Anatomical Mapping of the External Obturator Footprint: A Study In Cadavers with Implications for Direct Anterior THA

BackgroundThe external obturator footprint in the trochanteric fossa has been suggested as a potential landmark for stem depth in direct anterior THA. Its upper border can be visualized during surgical exposure of the femur. A recent study reported that the height of the tendon has little variability (6.4 ± 1.4 mm) as measured on CT scans and that the trochanteric fossa is consistently visible on conventional pelvic radiographs. However, it is unclear where exactly the footprint of this tendon should be templated during preoperative planning so that it can be useful intraoperatively.Questions/purposesIn this study, we sought: (1) to provide instructions on exactly where to template the external obturator footprint on a preoperative planning radiograph, and (2) to confirm the small variability in height of the external obturator footprint found on CT scans in a cadaver study.MethodsTwo-dimensional (2-D) and three-dimensional (3-D) imaging was used to map the anatomy of the external obturator footprint. This dual approach was chosen because of their complementarity; conventional 2-D radiographs translate to clinical practice but 3-D navigation-based digitalization combined with CT allows for a better understanding of the cortical lines that comprise the outline of the trochanteric fossa. In 12 (four males, mean age 80 years, range 69 to 88) formalin-treated cadaveric lower extremities including the pelvis, the external obturator tendon was dissected, and the top and bottom end of its footprint marked with two small needles, and calibrated radiographs were taken. For another five (three males, mean age 75.7 years, range 61 to 91) fresh-frozen cadaveric lower extremities, including femoral reflective marker frames, CT scans were obtained and the exact location of the external obturator footprint was recorded using 3-D navigation-based digitalization. Qualitative analysis of both imaging modalities was used to develop instructions on where the external obturator footprint should be templated on a preoperative planning radiograph. Quantitative analysis of the dimensions of the external obturator footprint was performed.ResultsThe lowest point of the external obturator footprint was consistently found (± 1 mm) at the intersection of the vertical line comprised of the lateral wall of the trochanteric fossa and the oblique line formed by the intertrochanteric crest and therefore allows templating of this structure on the preoperative planning radiograph. The median (range) height of the footprint measured 6.4 mm and demonstrated small variability (4.7 to 7.6).ConclusionsWe suggest templating a 6.4-mm circle with its bottom on the intersection described above.Clinical RelevanceThe distance between the templated shoulder of the stem and the top of the circle can be used intraoperatively for guidance. Discrepancy should lead to re-evaluation of stem depth and leg length. Future work will investigate the usability, validity, and reliability of the proposed methodology in daily clinical practice.     

Phylogenetic analysis of hepatitis D viruses indicating a new genotype I subgroup among African isolates.

Genetic analysis was performed on 13 hepatitis D virus (HDV) isolates from Ethiopia, Somalia, Jordan, Kuwait, Bulgaria, Moldavia, and Sweden. The complete nucleotide sequence and genomic organization are described for the first time for two African HDV isolates. Phylogenetic analysis showed all the African isolates to be intrarelated and to form a novel group within HDV genotype I; the suggested designation for this group is IC. The genetic distance to previously described type I isolates was about 0.15. The HDV genotype I isolates (total of 22 examined) phylogenetically formed three clusters, each of them corresponding to certain geographic regions; the "western" group consisted of six HDV isolates from western Europe and the United States plus one from Kuwait; the "eastern" group consisted of two isolates from Moldavia and one each from Bulgaria, Nauru, mainland China, and Taiwan; and the "African-Middle East" group consisted of six HDV isolates from Ethiopia and one from Somalia, Jordan, and Lebanon.     

