Effects of Malnutrition on Perioperative Outcomes of Total Hip Arthroplasty: A Systematic Review and Meta-Analysis.

Background: Malnutrition can play a significant role in wound healing, immune response, and conditioning. The purpose of this review is to characterize definitions of malnutrition in total hip arthroplasty (THA) and analyze its effects on postoperative outcomes. Methods: A systematic search was conducted using iterations of the key terms "total hip arthroplasty" and "malnutrition." Human studies describing malnutrition in patients undergoing primary THA for either traumatic or elective indications were included. Using the SPSS meta-analysis binary and continuous model function, the mean effect size estimate (MSE) or Cohen's d (Cd) statistic with 95% confidence interval was reported. Results: This search yielded a total of 555 studies, of which 9 articles comprising 495,657 patients undergoing primary THA were included, characterizing 16,895 patients (3.4%) as malnourished. Studies characterized malnutrition as albumin <3.5 g/dL (n = 7) and total lymphocyte count <1500 (n = 1). Malnutrition was associated with an increased rate of nonhome discharge (MSE = 0.81, [0.55-1.07]) and likelihood of readmission (MSE = 0.86, [0.75-0.97]). Malnutrition at the time of surgery was also associated with increased rates of any complication (MSE = 1.01, [0.46-1.57]), wound complications (MSE = 1.04, [0.72-1.36]), pulmonary complications (MSE = 1.54, [1.29-1.78]), need for transfusion (MSE = 0.75, [0.54-0.96]), periprosthetic fracture (MSE = 0.65, [0.47-0.82]), reoperation (MSE = 0.72, [0.58-0.86]), and perioperative mortality (MSE = 2.05, [1.76-2.33]). Conclusions: Malnutrition was found to have significant associations with complications and disposition following THA. The findings from this meta-analysis provide support for further investigation into perioperative nutritional supplementation strategies for surgeons to optimize at-risk patients prior to THA. Level of Evidence: III.