Publications by authors named "O'Callaghan W"

Background: Pelvic skeletal asymmetry can result in rotational differences and morphologic bony prominence variance between the left and right hemipelvis. When selecting bony reference points for modern computed tomography-based robotic total hip arthroplasty planning, it is unclear which bony landmarks are the most reliable and accurate, especially in the presence of significant pelvic asymmetry.

Methods: A retrospective study was conducted utilizing a database of computed tomography scans.

View Article and Find Full Text PDF

Background: Highly sensitive molecular assays have been developed to detect plasma-based circulating tumor DNA (ctDNA), and emerging evidence suggests their clinical utility for monitoring minimal residual disease and recurrent disease, providing prognostic information, and monitoring therapy responses in patients with solid tumors. The Invitae Personalized Cancer Monitoring assay uses a patient-specific, tumor-informed variant signature identified through whole exome sequencing to detect ctDNA in peripheral blood of patients with solid tumors.

Methods: The assay's tumor whole exome sequencing and ctDNA detection components were analytically validated using 250 unique human specimens and nine commercial reference samples that generated 1349 whole exome sequencing and cell-free DNA (cfDNA)-derived libraries.

View Article and Find Full Text PDF

Hypothesis: Glenoid baseplate positioning for reverse total shoulder arthroplasty (rTSA) is important for stability and longevity, with techniques such as image-derived instrumentation (IDI) developed for improving implant placement accuracy. We performed a single-blinded randomized controlled trial comparing glenoid baseplate insertion accuracy with 3D preoperative planning and IDI jigs vs. 3D preoperative planning and conventional instrumentation.

View Article and Find Full Text PDF

Purpose: The decision on which technique to perform a total knee arthroplasty (TKA) has become more complicated over the last decade. Perceived limitations of mechanical alignment (MA) and kinematic alignment (KA) have led to the development of the functional alignment (FA) philosophy. This study aims to report the 2-year results of an initial patient cohort in terms of revision rate, PROMs and complications for Computer Aided Surgery (CAS) Navigated FA TKA.

View Article and Find Full Text PDF

Purpose: Proximal femur fractures in geriatric patients are associated with increased morbidity and mortality. This study investigates Brain Natriuretic Peptide immunoassay levels taken at the time of hospital admission in predicting cardiac complications and mortality in geriatric patients with a proximal femur fracture.

Methods: A single-site prospective cohort study at a large tertiary care, level 1 trauma centre was conducted on all consecutive geriatric patients aged greater than 60 years who sustained a proximal femur fracture.

View Article and Find Full Text PDF

The decision on which technique to use to perform a total knee arthroplasty has become much more complicated over the last decade. The shortfalls of mechanical alignment and kinematic alignment has led to the development of a new alignment philosophy, functional alignment. Functional alignment uses preoperative radiographic measurements, computer-aided surgery, and intraoperative assessment of balance, to leave the patient with the most "normal" knee kinematics achievable with minimal soft-tissue release.

View Article and Find Full Text PDF

Purpose: As surgeons continue to grapple with persistent issues of patient dissatisfaction post-TKA, the literature has focused on the coronal plane when considering alignment strategies but has largely ignored the sagittal and axial planes. The purpose of this retrospective observational cohort study is to evaluate variability in knee anatomy and alignment beyond the coronal plane and rationalise how this relates to existing arthroplasty alignment philosophies.

Methods: 4116 knee CTs from 360 Knee Systems© database of arthritic pre-operative TKA patients were evaluated.

View Article and Find Full Text PDF

Background: The use of smartphones and multimedia messaging service (MMS) continues to increase in day to day orthopaedic clinical practice. However, there is limited evidence to support the safe utilisation of MMS.

Objectives: The aim of this study was to correlate the performance of MMS imaging to picture archiving and communication systems (PACS) imaging within the setting of diagnosis and management of ankle fractures.

View Article and Find Full Text PDF

Background: Anatomic ACL grafts routinely display the anisometric length-tension behaviour seen in the native ligament with maximum length in full knee extension. Recent improvements in hamstring graft preparation and fixation have improved graft rigidity to the point where total graft lengthening after implantation may be less than 1 mm. Despite this it remains common practice to fix these grafts in a knee flexed position.

View Article and Find Full Text PDF

Purpose: To determine the perceptions of surgeons at both consultant and resident level to the difficulties of performing knee arthroscopy and to determine their willingness to adopt robotic technology.

Methods: A questionnaire was designed to discern the attitude of orthopaedic consultants and residents to the technical challenges of performing knee arthroscopy and the possible role of robotically enhanced surgery. The questionnaire included 31 questions across five key domains.

View Article and Find Full Text PDF

Takotsubo cardiomyopathy is increasingly recognized as a distinct clinical entity. An association with thyroid disease has been identified in several case reports, mostly in the context of Grave disease. We report the case of a 67-year-old woman presenting with takotsubo cardiomyopathy and thyrotoxicosis secondary to toxic multinodular goiter.

