Does dynamic ultrasound help surgeons assess postoperative rotator cuff healing better than other imaging modalities?

Issue: August 2018

Click here to read the Cover Story, "Diagnostic potential of ultrasound not yet fully realized."

Range of advantages

Dynamic ultrasound is the best imaging modality to assess postoperative rotator cuff integrity and function for many clinical reasons. All patients can have an ultrasound study. Unlike with a CT scan, patients get no radiation exposure from ultrasound. There is no magnetic field necessary to create the image, so patients with implanted devices that may disqualify them from MRI scans can still undergo ultrasound examination. There are no known adverse events from having an ultrasound. Ultrasound imaging of the postoperative rotator cuff is unaffected by implants placed in the bone, regardless of whether the implants are made of metal, polyether-ether-ketone (plastic), all-suture or another material.

Ultrasound imaging is as accurate as MRI imaging. Multiple studies have shown that in the hands of a trained clinician, ultrasound has a diagnostic sensitivity and specificity that matches non-contrast MRI scans for rotator cuff pathology. Ultrasound is non-invasive. Many clinicians order MR arthrograms to assess the postsurgical rotator cuff, requiring the patient to go to a radiology facility and receive an invasive contrast injection that may have harmful effects on the joint or rotator cuff.

Ultrasound is a dynamic modality. Clinicians can see the repaired rotator cuff tendon move and assess function in real-time in the office. No other imaging modality is used to visualize the functioning rotator cuff in the office. Postsurgical rotator cuff dysfunction is often a dynamic problem. Being able to see the tendons and joint move in real-time makes for a better, more complete evaluation. Ultrasound is a point-of-care imaging modality for evaluation of the postoperative rotator cuff. Both clinicians and patients benefit from cost and time savings by being able to evaluate the rotator cuff in the office at the same visit. Ultrasound is typically the least expensive imaging modality to assess the postoperative rotator cuff. If ultrasound was the standard initial imaging modality for postoperative rotator cuff assessment, the savings in health care would be significant.

Don Buford, MD, RMSK, is founder of The Dallas PRP and Stem Cell Institute and co-owner of Sports Medicine Clinic of North Texas in Dallas.
Disclosure: Buford reports he is a consultant for Conmed Linvatec, Trice Medical and Celling Biosciences; is director of the Interventional Orthopedics Foundation and the Biologic Orthopedics Journal Association; and is course director of the Las Vegas MSK Ultrasound and Orthobiologics Course.

Similar to MRI

Dynamic in-office ultrasound may be a most accurate way to evaluate the healing of a rotator cuff repair. It is an effective modality to assess the integrity of rotator cuff repairs that is cost-effective, easy to use and can be used at all time points during the patient’s recovery. Dynamic ultrasound can accurately measure tendon thickness and assess the stability of the repair by having the patient contract the muscle during the exam. It is superior to other imaging modalities due to ease of use and availability in most clinics. It shows comparable results to more advanced imaging modalities, such as MRI. Although ultrasound accuracy is associated with a steep learning curve, it has a wide range of use when applied correctly and is easily tolerated by patients.

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Sensitivities and specificities have been comparable to MRI in the diagnosis of rotator cuff tears with rates up to 94% and 92%, respectively. Healing rates of rotator cuff repairs have been shown to correlate as much as 92% with standard MRI in a multicenter prospective study. Ultrasound also offers the benefit of assessing the quality of the rotator cuff in real-time and in multiple positions while simultaneously allowing repair integrity to be assessed dynamically in a simple, easy setting.

Ultrasound has its limitations; namely it has a lower accuracy when evaluating partial-thickness rotator cuff tears, higher initial cost and the technique requires practice to be used precisely.

References:
Codsi MJ, et al. J Shoulder Elbow Surg. 2014;doi:10.1016/j.jse.2014.01.045.
Roy JS, et al. Br J Sports Med. 2015;doi10.1136/bjsports-2014-094148.

Stephen G. Thon, MD, is the chief resident and clinical instructor in the department of orthopaedics at Tulane University School of Medicine in New Orleans.
Disclosure: Thon reports no relevant financial disclosures.

Learning curve

Determination of rotator cuff integrity following repair is a challenging clinical scenario. Despite better surgical techniques, a significant portion of patients have rotator cuff tears that do not heal or have symptoms that recur. According to the literature, the rate of retear is between 15% and 80%.

MRI is the standard of care imaging modality for assessing postoperative rotator cuff healing, but dynamic ultrasound may play an important role in this clinical scenario for some providers. The benefits include ease of comparison to the contralateral side, minimal post-surgical artifact, assessment of blood flow via Doppler and providing real-time results. In addition, ultrasound is mobile and relatively inexpensive. For each provider, these factors must be weighed against the potential limitations. Dynamic ultrasound has a significant learning curve; it requires surgeons to learn a whole new skillset that takes time and repetition to master. It also requires additional appointment time in the office and, ultimately, the imaging quality is user-dependent. Therefore, each provider must weigh the pros and cons of implementing dynamic ultrasound in their diagnostic algorithm in an already challenging clinical scenario.

Alexander Weber, MD, is an assistant professor of clinical orthopedic surgery at Keck School of Medicine of USC in Los Angeles.
Disclosure: Weber reports no relevant financial disclosures.