lens to be imaged on MRI. CONCLUSIONS: Intrapalpebral contact lens should be in the differential diagnosis of upper eyelid mass in patients with a history of contact lens wear. Magnetic resonance imaging may be a useful modality for imaging these rigid gas-permeable lenses.

Aged↗

PubMed1989

Increased scleral rigidity and age-related macular degeneration.

The coefficient of scleral rigidity of the eyes of 29 patients with age-related macular degeneration (ARMD) was significantly higher than the rigidity of 25 control patients, frequency matched for age. The data suggest that an increased scleral rigidity may be a significant risk factor for the development of the disorder.

Aged↗

PubMed1992

Complex orbital fracture repair using rigid fixation of the internal orbital skeleton.

Large orbital fractures involving more than one orbital wall are frequently associated with enophthalmos and vertical globe dystopia. The authors repaired 22 orbits in 20 patients using the technique of rigid fixation of the internal orbital skeleton. Eleven orbits were reconstructed with titanium or vitallium implants that were custom-shaped to span the bony defect and fixed to the orbital rim. Seven orbits were reconstructed with bone grafts rigidly supported by a miniplate, and, in four cases, direct lag screw support of bone grafts was used. The intraoperative goal was to restore the native orbital anatomy and volume. Autologous calvarial bone grafts were used to supplement the repair to achieve the desired volumetric effect and to cover additional wall defects. A reoperation for additional orbital augmentation was needed in one enophthalmic and one anophthalmic orbit. There were no cases of overcorrection, migration, infection, or extraocular muscle entrapment. In complex orbital fractures, the technique of rigid internal orbital fixation appears to yield a stable and predictable result with the prevention of postoperative globe malposition.

Adult↗

PubMed1996

Stability of orthognathic surgery: a review of rigid fixation.

The use of rigid fixation with orthognathic surgery was greeted by both excitement and healthy concern when it began to find its way into the literature approximately 10 years ago. The purpose of this paper is to review the literature and make comments based on the experience of the senior author on whether one of the early premises was true. Has rigid fixation improved stability with orthognathic surgery? The authors chose to examine mandibular advancements treated with a bilateral sagittal split osteotomy and maxillary osteotomies treated with a Le Fort I osteotomy. When compared to wire osteosynthesis, rigid fixation has improved stability; however, the individual move associated with the osteotomy must be considered. In some cases, auxiliary techniques should be used to ensure stability. Condylar resorption with mandibular advancement continues to be an area of concern.

Bone Plates↗

PubMed2001

Rigid bronchoscopy in the twenty-first century.

Rigid bronchoscopy, a procedure more than 100 years old, now has been performed in three centuries. The "open tube" bronchoscope provides safe access to the lower airways and has proved to be compatible with newer, more sophisticated therapies as they have been introduced into the practice of bronchology. The twenty-first century surely will provide the bronchoscopist with exciting new diagnostic and therapeutic tools for the management of lung diseases, and it is likely that the rigid bronchoscope will continue to play an important role in delivering these tools to the airways. Pulmonologists need to appreciate the use of this classic instrument and prevent rigid bronchoscopy from becoming a forgotten art.

Bronchoscopes↗

PubMed1993

Rigid skeletal fixation of fractures.

Rigid skeletal fixation of facial fractures has evolved from the principles established in orthopedics. It has taken a long time to develop rigid internal fixation devices that provide stability combined with safety. The application of rigid skeletal fixation to the facial skeleton requires the surgeon to pay strict attention to detail, which may add a small time increment to the procedure. However, the benefits to patients of having early use of the jaws and exact placement of bony segments seem to outweigh the disadvantages. The future of this constantly developing field will almost certainly center around technologic innovations that will make the application of fixation devices easier. It is likely that future research will provide devices that are more biocompatible, and perhaps just over the horizon, devices that are bioresorbable.

Bone Plates↗

PubMed1993

Evaluation of rigid internal fixation of mandible fractures performed in the teaching laboratory.

