Multi- and univariate analyses of the weekend effect for elective lower-limb joint replacements.

Introduction The weekend effect is a perceived difference in outcome between medical care provided at the weekend when compared to that of a weekday. Clearly multifactorial, this effect remains incompletely understood and variable in different clinical contexts. In this study we analyse factors relevant to the weekend effect in elective lower-limb joint replacement at a large NHS multispecialty academic healthcare centre. Materials and Methods We reviewed the electronic medical records of 352 consecutive patients who received an elective primary hip or knee arthroplasty. Patient, clinical and time-related variables were extracted from the records. The data were anonymised, then processed using a combination of uni- and multivariate statistics. Results There is a significant association between the selected weekend effect outcome measure (postoperative length of stay) and patient age, American Society of Anesthesiologists classification, time to first postoperative physiotherapy and time to postoperative radiography but not day of the week of operation. Discussion We were not able to demonstrate a weekend effect in elective lower-limb joint replacement at our institution nor identify a factor that would require additional weekend clinical medical staffing. Rather, resource priorities would seem to include measures to optimise at-risk patients preoperatively and measures to reduce time to physiotherapy and radiography postoperatively. Conclusions Our findings imply that postoperative length of stay could be minimised by strategies relating to patient selection and access to postoperative services. We have also identified a powerful statistical methodology that could be applied to other service evaluations in different clinical contexts.

Pregnancy outcomes using stallion epididymal sperm stored at 5 °C for 24 or 48 hours before harvest.

The cryopreservation of epididymal sperm can be useful in a variety of circumstances for ensuring genetic preservation of a valued stallion. Although early studies have reported pregnancy rates significantly lower than those achieved with cryopreserved ejaculated sperm, two recent studies report over 60% one-cycle pregnancy rates with epididymal sperm stored for 24 hours at 5 °C before harvest and cryopreservation. The aims of this study were to: (1) attempt to replicate the one-cycle pregnancy rate of over 60% using epididymal sperm cooled and stored within the epididymis for 24 hours before harvest and cryopreservation and (2) evaluate pregnancy outcome with sperm cooled and stored within the epididymis for 48 hours before sperm harvest and cryopreservation. Testicles were obtained from 13 stallions undergoing routine castration. The epididymides were stored at 5 °C for either 24 or 48 hours before sperm harvest and cryopreservation in an egg yolk and dimethylformamide-based freezing extender. Thirteen mares were bred on one cycle with cryopreserved epididymal sperm stored for 24 hours before harvest, and 10 of those 13 mares were also bred on a previous or subsequent cycle with samples from the same stallion that had been stored for 48 hours before harvest. Pregnancy occurred in 7 of the 13 inseminations of sperm stored for 24 hours before harvest, and in 4 of the 10 inseminations of sperm stored for 48 hours before harvest. The pregnancy rate using epididymal sperm stored for 24 hours before harvest is consistent with that of previous reports. In addition, these results provide evidence that pregnancies can be achieved when the epididymides are cooled and stored for 48 hours before sperm harvest and cryopreservation.

The incidence of noise generation arising from the large-diameter Delta Motion ceramic total hip bearing.

Noise generation has been reported with ceramic-on-ceramic articulations in total hip replacement (THR). This study evaluated 208 consecutive Delta Motion THRs at a mean follow-up of 21 months (12 to 35). There were 141 women and 67 men with a mean age of 59 years (22 to 84). Patients were reviewed clinically and radiologically, and the incidence of noise was determined using a newly described assessment method. Noise production was examined against range of movement, ligamentous laxity, patient-reported outcome scores, activity level and orientation of the acetabular component. There were 143 silent hips (69%), 22 (11%) with noises other than squeaking, 17 (8%) with unreproducible squeaking and 26 (13%) with reproducible squeaking. Hips with reproducible squeaking had a greater mean range of movement (p < 0.001) and mean ligament laxity (p = 0.004), smaller median head size (p = 0.01) and decreased mean acetabular component inclination (p = 0.02) and anteversion angle (p = 0.02) compared with the other groups. There was no relationship between squeaking and age (p = 0.13), height (p = 0.263), weight (p = 0.333), body mass index (p = 0.643), gender (p = 0.07) or patient outcome score (p = 0.422). There were no revisions during follow-up. Despite the surprisingly high incidence of squeaking, all patients remain satisfied with their hip replacement.

