Anteroinferior Quadrant Research Articles

Quantitative analysis of tympanic membrane disease using video-otoscopy.

To perform quantitative analysis of pathological changes in the tympanic membrane using video-otoscopic images. Prospective case-control study. Forty-two ears of children with chronic otitis media with effusion (OME) and 15 ears of normal children were included in this study. Tympanic membrane images were captured and digitized using a Welch-Allyn (Skaneatales Falls, NY) VDX-300 Illumination and Imaging system with S-VHS input to a MIRO DC 30 (Pinnacle Systems, Mountain View, CA) visual board in a Power PC-based computer. These images were visualized and recorded during static and pneumatic pressure changes. Quantitative analysis of tympanic membrane disease was performed using Image Pro Plus Imaging software (Media Cybernetics, Del Mar, CA). The measurements included area of the tympanic membrane and its quadrants, area of tympanic membrane involved by disease, angle formed at the umbo, and length of the malleus versus vertical length of the tympanic membrane. Tympanosclerosis was present in 57% of ears and occurred most frequently in the anteroinferior quadrant, but the maximum area of involvement was in the posteroinferior quadrant. The ratio of the angles formed at the umbo was significantly greater (P = .01) for the OME group compared with the control group. The ratio of the length of the umbo and the vertical length of the tympanic membrane was almost identical for the OME and the control groups (P = .4). Videootoscopic images can be used for quantitative analysis of tympanic membrane disease. The ratio of the posterior angle to the anterior angle formed at the umbo seems to be a more reliable indicator of post otitis media than is a reduced length of the long process of malleus.

Bone cement penetration of the acetabulum in total hip replacement. An experimental study.

Cones of cement passing through, or below, the acetabulum may be seen after total hip replacement and are due either to iatrogenic perforation of the wall or to substantial bony defects. An experimental study was undertaken to establish which structures might be affected by these cones. In 20 cadaveric specimens, the acetabula were divided into 4 quadrants and, after the cement was set, the structures within the pelvis were dissected. In the antero-inferior quadrant the cement impinged on either the obturator nerve or vein, or the external iliac vein. Anterosuperiorly, these structures and the external iliac artery were impinged. In the posterior quadrants, the obturator muscle and nerve, and vessels, were affected, and inferiorly the external obturator muscle was also involved. The size of the cones depended on the bony depth of the acetabulum. Compared with screws, the cement can cause late complications through heat necrosis and continuous friction. The posterosuperior quadrant is the safest area to make holes for anchoring the cup.

Tympanic membrane perforations in children

We have assessed children with perforations of the pars-tensa presenting to an otolaryngology clinic over a 7-year period. We found that over 70% of the perforations followed the insertion of a ventilation tube. Using a novel method of dividing the tympanic membrane into quadrants, we were able to assess the sites and grade the size of perforations. The most common site of involvement, in all perforations, was the antero-inferior quadrant. With the exception of perforations following the use of T-tubes, we found little difference between the sites, sizes and hearing levels of ventilation tube and non-ventilation tube related perforations. Larger perforations resulted in a greater degree of hearing loss.

外傷性鼓膜穿孔の臨床的検討

This is a retrospective study of 95 patients, aged 0 to 82 years, with traumatic tympanic membrane perforation.1) The ratio of direct to indirect injuries was 1:2.2) Most injuries were in the anteroinferior quadrant.3) Infection was a complication in 33%.4) Most of the perforations closed with conservative therapy. However, if the injury cannot be expected to close in 1 month, surgical repair should be performed.

Micropathologic changes of pars tensa in children with otitis media with effusion.

