Rabies and the Arctic Fox (Vulpes lagopus): A Review.

The Arctic fox (Vulpes lagopus) is the primary infection reservoir of Arctic rabies, the dynamics of which are poorly understood and subject to significant spatiotemporal variation. Although rabies presence has been documented in the region since the mid-19th century, there is currently no evidence of rabies impacting Arctic fox population size. Under the influence of climate change in a rapidly changing Arctic ecosystem, changes in transmission dynamics are predicted, with implications for this species. Concurrently, the World Health Organization leads the United Against Rabies collective in the aim of elimination of dog-mediated rabies by 2030, and although efforts have justifiably been directed to tropical regions, elimination will require a good understanding of rabies in the Arctic. Therefore, this review aimed to provide an overview of current Arctic rabies understanding, while identifying the key knowledge gaps. The review covered spatiotemporal trends in rabies populations, population dynamics of the host species, and current theories about Arctic rabies persistence. It is still unclear how Arctic rabies can persist under low host densities, which has led to several hypotheses in recent years. Creation of high animal density "hotspots" caused by heterogenic fox distribution and multispecies congregations in response to food availability, extensive Arctic fox migration patterns, and the potential evolution to a less lethal variant of rabies may all be part of the explanation. Evidence for these theories by using recent genetic and modeling studies was evaluated within the review. There is currently insufficient evidence about the efficacy and feasibility of vaccines against Arctic rabies. Key knowledge gaps need addressing to enable future control campaigns.

A SYSTEMATIC REVIEW OF RETROSPECTIVE MORBIDITY AND MORTALITY STUDIES ON CAPTIVE WILDLIFE SPECIES.

Zoological institutions manage animals for conservation, education, entertainment, and research purposes. Zoological staff have a responsibility to safeguard the welfare of animals in their care. Retrospective morbidity and/or mortality studies (MMSs) can be useful tools to highlight common diseases in captive wildlife populations. There is currently no standardized methodology for conducting MMSs. Variation in the methodology of MMSs, particularly the categorization of diseases, can make comparisons between studies challenging and may limit the applicability of the results. A Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) compliant systematic review was performed, which identified 67 MMSs describing 146 species of captive wildlife. These MMSs are becoming more common and were predominantly performed on mammals (76/146). Prospective authors are encouraged to perform MMSs on amphibians, birds, reptiles, fish, and invertebrates. The studied animals were mostly managed at institutions in the United States of America (28/67, 41.2%) and Europe (14/67, 20.9%). Classifying individuals into age groups facilitates the identification of disease trends within age classes. Only 22/67 (32.8%) studies cited justification for their age classification; classifications should be based on a referenced source on the breeding biology of the studied species. There is variation in the body systems used by authors and into which system a disease is categorized, which makes study comparisons challenging. Diseases were predominantly categorized by etiology and body system (28/77, 36.4%). Because of its ubiquity, the use of the categorization system employed by the pathology module of the Zoological Information Management System is recommended as a useful standard. This system is imperfect, and amendments to it are suggested. The results and recommendations of this study were discussed with a panel of zoo and wildlife experts; guidelines have been formulated for prospective authors aiming to conduct MMSs in captive wildlife.

A RETROSPECTIVE ANALYSIS OF THE MORBIDITY AND MORTALITY OF CAPTIVE NORTHERN BALD IBIS (GERONTICUS EREMITA), AFRICAN SACRED IBIS (THRESKIORNIS AETHIOPICUS), AND SCARLET IBIS (EUDOCIMUS RUBER) HOUSED AT THE LONDON ZOO FROM 2000 TO 2020.