Skyline patellofemoral radiographs can only exclude late stage degenerative changes.

Accurate preoperative assessment of the patellofemoral joint is especially important in compartment specific knee arthritis. This study aims to show the actual intraoperative grade of patellofemoral cartilage damage that may be reliably detected or excluded by preoperative standard radiographic views. 100 consecutive knees awaiting arthroplasty underwent preoperative lateral and skyline radiographs and were scored using the Ahlback score. Intraoperative cartilage damage was assessed using the Collins score. The sensitivity and specificity were calculated for each grade of cartilage damage. Preoperative anterior knee pain and function were assessed and correlated to the degree of cartilage damage. The lateral radiograph shows poor sensitivity for all grades of disease (0.05-0.23). The skyline shows good sensitivity for grade 4 (large full thickness) damage (0.90) but decreases substantially for grades 1-3 (0.19-0.46). Significantly more people with skyline radiograph joint space narrowing complained of anterior knee pain than those with a normal radiograph (p<0.001). There was only a poor correlation between preoperative anterior pain and intraoperative patellofemoral cartilage damage (r=0.24). The lateral radiograph cannot exclude even large areas of full thickness cartilage damage whereas a normal skyline radiograph can reliably exclude significant (grade 4) patellofemoral disease and should be used in addition to the lateral view.

Pharmacokinetic profile and behavioral effects of gabapentin in the horse.

Gabapentin is being used in horses although its pharmacokinetic (PK) profile, pharmacodynamic (PD) effects and safety in the equine are not fully investigated. Therefore, we characterized PKs and cardiovascular and behavioral effects of gabapentin in horses. Gabapentin (20 mg/kg) was administered i.v. or p.o. to six horses using a randomized crossover design. Plasma gabapentin concentrations were measured in samples collected 0-48 h postadministration employing liquid chromatography-tandem mass spectrometry. Blood pressures, ECG, and sedation scores were recorded before and for 12 h after gabapentin dosage. Nineteen quantitative measures of behaviors were evaluated. After i.v. gabapentin, the decline in plasma drug concentration over time was best described by a 3-compartment mammillary model. Terminal elimination half-life (t(1/2γ) ) was 8.5 (7.1-13.3) h. After p.o. gabapentin terminal elimination half-life () was 7.7 (6.7-11.9) h. The mean oral bioavailability of gabapentin (± SD) was 16.2 ± 2.8% indicating relatively poor absorption of gabapentin following oral administration in horses. Gabapentin caused a significant increase in sedation scores for 1 h after i.v. dose only (P < 0.05). Among behaviors, drinking frequency was greater and standing rest duration was lower with i.v. gabapentin (P < 0.05). Horses tolerated both i.v. and p.o. gabapentin doses well. There were no significant differences in and . Oral administration yielded much lower plasma concentrations because of low bioavailability.

Tendinopathy and tears of the rotator cuff are associated with hypoxia and apoptosis.

The aim of this study was to investigate the occurrence of tissue hypoxia and apoptosis at different stages of tendinopathy and tears of the rotator cuff. We studied tissue from 24 patients with eight graded stages of either impingement (mild, moderate and severe) or tears of the rotator cuff (partial, small, medium, large and massive) and three controls. Biopsies were analysed using three immunohistochemical techniques, namely antibodies against HIF-1alpha (a transcription factor produced in a hypoxic environment), BNip3 (a HIF-1alpha regulated pro-apoptotic protein) and TUNEL (detecting DNA fragmentation in apoptosis). The HIF-1alpha expression was greatest in mild impingement and in partial, small, medium and large tears. BNip3 expression increased significantly in partial, small, medium and large tears but was reduced in massive tears. Apoptosis was increased in small, medium, large and massive tears but not in partial tears. These findings reveal evidence of hypoxic damage throughout the spectrum of pathology of the rotator cuff which may contribute to loss of cells by apoptosis. This provides a novel insight into the causes of degeneration of the rotator cuff and highlights possible options for treatment.