Clinical studies have supported a relationship between otitis media with effusion in children and chronic otitis media in adults. Although clinical studies are numerous, relatively little is known about the histopathologic changes of the tympanic membrane in otitis media with effusion. Tympanic membranes were taken from the intermediate zone of the anteroinferior quadrant of the tympanic membrane during surgery for placement of tympanostomy tubes in 30 children (age range, 4 to 10 years) who did not show any improvement after 3 months of conservative treatment for otitis media with effusion. Control specimens were taken from normal temporal bones at autopsy. All specimens were observed with light and electron microscopy. Histologic degeneration of the tympanic membrane of patients with otitis media with effusion occurred most often in the lamina propria and the submucosal layer. There was an increase in the thickness of the tympanic membrane as a result of edema and fibrosis of the submucosal layer. A decrease in the thickness of the outer and inner fibrous layers occurred in the lamina propria. The histopathologic changes observed in the lamina propria may result in a change in the elastic properties of the tympanic membrane.

Tympanostomy Tube Insertion: Anterosuperior vs. Anteroinferior Quadrant

We studied the extrusion rate of Paparella type I tympanostomy tubes in the anterosuperior quadrant compared to those placed in the anteroinferior quadrant in a prospective study. Thirty-five patients were evaluated. The duration (mean +/- SEM) in the anteroinferior quadrant was 211 +/- 18 days, whereas the duration in the anterosuperior quadrant was 211 +/- 11 days. We conclude that placement in the anterosuperior quadrant does not prolong duration of these tympanostomy tubes.

The Relationship of the Intrapelvic Vasculature to the Acetabulum

The use of screw-fixation acetabular components in total hip arthroplasty could increase the incidence of vascular injury because of the increased use of drills and screws placed into the acetabulum in close proximity to major vessels. Analysis of two illustrative case studies, anatomic specimen cross sections, and computed tomographic scans demonstrate which vessels are at risk of injury should the inner cortex of the pelvis be penetrated. The iliac vessels are at risk of injury when penetration of the inner cortex of the pelvis occurs in the anterosuperior region of the acetabulum. The obturator vessels are at risk when penetration occurs in the anteroinferior quadrant of the acetabulum. The vessels can be within 0.5 cm of the inner cortex of the pelvis and tend to become closer with advancing age. Damage to the intrapelvic vessels may cause profound blood loss and hypotension when screw-fixation acetabular components are used. Rapid identification and immediate surgical repair of vessel lacerations are essential in the treatment of this complication.

Vascular anatomy in the suboccipital region and lateral cervical puncture.

The theoretical risk of injuring the vertebral artery or anomalous vessels at lateral cervical puncture is assessed. In just less than 30% of vertebral arteries the vessel overlies the lateral aspect of the spinal canal between the first and second cervical vertebrae, usually the antero-inferior quadrant. Directing the spinal needle to the posterior third of the canal virtually eliminates the possibility of injuring this and most anomalous arteries traversing the region. The likelihood of inducing subarachnoid haemorrhage by injuring these vessels would appear to be considerably less in lateral cervical than in cisternal puncture.

Hearing loss in perforations of the tympanic membrane.

70 patients with dry central perforations have been studied to assess the hearing loss. The hearing loss is greater at the lower frequencies and increases with the size of the perforation. Malleolar perforations cause more hearing loss than the non-malleolar unless the perforation involves less than 10 per cent of the tympanic membrane surface area. Perforations of the postero-inferior quadrant cause more hearing loss than those in the antero-inferior quadrant.

THE CONDUCTING SYSTEM IN CONGENITALLY CORRECTED TRANSPOSITION

In five hearts with congenitally corrected transposition, histological examination of the interatrial septum revealed, anterior to the coronary sinus, a hypoplastic atrioventricular node which made no contact with ventricular myocardium. Atrioventricular connection was effected through a second, anteriorly situated, node-like structure located at the junction of the right atrioventricular orifice and left border of the right atrial appendage, and to the right of the pulmonary-artery root. The atrioventricular bundle coursed anterior to the pulmonary artery to reach the anterior part of the interventricular septum. In the four hearts with a ventricular septal defect the bundle descended in the anterior rim of the defect and bifurcated in relation to its antero-inferior quadrant The bundle branches were inverted. Avoidance of these areas in surgical repair of ventricular septa defects and correction of subvalvar pulmonary stenosis, in such cases, should reduce the risk o: traumatic heart-block.