Perioperative malnutrition is a modifiable patient risk factor that has been associated with impaired wound healing, increased surgical site infections (SSIs), length of hospital stays, increased health care costs, and mortality in orthopedic surgery.1,2 The orthopedic literature defines albumin <3.5 g/dL, a total lymphocyte count <1500 cells/mm3, and/or a transferrin level <200 mg/dL to be serum markers of malnutrition, as levels below these thresholds have been linked to poor surgical outcomes. Surgical injury leads to immune suppression and impairment of the body’s ability to engage in key tissue healing and protection mechanisms.3 The cause of this immune defect may be acute deficiencies in key nutrients that the immune system requires to function correctly.4 Numerous studies indicate that both trauma and surgery lead to a rapid deficiency in key nutrients such as arginine that is essential to immune function. This evolutionarily conserved arginine depletion by myeloid derived suppressor cells following surgical injury and trauma directly leads to increased infection risk and impaired recovery.4,5 These deficiencies cause a direct defect in immune-cell function that occurs in both malnourished and well-nourished patients and can be corrected by therapy with oral arginine-containing immunonutrition supplements which have been shown to reduce postoperative infections and length of stay (LOS) in a range of surgical populations.4 Specific data to an orthopedic patient with arginine-containing oral nutrition supplements (ONSs) is limited and this is a key area for further research.
Several surrogates for malnutrition exist, including serologic markers (ie, serum albumin and total lymphocyte count), anthropometric measurements (ie, calf muscle circumference and triceps skinfold) and assessment and screening tools (ie, the Rainey-MacDonald Nutritional Index, the Mini Nutrition Assessment Short Form, the Malnutrition Universal Screening Tool, and the Nutrition Risk Screening 2002), however, there is no universal gold standard for screening or assessing nutritional risk and no accepted guideline for perioperative optimization of malnourished orthopedic surgical patients. Moreover, it is not uncommon for morbidly obese and diabetic patients to be malnourished and data suggests that morbid obesity has significantly increased risk of morbidity following orthopedic surgery.6 Therefore, adequate assessment of perioperative risk for malnutrition and preoperative nutrition optimization, including safe weight loss in the obese population, consumption on high protein oral nutritional supplements, immunonutrition delivery, and adequate glucose control, may improve perioperative outcomes.
THE IMPACT OF MALNUTRITION ON ORTHOPEDIC SURGICAL OUTCOME
Despite modern advances in surgical and anesthesia technique and improvements in perioperative care, the incidence of major infection from all-cause postoperative infections ranges from 3.1% to 45% depending on the risk factors of the patient and type of surgery. SSIs alone occur in 500,000 US patients per year7 and are the most common complication following orthopedic surgery.1 Greene et al8 reviewed the records of 217 patients who underwent primary total hip or total knee arthroplasty and found that patients with an albumin <3.5 g/dL had a 7-fold greater risk of major wound complication and patients with a total lymphocyte count <1500 cells/mm3 had a 5 times greater risk for developing a major wound complication after either a total knee or hip arthroplasty. Similarly, a retrospective study of 6489 total knee arthroplasties by Peersman et al9 found that poor nutrition, obesity, and diabetes mellitus were associated with prosthetic joint infections when compared with matched control.
In addition to SSI, malnutrition has been associated with increased LOS in orthopedic patients. Nicholson et al10 retrospectively studied 90 patients who underwent total hip arthroplasty (THA) or hemiarthroplasty and found that preoperative levels of serum albumin <3.5 g/dL or a total lymphocyte count <1.50 cells/mm3 was associated with a longer LOS following THA or hemiarthroplasty. Using the American College of Surgeons National Surgical Quality Improvement Program (NSQIP) database, Garcia and colleagues found the prevalence of malnutrition was 7.6% and total shoulder arthroplasty patients with preoperative albumin levels of <3.5 g/dL were at much higher risk for morbidity and death after surgery when compared to patients with normal albumin levels. Moreover, malnourished patients were at a significantly increased risk for blood transfusion, longer hospital LOS, and death within 30 days of surgery.11
Malnourished orthopedic patients also incur larger financial burdens and place more strain on hospital resources when compared with well-nourished patients. Lavernia and colleagues retrospectively studied the relationship between malnutrition and hospital resource consumption, LOS, in-hospital consults and the presence and number of complications in 119 patients undergoing hip and knee replacement surgery. After adjusting for medical severity of illness and age, patients with albumin levels <34 g/L had 32.7% higher charges ($50,108±8203 vs. $33,720±1128 SE, P<0.006), higher medical severity of illness (P=0.03) and longer LOS (8.6±1.7 vs. 5.2±0.356 SE days, P<0.001). Patients with TLC <1200 cells/µL had higher charges ($32,544±1050 vs. $42,098±3122 SE, P=0.004), and longer LOS (5.7±0.531 vs. 5.4±0.368 d, P=0.004).12 These data suggest that optimization of malnutrition should be a focus to improve hospital resource utilization and reduce cost.