Necropsy (n = 144) and medical (n = 121) records of captive northern bald ibis (NBI; Geronticus eremita), African sacred ibis (ASI; Threskiornis aethiopicus), and scarlet ibis (SCI; Eudocimus ruber) housed at the Zoological Society of London's London Zoo (LZ) from 2000 to 2020 were reviewed. Pododermatitis was a common cause of morbidity in all species (79 cases in 247 examinations). Trauma (58 of 144), the majority being caused by suspected collisions with stationary objects in the zoo's habitats, infectious diseases (32 of 144), predominantly valvular endocarditis (10 of 32), and aspergillosis (9 of 32) were major causes of mortality. The odds of a morbidity being related to toxicosis were 4.4 times greater in NBI than for ASI (95% CI, 1.5-13.3; P < 0.05); all cases in the NBI were plumbism. Overall, females of all species had 3.4 times greater odds of undetermined morbidity than males (95% CI, 1.5-7.9; P < 0.05), and the majority (16 of 25) were birds that were thin without an apparent cause. Nestlings had 11.3 times greater odds of nutritional morbidity than adults (95% CI, 1.7-73.0) and 5.5 times greater than juveniles (95% CI, 0.7-41.0; P < 0.05). These data have identified areas that require further study in the population of NBI, ASI, and SCI held at LZ.

Reporting of Freshwater Cyanobacterial Poisoning in Terrestrial Wildlife: A Systematic Map.

Global warming and over-enrichment of freshwater systems have led to an increase in harmful cyanobacterial blooms (cyanoHABs), affecting human and animal health. The aim of this systematic map was to detail the current literature surrounding cyanotoxin poisonings in terrestrial wildlife and identify possible improvements to reports of morbidity and mortality from cyanotoxins. A systematic search was conducted using the electronic databases Scopus and Web of Science, yielding 5059 published studies identifying 45 separate case reports of wildlife poisonings from North America, Africa, Europe, and Asia. Currently, no gold standard for the diagnosis of cyanotoxin intoxication exists for wildlife, and we present suggested guidelines here. These involved immunoassays and analytical chemistry techniques to identify the toxin involved, PCR to identify the cyanobacterial species involved, and evidence of ingestion or exposure to cyanotoxins in the animals affected. Of the 45 cases, our recommended methods concurred with 48.9% of cases. Most often, cases were investigated after a mortality event had already occurred, and where mitigation was implemented, only three cases were successful in their efforts. Notably, only one case of invasive cyanobacteria was recorded in this review despite invasive species being known to occur throughout the globe; this could explain the underreporting of invasive cyanobacteria. This systematic map highlights the perceived absence of robust detection, surveillance, and diagnosis of cyanotoxin poisoning in wildlife. It may be true that wildlife is less susceptible to these poisoning events; however, the true rates of poisoning are likely much more than is reported in the literature.

Effects of between and within Herd Moves on Elephant Endotheliotropic Herpesvirus (EEHV) Recrudescence and Shedding in Captive Asian Elephants (Elephas maximus).

Haemorrhagic disease associated with elephant endotheliotropic herpesvirus (Elephantid herpesvirus, EEHV) infections is the leading cause of death for Asian elephant (Elephas maximus) calves. This study assessed the effect of captive herd management on EEHV shedding, as evidence of latent infection reactivation, focusing on: (1) the influence of social change on the odds of recrudescence; (2) the respective effects of between and within herd moves; and (3) characteristics of recrudescent viral shedding. Trunk and conjunctival swabs (n = 165) were obtained from six elephants at an EAZA-accredited zoo, collected during a period of social stability, and at times of social change. Longitudinal sampling took place at times of moving two bulls out of the collection and one new bull into an adjacent enclosure to the cow herd (between herd moves), and during a period of mixing this new bull with the cow herd to facilitate mating (within herd moves). Quantitative PCR was employed to detect EEHV 1a/b, 4a/b, and EF-1-α (housekeeping gene). Generalised estimating equations determined EEHV recrudescence odds ratios (OR) and relative viral DNA load. Sixteen EEHV 1a/b shedding events occurred, but no EEHV 4a/b was detected. All management-derived social changes promoted recrudescence (social change OR = 3.27, 95% CI = 0.412-26, p = 0.262; and between herd moves OR = 1.6, 95% CI = 0.178-14.4, p = 0.675), though within herd movements posed the most significant increase of EEHV reactivation odds (OR = 6.86, 95% CI = 0.823-57.1, p = 0.075) and demonstrated the strongest relative influence (post hoc Tukey test p = 0.0425). Shedding onset and magnitude ranged from six to 54 days and from 3.59 to 11.09 ΔCts. Differing challenges are associated with between and within herd movements, which can promote recrudescence and should be considered an exposure risk to naïve elephants.

