Orthopaedic surgical site infection surveillance in NHS England: national audit of current practice

Getting it right first time: national survey of surgical site infection 2019

INTRODUCTION

Surgical site infections (SSIs) are associated with increased morbidity and mortality. Deep SSI, or prosthetic joint infection (PJI), is associated with revision surgery involving longer operative times with higher infection rates, longer length of stay (LoS) and high costs in addition to the catastrophic effect on the patient. The surveillance of SSI is important for patient decision making, identification of outliers for support and maximising focussed improvement. This paper reports the findings of the second Getting it Right First Time (GIRFT) national SSI survey for orthopaedic and spinal surgery.

METHODS

Data were submitted prospectively by 67 orthopaedic units and 22 spinal units between 1 May 2019 and 31 October 2019. For a patient to be included, they had to present with SSI within the study period and within 1 year of the index procedure.

RESULTS

A total of 309 SSIs were reported from primary and revision, total hip, knee, shoulder, elbow and ankle replacements, and 58 SSIs were reported from lumbar spine single level discectomy or decompression, lumbar spine single-level instrumented posterior fusion, posterior cervical spine decompression and instrumented fusion and posterior correction of adolescent idiopathic scoliosis. SSIs rates have remained low compared with the 2017 survey. There were variations in SSI rates by procedure, with primary shoulder replacement reporting the lowest (0.4%) and revision shoulder replacement the highest (2.5%) rates.

CONCLUSIONS

The authors recommend that the elective surgical restart following the COVID-19 pandemic provides a unique opportunity for all units to implement a full SSI prevention bundle to minimise the risk of infection and improve patient outcomes.

Materials-driven fibronectin assembly on nanoscale topography enhances mesenchymal stem cell adhesion, protecting cells from bacterial virulence factors and preventing biofilm formation

Post-operative infection is a major complication in patients recovering from orthopaedic surgery. As such, there is a clinical need to develop biomaterials for use in regenerative surgery that can promote mesenchymal stem cell (MSC) osteospecific differentiation and that can prevent infection caused by biofilm-forming pathogens. Nanotopographical approaches to pathogen control are being identified, including in orthopaedic materials such as titanium and its alloys. These topographies use high aspect ratio nanospikes or nanowires to prevent bacterial adhesion but these features also significantly reduce MSC adhesion and activity. Here, we use a poly (ethyl acrylate) (PEA) polymer coating on titanium nanowires to spontaneously organise fibronectin (FN) and to deliver bone morphogenetic protein 2 (BMP2) to enhance MSC adhesion and osteospecific signalling. Using a novel MSC-Pseudomonas aeruginosa co-culture, we show that the coated nanotopographies protect MSCs from cytotoxic quorum sensing and signalling molecules, enhance MSC adhesion and osteoblast differentiation and reduce biofilm formation. We conclude that the PEA polymer-coated nanotopography can both support MSCs and prevent pathogens from adhering to a biomaterial surface, thus protecting from biofilm formation and bacterial infection, and supporting osteogenic repair.

Length of stay and contributing factors in elderly patients who have undergone hip fracture surgery in a tertiary hospital in South Africa

BACKGROUND

Length of stay and factors that contribute to length of stay in elderly patients who have undergone hip fracture surgery is under researched in developing countries, including South Africa. The purpose of this study was to describe the factors that increase length of stay (LOS) among elderly patients who have had hip fracture surgery.

METHODS

A retrospective review of patient records of elderly (>65 years) patients who had hip fracture surgery in a public hospital in South Africa. Descriptive statistics were used to report demographic data, LOS and frequency distributions of individual factors relating to LOS. Two sample t-tests were used to compare the LOS in patients with and without main complications reported.

RESULTS

The mean total length of stay was 33 (19) days. Patients presented with numerous comorbidities, with hypertension (n = 93) being the most prevalent. The most frequently occurring complications included anaemia (n = 42) and wound infection (n = 21). The LOS was significantly lower for patients not presenting with wound infections compared to those who sustained a wound infection (p = 0.041). Social factors delayed departure from the hospital for 48 patients.

CONCLUSION

Elderly patients who had hip fracture surgery and developed wound infections had an increased LOS. However social issues also contributed to the increase in length of stay that could be addressed by proper planning and involvement of families and care givers. The factors identified could be used as a starting point for planning services aimed at decreasing the hospital stay of elderly patients.

Association between Allogeneic Blood Transfusion and Wound Infection after Total Hip or Knee Arthroplasty: A Retrospective Case-Control Study

Background: To assess using a retrospective case control study, whether patients undergoing primary, elective total hip or knee arthroplasty who receive blood transfusion have a higher rate of post-operative infection compared to those who do not.

Materials and Methods: Data on elective primary total hip or knee arthroplasty patients, including patient characteristics, co-morbidities, type and duration of surgery, blood transfusion, deep and superficial infection was extracted from the Alberta Bone and Joint Health Institute (ABJHI). Logistic regression analysis was used to compare deep infection and superficial infection in blood-transfused and non-transfused cohorts.