PERIOPERATIVE IDENTIFICATION OF THE MALNOURISHED SURGICAL PATIENT
Standardized malnutrition screening tools and malnutrition assessment tools are used to identify and quantify malnutrition in orthopedic patients. The Rainey-MacDonald nutritional index calculates malnutrition risk from serum albumin and serum transferrin,13,14 whereas the Mini Nutritional Assessment (MNA) has been shown to reliable assess malnutrition in the geriatric population by taking into account anthropometric measures, dietary habits, and other variables that affect nutritional status.15 The Malnutrition Universal Screening Tool (MUST) is a 5-step screening tool to identify adults who are malnourished, at risk of malnutrition, or obese and it also includes management guidelines.16 The Nutrition Risk Screening 2002 (NRS-2002) calculates the risk of malnutrition based on body mass index (BMI), weight loss within 3 months, and reduced dietary intake within 7 days in the context of any ongoing disease process.17
Koren-Hakim et al18 prospectively determined nutritional risk in 215 elderly patients undergoing hip arthroplasty for hip fractures using the Mini Nutrition Assessment Short Form (MNA-SF), MUST, and NRS-2002 and compared the ability of these screening and assessment tools to predict LOS, surgical complications, 6 months readmission, and up to 36 months mortality. BMI, weight loss, and food intake before admission were found to be related to the patients’ nutritional status (P<0.001) suggesting that these screening and assessment tools were all adequate in assessing malnutrition parameters in elderly patients who were operated on for hip fractures. Although no difference in LOS or surgical complication was found between the patients’ nutritional status of each screening tool, only the MNA-SF predicted that well-nourished patients would have fewer readmissions during a 6-month follow-up (P=0.024) and that 36-month mortality would be lower in the well-nourished patients versus the malnourished (P=0.001) and at risk of malnutrition patients (P=0.01).18
Whereas these screening tools have been validated for use in already hospitalized patients, there is no consensus related to the optimal screening tool in the preoperative patient. The Perioperative Nutrition Screen (PONS) (Fig. 1) was developed as a modified version of the MUST to assess specifically for malnutrition risk in perioperative patients. It identifies nutrition risk based on a patient’s preoperative serum albumin and BMI, the patient-reported recent decrease in dietary intake, and recent changes in weight.2 PONS allows quick and efficient preoperative malnutritional risk identification for preoperative nutrition intervention.
Anthropometric measurements (ie, calf muscle circumference) provide an indirect measure of malnutrition by identifying body composition.8 Arm muscle circumference of 60% to 90% of the standard for particular sex is a marker of moderate malnutrition, and circumference <60% is a marker of severe malnutrition.19 Body fat and skeletal muscle are depleted late in the course of malnourishment so these methods are less sensitive at identifying borderline nutritional deficiency since. Recent literature suggests that sarcopenia—the loss of skeletal muscle mass and quality that occurs as part of natural aging or due to malnutrition—is a possible predictor of adverse postoperative outcomes20 and computed tomography scan lean body mass (LBM) analysis is being used has been studied to assess preoperative “metabolic reserve” and “fitness for surgery.”21 New muscle-specific ultrasound technology (Musclesound, Denver, CO) has been developed to further assess the potential role of low LBM in perioperative optimization. Provides bedside measures of LBM, muscle glycogen and muscle quality. As muscle glycogen is known to change daily based on nutrition intake and “physical stress,” this bedside measurement of LBM could prove useful in assessing nutritional intervention in perioperative patients.22
PERIOPERATIVE NUTRITIONAL INTERVENTION OF THE MALNOURISHED ORTHOPEDIC PATIENTS
The impact of perioperative nutritional intervention has been previously described in the elderly population following THA as the morbidity and mortality rates can be as high as 24% in the first year following fracture. Nutritional status and functional condition can deteriorate after hip fractures and protein energy malnutrition is an important determinant of postsurgical complications such as impaired wound healing, infections, decubital ulcers, and death in older patient with hip fractures.8,23–25 Moreover, malnutrition and essential/nonessential amino acid deficiency increase the risk of nonunion development during bone fracture healing and osteoporotic fractures by reducing osteoblasts and callus production.26,27 Eneroth and colleagues performed a prospective, randomized, controlled clinical trial to determine if nutritional supplementation decreased fracture-related complications in patients with hip fractures. Contrary to the control group (standard hospital food and beverage), the intervention group was administered a 1000 kcal daily intravenous supplement for 3 days, followed by a 400-kcal oral nutritional supplement for 7 days. The incidence of fracture-related complications (infection and thrombophlebitis) was greater in the control group (70%) compared with the intervention group (15%).28 These results suggest that nutritional support with oral or intravenous multinutrient supplementation during hospital admission following a hip fracture is associated with reduced postoperative complications, length of hospital stays, in-hospital mortality, and 4- to 6-month mortality.
