Waiting times for arthroplasty surgery in Northern Ireland are among the longest in the National Health Service, which have been further lengthened by the onset of the SARS-CoV-19 global pandemic in March 2020. The Department of Health (DoH) in Northern Ireland has announced a new Elective Care Framework (ECF), with the framework proposing that by March 2026 no patient will wait more than 52 weeks for inpatient/day case treatment. We aimed to assess the feasibility of achieving this with reference to Total Hip Arthroplasty (THA).

Waiting list information was obtained via a Freedom of Information request to the DoH (May 2021) and National Joint Registry data was used to determine baseline operative numbers. Mathematical modelling was undertaken to calculate the time taken to meet the ECF target and also to determine the time to clear the waiting lists for THA using the number of patients currently on the waiting list and percentage operating capacity relative to pre-Covid-19 capacity to determine future projections.

As of May 2021, there were 3,757 patients awaiting primary THA in Northern Ireland. Prior to April 2020, there were a mean 2,346 patients/annum added to the waiting list for primary THA and there were a mean 1,624 primary THAs performed per annum.

The ECF targets for THA will only be achieved in 2026 if operating capacity is 200% of pre COVID-19 pandemic capacity and will be achieved in 2030 if capacity is 170%. Surgical capacity must exceed pre-Covid capacity by at least 30% to meet ongoing demand.

THA capacity was significantly reduced following resumption of elective orthopaedics post-COVID-19 (22% of pre-COVID-19 capacity – 355 THAs/annum post-COVID-19 versus 1,624/annum pre-COVID-19).

This modelling demonstrates that, in the absence of major funding and reorganisation of elective orthopaedic care, the targets set out in the ECF will not be achieved with regards to hip arthroplasty. Waiting times for THA surgery in the NHS in Northern Ireland are likely to remain greater than 52 weeks for most of this decade.

This multicentre audit assessed the total Tip Apex Distance (TAD) of sliding hip screws for intertrochanteric hip fractures in the 3 fracture hospitals in Northern Ireland (Ulster Hospital, Royal Victoria Hospital & Altnagelvin Hospital). Patient demographics and anaesthetic information was also reviewed. A sample of 140 patients with adequate screening films (39 UHD, 50 RVH & 51 Altnagelvin) were selected. The TAD was measured on AP & lateral screening films and compared to the standard of 25mm or less (total in 2 views) as recommended by Baumgaertner et al (JBJS (Am) 1995).

All 3 hospitals had an average of under 25mm (22.1, 19.9 & 19.6mm respectively) with overall average of 20.4mm, and a TAD of 25mm or less was achieved in 66.7%, 82% & 80.4% in respective hospitals (77.1% of patients overall). No patients were readmitted due to cut-out, despite 22.9% of patients having a TAD greater than 25mm. Among patients with TAD over 25mm the average TAD was 30.1mm

Demographics showed a 77.8% of patients to be female, with a slight predominance of left sided injuries. Most patients were of ASA grading 2–3. Anaesthetic method preferences varied between hospitals. Patients with TAD over 25mm were not significantly different from those with TAD of 25mm or less in age, gender, ASA or operated side.

Introduction: In patients presenting with an infected hip arthroplasty first-line antibiotics at our institution are Flucloxacillin and Fucidic Acid. It was observed that many patients needed their antibiotic regime changed once sensitivities became known. This was because of resistance to the first-line antimicrobial agents. This raised the question ‘How frequent is Flucloxacillin and Fucidic acid resistance in prosthetic hip infection and is there a more appropriate first-line antibiotic?’

Method: A computerised search of the Belfast Orthopaedic Information System (BOIS) identified all cases of infected hip arthroplasty from October 2001 to April 2005. All microbiology results of these patients were obtained and analysed to determine the infecting organism, sensitivity and resistance to Flucloxacillin, Fucidic acid and Teicoplanin.

Results: BOIS identified forty cases of infected hip arthroplasty, 35 primary arthroplasties and 5 revision arthroplasties. Of the 40 patients 36 had positive cultures, 3 had no growth and there was missing data on one patient. Flucloxacillin sensitivity occurred in 25% of patients with 58% resistance. With regard to Fucidic Acid sensitivity was 47 % with 44% resistance. There were no cases of Teicoplanin resistance. Teicoplanin sensitivity occurred in 78% of patients and with analysis by organism susceptibility sensitivity would measure 92% (8% were not tested against Teicoplanin).

Discussion: Flucloxacillin resistance is greater than sensitivity in infected hip arthroplasty in this study group. Fucidic Acid sensitivity and resistance are roughly equal. There are no cases of Teicoplanin resistance in our study population and with analysis with respect to the causative organism Teicoplanin sensitivity reaches 92%. It could be suggested therefore that the first-line agents of Flucloxacillin and Fucidic acid are inappropriate and that Teicoplanin may be a better choice.

The prospective evaluation of two hundred and seven symptomatic total knee arthroplasties presenting for revision total knee arthroplasty is reported. On univariate analysis patients who had infection differed significantly (p< .001) from those without infection with regards to: elevated ESR, CRP, positive aspiration, and history of; revision procedure less than two years since last surgery, early wound problems, ongoing pain since index procedure, and discharging wound. On multivariate analysis elevated ESR or CRP, positive aspiration, pain since index procedure and early wound complications were significant predictors of infection (p< .05). These variables were then used to formulate an evidence-based multivariate predictive algorithm to assist the clinician in decision making prior to surgery.

Differentiating septic from aseptic failure of total knee arthroplasty on the basis of clinical features and diagnostic tests can be troublesome for the clinician. The purpose of this paper is to describe significant differences between cases of septic and aseptic failure of total knee arthroplasty. The incorporation of these variables into a practical multivariate clinical prediction algorithm can provide assistance in establishing the diagnosis of infection prior to revision knee arthroplasty.

A simple clinical prediction algorithm can assist in the diagnosis of infection in patients with painful total knee arthroplasty. Patients with five of five criteria have a 99% probability of infection whereas patients with zero of five criteria have a 1% probability of infection.

This is the first multivariate evidence-based clinical prediction algorithm presented for use in decision making prior to revision total knee arthroplasty. The surgeon can use the information derived from clinical and laboratory assessment to compute an approximate pre-operative probability of infection prior to surgery (see table).

On multivariate analysis elevated ESR or CRP, positive aspiration, pain since index procedure and early wound complications were significant predictors of infection (p< .05). These variables were then used to formulate an evidence-based multivariate predictive algorithm to assist in clinical decision making.

Prospective data was collected on two hundred and seven symptomatic knee arthroplasties presenting for revision arthroplasty. A multivariate logistic regression model was used to determine the probability of infection using five significant variables. Combinations of these five variables can provide the clinician with an estimate of the probability of infection prior to revision knee arthroplasty.

Please contact author for tables and/or charts.