Sexual behavior and ejaculate characteristics in Pêga donkeys (Equus asinus) mounting estrous horse mares (Equus caballus).

The objectives were to (i) characterize sexual behavior of donkey stallions (jacks; Equus asinus) during on-farm semen collection using estrous horse mares (mares; Equus caballus); (ii) compare behavior of young (less experienced) versus older (more experienced) jacks; (iii) determine whether semen suitable for artificial insemination (AI) could be collected using mares; and (iv) determine the suitability of using mares in field collection of semen from jacks. Six Pêga jacks (3.5 to 16 yr old), previously conditioned to breed mares, were used. Mount mares were confirmed in estrus by a teaser horse stallion (stallion) and a jack. Semen was collected with an artificial vagina, at intervals of 48 to 72h (180 collections). The mean+/-SD (young [3.5 yr] vs. old [14 to 16 yr]) were Flehmen response frequency, 7.4+/-5.8 (8.1+/-3.0 vs. 7.0+/-2.0); number of mounts without erection, 1.1+/-1.3 (2.1+/-1.4 vs. 1.2+/-0.4, P<0.05); latency from first exposure to mare to full erection on the ejaculatory mount, 18.3+/-17.7min (25.3+/-21.3 vs. 12.2+/-6.2, P<0.05); latency from erection to insertion, 5.1+/-3.5sec (5.3+/-3.8 vs. 4.8+/-3.2); and duration of copulation from insertion to dismount after ejaculation, 25.4+/-7.8sec (22.1+/-2.9 vs. 28.1+/-9.3). In all jacks, sexual behavior was generally normal, with the notable absence of open mouth behavior. Mare estrous behavior was markedly less intense than that in the presence of a stallion and usually absent. Semen characteristics were gel free volume, 47.3+/-28.7mL; gel volume, 71.8+/-54.8mL; total motility, 84.3+/-6.0%; progressive motility, 74.3+/-74.5%; sperm vigor, 3.9+/-0.5 (scale 1 to 5); sperm concentration, 253x10(6) cells/mL; and total number of sperm, 10.3x10(9) cells. Copulation duration was significantly correlated with gel free volume (r=0.9) and gel volume (r=0.7). We concluded that (i) the sexual behavior of jacks during semen collection using mares was similar to that reported for natural mating to jennies, (ii) precopulatory and copulatory behavior for the young (less experienced) jacks and older (more experienced) jacks were generally similar (except number of mounts without erection and latency to full erection); (iii) semen obtained using mares as stimulus and mount females was similar to that reported with estrous jennies; and (iv) semen collection from previously conditioned jacks, using estrous mares, was appropriate for field collection of semen.

The morphological and immunocytochemical features of impingement syndrome and partial-thickness rotator-cuff tear in relation to outcome after subacromial decompression.

We assessed the predictive value of the macroscopic and detailed microscopic appearance of the coracoacromial ligament, subacromial bursa and rotator-cuff tendon in 20 patients undergoing subacromial decompression for impingement in the absence of full-thickness tears of the rotator cuff. Histologically, all specimens had features of degenerative change and oedema in the extracellular matrix. Inflammatory cells were seen, but there was no evidence of chronic inflammation. However, the outcome was not related to cell counts. At three months the mean Oxford shoulder score had improved from 29.2 (20 to 40) to 39.4 (28 to 48) (p < 0.0001) and at six months to 45.5 (36 to 48) (p < 0.0001). At six months, although all patients had improved, the seven patients with a hooked acromion had done so to a less extent than those with a flat or curved acromion judged by their mean Oxford shoulder scores of 43.5 and 46.5 respectively (p = 0.046). All five patients with partial-thickness tears were within this group and demonstrated less improvement than the patients with no tear (mean Oxford shoulder scores 43.2 and 46.4, respectively, p = 0.04). These findings imply that in the presence of a partial-thickness tear subacromial decompression may require additional specific treatment to the rotator cuff if the outcome is to be improved further.

