Factors associated with pressure ulcer onset after knee replacement

Objective: The aim of this study was to find the rate of pressure ulcers (PUs) in patients with knee replacements and identify predictive factors. The ability of the Braden scale to predict the onset of PUs was also investigated. Method: A retrospective prognostic cohort study was carried out involving all consecutive patients undergoing knee replacement surgery. The data were collected from patient records. The variables collected were grouped into two categories: those connected to the patient's own characteristics; and those linked to the care methods used. Results: The total number of patients included in the study was 565. Of these, 2.3% had developed a PU: 0.5% at the heel and 1.8% at the sacrum. Multivariate analysis showed that the variables actually correlated to the outcome were age (p=0.074; odds ratio (OR)=1.08), body mass index (BMI, p=0.037; OR=1.13) and Braden scale (p=0.029; OR=0.72). A combination of these three parameters showed better predictivity of PUs (area under the curve (AUC) 84%). Conclusion: Age, BMI and preoperative Braden score were shown to be independent predictive factors of the onset of PUs in patients with knee replacements. The combined use of all three variables increased the ability to identify the patients at most risk of developing a PU.