Approximately 20% of the U.S. population engaged in sports or exercise on a daily basis from 2010–2019.¹ As expected, exercise and sports-related injuries are common, not only in the elite athlete but also in the general population. These injuries frequently lead to sport participation absence (SPA) and often, contact with the health care system. Although history and physical examination are the primary tools of diagnosis, musculoskeletal ultrasound (MSK US) has become the “stethoscope” for evaluation of sports medicine patients.

POCUS can be quite useful to evaluate sports injuries. Propelled by advances in technology, the advent of compact, portable, and more affordable ultrasound machines may facilitate prompt diagnosis of sports injuries on the field and in the training room. The real-time nature of ultrasound provides the opportunity to interact with the athlete and correlate symptoms with sonographic findings. Patients enjoy this opportunity to “share their story” and often provide critical information to the diagnostic puzzle. They also appreciate the immediate findings the physician may be able to provide at the time of imaging. In fact, most patients actually prefer ultrasound to MRI.⁴ Other unique advantages of MSK US for sports imaging are the ability to easily assess the contralateral side as a control and the capability for dynamic imaging. Ultrasound guidance can also improve accuracy in targeted percutaneous injection therapies.⁴ Sports clinicians often encounter a treatment gap for a substantial percentage of young, active patients with a strong desire to return to activity, yet for whom conservative measures have failed and surgery is not indicated. Fueled by media coverage of the treatment of high-profile professional athletes, the field of orthobiologics has exploded in recent years. Ultrasound can provide target localization during administration of a wide array of injectable agents (prolotherapy, autologous whole blood, and platelet-rich plasma) in addition to image-guided peritendinous corticosteroid injections, tendon needling or fenestration, and even percutaneous ultrasonic tenotomy (Tenex).

With the development of high-frequency transducers, MSK US has equal diagnostic accuracy to magnetic resonance imaging (MRI) for evaluation of many superficial tendon and ligament abnormalities. In the current era of cost containment, the utilization of MSK US as an alternative to other more expensive imaging modalities may represent an effective way to save healthcare dollars.^{5, 6} However, many issues related to accuracy, observer variability, and high-quality training need to be considered, aside from pure economics, to ensure that MSK US is ethically and adequately performed in the best interest of patient care.

As any of us who have picked up a transducer know, some of the most significant disadvantages of ultrasound are the relatively long learning curve and inherent operator dependence. These challenges are compounded in MSK US by the complex anatomy, pathology, and terminology not often included in general ultrasound education programs. Dedicated training and standardized technique can minimize these limitations. Many subspecialty residency and fellowship programs have recognized the necessity of standardized, high-quality training and have strategically designed curricula to become proficient in the core competencies of MSK US.

In recent years, quantitative ultrasound methods, such as shear-wave elastography (SWE) and contrast-enhanced ultrasound, have emerged as an adjunct tool to standard B-mode imaging in the evaluation of various structures throughout the body. In particular, SWE has seen an exponential increase in the number of musculoskeletal applications. Shear-wave elastography can assess tissue stiffness by applying a mechanical stress that generates shear waves, which then travel through the tissue at a speed proportional to its stiffness. By quantifying mechanical and elastic tissue properties, SWE may provide important information about pre-clinical injuries in musculoskeletal tissues as well as tissue healing after injury. Although SWE is FDA-approved on most ultrasound platforms, its use for clinical imaging in musculoskeletal ultrasound has lagged behind research due to lack of standardization in study protocols, techniques, and outcomes measures. Nonetheless, SWE has a promising role in the future of ultrasonography in sports medicine and may help practitioners to better estimate injury severity and individualize the retraining plan for the injured athlete.

References

1. Hauret KG, Bedno S, Loringer K, Kao TC, Mallon T, Jones BH. Epidemiology of Exercise- and Sports-Related Injuries in a Population of Young, Physically Active Adults: A Survey of Military Servicemembers. Am J Sports Med. Nov 2015;43(11):2645-53. doi:10.1177/0363546515601990
2. Sharpe RE, Nazarian LN, Parker L, Rao VM, Levin DC. Dramatically increased musculoskeletal ultrasound utilization from 2000 to 2009, especially by podiatrists in private offices. J Am Coll Radiol. Feb 2012;9(2):141-6. doi:10.1016/j.jacr.2011.09.008
3. Kanesa-Thasan RM, Nazarian LN, Parker L, Rao VM, Levin DC. Comparative Trends in Utilization of MRI and Ultrasound to Evaluate Nonspine Joint Disease 2003 to 2015. J Am Coll Radiol. Mar 2018;15(3 Pt A):402-407. doi:10.1016/j.jacr.2017.10.015
4. Nazarian LN. The top 10 reasons musculoskeletal sonography is an important complementary or alternative technique to MRI. AJR Am J Roentgenol. Jun 2008;190(6):1621-6. doi:10.2214/ajr.07.3385
5. Parker L, Nazarian LN, Carrino JA, et al. Musculoskeletal imaging: medicare use, costs, and potential for cost substitution. J Am Coll Radiol. Mar 2008;5(3):182-8. doi:10.1016/j.jacr.2007.07.016
6. Bureau NJ, Ziegler D. Economics of Musculoskeletal Ultrasound. Curr Radiol Rep. 2016;4:44. doi:10.1007/s40134-016-0169-5

Dr. Cristy French (Twitter: @cristy_french) is an Associate Professor in the Division of Musculoskeletal Radiology at Penn State Health Milton S. Hershey Medical Center. She is the Director of Musculoskeletal Ultrasound as well as the Musculoskeletal Fellowship Director.