Trait-Based Vaccination of Individual Meerkats (Suricata suricatta) against Tuberculosis Provides Evidence to Support Targeted Disease Control.

Individuals vary in their potential to acquire and transmit infections, but this fact is currently underexploited in disease control strategies. We trialled a trait-based vaccination strategy to reduce tuberculosis in free-living meerkats by targeting high-contact meerkats (socially dominant individuals) in one study arm, and high-susceptibility individuals (young subordinates) in a second arm. We monitored infection within vaccinated groups over two years comparing the results with untreated control groups. Being a member of a high-contact group had a protective effect on individuals' survival times (Hazard Ratio = 0.5, 95% Confidence Interval, CI: 0.29-0.88, p = 0.02) compared to control groups. Over the study, odds of testing positive for tuberculosis increased more than five-fold in control groups (Odds Ratio = 5.40, 95% CI = 0.94-30.98, p = 0.058); however, no increases were observed in either of the treatment arms. Targeted disease control approaches, such as the one described in this study, allow for reduced numbers of interventions. Here, trait-based vaccination was associated with reduced infection rates and thus has the potential to offer more efficient alternatives to traditional mass-vaccination policies. Such improvements in efficiency warrant further study and could make infectious disease control more practically achievable in both animal (particularly wildlife) and human populations.

Combining Analytical Approaches and Multiple Sources of Information to Improve Interpretation of Diagnostic Test Results for Tuberculosis in Wild Meerkats.

Diagnostic tests are used to classify individual animals' infection statuses. However, validating test performance in wild animals without gold standard tests is extremely challenging, and the issue is further complicated in chronic conditions where measured immune parameters vary over time. Here, we demonstrate the value of combining evidence from different diagnostic approaches to aid interpretation in the absence of gold standards, large sample sizes, and controlled environments. Over a two-year period, we sampled 268 free-living meerkats (Suricata suricatta) longitudinally for Mycobacterium suricattae (a causative agent of tuberculosis), using three ante-mortem diagnostic tests based on mycobacterial culture, and antigen-specific humoral and cell-mediated immune responses, interpreting results both independently and in combination. Post-mortem cultures confirmed M. suricattae infection in 22 animals, which had prior ante-mortem information, 59% (13/22) of which were test-positive on a parallel test interpretation (PTI) of the three ante-mortem diagnostic assays (95% confidence interval: 37-79%). A similar ability to detect infection, 65.7% (95% credible interval: 42.7-84.7%), was estimated using a Bayesian approach to examine PTI. Strong evidence was found for a near doubling of the hazard of death (Hazard Ratio 1.75, CI: 1.14-2.67, p = 0.01), associated with a positive PTI result, thus demonstrating that these test results are related to disease outcomes. For individual tests, small sample sizes led to wide confidence intervals, but replication of conclusions, using different methods, increased our confidence in these results. This study demonstrates that combining multiple methodologies to evaluate diagnostic tests in free-ranging wildlife populations can be a useful approach for exploiting such valuable datasets.

The past, present and future of hormonal contraceptive use in managed captive female tiger populations with a focus on the current use of deslorelin acetate.

Tigers (Panthera tigris spp.) are endangered in the wild; ensuring sustainable insurance populations requires careful planning within zoological collections. In captive situations, contraceptives are often used to control breeding and ensure genetically viable populations that contain manageable numbers of animals; reversible contraceptives are ideal because they offer flexibility for breeding management. Historically, synthetic progestins, such as melengestrol acetate implants, were used in female tigers, but these are associated with an increased risk of reproductive pathology and subsequent infertility. Recent management advice to ex-situ collections has been to transition to the use of gonadotropin-releasing hormone agonists, such as deslorelin acetate implants, which do not appear to have a similar risk of reproductive pathology but are associated with highly variable reversal times in exotic felids. Using data from 917 contraceptive records in female tigers captured by the Association of Zoos and Aquariums Reproductive Management Center and the European Association of Zoos and Aquaria Reproductive Management Group's joint Contraception Database and from supplementary surveys, this study reviews the changing use of contraceptives in captive female tigers. The aim was to describe the historical and current use of contraceptives and provide a comprehensive assessment on the use of deslorelin implants, including data on product protocols, efficacy, pathology, and reversibility. This study determined that current dose, frequency, reversibility, and anatomical placement sites of deslorelin implants are highly variable, indicating that specific, readily available, unified, evidence-based recommendations on the use of deslorelin would be useful for future contraceptive use in managed tiger populations.

