The sports medicine community recently has witnessed significant growth in the development and application of portable ultrasound in the care of athletes. A number of techniques hold the potential for use directly by sports medicine clinicians, in a point-of-care fashion, rather than requiring the assistance of technicians in ultrasound laboratories. Not all proposed techniques have proven effective in this setting, and other putative techniques have uncertain clinical necessity. This manuscript reviews a number of these techniques and critically appraises the evidence that has been published hitherto to support application of ultrasound in point-of-care practice in sports medicine.
The use of ultrasound by clinicians holds a long history, dating as far back as 1942, when the physician researcher Karl Theo Dussik documented its potential as an imaging modality and diagnostic tool (59). Since then, ultrasound has developed both in its breadth of applicability as well as its portability and ease of use. The use of ultrasound now spans a wide spectrum, extending over almost every specialty of medicine: anesthesia, cardiology, critical care, emergency medicine, gynecology, neurology, obstetrics, orthopedics, pediatrics, and pulmonology.
Ultrasound also has become more portable, with smaller and more intuitive devices being developed every year (6). This has enabled clinicians to perform ultrasound studies themselves through “point-of-care” ultrasound, providing real-time diagnostic data and critical guidance for bedside procedures and interventions (36). Point-of-care ultrasound has been used to diagnose a number of pathologic conditions: cholelithiasis, cervical ectopic pregnancy, pediatric intussusceptions, abdominal aortic aneurysm, intraventricular hemorrhage in children, skull fractures in children with scalp hematomas, aortic occlusion, deep vein thrombosis, pericardial effusion and tamponade physiology, and pneumothorax. Ultrasound also has been used to aid in the completion of interventional procedures. For example, it has been used to predict difficulty in laryngoscopy through imaging of soft tissues of the neck (2). It also has been used to assist with lumbar puncture (8), paracentesis, thoracentesis (7), and umbilical catheter insertion in neonates (22).
Over the last couple of years, the sports medicine community has witnessed notable progress in terms of potential applications for point-of-care ultrasound in the care of athletes. These emerging applications were showcased in the 29th Summer Olympics, in which ultrasonography was used to treat athletes with a broad array of issues: abdominal pain, musculoskeletal disorders, gynecologic issues, cardiac conditions, small parts, and vascular problems (29). The review article presented here will examine potential applications that have been posited for use by sports medicine clinicians and will analyze the recent literature that has been published to support or discredit particular claims.
A PubMed search of the years 2010 to 2012 was performed using the terms “athlete” and “ultrasound” in all indexed journals. In addition, a focused PubMed search of the same years was performed using the term “ultrasound” in sports medicine journals. In addition, references from selected articles were examined. The results were further limited to clinical trials, meta-analyses, randomized controlled trials, case reports, comparative studies, controlled clinical trials, and multicenter studies. The studies matching these inclusionary criteria then were screened with the following exclusionary criteria: not written in or translated into English, involved animal subjects, did not employ ultrasound in diagnostic or therapeutic intervention, did not use athletes as subjects, were duplicated studies. The references acquired from the initial search were categorized depending on how ultrasound studies were obtained, whether by trained technicians in dedicated ultrasound laboratories or directly by clinicians. This was assessed from the methods section of the manuscripts reviewed. When this information was unavailable from the manuscript, corresponding authors were contacted to determine how ultrasound images were obtained.
Results and Discussion
The PubMed search produced a total of 473 manuscripts in the initial search, with 106 manuscripts obtained when limiting to clinical trials, meta-analyses, randomized controlled trials, case reports, comparative studies, controlled clinical trials, and multicenter studies. Of these, 35 manuscripts involved techniques employed by clinicians, while the remaining manuscripts involved ultrasound performed by technicians or in dedicated ultrasound laboratories.
Understandably point-of-care ultrasound in athletes has been examined most in the context of musculoskeletal disorders. Its use in the evaluation and treatment of midportion Achilles tendinopathy (MPT) has been of particular interest. Ultrasound has been used to elucidate the pathophysiology of MPT. A recent cross-sectional study of 50 healthy runners used synchronous real-time ultrasound to determine that Achilles tendon/aponeurosis strain is higher in male athletes with tendinopathy than in those without (14). There are also typical pathophysiologic findings detected by ultrasound at various stages of MPT (4). Ultrasound also has been used to determine potential prognostic factors in the development of MPT. In a recent prospective clinical trial involving 634 asymptomatic runners in an outpatient setting, investigators demonstrated that a spindle-shaped thickening of the tendon and increased intratendinous blood flow are associated with the development of MPT (30). Of note, however, these diagnostic applications of ultrasound were studied in the hands of trained technicians in dedicated diagnostic laboratories. Ultrasound thus has not been validated for use as a point-of-care diagnostic for Achilles tendinopathy.