Rigid internal fixation of mandible fractures is advocated as an effective means of providing undisturbed healing and immediate function. However, its application in the clinical setting has resulted in many technique-related failures. To determine the reasons for clinical failure and to help develop improved means of providing successful fixation, the results of plate application in the teaching laboratory were evaluated. Seventy-four surgeons taking the AO/Association for the Study of Internal Fixation (AO/ASIF) maxillofacial course in Davos, Switzerland and 56 surgeons taking the advanced AO/ASIF course in Naples, FL applied rigid internal fixation devices to a mandibular fracture model. Treatment was evaluated for anatomic morbidity and effectiveness. In Davos, 92 of 121 subcondylar, body, symphysis, and ramus fractures (76%) were treated effectively. This included 22 of 34 symphysis fractures (65%). In Naples, 11 of 28 symphyseal fractures (39%) were fixed effectively with lag screws without anatomic morbidity. Technique failure is a frequent event in the application of rigid internal fixation devices to mandible fractures. Lag screw fixation of symphyseal fractures had a particularly high rate of technique-related failure.

Bone Plates↗

PubMed1990

A 3-year evaluation of skeletal stability of mandibular advancement with rigid fixation.

The postsurgical changes associated with mandibular advancements using the sagittal ramus osteotomy and rigid fixation were evaluated. This retrospective study was based on examination of lateral cephalometric radiographs of 19 individuals (16 females and 3 males) with a mean age of 26.6 years. These radiographs were evaluated presurgically, immediately postsurgery, and 3 years postsurgically (2 years, 9 months to 4 years, 5 months). The mean amount of sagittal surgical advancement was 6.7 +/- 2.3 mm, and the mean amount of postsurgical relapse was 1.3 +/- 2.0 mm, representing a 14% relapse of the original surgical advancement. However, individual variation in the amount and direction of movement of the mandible was found during the follow-up period. Postsurgical relapse was found to be related to the amount of surgical advancement. Linear-regression analysis between these two variables resulted in an R2 value of 0.448. Fourteen of the subjects relapsed in the posterior direction, with 2 relapsing more than 50% of the surgical advancement. Five of the subjects moved further anteriorly, with 1 advancing as much as 50% more than the original advancement. The findings of this study suggest that mandibular advancement with the sagittal ramus osteotomy and rigid fixation does not provide consistently stable postsurgical results. However, when compared with previously reported relapse studies using nonrigid fixation techniques, rigid fixation yielded superior results.

Adolescent↗

PubMed1989

Internal screw fixation: comparison of placement pattern and rigidity.

Multiple screw placement patterns and techniques have been described for fixation of the sagittal split ramus osteotomy. This study evaluated transverse strength (rigidity) of six groups of simulated sagittal osteotomies fixed with different screw patterns and placement techniques. Osteotomies fixed with screws placed in an inverted L pattern were significantly more rigid than those fixed with screws placed in a linear pattern or K-wires placed in a triangular pattern (P less than .05). No significant difference in rigidity was noted between compression and bicortical screws placed in identical patterns.

Animals↗

PubMed1997

Rigid fixation and strain patterns in the pig zygomatic arch and suture.

PURPOSE: In orthognathic surgery, rigid fixation is routinely used to hold together bone fragments that may experience heavy force from attached masticatory muscles. Internal fixation plates are assumed to hold bony parts rigidly, but the mobility at such sites subjected to normal masticatory function has not been measured. The purpose of this study was to investigate in vivo the degree to which a linear plate immobilizes separated bones, specifically sutures. MATERIALS AND METHODS: Three female miniature pigs (Sus scrofa) had 1.3-mm Synthes titanium plates placed across the suture in the zygomatic arch. Foil strain gauges were used to record load deformation in the zygomatic and squamosal (temporal) bones and across the vertical and horizontal parts of the suture. Strain was recorded in vivo during mastication and in anesthetized pigs with electrical stimulation of masticatory muscles. RESULTS: Strain at the suture was not reduced from normal levels. The plate induced increases in strain within the bones, but the changes were slight. CONCLUSION: The results indicate that linear "rigid fixation" does not immobilize sutures.