A RETROSPECTIVE STUDY OF MORBIDITY AND MORTALITY IDENTIFIED AT POSTMORTEM EXAMINATION OF CAPTIVE LANGURS (TRACHYPITHECUS SPP) FROM SIX UNITED KINGDOM ZOOLOGICAL INSTITUTIONS: A 19-YEAR REVIEW.

Langurs are Asian primates belonging to the Colobinae subfamily. Langur populations are declining, with most species categorized as threatened by the International Union for Conservation of Nature. Investigation into the threats to population viability and sustainability would be beneficial but there is limited literature available on common diseases or causes of death in these species, either in captive or free-ranging settings. This study aimed to evaluate the most common causes of morbidity and mortality in Trachypithecus species submitted for postmortem examination by six United Kingdom zoological institutions between 2001 and 2020, to inform best practice husbandry guidelines. Necropsy and histopathology reports from 88 individuals of Trachypithecus species from six zoological organizations in the United Kingdom were analyzed. Species included Javan langurs (Trachypithecus auratus; n = 35), dusky langurs (Trachypithecus obscurus; n = 28), François' langurs (Trachypithecus francoisi; n = 16), purple-faced langurs (Trachypithecus vetulus; n = 4), silvered langurs (Trachypithecus cristatus; n = 4), and Phayre's langur (Trachypithecus phayrei; n = 1). Morbidities and causes of death were recorded. Gastrointestinal diseases and systemic infections were the leading causes of death (27.4% and 21.0% of cases where cause of death was known, respectively); linear foreign bodies were the most common cause of death. Interstitial pneumonia was frequently observed secondary to systemic infection. Heart abnormalities, anthracosis, and hemosiderosis were common but not directly associated with mortality. Further investigation is necessary to assess the importance of these conditions and whether they predispose to other diseases. This study provides a baseline for future research evaluating captive and free-ranging langur health and highlights husbandry practices that may decrease morbidity in these species.

Social and environmental factors affect tuberculosis related mortality in wild meerkats.

Tuberculosis (TB) is an important and widespread disease of wildlife, livestock and humans world-wide, but long-term empirical datasets describing this condition are rare. A population of meerkats (Suricata suricatta) in South Africa's Kalahari Desert have been diagnosed with Mycobacterium suricattae, a novel strain of TB, causing fatal disease in this group-living species. This study aimed to find characteristics associated with clinical TB in meerkats. These characteristics could subsequently be used to identify 'at-risk' animals within a population, and target these individuals for control measures. We conducted a retrospective study based on a unique, long-term life-history dataset of over 2000 individually identified animals covering a 14-year period after the first confirmatory diagnosis of TB in this population in 2001. Individual- and group-level risk factors were analysed using time-dependent Cox regression to examine their potential influence on the time to development of end-stage TB. Cases of disease involved 144 individuals in 27 of 73 social groups, across 12 of 14 years (an incidence rate of 3·78 cases/100 study years). At the individual level, increasing age had the greatest effect on risk of disease with a hazard ratio of 4·70 (95% CI: 1·92-11·53, P < 0·01) for meerkats aged 24-48 months, and a hazard ratio of 9·36 (3·34-26·25, P < 0·001) for animals aged over 48 months (both age categories compared with animals aged below 24 months). Previous group history of TB increased the hazard by a factor of 4·29 (2·00-9·17, P < 0·01), and an interaction was found between this variable and age. At a group level, immigrations of new group members in the previous year increased hazard by a factor of 3·00 (1·23-7·34, P = 0·016). There was weaker evidence of an environmental effect with a hazard ratio for a low rainfall (<200 mm) year of 2·28 (0·91-5·72, P = 0·079). Our findings identify potential individual characteristics on which to base targeted control measures such as vaccination. Additional data on the dynamics of the infection status of individuals and how this changes over time would complement these findings by enhancing understanding of disease progression and transmission, and thus the implications of potential management measures.

