Accuracy of medial-to-lateral transcondylar screw placement using an aiming device and preoperative computer tomography planning for the treatment of humeral intracondylar fissure.

OBJECTIVE: To determine the accuracy of transcondylar screws placed from medial-to-lateral using preoperative planning on computed tomography (CT) and an aiming device in elbows with humeral intracondylar fissures (HIFs). STUDY DESIGN: Retrospective case series. ANIMALS: Twenty-five client-owned dogs with HIF. METHODS: A 4.5-mm transcondylar screw was placed in 34 elbows with HIF. humeral condylar diameter (HCD) was measured at the humeral condylar isthmus on CT. Entry and exit points were planned at 0.3 × HCD cranial and 0.2 × HCD distal to the medial epicondyle and 0.3 × HCD cranial and 0.3 × HCD distal to the lateral epicondyle. An aiming device was used to guide drilling from the medial entry point to the lateral exit point. The difference between planned and actual screw entry and exit points, and the angular deviation of the actual screw axis from the planned screw axis, was assessed on the postoperative CT scans. RESULTS: Thirty-three out of 34 screws were completely within the humeral condyle. Thirteen out of 34 screws were placed less than 2 mm from planned entry and exit points in both the transverse and the frontal plane. The axis of the screw deviated by a mean of 3.2° (transverse plane) and 3.5° (frontal plane) from the planned axis. CONCLUSION: Humeral transcondylar screws placed with the technique tested here were entirely within the humeral condyle in 33 out of 34 elbows. CLINICAL SIGNIFICANCE: Use of CT planning and an aiming device allows accurate placement of transcondylar screws from medial-to-lateral in dogs with HIF.

Defining a safe corridor for transcondylar screw insertion across the canine humeral condyle: a comparison of medial and lateral surgical approaches.

OBJECTIVES: To (1) develop guidelines for the location of drill entry and exit points when inserting a transcondylar screw across the canine humerus; (2) compare the safe corridor for transcondylar screw insertion when drilling medial-to-lateral with drilling lateral-to-medial. STUDY DESIGN: Anatomic study. ANIMALS: Dogs (n = 43). METHODS: The optimum position of a transcondylar screw in 84 elbows was determined using CT multiplanar reconstructions. The positions of drill entry and exit points were defined relative to the epicondyles. Differences in elbow size were accounted for by dividing the measurements by the humeral condylar diameter (HCD), to give normalized measurements. Mean values of normalized measurements were used to develop universal guidelines for the location of drill entry and exit points. These guidelines were then applied to the 84 elbow CT reconstructions. The size of the safe corridor around this calculated drill line was determined, and expressed as tolerance angles in the frontal and transverse planes. The size of the safe corridors for medial-to-lateral and lateral-to-medial drilling were compared. RESULTS: The lateral entry/exit point was 0.3 × HCD cranial and 0.3 × HCD distal to the lateral epicondyle. The medial entry/exit point was 0.3 × HCD cranial and 0.2 × HCD distal to the medial epicondyle. Using these guidelines resulted in safe virtual screw placement in all 84 elbows. The tolerance angle in the frontal plane was significantly smaller when drilling medial-to-lateral compared with drilling lateral-to-medial (P < .001). CONCLUSIONS: Medial-to-lateral drilling for transcondylar screw placement carries a higher risk of inadvertently penetrating the joint compared with lateral-to-medial drilling.

Clinical and organizational factors associated with mortality during the peak of first COVID-19 wave: the global UNITE-COVID study.

