CORR Insights^®: Is Potential Malnutrition Associated With Septic Failure and Acute Infection After Revision Total Joint Arthroplasty?

Where Are We Now?

Malnutrition and its potential association with periprosthetic infections have been underrepresented in the orthopaedic literature, and infrequently discussed at specialty meetings. I believe orthopaedic researchers have largely ignored this topic because of (1) the enigmatic definitions of malnutrition, (2) the condition often falling outside orthopaedists’ primary scope of practice, and (3) the incorrect assumption that malnutrition is only a marginal problem in total joint arthroplasty (TJA).

Malnutrition results from eating a diet that lacks certain essential nutrients or is calorically insufficient, but can also be caused by chronic conditions like inflammation. Trauma and major surgery can induce a state of malnutrition and a resulting loss of immunocompetence [3]. This condition has been linked to postoperative complications in TJA, including deep infection [1, 4]. But a clear characterization of malnutrition has eluded us. Clinical and subclinical adult malnutrition can be suspected in the presence of abnormal laboratory parameters like serum albumin, total lymphocyte count, transferrin, and antropometric measurements. A recent consensus paper by White and colleagues [5] comprehensively described the various characteristics required for the identification of this condition, including history of presence of chronic inflammation, physical exam, anthropometric data, laboratory data and nutritional intake patterns. I note that, according to the authors, consensus on recognition of adult malnutrition is still a work in progress.

The paper by Yi et al. is a valuable contribution in the quest to shed some light on the subject. If their thesis is confirmed, the identification and correction of malnutrition before surgery will possibly allow a sensible reduction of patient-related risk for PJI. This point is particularly relevant in today’s challenging times of accountable care, where the ability to accurately identify high-risk patients is of paramount importance for healthcare providers.

Where Do We Need To Go?

To date, there is little evidence suggesting a causative link between malnutrition and periprosthetic joint infection (PJI) after revision TJA. The clinical investigation by Yi et al. represents a relevant step toward a better understanding of malnutrition in TJA. Their study shows that abnormal laboratory parameters suggestive of malnutrition are common among patients with revision TJA. The authors found that serum albumin, total lymphocyte count, and transferrin are independently associated with PJI. However, because of the retrospective nature of the study, they could not demonstrate a causal effect of malnutrition on joint infection. Malnutrition is more than an abnormal laboratory test. Therefore, the findings of the study are related to the potential condition of malnutrition, rather than to a confirmed diagnosis of malnutrition. Laboratory parameters used to define malnutrition can also be affected by various disorders including stress and chronic PJI. Future studies will need to focus on this key question: Is infection causing malnutrition, or the other way around?

How Do We Get There?

Yi et al. added a relevant piece of information into this controversial debate, and I expect that their important work will prompt further research with appropriate methodology and suitable sample size. Undoubtedly, projects for further research in this field offer great potential to provide highly relevant information for the clinical practice. Our ability to accurately identify high-risk PJI patients will improve if we can demonstrate a causative link with malnutrition. As already mentioned in the current study, work for such clinical research is reportedly at the implementation stage [2]. This type of study will require multicenter, prospective study designs, with standardized protocols for malnutrition screening and subsequent correction, as well as sufficient funding and personnel. Is a control group required for a clinical trial of this kind? With the current evidence, is it reasonable to deny correction of malnutrition in patients who undergo primary and revision TJA? I suspect that the designated ethics committee will face a lively debate on this topic.