In practice, Achilles tendinopathy is primarily a clinical diagnosis, with ultrasound as an adjunct in management. Rather than relying on ultrasound for diagnostic purposes, it may provide more utility as a prognostic tool. In a manuscript comparing ultrasound and magnetic resonance imaging (MRI) images to surgical findings in patients with Achilles tendinopathy, Aström et al. (5) concluded that these imaging modalities are not required for diagnosis but are helpful as prognostic tools to assist in preoperative planning. Regardless of how ultrasound will be used in diagnostic work-up and therapeutic planning, the validity of ultrasound as a diagnostic tool for Achilles pathology is under development, and the question of relevance to point-of-care diagnostics by clinicians remains to be proven.
This is in contrast to studies regarding point-of-care ultrasound in the treatment of Achilles tendinopathy. Historically point-of-care ultrasound has been used to aid in the injection of various therapeutics for Achilles tendinopathy: sclerosis of neovessels (52), peritendinous injection of steroids (25), intratendinous injection of hyperosmolar dextrose (42), and peritendinous injections of immunomodulators such as adalimumab and anakinra (26). By allowing visualization of needle passage and anatomical localization of injectant, ultrasound-guided injections improve accuracy of injections and now are considered a best-practice standard for this form of treatment (56). Most recently, ultrasound guidance has been used in the application and evaluation of platelet-rich plasma (PRP) treatment for Achilles tendinopathy (67). So far, studies of PRP treatment have not documented significant differences with regard to the Victorian Institute of Sports Assessment — Achilles Score, neovascularization, or ultrasonographic tendon structure (20,21). Point-of-care ultrasound therefore has been utilized and investigated considerably within the context of therapeutic interventions for Achilles tendinopathy, though the efficacy of specific treatments remains to be established.
In contrast to its use in Achilles tendinopathy, ultrasound has been used readily in the diagnosis of Achilles tendon rupture. A recent prospective study demonstrated that ultrasound is helpful to diagnose partial midportion Achilles tendon rupture using characteristic findings on ultrasound: a disrupted dorsal tendon line and high blood flow in the structurally abnormal dorsal tendon (3). The accuracy and reliability of point-of-care ultrasound in the hands of clinicians has not been validated yet with large studies, however. Evidence thus far has been limited to case reports, such as a recent case report in which clinicians diagnosed Achilles tendon rupture in volleyball player presenting to an emergency room (1).
Ultrasound also has been used to evaluate and treat patellar tendon derangements in athletes. In the hands of trained technicians, ultrasound has been used to characterize a new continuum model in patellar tendinopathy (16). Particular measurements, such as the anteroposterior diameter of the patellar tendon, also have been studied as an indicator of severity of tendinopathy (40). These studies were performed in dedicated laboratories, however, and have not been studied yet in the context of point-of-care diagnostics. Case studies have been reported on the use of point-of-care ultrasound in diagnosing patellar tendon rupture, however (27). Further reports and prospective studies of the application and efficacy of point-of-care ultrasound in diagnosing patellar tendon pathology will be required to validate these techniques. As with Achilles tendinopathy and shoulder injuries, however, the diagnostic adequacy of clinical examination combined with MRI imaging may explain why point-of-care ultrasound has not been investigated actively. The necessity of point-of-care ultrasound in this setting will thus become a relevant point of discussion if this application of ultrasound is developed in the future.
In contrast to the dearth of research involving diagnostic utility of point-of-care ultrasound in patellar tendon pathology, a number of recent studies have been published regarding its use in guiding treatment modalities. In a recent, randomized, controlled study, Hoksrud and Bahr (31) demonstrated that ultrasound-guided sclerosing treatment with polidocanol is effective for the majority of patients with patellar tendinopathy. A recent study by Willberg et al. (68) also demonstrated the efficacy of ultrasound-guided sclerosing treatment. However, they also demonstrated that ultrasound-guided arthroscopic shaving was superior to sclerosing treatment, since it led to decreased pain and increased patient satisfaction from a quicker return-to-play time. The use of ultrasound-guided injection of hyperosmolar dextrose also was studied recently in a pilot study, providing evidence that this treatment may be effective in treating patellar tendinopathy (57). Yet another study provided preliminary evidence that ultrasound-guided needle fenestration could provide a means to treat recalcitrant patellar tendinopathy (33). A recent case report of using ultrasound to guide PRP injection in patellar tendinopathy also was published (10). The data on these potential uses of ultrasound are promising but warrant further evaluation to evaluate their clinical utility with regard to outcomes when compared with placebo or alternate forms of treatment.
