There is a growing body of literature to suggest that nutritional status is as important as obesity and other variables as an independent risk factor for TJA complications. Nutritional deficiency prevents normal wound healing and is associated with impaired immune function.
Malnutrition status is defined as Total WBC (< 1500), and Albumin (< 3.5). Other markers include transferrin, or Prealbumin.
Hypoalubminemia (<3.5) is the parameter most commonly studied in the TJA literature, and it is associated with higher rates of prothetic joint infection (PJI), delayed wound healing   and prolonged wound drainage.
However, many of these studies obtain data from large registries, and its unclear whether albumin deficiency is simply a marker for really significant comorbidities (such as cancer) or if controlling for comorbidities, it independently identifies patients with generally poor health and disabled healing potential . A recent study however controlled for such comorbidities and found a correlation with risk for PJI, longer hospital stay, pneumonia, and readmission .
1. Gherini, S., et al., Delayed wound healing and nutritional deficiencies after total hip arthroplasty. Clin Orthop Relat Res, 1993(293): p. 188-95.
2. Del Savio, G.C., et al., Preoperative nutritional status and outcome of elective total hip replacement. Clin Orthop Relat Res, 1996(326): p. 153-61.
3. Jaberi, F.M., et al., Procrastination of wound drainage and malnutrition affect the outcome of joint arthroplasty. Clin Orthop Relat Res, 2008. 466(6): p. 1368-71.
4. Bohl, D.D., et al., Hypoalbuminemia Independently Predicts Surgical Site Infection, Pneumonia, Length of Stay, and Readmission After Total Joint Arthroplasty. J Arthroplasty, 2016. 31(1): p. 15-21.