In their Article in
The Lancet Infectious Diseases, Erik Lenguerrand and colleagues
identify several risk factors associated with increased or decreased risk of revision due to prosthetic joint infection (PJI) after primary total hip arthroplasty (THA). In this cohort study, the largest to date, the authors followed a novel analytical approach in which they stratified multiple patient, surgery, and health-care system-related risk factors for developing PJI over several chronological postoperative periods. In addition to adding stronger evidence on previously known risk factors,
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the study also identified novel factors, including previous native hip infections and the use of lateral surgical approach. Furthermore, the authors provided stronger evidence to the role of the bearing surface, showing a potentially lower risk with ceramic bearings than metal bearings.
PJI remains a rare but catastrophic complication that follows THA and is associated with substantial patient morbidity. Successful management requires costly revision procedures and an experienced multidisciplinary approach to eradicate the infection and reliably restore function. Despite global collaborative efforts and initiatives aiming to improve diagnosis and optimise surgical treatment, reports have indicated that the incidence of PJI is not declining and with the projected increase in THA use, PJI incidence is expected to rise.
In this realm, identifying and quantifying risk factors that might be responsible for the development of PJI become extremely important to the firstline of defence, namely prevention.
It is self-evident that optimisation of any modifiable conditions before elective THA by medical interventions and team approaches, will help lessen the risk for PJI. Lenguerrand and colleagues have shown that patients with chronic pulmonary disease, liver disease, or dementia had increased risk of PJI. Additionally, understanding which risk factors might come into play during each specific postoperative period will help refine surveillance strategies to prevent the occurrence of PJI. Previous studies have attempted to quantify the overall risk for multiple factors (high vs low). However, little is known about the effects exerted by different risk factors in the specific postoperative stage after primary THA. The authors have shown that patients with liver disease were at higher risk for PJI only after 24 months from the index procedure. This finding shows that in some patient populations, clinicians might be doing well in optimising patients for elective surgery, but they are not performing as well in close monitoring and long-term follow-up. Timing of increased risk of developing PJI after THA might be particularly important in patients with non-modifiable risk factors. For example, those who had THA for indications other than hip osteoarthritis, such as fractured neck of femur and osteonecrosis, and those with previous native joint infection, were at higher risk for early PJI.
One finding from the present study
that we found particularly interesting was the reduced risk of PJI in patients who received ceramic bearing prostheses. Although this finding has been suggested by a few previous studies,
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the evidence was inconclusive because these implants were typically used in younger patients who tend to have fewer comorbidities. However, Lenguerrand and colleagues
accounted for age and comorbidities, and they were able to show stronger evidence suggesting that ceramic-on-ceramic and ceramic-on-polyethylene implants have a lower risk of PJI than metal-on-polyethylene THAs, which also showed a higher long-term risk of revision due to PJI. This particular risk factor needs to be assessed with prospective randomised studies to clarify its real effect on infections.
Identification and understanding the dynamics of various risk factors that might contribute to the development of PJI after primary THA will continue to be the aim of future studies. The role of surgeon and hospital volumes, surgical approach selection, and other factors that might exhibit a time-specific influence are yet to be explained by further research. Nevertheless, Lenguerrand and colleagues present an updated and comprehensive reference for clinicians who are at the forefront of battling prosthetic hip joint infections.
Link to article