Genetic influences in the aetiology of anteromedial osteoarthritis of the knee.

We report a study of 112 patients with primary anteromedial osteoarthritis of the knee and their families. Sibling risk was determined using randomly selected single siblings. Spouses were used as controls. The presence of symptomatic osteoarthritis was determined using an Oxford knee score of > or= 29 supported by a Kellgren and Lawrence radiological score of II or greater. Using Fisher's exact test we found that there was a significant increased risk of anteromedial osteoarthritis (OA) relative to the control group (p = 0.031). The recurrence risk of anteromedial OA to siblings was 3.21 (95% confidence interval 1.12 to 9.27). These findings imply that genetic factors may play a major role in the development of anteromedial OA of the knee.

Real-time ultrasound measure of the fetal eye (vitreous body) for prediction of parturition date in small ponies.

Ultrasonographic fetal eye measures have been used to estimate gestational age of the fetus in light horse mares. However, fetal eye measures have not been published for smaller pony breeds. This study was conducted to develop reference ranges for ultrasonographic measures of fetal eyes in small ponies for the purpose of predicting days before parturition (DBP) when breeding or ovulation dates are unknown. Twenty-three Shetland-type pony mares were studied across one (n = 10) or two (n = 13) gestations in 2004 (18 pregnancies) and 2005 (18 pregnancies). Measurements of fetal eyes were obtained during transrectal ultrasound examination. Examinations were conducted once monthly in a field situation beginning in December (2003) or August (2004) until mares foaled (March through July). The length (from sclera to sclera) and width (from retina to cornea) of the vitreous body were measured. For the 273 examinations in which gestation age was greater than 2 months, eye measures were obtainable in 248 (91%). Mixed-effects linear regression modeling was used to account for serial growth measures within pregnancy, repeated measurements across mares, and unbalanced study design. Independent variables evaluated included vitreous body length, vitreous body width, the ratio of length to width, parity, and mare height at the withers at parturition. Eye length was the best single predictor of days before parturition, with almost no additional predictive value of the other variables considered. Our resulting regression equation is: days before parturition=265.16-0.21*(vitreous body length in mm)(2). This study suggests that measure of the fetal eye is a practical on-farm procedure for estimating days before parturition in small ponies.

Hoof growth and wear of semi-feral ponies during an annual summer 'self-trimming' period.

REASONS FOR PERFORMING STUDY: Despite growing interest in application natural models of hoof-maintenance in domestic horses, little data is available to describe natural conformation and proposed mechanisms of self-maintenance. OBJECTIVES: Quantitatively describe hoof growth and wear during a period of 'self-trimming' within a herd of semi-feral ponies. METHODS: Hoof length, growth and wear were measured for a sample of 40 animals during a period of 'self-trimming' from June through September, 2005. RESULTS: For front hooves, mean toe lengths in July, August and September were significantly less than in June. For the hind, mean toe length in August was significantly less than in June, July and September. Increased rate of wear, as opposed to decreased growth rate, was the major contributor to overall shorter hoof lengths. Cumulative wear expressed as a percentage of the June baseline toe length ranged from 21-57% (mean 38%) for the front and 12-46% (mean 32%) for the hind. CONCLUSIONS: Significant cracking, tearing and increased wear, known as 'self-trimming' is a measurable herd-wise phenomenon in horses maintained under natural social and environmental conditions. POTENTIAL RELEVANCE: Although just one example herd, these data provide quantitative support of anecdotal reports of 'self-trimming' as a mechanism contributing to natural self-maintenance of the equine hoof.

Color Doppler ultrasound evaluation of testicular blood flow in stallions.