Results: Of the 27892 patients identified, 3098 (11.1%) received blood transfusion (TKA 9.7%; THA 13.1%). Overall, the rate of superficial infection (SI) was 0.5% and deep infection (DI) was 1.1%. The infection rates in the transfused cohort were SI 1.0% and DI 1.6%, and in the non-transfused cohort were SI 0.5% and DI 1.0%. The transfused cohort had an increased risk of superficial infection (adjusted odds ratio (OR) 1.9 [95% CI 1.2-2.9, p-value 0.005]) as well as deep infection (adjusted OR 1.6 [95% CI 1.1-2.2, p-value 0.008]).

Conclusion: The odds of superficial and deep wound infection are significantly increased in primary, elective total hip and knee arthroplasty patients who receive blood transfusion compared to those who did not. This study can potentially help in reducing periprosthetic hip or knee infections.

The effectiveness of ultra-clean air operating theatres in the prevention of deep infection in joint arthroplasty surgery

Deep infection was identified as a serious complication in the earliest days of total hip arthroplasty. It was identified that airborne contamination in conventional operating theatres was the major contributing factor. As progress was made in improving the engineering of operating theatres, airborne contamination was reduced. Detailed studies were carried out relating airborne contamination to deep infection rates.

In a trial conducted by the United Kingdom Medical Research Council (MRC), it was found that the use of ultra-clean air (UCA) operating theatres was associated with a significant reduction in deep infection rates. Deep infection rates were further reduced by the use of a body exhaust system. The MRC trial also included a detailed microbiology study, which confirmed the relationship between airborne contamination and deep infection rates.

Recent observational evidence from joint registries has shown that in contemporary practice, infection rates remain a problem, and may be getting worse. Registry observations have also called into question the value of “laminar flow” operating theatres.

Observational evidence from joint registries provides very limited evidence on the efficacy of UCA operating theatres. Although there have been some changes in surgical practice in recent years, the conclusions of the MRC trial remain valid, and the use of UCA is essential in preventing deep infection.

There is evidence that if UCA operating theatres are not used correctly, they may have poor microbiological performance. Current UCA operating theatres have limitations, and further research is required to update them and improve their microbiological performance in contemporary practice.

Cite this article: Bone Joint J 2018;100-B:1264–9.

The biofilm eradication activity of acetic acid in the management of periprosthetic joint infection

Objectives

Periprosthetic joint infection following joint arthroplasty surgery is one of the most feared complications. The key to successful revision surgery for periprosthetic joint infections, regardless of treatment strategy, is a thorough deep debridement. In an attempt to limit antimicrobial and disinfectant use, there has been increasing interest in the use of acetic acid as an adjunct to debridement in the management of periprosthetic joint infections. However, its effectiveness in the eradication of established biofilms following clinically relevant treatment times has not been established. Using an in vitro biofilm model, this study aimed to establish the minimum biofilm eradication concentration (MBEC) of acetic acid following a clinically relevant treatment time.

Materials and Methods

Using a methicillin-sensitive Staphylococcus aureus (MSSA) reference strain and the dissolvable bead assay, biofilms were challenged by 0% to 20% acetic acid (pH 4.7) for ten minutes, 20 minutes, 180 minutes, and 24 hours.

Results

The MBEC of acetic acid was found to be: 15%, 11%, 3.2%, and 0.8% following a ten-minute, 20-minute, 180-minute, and 24-hour treatment, respectively.

Conclusion

This study found that the MBEC of acetic acid following a 10- or 20-minute treatment time exceeded its safety threshold, making these concentrations unsuitable as a topical debridement adjunct. However, a clinically acceptable concentration (5%) was still found to eliminate 96.1% of biofilm-associated MSSA following a 20-minute treatment time.

Cite this article: S. T. J. Tsang, P. J. Gwynne, M. P. Gallagher, A. H. R. W. Simpson. The biofilm eradication activity of acetic acid in the management of periprosthetic joint infection. Bone Joint Res 2018;7:517–523. DOI: 10.1302/2046-3758.78.BJR-2018-0045.R1

The effect of triclosan-coated sutures on the rate of surgical site infection after hip and knee arthroplasty: a double-blind randomized controlled trial of 2546 patients

Aims

Surgical site infection (SSI) is a common complication of surgery with an incidence of about 1% in the United Kingdom. Sutures can lead to the development of a SSI, as micro-organisms can colonize the suture as it is implanted. Triclosan-coated sutures, being antimicrobical, were developed to reduce the rate of SSI. Our aim was to assess whether triclosan-coated sutures cause a reduction in SSIs following arthroplasty of the hip and knee.

Patients and Methods

This two-arm, parallel, double-blinded study involved 2546 patients undergoing elective total hip (THA) and total knee arthroplasty (TKA) at three hospitals. A total of 1323 were quasi-randomized to a standard suture group, and 1223 being quasi-randomized to the triclosan-coated suture group. The primary endpoint was the rate of SSI at 30 days postoperatively.

