Color vision in civil aviation

Color vision deficiency (CVD) is a condition that results in individuals being unable to distinguish differences between certain colors. Occupational color vision standards were introduced in aviation in 1919 by The Aeronautical Commission of the International Civil Air Navigation Authority. Concern has been expressed during the last few years that the current color vision standards in aviation may be too stringent and, at the same time, also variable across the world. The tests employed do not always reflect the tasks pilots encounter in today’s aviation environment. This ambiguity leads to the possible exclusion of deserving applicants for selection as aircrew. The compatibility of CVD with aircraft crew is assessed by medical personnel using clinical diagnosis tests on the ground level. These clinical tests were developed specifically to detect the presence, nature, and severity of CVD. No clinical tests yet provide a measure of operational performance in operating an aircraft. Arbitrary pass marks have been assigned to clinical tests such that a failing candidate will either be subject to operational restrictions or excluded completely. The prescribed clinical tests and associated pass marks vary considerably between regulators. While an individual may be subject to no restrictions in one jurisdiction, they may be excluded in another. This article highlights newer diagnostic techniques adopted by different countries for assessing color vision to see for the scope of evidence-based guidelines for minimum color vision requirements for flight crew as well as for civil aviation in India.     

Avoiding unfavourable outcomes in liposuction

The origin of liposuction can be traced to an adverse event by Dujarrier in 1921 when he used a uterine curette to remove fat from the knees of a ballerina ending in an amputation secondary to damage of the femoral artery. The history of liposuction since then has been one of avoiding complications and optimising outcome. After this adverse event, liposuction was abandoned until the 1960''s when Schrudde revived the practice using small stab incisions and sharp curettage with the secondary suction to aspirate the freed tissue. This technique was associated with a high incidence of complications especially seroma and skin necrosis. Illouz then replaced the curette with a blunt cannula connected to vacuum pump thus avoiding the complications of a sharp curette. Despite the presence of various techniques for liposuction, suction assisted liposuction (SAL) is still the standard technique of liposuction. This article aims to discuss literature regarding the various aspects of liposuction (SAL) and to highlight the salient points in the literature and in the senior author''s experience in order to avoid unfavourable outcomes in liposuction. A literature review on avoiding complication is in liposuction including some of the seminal papers on liposuction. Liposuction is generally a safe procedure with reproducible outcome. Just like any surgical procedure it should be treated with the utmost care. Illouz published 10 commandments for liposuction in 1989 and we review these commandments to demonstrate how liposuction has evolved.KEY WORDS: Complications, liposuction, suction assisted liposuction     

Trochlear Inclination Angles in Normal and Dysplastic Knees

Trochlear morphology impacts component position in patellofemoral arthroplasty. We devised a measurement of the trochlear inclination angle (TIA) and determined the average TIA in normal and dysplastic knees. Three hundred twenty-nine consecutive magnetic resonance imagings of normal and dysplastic knees were evaluated. The TIA was measured by 2 reviewers. The Student t test was used, and intraobserver reliability measurements were made. The mean TIA in normal and dysplastic knees was internally rotated 11.4° (range, 6°-20°) and 9.4° (range, 4°-15°), respectively. The mean TIA did not differ significantly by sex or age. Trochlear inclination angles in both normal and dysplastic knees tend toward internal rotation. Positioning a trochlear patellofemoral arthroplasty component flush with the articular surface of the native trochlea would result in internal rotation malposition.     

Prospective Study of Unplanned Admission to the Intensive Care Unit after Total Hip Arthroplasty

The morbidity associated with elective total hip arthroplasty (THA) may result in intensive care unit (ICU) admission. A total of 175 consecutive THA patients were prospectively triaged to either an ICU bed or routine post-operative floor according to admission criteria based on a prior published study of 1259 THA patients. Primary end points were a reduction in unplanned ICU admission, as well as major complications. With our triage model, the rate of unplanned ICU admissions dropped from 7.1% to 2.2% (P = 0.013). The as-treated odds of unplanned admission pre- versus post-intervention were 3.2 (1.2, 10.6). The complication rate fell from 12.5% to 2%, and the mortality index decreased from 4.77 to 1.62. Triage according to selected risk factors affects a reduction in unplanned ICU admissions and major complications after THA.     

Morphological Differences between Ruptured and Unruptured Basilar Bifurcation Aneurysms

Background Aspect ratio (AP), daughter artery ratio (DA), and lateral angle ratio (LA) have been reported in middle cerebral artery bifurcation aneurysms to correlate with rupture status.Objective To study the differences in AP, DA, LA, and aneurysm orientation between ruptured and unruptured basilar bifurcation aneurysms.Methods Three-dimensional (3D) angiograms of patients with basilar bifurcation aneurysms were analyzed for AP, DA, and LA. Aneurysm projection was classified as type A if the long axis of aneurysm was along basilar artery and type-B if otherwise.Results Thirty-one ruptured and 17 unruptured aneurysms were analyzed. The APs were significantly different (p = 0.008), 2.63 ± 1.1 for ruptured aneurysms and 1.7 ± 0.55 for unruptured aneurysms. AP ≥ 1.9 correlated with rupture status with 68% sensitivity and 70% specificity. Type-A configuration was significantly associated with ruptured aneurysms with an odds ratio (OR) of 5.9. LAs were 0.9 ± 0.4 and 1.4 ± 0.8 for ruptured and unruptured aneurysms, respectively, and the difference tended to be significant (p = 0.56). DAs were 1.25 ± 0.22 and 1.21 ± 0.19 for ruptured and unruptured aneurysms without any statistical difference.Conclusion AP > 1.9, type-A configuration, and lower LA is associated with ruptured basilar bifurcation aneurysms. DA did not differ between ruptured and unruptured aneurysms