Development and evaluation of a diagnostic cytokine-release assay for Mycobacterium suricattae infection in meerkats (Suricata suricatta).

BACKGROUND: Sensitive diagnostic tools are necessary for the detection of Mycobacterium suricattae infection in meerkats (Suricata suricatta) in order to more clearly understand the epidemiology of tuberculosis and the ecological consequences of the disease in this species. We therefore aimed to develop a cytokine release assay to measure antigen-specific cell-mediated immune responses of meerkats. RESULTS: Enzyme-linked immunosorbent assays (ELISAs) were evaluated for the detection of interferon-gamma (IFN-γ) and IFN-γ inducible protein 10 (IP-10) in meerkat plasma. An IP-10 ELISA was selected to measure the release of this cytokine in whole blood in response to Bovigam® PC-HP Stimulating Antigen, a commercial peptide pool of M. bovis antigens. Using this protocol, captive meerkats with no known M. suricattae exposure (n = 10) were tested and results were used to define a diagnostic cut off value (mean plus 2 standard deviations). This IP-10 release assay (IPRA) was then evaluated in free-living meerkats with known M. suricattae exposure, categorized as having either a low, moderate or high risk of infection with this pathogen. In each category, respectively, 24.7%, 27.3% and 82.4% of animals tested IPRA-positive. The odds of an animal testing positive was 14.0 times greater for animals with a high risk of M. suricattae infection compared to animals with a low risk. CONCLUSION: These results support the use of this assay as a measure of M. suricattae exposure in meerkat populations. Ongoing longitudinal studies aim to evaluate the value of the IPRA as a diagnostic test of M. suricattae infection in individual animals.

The influence of implant articular thickness and glenohumeral conformity on stability of an all-metal glenoid component.

The objective of this study was to determine the effect of implant thickness and glenohumeral conformity on fixation of an all-metal glenoid component. A stainless steel glenoid component was designed and implanted in 10 cadaveric scapulae. A testing apparatus capable of producing a loading vector at various angles, magnitudes, and directions was used. The independent variables included 6 directions and 3 angles of joint load, 3 implant thicknesses, and 4 glenohumeral conformities. Implant micromotion relative to bone was measured by use of 4 displacement transducers at the superior, inferior, anterior, and posterior sites. The components displayed a consistent response to loading of ipsilateral compression and contralateral distraction. Stability decreased as the load application angle increased (P < .05). A decrease in the implant thickness and glenohumeral conformity resulted in increased implant stability (P < .05). Decreasing implant thickness and glenohumeral conformity reduce the eccentric component of loading and may improve the durability of glenoid implants.

Glenoid vault endosteal dimensions: an anthropometric study with special interest in implant design.

An understanding of the morphology of the glenoid is important from the viewpoint of implant design and selection. This study describes the endosteal dimensions and shape of the glenoid and correlates these results with age, gender, and the presence of osteoarthritis. This study used 72 scapulae. Data were obtained from computed tomography scans of both cadaveric and in vivo glenoids. The glenoid is relatively straight-sided in the coronal plane and more highly fluted in the transverse plane. The endosteal dimensions were larger for male specimens, but there was no difference in endosteal shape with respect to gender. These findings were not influenced by age or the presence of osteoarthritis. This study suggests that traditional glenoid component designs may not be optimal. To maximize fixation, a rectangular keel may be most effective in the coronal plane and a triangular keel may be most effective in the transverse plane.

Outcome after open reduction and internal fixation of capitellar and trochlear fractures.

