Background/Purpose
Few medical schools offer a formal curriculum in musculoskeletal ultrasound (MSUS); the success of such a program in terms of skills and knowledge acquisition and durability of response has not been clearly documented. The purpose of this study was to assess second year students’ ability to identify the presence of pre-loaded suprapatellar effusions using a cadaver model following a formal MSUS curriculum and assess their skill and knowledge retention rate at 6 months.

Methods

As part of a longitudinal US curriculum at Hofstra NSLIJ SOM, 3 sessions were reserved for MSUS during the 2^nd year of study. There were pre-assigned readings prior to each session. The 1^st session reviewed probe selection, patient positioning, and recognition of tissues (tendon, muscle, bone, cartilage, etc). The 2^nd session demonstrated normal and pathologic knee anatomy on a cadaveric model. Multiple choice question style pre-assessment was given prior to this session. In the 3^rd session, students performed a standard knee US exam with the guidance of MSUS-trained faculty.  The summative assessment evaluated the students’ ability to perform a standard knee exam, label knee anatomy on acquired images, and identify a suprapatellar “effusion” in a cadaver preinjected with a gelatin mixture. This exercise was repeated 6 months later in a smaller, voluntary group of students to assess retention of skills and knowledge. 

Results

In the pre-assessment 22/57 (38.5%) students correctly identified the US image with a knee effusion although only 2 students could label it correctly compared to 37/57 (67%) in the summative assessment (p= .003 correct answer and p<.0001 labeling).  Thirteen students volunteered to participate in the 6 month extension; they did not prepare in advance nor have significant opportunities for MSK US in the intervening months.  Eleven of these students (84.6%) had identified the anatomy and 10 (76.9%) had identified the effusion during the summative assessment in December.  In June, a decrease in both knowledge (table) and skills (84.6% of images were of poor quality or taken in non-standard locations) was found although the majority (61.5%) was still able to identify the pathology. 

Conclusion
Following a formal MSUS curriculum, the majority of the 2nd year medical students were able to demonstrate their skill in the acquisition of images, distinguish pathologic from normal findings, and identify knee structures by US. However the retention rate for quality images and identifying anatomical structures decreased at 6 months.   Yet, a majority of students identified fluid and bone in the knee that helped to obtain their respective images and assess the location and nature of the effusion. Thus, although anatomy would have to be further reinforced, student’s identification of effusions was durable at 6 months.