An interexaminer agreement and reliability study on cadavers with musculoskeletal ultrasound of the shoulder performed by physiotherapists and radiologists compared with dissection

STUDY DESIGN: A cross-sectional inter-examiner agreement and reliability study on fresh frozen cadaver shoulders.

BACKGROUND: Musculoskeletal ultrasound (MSU) is frequently used by physical therapists and radiologists to improve specific diagnosis in rotator cuff related pathology. The evaluation of the rotator cable seems to be important as stabilizing structure when cuff tears occur.

OBJECTIVES: To evaluate the inter-examiner agreement and reliability of MSU of the shoulder to detect rotator cuff-pathology and the involvement of the rotator cable in comparison to "dissection".

METHODS: Physical therapists, a radiologist and an orthopedic surgeon (dissection) investigated 40 fresh frozen cadaver shoulders in order to detect shoulder pathology including rotator cable involvement. Examiners were blinded to each other's findings.

RESULTS: We found a strong and significant agreement between the raters: PTs, the radiologist and the dissector in this cadaver study for all rotator cuff, the long head of the biceps pathologies and in detecting abnormalities of the rotator cable. The kappa value was substantial to (almost) perfect agreement for all diagnostic outcome categories.

CONCLUSIONS: This study shows that among a limited group of physical therapists, one radiologist and a dissector a strong level of agreement with kappa values from substantial to (almost) perfect in finding subacromial pathology.