Clinical and biochemical prediction of early fatal outcome following hip fracture in the elderly

Abstract

Hip fracture, a moderate musculoskeletal trauma, is associated with a high postoperative mortality. Most patients are elderly, with comorbid conditions and often with heart disease. The objective of this study was to find out if clinical parameters and analyses of specific muscle enzymes could predict three month postoperative mortality. A total of 302 patients above 75 years of age with hip fracture were consecutively enrolled. Baseline information on age, sex and comorbidity assessed with the American Society of Anesthesiologists (ASA) score was obtained before surgery. Creatine kinase (CK), myocardium-specific creatine kinase (CK-MB) and troponin T (TnT) were analysed from venous blood, collected the day before surgery (-1) and postoperatively, within 24 hours (0) and on days one (+1) and four (+4). The overall three month mortality was 19.5%. Multivariate analyses showed that age, male sex and comorbidity (ASA) correlated with mortality (p = 0.027, p = 0.002, p < 0.001, respectively). Surgery induced a two- to threefold increase of CK and CK-MB but without any correlation with mortality. However, high TnT levels >0.04 μg/l correlated significantly with death (days -1, +1 and +4, p = 0.003, p = 0.005 and p = 0.003, respectively). Multivariate analyses, adjusted for age, sex and ASA category, confirmed this correlation (day +4, p = 0.008). Thus, in elderly patients with comorbidities undergoing hip fracture surgery information on sex, age, ASA category and postoperative laboratory analyses on TnT provide the clinicians with useful information on patients at risk of fatal outcome.

Fig. 1

Mean and 95% confidence intervals for troponin T, creatine kinase (CK), myocardium-specific creatine kinase (CK-MB) and ratio of CK-MB to CK before surgery, perioperatively and 1 and 4 days after surgery for 3-month mortality. Statistical significance (p < 0.05) between mortality groups is indicated by an asterisk. Statistically significant (p < 0.05) differences between before surgery and during follow-up are indicated by the connecting lines. Day −1 1 day before surgery, day 0 within 24 h after the operation, day +1 24–48 h postoperatively, day +4 4 days after surgery