325 The Role of Point of Care Ultrasound in the Diagnosis and Management of Shoulder Dislocation

Abstract

Interest in the use point-of-care ultrasound (POCUS) for diagnosis and reduction confirmation in shoulder dislocations is continually emerging. There is hesitance though because of the potential to miss humerus fractures with or without an associated shoulder dislocation. The objective of this study was to evaluate the use of POCUS in the diagnosis and management of individuals with shoulder pain where there is a clinical suspicion for shoulder dislocation and/or proximal humeral fractures. This was a retrospective chart review conducted at an academic level I trauma center with an emergency medicine (EM) residency and 64, 000 annual visits. All patients who underwent a shoulder POCUS between the dates of 07/01/2016 and 2/28/2021 were included. Data was collected from both QPath (point of care ultrasound workflow manager) and EPIC (electronic medical record software). The majority of the ultrasounds were performed by resident physicians, who had been formally trained in shoulder and musculoskeletal POCUS. Results of the shoulder ultrasounds, as documented by the performing physician, were compared against pre- and post-reduction x-rays if there was a dislocation, and against solitary x-ray if no dislocation. Emergency department (ED) patient care timelines were reviewed to determine time to pre-reduction x-ray, post-reduction x-ray, initial ultrasound and reduction ultrasound. Statistical analysis was performed to calculate sensitivity, specificity, positive predictive and negative predictive values. In total, 85 shoulder ultrasounds were performed, with 38 being on dislocated shoulders. Shoulder ultrasound showed a 97% sensitivity, 100% specificity, 100% positive predictive value, and 98% negative predictive value when evaluating for shoulder dislocation and successful post reduction. Overall, shoulder ultrasound displayed a 92% sensitivity and 100% specificity in all pathology compared with x-ray. All 8 humerus fractures seen on x-ray were identified on ultrasound. Ultrasound visualized 2 cases of bursitis, 5 cases of effusions, and 1 torn pectoral muscle not seen on x-ray. Of the 85 cases, 22 cases had missed diagnosis on ultrasound compared to x-ray with 16 Hill-Sachs lesions, 2 Bankart lesions, 2 clavicle fractures, 1 Acromioclavicular (AC) separation and 1 shoulder dislocation. Time to first x-ray and ultrasound averaged 75 and 92 minutes but was not statistically significant (p=0.15). There was a statistically significant difference in time to post reduction radiograph and ultrasound (169 vs 138 minutes, p<0.0001) Shoulder ultrasound is highly sensitive and specific in evaluating for shoulder dislocation and missed no proximal humerus fractures. Although, it may be limited in identifying other injuries such as Hill-Sachs lesions, Bankart lesions, clavicle fractures, and AC separations. In cases of shoulder dislocations, ultrasound demonstrated a statistically significant decrease in time to post reduction imaging compared to plain radiographs. This may help decease ED length of stay and improve throughput with minimal risk of missing significant injury.