Delmi and colleagues similarly studied the influence of the nutritional intervention on orthopedic surgical outcome in 59 elderly patients (mean age 82) with femoral neck fractures randomized to receive daily ONS (250 mL, 20 g protein, 254 kcal) versus control. The rates of complications and deaths were significantly lower in supplemented patients (44% vs. 87%), the rates of complications and mortality 6 months after the fracture were significantly lower in supplemented patients (40% vs. 74%), and the median duration of hospital stay was significantly shorter in the supplemented group (24 vs. 40 d).29 Thus the clinical outcome of elderly patients with femoral neck fracture can be improved by once-daily dietary oral supplementation.
CAN WE IMPROVE MALNUTRITION SCREENING AND NUTRITION CARE IN ORTHOPEDIC SURGERY PATIENTS?
New innovations are urgently needed to improve identification of malnourished patient preoperatively. Further, simple pathways to provide perioperative nutrition optimization to malnourished patients is also needed. These challenges have led to recent surgical nutrition guidelines being published addressing optimal care guidelines to address perioperative nutrition.2 Currently, at Duke University we have instituted a perioperative enhancement team (POET) clinic focused on nutrition optimization before major surgery. As part of the routine preoperative phone screen of all surgery patients at Duke patients are asked: “Have you lost more than 8-10 pounds in the last 6 months without trying?” If the answer is yes and/or if their BMI is low (<20 in age above 65 y and <18.5 in age below 65 y) they are required to come to a preoperative clinic visit where they are seen by a registered dietician (RD) who further assesses the PONS score criteria and perform further nutritional evaluation. If an RD is not available, the PONS score may also be administered by preoperative clinic staff. If any positive answer to any of the PONS score questions is found then patients are found to be at high-risk for surgical malnutrition. These patients are placed on the high-risk nutrition pathway (as shown in Fig. 1) and receive high protein ONS for 2 to 4 weeks before surgery. Patients also receive immunonutrition supplements for 5 days preoperatively and a complex carbohydrate loading drink the morning of surgery (>2 h preanesthesia). The patient then receives 7 days of postoperative immunonutrition and 1 month of high protein ONS postoperatively. Patients with no positive PONS responses also receive nutrition intervention as described in low-risk nutrition pathway in Figure 1. It is hoped that simple pathways like this, with some substituting of targeted ONS supplements made for diabetic and renal dysfunction patients when indicated will simplify perioperative nutrition care. Some consideration of screening for vitamin D deficiency and preoperative correction of vitamin D levels <20 ng/mL should be considered as low vitamin D levels have been associated with increased risk of surgical infection and poor surgical outcomes in a range of surgical patients.30 It is key to note the nutrition care of the surgical patient will be greatly enhanced by the presence of an RD on the surgical team who can participate in the preoperative and postoperative care of the patient.
Perioperative malnutrition is associated with increased mortality, morbidity, LOS, and increased hospital cost in orthopedic surgery. Simple malnutrition screening tools, such as the PONS score have been recently created to assess risk for inpatients, predicting nutritional risk of patients in the preoperative setting and the consequence of treatment remains untested. Further, based on recent surgical guidelines simple nutrition care pathways as described in Figure 1 now need implementation. Study of these quality improvement pathways for nutritional optimization in orthopedic surgery patients are urgently needed. Finally, we hope the presence of a RD will become standard of care in all preoperative clinics worldwide. Without doubt, the nutrition care and overall outcomes of surgical patients would be significantly improved by the addition of the RD as key member of the surgery team.
1. Yuwen P, Chen W, Lv H, et al. Albumin and surgical site infection risk in orthopaedics: a meta-analysis. BMC Surg. 2017;17:7.
2. Wischmeyer PE, Carli F, Evans DC, et al. American Society for Enhanced Recovery and Perioperative Quality Initiative Joint Consensus Statement on nutrition screening
and therapy within a surgical enhanced recovery pathway. Anesth Analg. 2018;126:1883–1895.
3. Angele MK, Chaudry IH. Surgical trauma and immunosuppression: pathophysiology and potential immunomodulatory approaches. Langenbecks Arch Surg. 2005;390:333–341.
4. Wischmeyer P. Nutritional pharmacology in surgery and critical care: “you must unlearn what you have learned”. Curr Opin Anaesthesiol. 2011;24:381–388.
5. Popovic PJ, Zeh HJ III, Ochoa JB. Arginine and immunity. J Nutr. 2007;137:1681S–1686S.
6. Dowsey MM, Choong PF. Obese diabetic patients are at substantial risk for deep infection after primary TKA. Clin Orthop Relat Res. 2009;467:1577–1581.
