What Factors are Associated with Early Mobility after Total Hip Replacement in Brazilian Older Adults with Fragility Fractures?

INTRODUCTION: Total hip replacement (THR) is common in older adults with fragility fractures. Early mobilization is a key goal, but optimizing recovery remains challenging. Identifying factors associated with postoperative standing and walking abilities can support targeted interventions. OBJECTIVE: To analyze recovery of standing and walking within 3 days after THR in older adults with femoral neck fractures, and to assess associations with age, cognitive status, body mass index (BMI), sarcopenia, and functional capacity. METHODS: This was a prospective study of 71 older adults with femoral neck fractures undergoing THR between 2021 and 2024 at a reference hospital in Brazil. Preoperative assessments included age, BMI, cognitive status (Mini-Mental State Examination), functional capacity (Modified Barthel Index), and sarcopenia (handgrip dynamometry and calf circumference). Immediate postoperative evaluations (up to the third day) included standing ability (1 minute) and ambulation capacity (≥10 steps), with patients classified as able or unable for each task. Associations between predictors and outcomes were analyzed using multivariate analysis of covariance, Kaplan-Meier curves, and receiver operating characteristic analyses. RESULTS: Mean age and BMI were 75.9 years and 23.1 kg/m2; 66.2% were female. By day 3, 50.7% stood and 39.4% walked ≥10 steps. Standing ability was associated with younger age, better cognition status, and higher functional capacity, while ambulation was additionally linked to the absence of sarcopenia. Kaplan-Meier analyses showed faster recovery in participants aged <80 years, with preserved cognition, functional independence, and no sarcopenia. Receiver operating characteristic curve analysis confirmed good predictive accuracy. CONCLUSION: Advanced age, cognitive impairment, and low prefracture functional capacity were associated with delayed recovery of standing and walking in the first 3 postoperative days. Sarcopenia showed a weaker but relevant association; BMI was not predictive. These findings highlight the value of preoperative clinical and functional factors and the need for targeted strategies to optimize early recovery.