Neurotensin-like Peptides in the CNS of Lampreys: Chromatographic Characterization and Immunohistochemical Localization with Reference to Aminergic Markers

Neurotensin (NT)-like peptides in the CNS of the lamprey Lampetra fluviatilis were studied by radioimmunoassay (C-terminal specific NT antiserum), reverse-phase HPLC and immunohistochemistry. Multiple peaks of NT-immunoreactive (-ir) material were observed upon HPLC, of which a major peak eluted in the position of bovine NT. Immunofluorescence histochemistry showed that a monoclonal antibody recognizing the N-terminal (1 - 11) fragment of NT, as well as two polyclonal NT antisera labelled a large number of cell bodies in the periventricular area of hypothalamus, including the postinfundibular commissural nucleus and the ventral and dorsal hypothalamic nuclei. Additional groups of NT-ir cells were observed in the preoptic nucleus, the postoptic commissural nucleus, the mesencephalic tegmentum (L.fluviatilis), and in the spinal cord (L.fluviatilis and Ichtyomyzon unicuspis). Dense NT-ir fibre plexuses were present in the caudal hypothalamus, corpus striatum, ventral mesencephalon, and in the dorsal horn and lateral margin of the spinal cord. At the ultrastructural level the lateral spinal margin showed NT-ir terminal structures, which in most cases were not associated with synaptic specializations, although occasional synaptic contacts with unlabelled elements were found. The relation between NT-ir and monoamine-containing cells was examined with immunofluorescence double-staining, using antisera to tyrosine hydroxylase (TH), 5-hydroxytryptamine (5-HT), and histamine respectively. In the periventricular nuclei of hypothalamus numerous TH-, 5-HT-, as well as histamine-ir cells were located in close association with NT-ir cells, but none of the aminergic markers could be detected within NT-ir neurons. The chemical properties as well as the anatomical distribution of lamprey NT-like peptides show several similarities with those present in mammals, suggesting that NT-containing neuronal systems in the CNS developed early in vertebrate phylogeny.     

The reliability of auscultatory measurement of arterial blood pressure. A comparison of the standard and a new methodology

In 48 individuals with a wide range of arm circumferences blood pressure measured indirectly with two different cuffs was compared to direct intraarterial measurements. The two cuffs were a standard size cuff (12 X 35 cm) and a newly developed cuff, containing three rubber bags of different sizes, which automatically selects the appropriately sized bag in relation to arm circumference (Tricuff, Pressure Group AB, Sweden). The Tricuff correctly placed 42 of the 43 patients in the "normotensive" range, ie, diastolic blood pressure less than 90 mm Hg, whereas the standard cuff put only 33 of 44 patients in this range (P less than .005). The discrepancy was not only due to the expected better performance in patients with obese arms, but also in the subgroup of patients with arms in the range 22 to 31 cm, in which group both cuffs would measure blood pressure with a 12 cm wide rubber bag. The number of correctly identified "normotensive" patients was noticeably higher with the Tricuff than with the standard cuff (30/31 v 25/32, P = .053). The better specificity of the new cuff thus offers an improvement over the standard cuff. There are several potential clinical advantages of this, mainly that the risk of erroneously labelling normotensive individuals as hypertensive is reduced.     

Elévation de la tension artérielle lors de chirurgie sous garrot pneumatique: un mécanisme indépendant de la rénine?

Le but de ce travail a été d’évaluer l’efficacité du captopril dans la prévention de l’élévation de la pression artérielle lors de chirurgie du membre inférieur sous garrot pneumatique en anesthésie balancée. Vingt patients consécutifs ont été inclus dans cette étude et randomisés en deux groupes. L’un (n = 10), recevant un comprimé de captopril de 50 mg avec la prémédication, l’autre (n = 10), recevant un comprimé de placebo au même moment. Les différentes variables étudiées (tension artérielle, fréquence cardiaque) ont été mesurées continuellement. Cette étude a démontré, que le prétraitement par du captopril ne permet pas de prévenir une augmentation de la pression artérielle pendant la durée de gonflage d’un garrot pneumatique, les moyennes des tensions artérielles systoliques et diastoliques, à la fin de la période de gonflage du garrot, s’élèvent à 128 /86 et 128/81 dans le groupe captopril et dans le groupe placebo, respectivement. Ce résultat montre que le système rénine-angiotensine n’intervient pas, ou que peu, dans le phénomène d’augmentation des valeurs tensionnelles induite par un garrot pneumatique. The aim of this study was to evaluate the effectiveness of captopril for the prevention of the increase of arterial pressure during orthopaedic surgery requiring the application of lower limb tourniquets with balanced anaesthesia. Twenty consecutive patients were included in the study and were randomly divided into two groups. The first (n = 10) received 50 mg captopril orally together with the preanaesthetic medication, the second (n = 10) received a placebo at the same time. The different variables studied (arterial pressure, heart rale) were continuously measured. This study demonstrated that the pretreatment with captopril did not prevent an increase of the arterial pressure during the application of a tourniquet. The means of the systolic and diastolic arterial pressures at the end of the application of the tourniquet were 128/86 and 128/81 in the captopril group and the placebo group, respectively. This result shows that the renin-angiotensin system does not significantly contribute to the increase of the arterial pressure induced by a tourniquet.     

