Does the Timed-Up-and-Go Test Predict Length of Stay After Total Hip Arthroplasty? A Retrospective Study

The prevalence of ambulatory total hip arthroplasty (THA) is rising, but it is not appropriate for all patients. Preoperative patient selection considers medical and social factors but overlooks patients' prior level of physical function.

The aim of this study was to evaluate if preoperative physical function, measured by the Timed-Up-and-Go (TUG) test, is associated with length of stay (LOS) in patients who underwent primary THA.

A retrospective study was performed using 396 patients who underwent primary THA within a 2-month period at a single institution. Regression analysis evaluated the relationship between preoperative TUG scores and hospital LOS. Receiver-operating characteristic (ROC) curves were generated to identify a cutoff TUG score associated with LOS longer than 24 hours.

Univariate regression analysis of those discharged in less than 24 hours and those discharged in more than 24 hours found lower TUG scores (10.7 vs 13.7, respectively) were associated with patient discharge within 24 hours. Multivariate regression analysis showed a higher TUG score (adjusted odds ratio [aOR]: 0.91, 95% confidence interval [CI]: 0.84-0.99) was associated with decreased odds of discharge within 24 hours. Receiver-operating characteristic curve analysis was performed on the entire study cohort and the ambulatory surgery group and identified TUG scores of 10.3 and 10.5 seconds, respectively, associated with LOS of less than 24 hours (OR full cohort: 3.02, 95% CI: 1.94-4.71; OR ambulatory surgery: 2.97, 95% CI: 1.90-4.60). Sensitivity and specificity were not sufficient to support the use of these cutoff scores alone in predicting LOS.

Although we were unable to establish a cutoff TUG score in patients who underwent primary THA that could determine LOS of more than 24 hours, the preoperative TUG score may be useful as a tool to aid in identifying patients who may require a longer hospital LOS. Further study is needed.