7. Anderson DJ, Podgorny K, Berrios-Torres SI, et al. Strategies to prevent surgical site infections in acute care hospitals: 2014 update. Infect Control Hosp Epidemiol. 2014;35:605–627.
8. Greene KA, Wilde AH, Stulberg BN. Preoperative nutritional status of total joint patients: relationship to postoperative wound complications. J Arthroplasty. 1991;6:321–325.
9. Peersman G, Laskin R, Davis J, et al. Infection in total knee replacement: a retrospective review of 6489 total knee replacements. Clin Orthop. 2001;392:15–23.
10. Nicholson JA, Dowrick AS, Liew SM. Nutritional status and short-term outcome of hip arthroplasty. J Orthop Surg (Hong Kong). 2012;20:331–335.
11. Garcia GH, Fu MC, Dines DM, et al. Malnutrition
: a marker for increased complications, mortality, and length of stay after total shoulder arthroplasty. J Shoulder Elbow Surg. 2016;25:193–200.
12. Lavernia CJ, Sierra RJ, Baerga L. Nutritional parameters and short term outcome in arthroplasty. J Am Coll Nutr. 1999;18:274–278.
13. Rainey-Macdonald CG, Holliday RL, Wells GA, et al. Validity of a two-variable nutritional index for use in selecting candidates for nutritional support. JPEN J Parenter Enteral Nutr. 1983;7:15–20.
14. Guo JJ, Yang H, Qian H, et al. The effects of different nutritional measurements on delayed wound healing after hip fracture in the elderly. J Surg Res. 2010;159:503–508.
15. Murphy MC, Brooks CN, New SA, et al. The use of the Mini-Nutritional Assessment (MNA) tool in elderly orthopaedic patients. Eur J Clin Nutr. 2000;54:555–562.
16. Elia M, ed. The MUST report. Nutritional screening for adults: a multidisciplinary responsibility. Development and use of the ‘Malnutrition
Universal Screening Too’ (MUST) for adults. A report by the Malnutrition
Advisory Group of the British Association for Parenteral and Enteral Nutrition; 2003.
17. Kondrup J, Rasmussen HH, Hamberg O, et al. Nutritional risk screening (NRS 2002): a new method based on an analysis of controlled clinical trials. Clin Nutr. 2003;22:321–336.
18. Koren-Hakim T, Weiss A, Hershkovitz A, et al. Comparing the adequacy of the MNA-SF, NRS-2002 and MUST nutritional tools in assessing malnutrition
in hip fracture operated elderly patients. Clin Nutr. 2016;35:1053–1058.
19. Pratt WB, Veitch JM, McRoberts RL. Nutritional status of orthopedic patients with surgical complications. Clin Orthop Relat Res. 1981;155:81–84.
20. Foss NB, Jensen PS, Kehlet H. Risk factors for insufficient perioperative oral nutrition after hip fracture surgery within a multi-modal rehabilitation programme. Age Ageing. 2007;36:538–543.
21. Kim JM, Park JH, Jeong SH, et al. Relationship between low body mass index and morbidity after gastrectomy for gastric cancer. Ann Surg Treat Res. 2016;90:207–212.
22. Looijaard W, Molinger J, Weijs PJM. Measuring and monitoring lean body mass
in critical illness. Curr Opin Crit Care. 2018;24:241–247.
23. Houwing R, Rozendaal M, Wouters-Wesseling W, et al. A randomised, double-blind assessment of the effect of nutritional supplementation on the prevention of pressure ulcers in hip-fracture patients. Clin Nutr. 2003;22:401–405.
24. Bourdel-Marchasson I, Barateau M, Rondeau V, et al. A multi-center trial of the effects of oral nutritional supplementation in critically ill older inpatients. Nutrition. 2000;16:1–5.
25. Koval KJ, Maurer SG, Su ET, et al. The effects of nutritional status on outcome after hip fracture. J Orthop Trauma. 1999;13:164–169.
26. Cederholm T, Hedström M. Nutritional treatment of bone fracture. Curr Opin Clin Nutr Metab Care. 2005;8:377–381.
27. Calori GM, Albisetti W, Agus A, et al. Risk factors contributing to fracture non-unions. Injury. 2007;38(suppl 2):S11–S18.
28. Eneroth M, Olsson UB, Thorngren KG. Nutritional supplementation decreases hip fracture-related complications. Clin Orthop Relat Res. 2006;451:212–217.
29. Delmi M, Rapin CH, Bengoa JM, et al. Dietary supplementation in elderly patients with fractured neck of the femur. Lancet. 1990;335:1013–1016.
30. Iglar PJ, Hogan KJ. Vitamin D status and surgical outcomes: a systematic review. Patient Saf Surg. 2015;9:14.