Animals↗

PubMed1999

Stability of the Le Fort I maxillary osteotomy after rigid internal fixation.

PURPOSE: The purpose of this study was to evaluate the postsurgical stability of the Le Fort I osteotomy with impaction in which rigid internal fixation was used for stabilization. MATERIALS AND METHODS: Lateral cephalograms of 19 patients were evaluated. Descriptive statistics were compiled that included absolute linear and angular measurements as well as absolute changes in measurements for successive cephalometric radiographs. Comparisons were made from 1) presurgery to immediate postsurgery, 2) immediate postsurgery to splint removal, 3) splint removal to longest follow-up, and 4) immediate postsurgery to longest follow-up. Repeated measures analysis of variance were used to describe significant differences for absolute changes in measurements. RESULTS: All surgical movements were significant except for horizontal position of dental structures, horizontal position of the posterior mandible, and posterior vertical facial height. All significant movement from immediate postsurgery to splint removal was secondary to removal of the occlusal splint. Changes were minimal from splint removal to longest follow-up, with only 3 of 24 measurements showing statistically significant differences. These measurements related to tooth position and were affected by postsurgical orthodontics. The data derived from this study were also compared with those found in similar studies in which fixation was by wire osteosynthesis. CONCLUSIONS: The magnitude of postoperative movement was considerably less with rigid internal fixation than that reported with the use of wire fixation. This is attributed to the increased stabilizing effect of rigid internal fixation.

Bone Plates↗

PubMed1999

Condylar position with rigid fixation versus wire osteosynthesis of a sagittal split advancement.

PURPOSE: In this randomized clinical study, two groups of patients who underwent a bilateral sagittal split osteotomy and either wire osteosynthesis or rigid fixation were compared. PATIENTS AND METHODS: Cephalometric radiographs obtained before surgery, immediately after surgery, and at 8 weeks, 6 months, and 1 and 2 years after surgery were available for 125 of these patients, 63 with wire fixation and 62 with rigid fixation. All were traced by an independent examiner, and vertical and horizontal changes in condylar position were recorded for each period. RESULTS: Condylar movement was slightly different with the two fixation techniques beyond 8 weeks postsurgery, but the ultimate position of the condyle was not different. The condyles in both groups moved posterior and superior. There initially was a correlation between the amount of advancement and the amount the condyle moved inferior in both groups, but this diminished with time. In addition, there was a weak but significant positive relationship between forward rotation of the proximal segment and superior condylar position immediately after surgery, which did not exist at later periods. CONCLUSIONS: Whether wire osteosynthesis or rigid fixation was used, the ultimate condylar position was posterior and superior after a bilateral sagittal split osteotomy to advance the mandible. No single factor could be identified to account for this change. It is suggested that change in mechanical load may have resulted in remodeling and adaptation of the condyles.

Adolescent↗

PubMed1986

The rigid spine syndrome and Emery-Dreifuss muscular dystrophy.

We present five patients, three of whom suffered from a rigid spine syndrome and two from Emery-Dreifuss muscular dystrophy. One patient with rigid spine syndrome showed a nonprogressive course, normal cardiac rhythm and mild myopathic changes in muscle histology, while in the other two patients there was a rapidly progressive course, sinus tachycardia without cardiac conduction defects and marked fiber necrosis in muscle histology. The two patients suffering from Emery-Dreifuss muscular dystrophy showed a very mildly progressing course, myopathic changes in muscle histology, cardiac conduction defects and deviations in electrocardiograms. These findings show that rigid spine syndrome can be distinguished from Emery-Dreifuss muscular dystrophy.

Adolescent↗

PubMed2002

The in vivo and in vitro interactions of elastic and rigid vesicles with human skin.