BACKGROUND: Capitellar and trochlear fractures are uncommon fractures of the distal aspect of the humerus. There is limited information about the functional outcome of patients managed with open reduction and internal fixation. METHODS: The functional outcome of twenty-eight patients, with a mean age (and standard deviation) of 43 +/- 13 years, who were treated with open reduction and internal fixation for capitellar and trochlear fractures was evaluated at a mean duration of follow-up of 56 +/- 33 months. Patient outcomes were assessed with physical and radiographic examination, range-of-motion measurements, strength testing, and self-reported questionnaires (Short Form-36, Mayo Elbow Performance Index, American Shoulder and Elbow Surgeons Elbow Assessment Form, and Patient-Rated Elbow Evaluation scales). RESULTS: Eleven fractures involved the capitellum with or without fracture of the lateral ridge of the trochlea, four involved the capitellum and trochlea as one piece, and thirteen involved the capitellum and trochlea as separate fragments. These fractures were further characterized by the presence or absence of posterior comminution. Fourteen patients had isolated fractures, and fourteen had other elbow, forearm, or wrist injuries. Patients with more complex fractures required more extensive surgery, had more complications resulting in secondary procedures, and had poorer outcomes compared with those with simple fractures. The average score on the Mayo Elbow Performance Index (91 +/- 11), the average quality-of-life scores (46 on the physical component and 50 on the mental component of the Short Form-36), and the average range of motion (19 degrees to 138 degrees ) suggest favorable patient outcomes overall. Two comminuted fractures did not unite and required conversion to a total elbow arthroplasty. CONCLUSIONS: Patients with isolated noncomminuted capitellar and/or trochlear fractures have better results than those with more complex fractures. A classification system based on the radiographic patterns of these fractures is recommended.

Quality-of-life outcome following hemiarthroplasty or total shoulder arthroplasty in patients with osteoarthritis. A prospective, randomized trial.

BACKGROUND: Both total shoulder arthroplasty and hemiarthroplasty have been used commonly to treat severe osteoarthritis of the shoulder; however, their effect on disease-specific quality-of-life outcome is unknown. The purpose of this study was to compare the quality-of-life outcome following hemiarthroplasty with that following total shoulder arthroplasty in patients with osteoarthritis of the shoulder. METHODS: Forty-two patients with a diagnosis of osteoarthritis of the shoulder were randomized to receive a hemiarthroplasty or a total shoulder arthroplasty. One patient died, and all others were evaluated preoperatively and at six weeks and three, six, twelve, eighteen, and twenty-four months postoperatively with use of a standardized format including a disease-specific quality-of-life measurement tool (Western Ontario Osteoarthritis of the Shoulder [WOOS] index), general shoulder rating scales (University of California at Los Angeles [UCLA] shoulder scale, Constant score, and American Shoulder and Elbow Surgeons [ASES] evaluation form), general pain scales (McGill pain score and visual analogue scale), and a global health measure (Short Form-36 [SF-36]). When a patient required revision of a hemiarthroplasty to a total shoulder arthroplasty, the last score before he or she "crossed over" was used for the analysis. RESULTS: Significant improvements in disease-specific quality of life were seen two years after both the total shoulder arthroplasties and the hemiarthroplasties. There were no significant differences in quality of life (WOOS score) between the group treated with total shoulder arthroplasty and that treated with hemiarthroplasty (90.6 +/- 13.2 and 81.5 +/- 24.1 points, respectively; p = 0.18). The other outcome measures demonstrated similar findings. Two patients in the hemiarthroplasty group crossed over to the other group by undergoing a revision to a total shoulder arthroplasty because of glenoid arthrosis. CONCLUSIONS: Both total shoulder arthroplasty and hemiarthroplasty improve disease-specific and general quality-of-life measurements. With the small number of patients in our study, we found no significant differences in these measurements between the two treatment groups. LEVEL OF EVIDENCE: Therapeutic Level I.

The impact of rotator cuff pathology on isometric and isokinetic strength, function, and quality of life.

