by Richard J. Nasca M.D., FAAOS
Nearly half a million people are affected with rotator cuff tears each year. Most, but not all, patients with rotator cuff tears give a history of injury to the shoulder at the onset of their pain, decreased range of motion with altered function and persistent night pain that interferes with their sleep.
The examiner will find weakness of the torn rotator cuff muscles during manual muscle testing, a disconnect in scapulohumeral rhythm and poor control of the unsupported, abducted upper extremity.
A reliable, non-radiographic method for confirming the diagnosis would be welcomed by patients and providers. Several studies comparing, Ultrasonography and magnetic resonance imaging (MRI) have demonstrated ultrasound to be as reliable and accurate in confirming full thickness rotator cuff tears as MRI. (1,2,3,4)
Ultrasound is readily available during an office visit, more cost effective than MRI and can be used when metal artifact would be an issue with MRI. Unlike MRI, ultrasound can be done without delay bypassing the difficulty in getting insurance approval and scheduling MRI, all of which can sidetrack definitive treatment.
Considering that ultrasound has been found to be reliable and accurate in confirming full thickness rotator cuff tears when performed by experienced operators using high-quality units, why is there still the need to order MRI which may not be readily available, very expensive and sometimes an uncomfortable experience for a claustrophobic patient to undergo?
Other than concerns about the quality of the unit and experience of the operator, I can see no reason that if a tear is seen on ultrasound and the history and physical examination also support the diagnosis, the surgeon should feel compelled to order an MRI. Rather it would seem prudent and reasonable for him or her to perform surgical repair with confidence.
References:
- Diagnostic Accuracy of Ultrasound in Rotator Cuff Tears, Okoroba KR, Fidal MS, Tramer JS, Davis KD. Ultrasonography; Nov 2018, 38(3),1-15.
- Effect of surgeon -sonographer interaction on ultrasound diagnosis of rotator cuff tears: a five -year cohort study in 775 shoulders. Kurz AZ, Kelly MJ Hackett L, Murrell GA. J Shoulder Elbow Surg 2016;25:1385-1394.
- Diagnostic accuracy of ultrasound for rotator cuff tears in adults: A systemic review and meta-analysis. Smith TO, Back T, Toms AP, Hing CB. Clinical Radiology 2011; 66: 1036-1048
- Accuracy of MRI, MR arthrography and ultrasound in the diagnosis of rotator cuff tears: a meta-analysis. De Jesus JO, Parker L, Frangos AJ, Nazarian LN. AJR Am J Roentgenol 2009,192:1701-1707
- Detection and measurements of rotator cuff tears with sonography: analysis of diagnostic errors. Teefey SA, Middelton WD, Payne WT, Yamaguchi K. AMJ Am JRotengen 2005;184:1768-1773.
Dr. Nasca was born in Elmira NY and is a graduate of Georgetown College and Georgetown Medical School. He completed his internship at the Hospital of the University of Pennsylvania and post graduate training in Surgery and Orthopaedics at Duke University Medical Center and Affiliated Hospitals. Dr. Nasca served as Chief of the Amputee and Hand Services at the Philadelphia Naval Hospital caring for Vietnam casualties.
Dr. Nasca held teaching appointments in orthopaedic surgery at the University of Arkansas School of Medicine and the University of Alabama School of Medicine. During his time in practice he specialized in caring for patients with spine deformities, injuries and disorders.
MSK ultrasound is certainly accurate at determining full thickness cuff tears. However; it is also accurate and specific in identifying bursal vs articular side partial tears as well as intra-substance tears. Furthermore; it can determine the “current physiologic state” of the cuff. In other words…. a degenerative… weak tendon.
All of this diagnostic information is extremely useful and needed in non-surgical cases. With the expanding effectiveness of non-surgical treatments MSK ultrasound is the clear choice in diagnosis and monitoring response to treatment.
Having worked extensively with the Orthopedic Community in the past (currently retired radiologist), the utility of ultrasound in characterizing the rotator cuff in symptomatic patients is remarkable. Large and moderate size tears are recognized at virtually 100% rate. Small anf partial tears in additon to a degenerated cuff are also well visualized. As orthopedists fully recognize, the patient’s symptoms are not well correlated with the degree of damage to the cuff, thus it is imperative to fully delineate the degree of injury in order to select the most appropriate method of treatment and counsel the patient regarding post operative expectation.
Working against the use of ultrasound is the fact that the exam is highly observer dependent, can be time consuming and some (radiologists and orthopedists) may have financial incentives towards MR, which is no doubt a remarkable and highly accurate imaging modality.