Elevated synovial leukocyte count is a minor criterion derived from the musculoskeletal infection society (MSIS) widely used in clinical practice for diagnosis of prosthetic joint infection. There is evidence to suggest analysis within 1 hour, preferentially within 30 minutes, of aspiration reduces the risk of ex vivo cell lysis occurring during prolonged transport. Multiple site working is more common practice and the availability of a lab on site to perform these tests is not always possible. We aimed to assess whether we could safely perform synovial leukocyte counts within our cold site in the diagnosis of prosthetic joint infection.

We reviewed all orthopaedic synovial fluid aspirates within the lower limb arthroplasty unit from April 2021 – April 2022 performed at South Tees NHS Foundation Trust. We assessed time from aspirate to the lab using electronic data resources. This information was compared with the labs ability to perform a synovial leukocyte count to determine the impact of delays on testing.

110 patients (34.5% hips and 63.6% knees) were identified between two sites. Time from aspirate to lab ranged from 0 mins to 26 hrs 34 mins. Mean time to processing was 3hrs 10 mins. 50% of all samples had a synovial leukocyte count performed. 67% of patients had a cell differential performed. There was no difference in the ability to perform a synovial leukocyte count between samples process in < 2hours vs > 6 hours.

We conclude that it is safe practice to perform joint aspirates for the work up of periprosthetic joint infections in sites where no laboratory is immediately available as the delay to processing synovial fluid does not alter the ability to perform a synovial leukocyte count. This study will provide evidence to enable the work up of periprosthetic joint infections in cold centres and therefore reduce the delay in diagnosis and proceeding management.

Hip fracture principally affects the frailest in society, many of whom are care dependent, and are disproportionately at risk of contracting COVID-19. We examined the impact of COVID-19 infection on hip fracture mortality in England.

We conducted a cohort study of patients with hip fracture recorded in the National Hip Fracture Database between 1st February 2019 and 31st October 2020, in England. Data were linked to Hospital Episode Statistics to quantify patient characteristics and comorbidities, Office for National Statistics mortality data, and Public Health England's SARS-CoV-2 testing results. Multivariable Cox regression examined determinants of 90-day mortality. Excess mortality attributable to COVID-19 was quantified using Quasi-Poisson models.

Analysis of 102,900 hip fractures (42,630 occurring during the pandemic) revealed that amongst those with COVID-19 infection at presentation (n=1,120) there was a doubling of 90-day mortality; hazard ratio (HR) 2.05 (95%CI 1.86–2.26), while for infections arising between 8–30 days after presentation (n=1,644) the figure was even higher at 2.52 (2.32–2.73). Malnutrition [1.44 (1.19–1.75)] and non-operative treatment [2.89 (2.16–3.86)] were the only modifiable risk factors for death in COVID-19 positive patients. Patients with previous COVID-19 initially had better survival compared to those who contracted COVID-19 around the time of their hip fracture; however, survival rapidly declined and by 365 days the combination of hip fracture and COVID-19 infection was associated with a 50% mortality rate. Between 1st January and 30th June 2020, 1,273 (99.7%CI 1,077–1,465) excess deaths occurred within 90 days of hip fracture, representing an excess mortality of 23% (20%–26%), with most deaths occurring within 30 days.

COVID-19 infection more than doubled early hip fracture mortality; the first 30-days after injury were most critical, suggesting that targeted interventions in this period may have most benefit in improving survival.

Background

There is significant variation and inconsistencies in the current advice and information delivered to patients undergoing total hip replacement (THR). The aim of this study was to assess a locally developed web-based electronic resource system for patients undergoing total hip replacement (THR) surgery to see if this improves and standardises the content, structure, and delivery of information delivered to patients prior to and after surgery.

Introduction

Periprosthetic joint infection (PJI) can be difficult to diagnose. A variety of techniques have been described. The efficacy of the alpha-defensin laboratory test was examined and compared with other established modalities in the diagnostic workup of ‘real world’ arthroplasty patients.

Aims

The highly cross-linked polyethylene Exeter RimFit flanged cemented acetabular component was introduced in the United Kingdom in 2010. This study aimed to examine the rates of emergence of radiolucent lines observed when the Rimfit acetabular component was implanted at total hip arthroplasty (THA) using two different techniques: firstly, the ‘rimcutter’ technique in which the flange sits on a pre-prepared acetabular rim; and secondly, the ‘trimmed flange’ technique in which the flange is trimmed and the acetabular component is seated inside the rim of the acetabulum.

Introduction

The Exeter RimFit™ flanged cemented cup features ultra-highly cross-linked polyethylene and was introduced onto the market in the UK in 2010. We aimed to examine the rates of radiolucent lines observed when the Rimfit™ cup was implanted using a ‘rimcutter’ technique with the cup sitting on a prepared acetabular rim, and a ‘trimmed flange’ technique were the flange is cut so that it sits inside the prepared acetabular rim.