Musculoskeletal ultrasound is being used in the diagnosis and therapeutic management of hip and thigh pathology in athletes. Along with MRI and computed tomography, ultrasound has become a critical diagnostic technique used to evaluate hip pathology in athletes, including skeletal, intraarticular, and extraarticular abnormalities (9). With regard to imaging of the hip, ultrasound has been used to evaluate pathology in hips with surgical hardware, which otherwise poses a challenge for imaging diagnostics due to artifact (49). Recently ultrasound also has been used to document isolated injuries to the gracilis muscle in athletes, which previously was thought to be a rare injury (54). Musculoskeletal ultrasound also has been used to detect injuries to the hamstring muscles and to evaluate posterior thigh injuries in athletes (41).
Musculoskeletal ultrasound not only has been used in the diagnostic management of hip and thigh conditions in athletes but also is being used in therapeutic management. Using ultrasound to guide joint injections of the hip has proven effective, and it is used increasingly to guide intraarticular hip injections due to ease of use and accuracy (60). Ultrasound-guided injections of traditional agents such as corticosteroids, anesthetic agents, and hyaluronic acid have been used previously for painful conditions of the hip (6,44,69). Novel injectants such as PRP also have been studied in the setting of ultrasound guidance but will require further outcomes research to establish efficacy and superiority over other treatment modalities (58). Ultrasound also has been used to diagnose and guide treatment (arthrocentesis) of septic hip (45). More recently, shockwave therapy using ultrasound also has been used in conditions such as chronic proximal hamstring tendinopathy. A recent randomized controlled trial comparing shockwave therapy to traditional conservative therapy in professional athletes demonstrated reduction in pain scores and improvement in return-to-play outcomes in patients with this condition (63).
Ultrasound of hand and wrist pathology is also common. It has been applied to assess synovitis related to rheumatoid arthritis affecting wrist joints. Recent investigation has identified the radiocarpal joint as particularly reliable for these measurements (39). Ultrasound also has been used to demonstrate tendon involvement of the wrist and hand in rheumatoid arthritis (23). These techniques are relatively simple, and programs have been developed to train clinicians on how to employ these techniques in the diagnosis and management of this condition (38). These techniques thus hold potential for use as a point-of-care diagnostic by clinicians but will require additional studies to confirm and validate their validity in the hands of clinicians.
Musculoskeletal ultrasound also has been applied to other pathology of the hand and wrist. For example, it has been used to evaluate pronator quadratus physiology (17), median neuropathy in carpal tunnel syndrome (12,34), and De Quervain disease (15). These techniques do not require specialized procedures or contrast and thus hold potential as point-of-care diagnostics. For these reasons, musculoskeletal ultrasound of the hand and wrist is being incorporated into training programs for musculoskeletal ultrasound performed by physicians and trainees (24).
Musculoskeletal ultrasound also has been employed as a diagnostic and therapeutic tool for elbow pathology in athletes. As a diagnostic tool, it has been used to assess partial- and full-thickness tears of the biceps and triceps tendons, common extensor and flexor tendinosis, medial and lateral epicondylitis, radial and ulnar collateral ligament tears, ulnar nerve entrapment, cubital or olecranon bursitis, joint effusions, and intraarticular bodies (65). The application of ultrasound in lateral epicondylitis in athletes has been of particular interest to researchers recently. Increased maximal extensor tendon thickness and cross-sectional area have been demonstrated to be highly predictive of lateral epicondylitis (37). These techniques do not require specialized technique or procedures and thus hold promise as point-of-care diagnostics.
There is also potential for elbow ultrasound as a therapeutic adjunct. Most research recently has focused on its use in treating chronic severe elbow tendinosis (46). Ultrasound-guided PRP injections have proven particularly effective in treating chronic severe elbow tendinosis when compared with corticosteroid injections (47). Elbow ultrasound thus holds promise as a point-of-care diagnostic and therapeutic tool in the care of athletes.