Results

The baseline characteristics of age, gender and comorbidities were well matched in the two groups. The rates of superficial SSI were 0.8% in the control group and 0.7% in the intervention group (p = 0.651), and when deep and superficial SSIs were combined the rates were 2.5% and 1.8 (p = 0.266). The length of stay in hospital and the rates of medical complications did not differ significantly between the groups (p = 1.000).

Conclusion

This trial provided no evidence that the use of triclosan-coated sutures at THA and TKA leads to a reduction in the rate of SSI. Cite this article: Bone Joint J 2018;100-B:296-302.

Risk factors of fixation failure in basicervical femoral neck fracture: Which device is optimal for fixation?

BACKGROUND

Basicervical femur neck fracture (FNF) is a rare type of fracture, and is associated with increased risk of fixation failure due to its inherent instability. The purpose of this study was (1) to investigate the incidence of fixation failure and (2) to determine risk factors for fixation failure in basicervical FNF after internal fixation.

METHODS

To identify basicervical FNF with a minimum of 12 months follow-up, we retrospectively reviewed records of 3217 patients who underwent hip fracture surgery from May 2003 to March 2016. Among the identified 77 patients with basicervical FNF, 69 patients were followed up for at least 12 months. We evaluated the rate of collapse of fracture site and reoperation due to fixation failure. We performed a multivariable analysis to determine risk factors associated with fracture site collapse and fixation failure.

RESULTS

Among the 69 patients with basicervical FNF, 17 (24.6%) showed collapse of fracture site, and 6 (8.6%) underwent conversion to arthroplasty because of fixation failure. In the multivariable analysis, use of extramedullary plating with a sliding hip screw was an independent significant risk factor for both collapse of fracture site (odds ratio 6.84; 95% confidence interval 1.91-24.5, p = 0.003) and fixation failure (odds ratio 12.2; 95% confidence interval 1.08-137.7, p = 0.042).

CONCLUSIONS

Basicervical FNF treated with extramedullary plate with a sliding hip screw is more likely to fail than that treated with intramedullary nail with a helical blade. Our results suggested that intramedullary nail with a helical blade is more recommended for basicervical FNF compared with extramedullary plate with a sliding hip screw.

LEVEL OF EVIDENCE

III, Retrospective cohort study.

Underestimation of Staphylococcus aureus (MRSA and MSSA) carriage associated with standard culturing techniques: One third of carriers missed

OBJECTIVES

Nasal carriers of Staphylococcus (S.) aureus (MRSA and MSSA) have an increased risk for healthcare-associated infections. There are currently limited national screening policies for the detection of S. aureus despite the World Health Organization's recommendations. This study aimed to evaluate the diagnostic performance of molecular and culture techniques in S. aureus screening, determine the cause of any discrepancy between the diagnostic techniques, and model the potential effect of different diagnostic techniques on S. aureus detection in orthopaedic patients.

METHODS

Paired nasal swabs for polymerase chain reaction (PCR) assay and culture of S. aureus were collected from a study population of 273 orthopaedic outpatients due to undergo joint arthroplasty surgery.

RESULTS

The prevalence of MSSA nasal colonization was found to be between 22.4% to 35.6%. The current standard direct culturing methods for detecting S. aureus significantly underestimated the prevalence (p = 0.005), failing to identify its presence in approximately one-third of patients undergoing joint arthroplasty surgery.

CONCLUSION

Modelling these results to national surveillance data, it was estimated that approximately 5000 to 8000 S. aureus surgical site infections could be prevented, and approximately $140 million to $950 million (approximately £110 million to £760 million) saved in treatment costs annually in the United States and United Kingdom combined, by using alternative diagnostic methods to direct culture in preoperative S. aureus screening and eradication programmes.Cite this article: S. T. J. Tsang, M. P. McHugh, D. Guerendiain, P. J. Gwynne, J. Boyd, A. H. R. W. Simpson, T. S. Walsh, I. F. Laurenson, K. E. Templeton. Underestimation of Staphylococcus aureus (MRSA and MSSA) carriage associated with standard culturing techniques: One third of carriers missed. Bone Joint Res 2018;7:79-84. DOI: 10.1302/2046-3758.71.BJR-2017-0175.R1.

Primary hip and knee arthroplasty in a temporary operating theatre is associated with a significant increase in deep periprosthetic infection

Aims

Infection following total hip or knee arthroplasty is a serious complication. We noted an increase in post-operative infection in cases carried out in temporary operating theatres. We therefore compared those cases performed in standard and temporary operating theatres and examined the deep periprosthetic infection rates.

Patients and methods

A total of 1223 primary hip and knee arthroplasties were performed between August 2012 and June 2013. A total of 539 (44%) were performed in temporary theatres. The two groups were matched for age, gender, body mass index and American Society of Anesthesiologists grade.

Results

The deep infection rate for standard operating theatres was 0 of 684 (0%); for temporary theatres it was eight of 539 (1.5%) (p = 0.001).

Conclusion

Use of a temporary operating theatre for primary hip and knee arthroplasty was associated with an unacceptable increase in deep infection. We do not advocate the use of these theatres for primary joint arthroplasty. Cite this article: Bone Joint J 2017;99-B:917–20.