The objectives of this study were to evaluate the potential use of color Doppler ultrasound to characterize blood flow to the stallion testis, and to establish reference values for Doppler measures of blood flow in the testicular artery of the stallion. Both testes from each of 52 horses were examined using a pulsed-wave color Doppler ultrasound with a sector array 5/7.5 MHz transducer with a 1mm gate setting. Peak systolic velocity (PSV), end diastolic velocity (EDV), resistive index (RI), and pulsatility index (PI) of the testicular artery were measured in each of two locations, the convoluted aspect (spermatic cord) and the marginal aspect of the artery (on the epididymal edge of testis). We found that: (1) all measures were obtainable; (2) except for EDV, the majority of the measures were higher at the cord location than at the marginal aspect of the artery (P < 0.05); and (3) measures for left and right testes were similar (P > 0.10). Resulting measures from 41 of these stallions (82 testes) that appeared free of testicular pathology provide useful reference values for clinical evaluation. Evaluation of 11 cases with testicular pathology suggested further investigation of possible effects of these various conditions on testicular blood flow and testicular function.

Alkaline phosphatase in stallion semen: characterization and clinical applications.

Significant amounts of alkaline phosphatase (AP) activity have been found in semen plasma from numerous species. In species in which the majority of semen plasma AP (SPAP) activity originates from the epididymis and testicle, SPAP activity can be used clinically as a marker to differentiate testicular origin azoospermia or oligospermia from ejaculatory failure. Information on SPAP activity in stallions to date has been limited. In this study, a standard clinical chemistry analyzer was used to determine AP activity in pre-ejaculatory fluid and ejaculates from groups of normal stallions. Additionally, accessory glands, epididymides, testicles and other components of the urogenital tract of normal stallions were assayed to determine which tissues contain SPAP activity. The results indicated that levels of AP activity are low in pre-ejaculatory fluid, but significantly higher in ejaculatory fluid from normal stallions. Spermatozoa were not a significant source of SPAP activity. High levels of SPAP activity were found in the testes and epididymides. These findings suggest that SPAP activity is a candidate for a sperm-independent marker for ejaculation in the stallion. Finally, AP activity was determined in ejaculatory fluid from a stallion with bilaterally blocked ampullae, both before and after relief of the blockage. While the blockage was present, AP activity in ejaculatory fluid was low. However, following relief of the blockage, AP activity in ejaculatory fluid rose dramatically, thus suggesting that AP activity will be useful as an inexpensive, simple clinical assay for differentiating ejaculatory failure or excurrent duct blockages from testicular origin azoospermia and oligospermia.

Ultrasonographic measurements of accessory sex glands, ampullae, and urethra of normal stallions of various size types.

For the purpose of establishing clinical reference values, this paper reports results of ultrasonographic examination and measurement of accessory sex glands, ampullae, and the pelvic urethra of 102 mature, healthy breeding stallions (2-29 years of age) of various size types (7 Miniature Horses, 27 small ponies, 53 light horses and 15 heavy horses). Examinations were done per rectum in mostly unsedated stallions using an Aloka 210 scanner with a 7.5 MHz linear veterinary transrectal transducer (Corometrics Medical Systems, Inc., North Wallingford, CT, USA). Most measures of accessory sex glands, ampullae and the urethra were larger in horses of larger sizes. Except for vesicular glands, the majority of the measures for all glands were smaller for Miniature Horses and ponies than for light horses and heavy horses (P < 0.05). For vesicular glands, measures for heavy horses were greater than for those of other groups (P < 0.05). Measures were similar for Miniature Horses and ponies, and for light horses and heavy horses. For all measures, differences between left and right paired glands were not different (P > 0.10). The lumen diameter of vesicular glands and ampullae as well as prostate lobe thickness showed the greatest asymmetry. Although there were too few representatives of various breeds for statistical comparison, among the light horse breeds Arabian stallions had the smallest mean values for the majority of the measures. Among stallions, echogenic characteristics of accessory sex glands, particularly vesicular glands, varied widely, possibly related to variation in recent sexual activity. For some stallions, echogenic character, particularly that of vesicular glands, varied remarkably from left to right gland within stallions. For ampullae, there was also wide variation in lumen contents between stallions. These data are generally consistent with previous reports with smaller numbers of stallions, as well as consistent with in vitro measures in previous studies. The results provide useful clinical guidelines for size measures of accessory sex glands in horses.