The purposes of this study were to determine the reliability of strength and self-reporting measures, the relationship of different strength measures to function, and the impact of rotator cuff pathology on patients' quality of life. Patients with nonoperated rotator cuff pathology (n = 36) and unaffected control subjects (n = 48) were assessed by use of the LIDO dynamometer to determine isometric and isokinetic (concentric and eccentric) strength of the shoulder rotators. The Shoulder Pain and Disability Index and Short Form-36 were self-reported by patients. Intraclass correlation coefficients (ICCs) were used to assess reliability, and Pearson correlations and multiple linear regression were used to determine the relationship between strength and function. The findings of this study include the following: (1) measures of self-reported physical disability had high reliability (ICC = 0.89); (2) the LIDO dynamometer reliably measured internal and external shoulder rotation strength in both concentric and isometric modes of testing (ICC = 0.78-0.94), whereas eccentric muscle actions had lower reliability; (3) all shoulder rotation strength measures were predictive of disability, with isometric external rotation strength being the most predictive (r = 0.56); and (4) the presence of rotator cuff pathology was highly predictive of impaired physical health quality of life (R(2) = 0.71, P < .001).

Internal fixation of radial neck fractures: an in vitro biomechanical analysis.

OBJECTIVE: To assess the fixation rigidities of a custom designed blade plate, a 2.7 mm T-plate and 3.0 mm cannulated screws. DESIGN: A cadaveric non-comminuted radial neck fracture model was employed to test the three fixation methods, using a multi-directional shear loading protocol. BACKGROUND: The management of displaced radial neck fractures in adults remains unsatisfactory due to failure of internal fixation with secondary loss of reduction, and non-unions. METHODS: The stiffness of the various fixation methods was measured in five directions of loading in the transverse plane. Failure testing was performed on the final testing condition for each specimen, in a posteroulnar to anteroradial direction. RESULTS: The direction of specimen loading did not have a significant effect on the stiffness of the various methods of fixation (P = 0.4). There was no significant difference in the fixation stiffness between the 3.0 mm screws or blade plate, however, both were superior to the T-plate (P < 0.05). CONCLUSIONS: Although the 2.7 mm T-plate has been reported in the literature as a viable method of fixation for radial neck fractures, it may not be optimal from the viewpoint of fixation stability. In the setting of a non-comminuted radial neck fracture, the use of cross-cannulated screws or blade plate fixation is preferred.Relevance This study supports the use of cross-cannulated screws or blade plate fixation for non-comminuted fractures of the radial neck.

Does keel size, the use of screws, and the use of bone cement affect fixation of a metal glenoid implant?

The objective of this study was to determine the effect of screws and keel size on the fixation of an all-metal glenoid component. A prototype stainless-steel glenoid component was designed and implanted in 10 cadaveric scapulae. A testing apparatus capable of producing a loading vector at various angles, magnitudes, and directions was used. The independent variables included six directions and three angles of joint load, and five fixation modalities-three different-sized cross-keels (small, medium, and large), screws, and bone cement. Implant micromotion relative to bone was measured by four displacement transducers at the superior, inferior, anterior, and posterior sites. The components displayed a consistent response to loading of ipsilateral compression and contralateral distraction. Use of progressively larger keels did not significantly improve implant stability. Stability decreased as the angle of load application increased (P <.05). Screw and cement fixation resulted in the most stable fixation (P <.05).

Distal biceps tendon repair: comparison of surgical techniques.

PURPOSE: Various surgical repair techniques for distal biceps tendon ruptures have been reported, however, the optimal technique is unknown. METHODS: Over a 4-year period 19 distal biceps tendon ruptures were repaired: 9 using a single anterior incision and 10 using a modified 2-incision Boyd and Anderson technique. The patients were followed-up prospectively and independently reviewed. RESULTS: Patient-rated elbow evaluation and Short Form-36 (SF-36) scores improved with time independent of surgical technique. At 1 year the 1-incision group regained more flexion (142.8 degrees vs 131.1 degrees ) than the 2-incision group. There was no difference between groups in supination motion, supination strength, or flexion strength, although recovery of flexion strength was initially more rapid for the 2-incision group. Complications were encountered in 44% of cases treated with a 1-incision technique and in 10% of cases treated with the 2-incision technique; however, most of these were minor transient paresthesias. CONCLUSIONS: The differences between the 2 groups were relatively minor with the Morrey 2-incision technique showing a slightly more rapid recovery of flexion strength and fewer complications as compared with the 1-incision technique.