Sarcopenia index based on serum creatinine and cystatin C predicts the risk of postoperative complications following hip fracture surgery in older adults

Objective To assess the utility of the preoperative Sarcopenia index (SI) as a predictive marker of the risk of postoperative complications following hip fracture surgery in older adults. Study design This observational study enrolled older adults with hip fracture who were hospitalized in the Department of Orthopedics of West China Hospital, Sichuan University, from December 7, 2010 - June 14, 2017, and who underwent hip fracture surgery. Primary outcome and measures Clinical data were collected from medical records and serum creatinine and cystatin C were measured before surgery. Outcomes included postoperative complications such as pneumonia, urinary tract infection, respiratory failure, heart failure, and non-grade A healing. Binary logistic regression analyses were used to analyze association between SI and postoperative complications. Results A total of 897 patients aged 60 years and over were enrolled in this study (age range: 60 - 100 years), of whom 306(34.1%)were male, and 591(65.9%)were female. Postoperative complications included pneumonia (12%), urinary tract infections (1.8%), respiratory failure (1.5%), heart failure (1.6%), and non-A- grade healing (3.6%). In the patient group that received joint replacements, the incidence of pneumonia was negatively associated with SI values. After adjusting for potential confounding factors, binary logistic regression analyses showed that a higher SI was independently associated with a lower risk of pneumonia after joint replacement surgery (OR:0.39, 95% CI:0.18-0.89, P<0.05). However, we did not find statistically significant association between SI and the risk of postoperative complications other than pneumonia among patients with two types of hip fracture surgery. Conclusion The SI based on serum creatinine and cystatin C can predict pneumonia rather than other postoperative complications among older patients with hip fracture after joint replacement surgery.