Interview based malnutrition assessment can predict adverse events within 6 months after primary and revision arthroplasty - a prospective observational study of 351 patients

Background: Being at risk for malnutrition can be observed among hospitalized patients of all medical specialties. There are only few studies in arthroplasty dealing with defining and assessing malnutrition as such a potentially risk. This study aims to identify the risk for malnutrition following primary (pAP) and revision arthroplasty (rAP) (1) using non-invasive interview based assessment tools and to analyze effects on clinical outcome (2) and quality of life (3).

Methods: A consecutive series of hospitalized patients of a Department of Arthroplasty at a Level 1 Trauma Center in Western Europe was observed between June 2014 and June 2016. Patients were monitored for being at risk for malnutrition at hospital admission (T1) and 6 months post surgery (T2) by non-invasive interview based assessment tools (NRS 2002, SF-MNA, MNA). Adverse events, length of hospital stay and quality of life (HRQL, SF-36) were monitored.

Results: 351 (283 pAP/ 68 rAP) patients were included. At T1, 13.4% (47) / 23.9% (84) / 27.4% (96) and at T2 7.3% (18) / 17.1% (42) / 16.0% (39) of all patients were at risk for malnutrition regarding NRS/SF-MNA/MNA. Prevalence of malnutrition risk was higher in rAP (22.1-29.4%) compared to pAP (11.3-26.9%). Patients being at risk for malnutrition showed prolonged hospitalization (NRS 14.5 to 12.5, SF-MNA 13.7 to 12.4, MNA 13.9 to 12.3 days, p < 0.05), delayed mobilization (NRS 2.1 to 1.7, SF-MNA 1.8 to 1.7, MNA 1.9 to 1.7 days), lower values in HRQL and more adverse events.

Conclusions: There is a moderate to high prevalence of risk for malnutrition in arthroplasty that can easily be assessed through interview based screening tools. Being at risk for malnutrition can reduce the clinical outcome following pAP and rAP. Patients with an impaired nutritional status show reduced values in physical and mental aspects of HRQL. Non-invasive interview-based nutritional assessment can predict adverse events in primary and revision total arthroplasty and can therefore help identifying patients at risk before surgery.

Trial registration: The study protocol was approved by the local ethics committee (193/2014BO2) and registered at the German Clinical Trials Register according to WHO standard ( DKRS00006192 ).