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.

Abstract

Abstract

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.

Aim

This study aimed to identify risk factors for development of deep periprosthetic joint infection (PJI) in patients following surgical treatment of neck of femur fracture.

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.

The aim of this study was to review the role of clinical trial networks in orthopaedic surgery. A total of two electronic databases (MEDLINE and EMBASE) were searched from inception to September 2013 with no language restrictions. Articles related to randomised controlled trials (RCTs), research networks and orthopaedic research, were identified and reviewed. The usefulness of trainee-led research collaborations is reported and our knowledge of current clinical trial infrastructure further supplements the review. Searching yielded 818 titles and abstracts, of which 12 were suitable for this review. Results are summarised and presented narratively under the following headings: 1) identifying clinically relevant research questions; 2) education and training; 3) conduct of multicentre RCTs and 4) dissemination and adoption of trial results. This review confirms growing international awareness of the important role research networks play in supporting trials in orthopaedic surgery. Multidisciplinary collaboration and adequate investment in trial infrastructure are crucial for successful delivery of RCTs.

Cite this article: Bone Joint Res 2014;3:169–74.

Introduction

National Institute for Health and Clinical Excellence (NICE) guidelines recommend the use of total hip replacement (THR) for displaced intracapsular fractured neck of femur (NOF) in cognitively intact patients who were independently mobile prior to the injury. The National Joint Registry for England and Wales (NJR) has collected data on THRs performed since 2003. This retrospective cohort study explores risk factors independently associated with implant failure and perioperative mortality.

Background

Current analysis of unicondylar knee replacements (UKR) by national registries is based on the pooled results of medial and lateral implants. Using data from the National Joint Registry for England and Wales (NJR) we aimed to determine the proportion of lateral UKR implanted, their survival and reason for failure in comparison to medial UKR.

Background

Both surgeon and hospital volume influence patient outcomes following revision knee arthroplasty.

Introduction

Following in-depth analysis of the market leading brand combinations in which we identified implant influences on risk of revision, we compared revision in patients implanted with different categories of hip replacement in order to find implant with the lowest revision risk, once known flawed options were removed.

Purpose

To determine how patient characteristics; health status and pre-operative knee function effect patient reported satisfaction and operative success following total knee replacement (TKR). We hypothesised that a number of patient factors would influence the reported levels of symptomatic improvement (success) and satisfaction and that these two outcomes would represent different aspects of the patient's perception of outcome.

Background

The most appropriate form of chemical thromboprophylaxis following knee replacement is a contentious issue. Most national guidelines recommend the use of low molecular weight Heparin (LMWH) whilst opposing the use of aspirin. We compared thromboembolic events, major haemorrhage and death after knee replacement in patients receiving either aspirin or LMWH.

Purpose

To examine how patients viewed the outcome of their joint replacement at least one year post surgery. Emphasis was placed on investigating the relative influence of ongoing pain and functional limitation on patient satisfaction.

Introduction

We have carried out a 15 year survival analysis of a prospective, randomised trial comparing cemented with cementless fixation of press-fit condylar primary total knee replacements.

Introduction

Electrolyte imbalance in the elderly is a clinical problem faced by both elderly care physicians and orthopaedic surgeons alike. Hyponatraemia is a common condition with a vague clinical profile and severe consequences if untreated. Recent medical editorials have criticised orthopaedic handling of this problem. We therefore sought to establish the incidence of hyponatraemia within our orthopaedic population and a similar age-matched elderly care population in the light of changing attitudes to fluid management.

Introduction: The recent UK national comparative audit of the use of blood in primary, elective, unilateral THR found that 25% of patients required a peri-operative transfusion. We felt this figure was higher than should be expected, especially of surgeons with a dedicated arthroplasty subspecialty. We therefore audited our own practice with particular emphasis on the relationship between surgeon volume, implant and the need for transfusion.

Methods: A retrospective review of 508 consecutive primary, elective, unilateral hip and knee arthroplasties performed over a 12 month period. Pre- and post- operative haemoglobin levels, need for transfusion, and the timing and volume of any transfusion were recorded for each patient. Analysis determined the overall rate of transfusion, the details of any such transfusion, and the effects of surgeon volume upon the transfusion rate.

Results: The transfusion rate following THR (10%) was significantly lower than those found in the national audit. The transfusion rate following TKR was 7%. Multivariate analysis demonstrated that surgeon volume (< 50 THRs/yr Vs > 50 THRs/yr) and a preop-erative Hb < 12g/dl were the only significant determinants of a need for post operative transfusion (Both p< 0.05) following both THR and TKR. Other variables (age, gender, anaesthetic type, ASA, indication, surgeon grade and experience, implant, approach) were not significant. A preoperative haemoglobin of < 12g/dl was associated with a 6 fold and 3 fold increased risk of needing a transfusion following hip and knee replacement respectively.

Discussion: The need for allogenic blood transfusion following primary arthroplasty is influenced by both patient and surgeon related factors. Surgeons who have a dedicated arthroplasty practice and perform a high volume of procedures have significantly lower transfusion rates when compared to nationally accepted figures. This has implications for both patient care and resource management.

Introduction: The Oxford Knee Score (OKS) is commonly used in the assessment of outcome for knee arthroplasty. All patients having knee arthroplasty at our institution undergo OKS at both nurse led pre-assessment and admission physiotherapy visit, a period of 10 to 30 days pre-operatively. At both instances, the scoring form is left with the patient and collected at the end of the visit.

Anecdotal evidence from our centre suggested that patients attending for arthroplasty surgery were scoring differently at each visit.

The aim of this study is to establish if there is a significant difference OKS at pre-assessment visit and on admission to the ward.

Statistical Method: A pilot study was carried out. A power calculation revealed a requirement for 44 patients to enter the study. The resultant probability was 90 percent that the study would detect a difference at a two sided 5.0 percent significance level, if the minimum clinical difference is 3 points. This is based on the standard deviation of the difference in the response variables of 6. A clinical difference of 3 is drawn from previous studies investigating the use of the OKS.

44 patients undergoing arthroplasty surgery had their OKS for both visits retrospectively analysed.

The mean of the totals of both visits was analysed and found to conform to normality and hence was further investigated by a paired samples t test.

Comparison of individual scoring revealed a violation of normality and hence was further analysed using a Wilcoxon Signed Ranks Test.

Results: A statistically significant result at the 5% level was observed t= 2.197 (44df), p= 0.03. OKS at pre-assessment was lower than at admission to the ward by 1.1 point. (−2.1 – 0.9 95% CI).

Analysis of the individual scoring at both intervals revealed only three of the pairs achieved statistical significance and in each case, the difference was less than 3 scoring units. No significant difference was seen when time between assessments was analysed.

Conclusion: This study demonstrates that although there is a difference in total scoring using the OKS between two patient episodes prior to arthroplasty, a clinically relevant difference is not detected, and neither is a statistically significant difference detected when all scoring steps are analysed.

This work supports earlier studies that pre-operative assessment using the OKS is robust to variance in the pre-operative scoring window.