View Article and Find Full Text PDF

This paper describes how a new framework for clinical nursing education was introduced at Counties Manukau District Health Board (CMDHB), New Zealand. The project was initiated in response to the significant legislative and post registration nursing education changes within New Zealand. The journey of change has been a significant undertaking, and has required clear management, strong leadership, perseverance and understanding of the organisation's culture.

View Article and Find Full Text PDF

This paper describes how a new framework for clinical nursing education was introduced at Counties Manukau District Health Board (CMDHB), New Zealand. The project was initiated in response to the significant legislative and post registration nursing education changes within New Zealand. The journey of change has been a significant undertaking, and has required clear management, strong leadership, perseverance and understanding of the organisation's culture.

View Article and Find Full Text PDF

The usefulness of the response to single and double ventricular premature complexes (VPCs) introduced during reciprocating tachycardia (RT) in predicting the location of a left free wall accessory pathway was studied in 55 patients with the Wolff-Parkinson-White syndrome. One VPC introduced from the right ventricle into narrow QRS RT when the His bundle was refractory resulted in retrograde atrial preexcitation in 25 of 55 (45%) patients, while 30 (55%) showed no preexcitation. Double VPCs produced retrograde atrial preexcitation in 9 of 26 patients not responding to a single VPC.

View Article and Find Full Text PDF

The late restenosis rate after emergent percutaneous transluminal coronary angioplasty for acute myocardial infarction was assessed by performing outpatient follow-up cardiac catheterization in 79 (87%) of 91 consecutive patients who had been discharged from the hospital with a successful coronary angioplasty. The majority of patients (90%) received high dose intravenous thrombolytic therapy with streptokinase in addition to angioplasty. Similar follow-up data were obtained in 206 (90%) of 228 consecutive patients who had successful elective angioplasty during the same period.

View Article and Find Full Text PDF

Two hundred and sixteen patients with acute myocardial infarction were treated with immediate infusion of high-dose (1.5 million units) intravenous streptokinase followed by emergency coronary angioplasty. The infarct lesion was crossed and dilated in 99% and persistent coronary perfusion after the procedure was achieved in 90% (including 3% with significant residual stenosis).

View Article and Find Full Text PDF

Although initial success rates for coronary angioplasty have improved, the rate of restenosis within 6 months of the procedure has persisted at 30 to 40%. The relation of restenosis to initial success, recurrence of symptoms and risk factors suggests that high grade or total lesions, long lesions, lesions in the proximal left anterior descending artery or in saphenous grafts, and the absence of intimal dissection after angioplasty are associated with an increased risk of restenosis. Unstable angina, male sex and diabetes are clinical factors associated with a greater risk of restenosis.

View Article and Find Full Text PDF

Multiple accessory atrioventricular (AV) pathways were documented in 52 of 388 patients (13%) who underwent detailed electrophysiologic evaluation. Multiple AV pathways were identified during intraoperative mapping or electrophysiologic study by different patterns of ventricular preexcitation during atrial fibrillation, flutter or atrial pacing with different delta-wave morphologic and ventricular activation patterns; different sites of atrial activation during right ventricular pacing or orthodromic reciprocating tachycardia; or preexcited reciprocating tachycardia using a second pathway as the retrograde limb of the tachycardia. A logistic model was used to determine which clinical, electrocardiographic and electrophysiologic variables were associated with multiple AV pathways.

View Article and Find Full Text PDF

Accessory pathway electrograms are rarely recorded in patients with Wolff-Parkinson-White syndrome. In one patient, during electrophysiologic study, simultaneous local ventricular (V) accessory pathway (AP) and atrial (A) deflections were recorded during bipolar catheter endocardial mapping over the pathway. Analysis of changes in electrographic intervals during performance of the ventricular extrastimulus technique allowed characterization of the retrograde conduction properties of the pathway.

View Article and Find Full Text PDF

Antiarrhythmic agents may depress cardiac contractility and worsen heart failure. Few data are available describing the chronic effects of amiodarone on myocardial function. To assess the effects of amiodarone on cardiac function, we studied 41 consecutive patients with first-pass or equilibrium radionuclide angiography prior to and 3 months after drug therapy was initiated.

View Article and Find Full Text PDF

We sought to determine if verapamil induces frequency-dependent prolongation of atrioventricular nodal conduction in 10 consecutive patients studied in the electrophysiology laboratory. We used a maintenance infusion of verapamil designed to produce plasma concentrations of verapamil in the "therapeutic" range and that did not alter heart rate or blood pressure significantly. Frequency-dependent prolongation of atrioventricular nodal conduction (AH interval) was demonstrated in all 10 patients (p less than .

View Article and Find Full Text PDF