High exposures to organic solvents among graffiti removers

Summary The exposure to organic solvents among 12 graffiti removers was studied. Health effects were also assessed by structured interview and a symptom questionnaire. Blood and urine samples were collected at the end of the day of air sampling. The concentrations of dichloromethane, glycol ethers, trimethylbenzenes and N-methyl-2-pyrrolidinone in the breathing zone of each worker were measured during one working day. The 8-h time-weighted average exposure to dichloromethane ranged from 18 to 1200 mg/m³. The Swedish Permissible Exposure Limit value for dichloromethane is 120 mg/m3. The air concentrations of glycol ethers, trimethylbenzens and N-methyl-2-pyrrolidinone were low or not detectable. No exposure-related deviations in the serum concentrations of creatinine, aspartate transaminase, alanine transaminase, -glutamyl transpeptidase or hyaluronan or the urine concentrations of ₁-microglobulin, R2-microglobulin or N-acetyl--glucos-aminidase were found. Irritative symptoms of the eyes and upper respiratory tract were more prevalent than in the general population. This study demonstrates that old knowledge about work harzards is not automatically transferred to new professions. Another aspect is that the public is also exposed as the job is performed during daytime in underground stations. At least for short periods, bystanders may be exposed to high concentrations of organic solvent vapours. People with predisposing conditions, e.g. asthmatics, may risk adverse reactions.     

Tolerance of human fetal retinal pigment epithelium xenografts in monkey retina

Background: RPE transplantation offers the possibility of treating certain forms of retinal degeneration. Understanding how to optimize the surgical technique for performing RPE transplantation, especially in primates, is therefore of considerable interest. Methods: Fifteen patch RPE transplants were performed in six monkeys. The transplant sites were examined at follow-up by ophthalmoscopy, biomicroscopy, fluorescein angiography and histology. Foveal and peripheral retinal transplants were compared. Results: Human fetal RPE xenografts can survive without rejection for at least 6 months after transplantation in monkey retina. Such grafts form a basal lamina and make intimate contacts with the outer segments of the host. Both rods and cones retain a normal appearance when in contact with unrejected transplants. Rejection occurred in only 30% (3/10) of the peripheral but in 60% (3/5) of the foveal transplants. Conclusions: Cultured human fetal RPE patch transplants can survive and maintain local photoreceptor integrity for relatively long periods of time in monkey subretinal space without immunosuppression. Rejection, when it occurs, is more frequent near the fovea.     

Intelligence and temperament as protective factors for mental health. A cross-sectional and prospective epidemiological study

The Sjöbring system of personality dimensions measuring intellectual capacity, activity, impulsivity and sociability was used to study possible salutogenic (i.e. causes of health) effects. The study comprised 590 subjects investigated in 1947, 1957, 1972 and 1988–1989 in the Lundby project, an epidemiological study in Sweden. Psychiatric diagnoses were made in 1947, 1957 and 1972. Mental health was estimated in 1988–1989 using the concept love well, work well, play well and expect well. The Sjöbring dimensions were clinically assessed in 1972. Both in the concurrent study in 1972 and in the prospective study in 1988–1989 super capacity (high intellectual function), super validity (high activity level) and super solidity (low impulsivity) were statistically associated with lower frequencies of certain psychiatric diagnoses and a higher frequency of positive mental health. These variables are proposed to increase coping capacity, and therefore increase stress resilience.