Oral imipramine and intravenous xylazine for pharmacologically-induced ex copula ejaculation in stallions.

This study is part of ongoing work toward developing pharmacological methods for enhancing and inducing ejaculation in stallions with ejaculatory dysfunction or disabilities that interfere with normal breeding behavior. The objective was to evaluate a treatment regimen involving oral imipramine followed by intravenous xylazine that, in uncontrolled field clinical trials, had shown promise for a higher rate of ejaculation and fewer side effects using a more easily obtained and administered form of imipramine. Eight stallions each underwent eight trials in which treatment consisted of imipramine hydrochloride (3mg/kg, orally in a small portion sweet feed) followed 2h later by xylazine hydrochloride (0.66 mg/kg, intravenously). Trials were conducted with the stallion in a stall. Semen was collected using a collection bag secured over the prepuce with a girth band. Overall, 44 of the 64 attempts (68%) resulted in ejaculation. Within-stallion ejaculation rate ranged from 3 of 8 to 7 of 8 attempts. Interval from xylazine treatment to ejaculation ranged from 1.2 to 14 min. As is typical for induced ejaculations in which imipramine is included in the treatment regimen, ejaculates were of low volume, high sperm concentration, and with a higher total number of sperm than for in copula ejaculates of these stallions. These results represent a modest improvement in rate of ejaculation over previous treatment regimens.

Partnerships in international applied epidemiology training and service, 1975-2001.

In 1951 the Centers for Disease Control and Prevention created the Epidemic Intelligence Service to provide training and epidemiologic service on the model of a clinical residency program. By January 2001, an additional 28 applied epidemiology and training programs (AETPs) had been implemented around the globe (with over 945 graduates and 420 persons currently in training). Field Epidemiology Training Programs and Public Health Schools Without Walls are the most common models. Applied epidemiologists, or field epidemiologists, use science as the basis for intervention programs designed to improve public health. AETPs train people by providing them with health competencies through providing service to public health intervention programs and strengthening health systems. AETPs are relatively expensive to create and maintain, but they are highly sustainable and can produce immediate benefits. Of the 19 programs that began before 1997, 18 (95%) continue to produce graduates. The Training Programs in Epidemiology for Public Health Interventions Network was organized in 1997 to provide support, peer review, and quality assurance for AETPs. In 2001, new programs are planned or in development in India, Argentina, China, and Russia.

Severity of iron overload in hemochromatosis: effect of volunteer blood donation before diagnosis.

BACKGROUND: An effort was made to determine if volunteer blood donation before diagnosis decreases the severity of iron overload at diagnosis in persons with hemochromatosis. STUDY DESIGN AND METHODS: A study was performed in 1089 persons in the United States with hemochromatosis who responded to a convenience sample survey and in 124 C282Y/C282Y hemochromatosis probands diagnosed during routine medical care. RESULTS: Less than half of questionnaire respondents (46.2%) and probands (35.5%) reported that they had been volunteer blood donors; 5.4 percent and 4.0 percent, respectively, had donated >20 units of blood. In either subject group, there were no significant differences according to age in the mean numbers of units that needed to be removed by therapeutic phlebotomy to induce iron depletion in subgroups of men and women, respectively. Similarly, there was no significant correlation of units of voluntary blood donation or of therapeutic phlebotomy index (= therapeutic phlebotomy units/age in years) with the number of therapeutic phlebotomy units needed to induce iron depletion. When questionnaire respondents were stratified by sex, there was no significant correlation of units of blood donation with the number of therapeutic phlebotomy units needed to induce iron depletion or with the therapeutic phlebotomy index. CONCLUSION: Routine blood donation does not, on average, decrease the severity of iron overload in persons with hemochromatosis. These findings have implications for the understanding of the severity of iron overload and its complications in hemochromatosis, for advising persons with hemochromatosis about treatment, and for considering persons with hemochromatosis as possible blood donors.