PURPOSE: To accommodate the unprecedented number of critically ill patients with pneumonia caused by coronavirus disease 2019 (COVID-19) expansion of the capacity of intensive care unit (ICU) to clinical areas not previously used for critical care was necessary. We describe the global burden of COVID-19 admissions and the clinical and organizational characteristics associated with outcomes in critically ill COVID-19 patients. METHODS: Multicenter, international, point prevalence study, including adult patients with SARS-CoV-2 infection confirmed by polymerase chain reaction (PCR) and a diagnosis of COVID-19 admitted to ICU between February 15th and May 15th, 2020. RESULTS: 4994 patients from 280 ICUs in 46 countries were included. Included ICUs increased their total capacity from 4931 to 7630 beds, deploying personnel from other areas. Overall, 1986 (39.8%) patients were admitted to surge capacity beds. Invasive ventilation at admission was present in 2325 (46.5%) patients and was required during ICU stay in 85.8% of patients. 60-day mortality was 33.9% (IQR across units: 20%-50%) and ICU mortality 32.7%. Older age, invasive mechanical ventilation, and acute kidney injury (AKI) were associated with increased mortality. These associations were also confirmed specifically in mechanically ventilated patients. Admission to surge capacity beds was not associated with mortality, even after controlling for other factors. CONCLUSIONS: ICUs responded to the increase in COVID-19 patients by increasing bed availability and staff, admitting up to 40% of patients in surge capacity beds. Although mortality in this population was high, admission to a surge capacity bed was not associated with increased mortality. Older age, invasive mechanical ventilation, and AKI were identified as the strongest predictors of mortality.

Displacement of an Ununited Medial Humeral Condylar Ossification Centre in the Cat.

A 2-year-old cat was presented with the complaint of acute-onset non-weight-bearing lameness of the right forelimb. When examined, the cat was of short stature and had multiple joint and cartilaginous abnormalities suggestive of chondrodysplasia. The cause of the acute lameness was radiographically identified as a displaced osseous fragment from the medial portion of the right humeral condyle. The features of the osseous fragment were consistent with an ununited medial condylar ossification centre of the distal humerus. Furthermore, a nondisplaced ununited ossified fragment of similar appearance and size was present in the contralateral elbow. Surgical treatment by excision of the displaced fragment resulted in a preinjury level of limb function in the long-term outcome evaluation.

Simultaneous permeation of tamoxifen and gamma linolenic acid across excised human skin. Further evidence of the permeation of solvated complexes.

Tamoxifen is the hormonal treatment of choice in women who have hormone-dependent breast cancer and its efficacy in those women considered to have a high risk of developing breast cancer, has also been established. Gamma linolenic acid (GLA) has been shown to decrease the invasion of breast cancer and recent studies have demonstrated that GLA can enhance the oestrogen receptor down-regulation induced by tamoxifen. However, tamoxifen is associated with serious side-effects due mainly to systemic delivery, and targeted delivery of both tamoxifen and GLA would be highly beneficial. This work was a preliminary study for the development of a transcutaneous system to simultaneously deliver both tamoxifen and GLA directly to the breast. Full thickness human skin was dosed with 500 microl saturated solution of tamoxifen in borage oil (25% GLA) and the simultaneous permeation of the two actives determined. There was rapid flux with minimal lag time, the cumulative permeation at 24 h was 764.3 +/- 94.2 microg cm(-2) for GLA and 5.44 +/- 0.67 microg cm(-2) for tamoxifen: the latter being comparable to the amount of tamoxifen associated with cancerous breast tissue from a 20 mg oral dose. The ratio of GLA/tamoxifen permeated at different timepoints was quite consistent, both in terms of mass (mean 138, S.D. 15.1) and mols (mean 184, S.D. 20.3). It was determined that 2.5 molecules of GLA were associated with each molecule of tamoxifen in the permeation process, equating to a solvation cage of three molecules of triacylglycerol. This study has demonstrated the feasibility of administering simultaneously tamoxifen and GLA using borage oil as vehicle, which warrants further investigation as a novel topical two-component system in relation to or prophylaxis of those perceived at high risk of developing breast cancer. The study also provides further evidence of the permeation of solvated complexes across skin, rather than discrete penetrant molecules.

The wood mouse is a natural host for Murid herpesvirus 4.

Infection of laboratory mice by the Murid herpesvirus 4 (MHV-4) is a much studied model system for gammaherpesvirus pathogenesis. Little, however, is known about its natural host range, epidemiology and pathogenesis outside the laboratory. We have studied MHV-4 infection in free-living murids in the UK. Using a combination of serology and PCR analysis, we found that MHV-4 was endemic in wood mice (Apodemus sylvaticus) but not in two species of voles (Clethrionomys glareolus, Microtus agrestis). The sites of detection of viral DNA were the lungs and, less commonly, the spleen, emphasizing the importance of the former in virus persistence during natural infection and confirming similar data in laboratory mice.