Objectives: Bipolar hemiarthroplasty is commonly performed to treat displaced femoral neck fractures in osteo porotic patients. This study aimed to assess the occurrence and outcomes of unplanned return visits to the emergency department (ED) within 90 days following bipolar hemiarthroplasty for displaced femoral neck fractures. Methods: The clinical data of 1322 consecutive patients who underwent bipolar hemiarthroplasty for osteoporotic femoral neck fractures at a tertiary medical center were analyzed. Data from the patients’ electronic medical records, including demographic information, comorbidities, and operative details, were collected. The risk factors and mortality rates were analyzed. Results: Within 90 days after surgery, 19.9% of patients returned to the ED. Surgery-related reasons accounted for 20.2% of the patient’s returns. Older age, a high Charlson comorbidity index score, chronic kidney disease, and a history of cancer were identified as significant risk factors for unplanned ED visits. Patients with uncemented implants had a significantly greater risk of returning to the ED due to periprosthetic fractures than did those with cemented implants (P = 0.04). Patients who returned to the ED within 90 days had an almost fivefold greater 1-year mortality rate (15.2% vs 3.1%, P < 0.001) and a greater overall mortality rate (26.2% vs 10.5%, P < 0.001). Conclusions This study highlights the importance of identifying risk factors for unplanned ED visits after bipolar hemiarthroplasty, which may contribute to a better prognosis. Consideration should be given to the use of cemented implants for hemiarthroplasty, as uncemented implants are associated with a greater risk of peri prosthetic fractures.

Objective To investigate the acute effect of local vibration stimulus with low frequency on hand control ability, flexibility, grip strength, and muscle EMG activity. Methods 10 subjects in this study held a vibrator for 20 seconds with isometric contraction at the vibration frequency of 12.5 Hz (vibration group, VIB) or with only isometric contraction (control group, CON). The same procedure measurement, including control ability, flexibility, grip strength, and muscle activity, were recorded both at pre-stimulus (pre-test) and 60-second after stimulus (post-test), respectively. Paired-t test was used to compare the values between pre-test and post-test and the changing rate between groups. Results The control ability and flexibility in pre-post test showed significant improvement after VIB intervention in VIB (P＜0.05). The changing rate of grip strength and EMG in VIB was significantly higher than those in CON (P＜0.05). Conclusions Acute local vibration stimulus with low frequency can be used to improve the hand control ability and flexibility for those who need better hand functional ability in the future.