Patients with nutritional disorders may face increased risks of mortality, postoperative complications, and prolonged hospitalization following hip and knee arthroplasty, a systematic review found. Associations varied across malnutrition, frailty, and sarcopenia, as well as diagnostic criteria and surgical procedures.
The researchers reviewed 58 studies involving 2,076,289 patients undergoing primary or revision hip and knee arthroplasty or surgery for hip fracture. The review followed Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines and included randomized controlled trials, registry studies, cohort studies, and case series published after2000. Searches of 6 electronic databases were updated in March 2024. Researchers evaluated nutritional disorders using diagnostic criteria recommended by the European Society for Clinical Nutrition and Metabolism (ESPEN), as well as other definitions reported in the included studies.
The outcomes of interest included mortality, postoperative complications, reoperation and revision rates, prosthetic joint and surgical site infections, patient-reported outcomes, hospital length of stay, and health care costs. The researchers assessed study quality using the Risk of Bias in Non-randomized Studies of Interventions tool. Although pooled analyses were planned, differences in patient populations, nutritional disorder definitions, and outcome reporting prevented meta-analysis.
Frailty was associated with poorer clinical outcomes following primary, revision, and hip fracture arthroplasty. In a study involving 179,702 patients undergoing primary total knee arthroplasty, 30-day mortality was 0.2% among patients with frailty vs 0.1% among those without frailty, corresponding to 2.35 times the odds of death. Frailty was also associated with increased postoperative complications, infections, and longer hospital stays across the included arthroplasty populations.
Malnutrition identified using ESPEN-recommended criteria was associated with increased mortality, postoperative pain, and hospital length of stay. In a study of patients undergoing arthroplasty following hip fracture, delayed wound healing occurred in 28.5% of those at risk of malnutrition and 25% of those classified as malnourished, compared with 7% of patients with normal nutritional status. Other included studies linked nutritional impairment to mortality at follow-up intervals ranging from 1 to 12 months.
Sarcopenia was also associated with adverse postoperative outcomes. Among patients undergoing arthroplasty following hip fracture, low muscle mass, measured using the psoas-to-lumbar vertebrae index, was more common among those who died than among survivors (58.4% vs 40%). Other studies linked sarcopenia to increased prosthetic joint infections following primary arthroplasty and poorer postoperative functional outcomes.
One included study evaluated health care costs among 882,479 patients undergoing primary total knee arthroplasty using an ESPEN-recommended definition of frailty. Health care costs were $19,841 among patients with frailty vs $6,104 among those without, representing more than a 3-fold difference. Hospital stays were also longer among patients with frailty, averaging 4.1 days vs 2.2 days.
However, the associations were not consistent across all nutritional measures. Malnutrition defined solely by a body mass index below 18.5 was generally not associated with adverse outcomes following primary hip or knee arthroplasty, apart from small differences in operative time and hospital length of stay reported in 1 study. Hypoalbuminemia was frequently used to identify nutritional impairment and was associated with adverse outcomes, despite serum albumin no longer being recommended by ESPEN as a standalone diagnostic marker of malnutrition.
The review had several limitations. Of the 58 included studies, 34 had moderate risk of bias, and 24 had serious risk. Heterogeneity across studies limited the ability to quantify associations across arthroplasty populations. Some studies used overlapping patient databases, and the exclusion of studies with fewer than 50 cases may have omitted additional findings.
Economic evidence was particularly limited, with only 1 study evaluating costs. Despite this, the researchers suggested that poorer postoperative outcomes associated with nutritional disorders could contribute to higher health care expenditures. They called for prospective studies to determine whether treating nutritional disorders could improve postoperative outcomes and reduce costs.
“We conclude that nutritional disorder has detrimental effects on clinical outcomes following hip and knee arthroplasty,” wrote lead study author Christopher David John Little, of the Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, Oxford, UK, and colleagues.
The authors reported no funding or conflicts of interest.
