New research by orthopaedic specialists at the University of Oxford showed that high-dose dual antibiotic-loaded cement was unlikely to reduce the risk of infection after hip replacement surgery for hip fracture.
The study, published in The Lancet, dashed hopes that the technique might reduce the incidence of surgical site infections, and demonstrated it was unlikely to be cost effective. The researchers said the study's results had "the potential to change clinical practice and eventually save money for the NHS".
In the UK, the incidence of hip fractures is nearly 76,000 cases annually , with the vast majority occurring in patients over the age of 70 years and with significant comorbidities. Fragility hip fractures have an overall mortality risk in the range of 10-40 % in the first year, much of it attributed to post-operative complications, with deep surgical site infection a significant contributor to this.
Approximately half of hip fractures occur at the neck of the femur, and these intracapsular fractures are typically treated with a hemiarthroplasty, in which the broken head of the femur is replaced with a metal implant. Recent evidence suggested that the hemiarthroplasty should be fixed to the patient's bone using bone cement, and now most arthroplasties (over 92%) are cemented .
High Incidence of Prosthetic Joint Infection
Prosthetic joint infection occurs in up to 7.3% of operations, leading to severe pain, reduced physical function and an increased mortality risk – over 10% for patients aged over 80.
The usual treatment, revision surgery, can be prolonged and complex, and carries an additional risk of complications, including a 4% risk of a further prosthetic joint infection, along with substantial healthcare costs estimated at around £36,000 per infected arthroplasty.
The team noted that, in order to try to allay this, in recent years there had been "a significant increase in the use of antibiotic-loaded bone cement in such fractures and procedures treated with a partial hip replacement or hemiarthroplasty".
The researchers set out to compare the rate of deep surgical site infection in patients aged over 60 receiving high-dose dual antibiotic-loaded cement with standard care single antibiotic-loaded cement. The study, called the World Hip Trauma Evaluation (WHITE) White 8 Trial, involved 4936 patients undergoing cemented hemiarthroplasty at 26 UK hospitals between August 2018 and August 2021. They were randomly allocated 1:1 to standard care single-antibiotic loaded cement or high-dose dual antibiotic-loaded cement.
No Significant Infection Reduction with Dual Antibiotic-Loaded Cement
Deep surgical site infection after 90 days occurred in 1.7% of participants in the single-antibiotic loaded cement group, compared with 1.2% in the high-dose dual antibiotic-loaded cement group, an insignificant difference (adjusted odds ratio 1.43; 95% CI 0.87 to 2.35; P=0.16). There was no difference in quality of life, mortality, antibiotic use, mobility, or residential status at follow up to 120 days.
The team concluded that the trial, which represented the largest study into the issue so far, "contradicts the findings of previous studies, which have indicated a benefit from the use of high-dose dual antibiotic-loaded bone cement in reducing the rate of all types of surgical site infection". The evidence should inform future guidelines, they said.
Co-lead author, Matt Costa, professor of orthopaedic trauma surgery in the Nuffield Department of Orthopaedics, Rheumatology, and Musculoskeletal Sciences at the University of Oxford, said: "Over the last 2 years, based upon previous smaller trial data, there has been a big increase in the use of high-dose, dual-antibiotic bone cement. However, this large-scale trial shows that there is unlikely to be a benefit in terms of reducing the risk of infection in the hip replacement.
"Furthermore, the economic analysis in this trial suggests that the more expensive high-dose dual-antibiotic cement is unlikely to be cost effective." He anticipated that the findings would "change clinical practice and reverse the trend of using this new bone cement", and so save money for the NHS.
Funding for the study was provided by Heraeus Medical, which is supported by the UK National Institute for Health and Care Research Oxford Biomedical Research Centre and sponsored by the Northumbria Healthcare NHS Foundation Trust. MLC is an NIHR Senior Investigator and member of the NIHR Health Technology Assessment General Board. NRA, SJD, and MRR declare an institutional grant from Heraeus, related to this study. NRA and MRR declare personal payments for lectures from Heraeus, unrelated to this study. MRR also declares further personal and institutional grants from Heraeus, unrelated to this study.