Elastic vesicles are the most novel development in vesicular systems design for dermal and transdermal drug delivery. However, interactions between these vesicles and human skin are not yet fully understood. In this study, the in vivo and in vitro interactions between elastic-, rigid vesicles and micelles with human skin were investigated. Vesicle and micelle solutions were applied onto human skin in vitro and in vivo. Subsequently, a series of tape strippings were performed, which were visualised by freeze fracture electron microscopy (FFEM). The results showed no ultrastructural changes in skin treated with rigid vesicles. Skin treated with elastic vesicles, however, showed a fast partitioning of intact vesicles into the deeper layers of the stratum corneum (SC), where they accumulated in channel-like regions. Only little vesicle material was found in the deepest layers of the SC, suggesting that the partitioning of intact vesicles from the SC into the viable epidermis is unlikely to happen. Treatment with micelles resulted in rough, irregular fracture planes. Similar results were obtained in vitro and in vivo, indicating an excellent in vitro/in vivo correlation. These results support the hypothesis that elastic vesicles have superior characteristics to rigid vesicles for the interaction with human skin. Elastic vesicles and micelles demonstrated very different interactions with human skin and hence probably also have different mechanisms of action for the enhancement of drug transport.

Buffers↗

PubMed2003

A randomized trial evaluating rigid immobilization for pelvic irradiation.

BACKGROUND: Accuracy and reproducibility of the patient's position is fundamental to the successful delivery of radiation therapy. In recent years, a number of pelvic immobilization techniques have been developed. Few have been evaluated in randomized trials, and many of these studies have produced contradictory and inconclusive results. PURPOSE: To assess whether the use of rigid immobilization devices improve the accuracy and reproducibility of prostate irradiation to a clinically useful degree. METHODS AND MATERIALS: A total of 100 patients receiving radical irradiation for either prostate or bladder cancer were randomized to be treated with or without the use of rigid immobilization (RI) devices. Of these, 96 patients were suitable for analysis. The control group consisted of the patients being simulated and treated in the prone position with no immobilization devices. Patients randomized to the immobilized arm were simulated and treated prone using a customized Uvex cast of the pelvis as well as ankle- and shoulder-stabilizing devices. Weekly orthogonal port films (PFs) were obtained for each patient. Using previously specified bone landmarks, we measured variations in the isocenter position on each PF compared with the simulation film. The assessors were unaware of the treatment assignment. Patient comfort, skin toxicity, and treatment times were recorded. RESULTS: The average simulation-to-treatment deviation of the isocenter position was 8.5 mm in the control group and 6.2 mm in the immobilization group (p < 0.001). In the control arm, 30.9% of port films had isocenter deviations >10 mm compared with 10.6% in the immobilized arm (p = 0.001). For the control group, average deviations in the anteroposterior, right-left, and superior-inferior directions were 5.2 mm, 3.2 mm, and 4.3 mm, respectively, compared with 2.9 mm, 2.1 mm, and 3.9 mm for the immobilized group (p = <0.001, p < 0.001, p = 0.55). The RTOG skin reaction was greater with in patients with a cast (28% having Grade 2 toxicity vs. 10% in the control arm), although this was not statistically significant (p = 0.68). Patients in both groups found the treatment position comfortable: 90% in the immobilized group and 87% in the control group scored the treatment position either reasonably or very comfortable. Treatment times were very similar between the two groups: the average treatment time was 15.5 min in the control group vs. 16.1 min in the immobilized group (p = 0.82). CONCLUSIONS: The use of rigid immobilization improves the accuracy of treatment delivery for the prone position, especially in the anteroposterior direction. Of clinical importance, the number of major deviations >10 mm (that is, that would result in a geographic miss) was reduced from 31% to 11%.

Aged↗

PubMed1982

A phalangeal fracture model--quantitative analysis of rigidity and failure.

Nine types of internal fixation techniques were tested in 4-point bending using a pig metacarpal model for phalangeal fractures. Levels of bending rigidity and bending moments at failure were determined, and the modes of failure are described. Plate and screw fixation afforded the greatest rigidity, and epiphyseal fractures occurred, leaving intact the test section. Flexible wire loop fixation failed by wire cutting into bone when a square knot was used. Twisted wire unraveled when placed in tension. Depending on the fracture type and the wire placement. Kirschner wires failed either by slipping in the bone, twisting in the bone cortex, or bending at the bone cortex interface. Rigidity varied widely depending on the way in which the wires were employed.

Animals↗