Musculoskeletal ultrasound also has been used as a diagnostic tool for shoulder pain. Techniques in ultrasound have been employed to identify overhead athletes at risk for development of shoulder pathology. A recent study identified that subclinical effusions of the subacromial and subdeltoid bursae may serve as early signs of shoulder pathology (50). Ultrasound also has been employed to evaluate rotator cuff tears and acromioclavicular pathology in athletes (35). The later techniques in particular are relatively straight forward and will likely find increasing application as a point-of-care diagnostic by clinicians in the future.
Point-of-care ultrasound of the shoulder also is being used increasingly to aid with therapeutic procedures (13). A recently published randomized controlled trial demonstrated that ultrasound-guided injection of the biceps tendon sheath by clinicians is more precise than blind injections using palpable landmarks in the treatment of anterior shoulder pain related to biceps tendinopathy (28). A recent review by Soh et al. (62) described how ultrasound-guided corticosteroid injection of the shoulder offers significantly greater clinical improvement over landmark-guided injections. However, they also point to the need for randomized controlled trials to substantiate the preliminary evidence that has been gathered thus far.
The application of ultrasound in athletes has extended beyond the musculoskeletal system to encompass a wider spectrum of disease. For instance, abdominal ultrasound has been posited as a method to evaluate spleen size in athletes with mononucleosis, helping inform decisions regarding return to play in contact sports. Limited abdominal ultrasound by trained technicians has been used previously to assess splenic enlargement and to assess the time required for regression of splenomegaly (32).
More recently, this technique was investigated in the hands of clinicians. In a prospective cohort observational study, investigators used abdominal ultrasound to establish normative parameters for spleen size in tall athletes, a group of athletes previously posing a challenge with regard to clinical assessments for return to play (43). The study was instrumental in establishing normative parameters for spleen size in tall athletes and has set the stage for further studies investigating the utility of ultrasound in the monitoring and management of athletes with mononucleosis. Future studies of point-of-care ultrasound performed on athletes with mononucleosis will provide the next steps in establishing its utility in this setting.
Further investigation also should focus on how this technique will impact return-to-play decisions. A recent case series provided preliminary evidence of how serial ultrasound could prove useful in this manner (51). In that study, 84% of athletes had a return of splenic size to baseline at 1-month follow-up. However, the ultrasound images were performed by trained technicians, so its applicability to point-of-care practice is limited. Additional investigations of such approaches in the hands of clinicians will provide insight into its potential utility as a point-of-care diagnostic in sports medicine.
Other applications of ultrasound also have been developed, although they only have been studied in the hands of technicians. Specialized techniques such as three-dimensional echocardiography (ECHO) and two-dimensional speckle tracking ECHO have made significant contributions in assessing morphologic characteristics, determinants, and physiologic limitations of cardiac remodeling in athletes (11,19). Techniques in pulmonary ultrasound have been developed to evaluate pulmonary edema in athletes (55). Ultrasound velocity techniques have been developed to evaluate hydration status in athletes (66). Case reports of the use of ultrasound to diagnose deep vein thrombosis in athletes with atraumatic and traumatic mechanisms also have been reported (53,64,70). Techniques also have been developed for the use of ultrasound to assess bone mineralization, as an alternative to DEXA (dual energy x-ray absorptiometry) scan (48). Before these techniques can be utilized by clinicians, however, future studies using clinician operators would be required to establish their validity in point-of-care clinical practice.
The potential applications of diagnostic point-of-care ultrasound are therefore broad, but the utility of each application will have to be justified before implementing these techniques into practice. One point that must be addressed is how each application of point-of-care ultrasound fits into existing diagnostic schemes for clinical entities in sports medicine. Some may point to the adequacy of existing diagnostic modalities in a given clinical scenario to argue that a specific technique in ultrasound is superfluous. Although current diagnostic algorithms for the care of athletes may provide adequate detection rates, there are advantages to developing point-of-care diagnostics rather than relying on specialized laboratory studies.
With the development and validation of point-of-care ultrasound techniques, clinicians would be able to provide “one-stop clinics” that can provide assessment and treatment of athletes in a single clinical encounter. The advantages of such services were discussed recently by Sivan et al. (61). According to their analysis, the application of point-of-care ultrasound has proven to be cost-effective and has increased patient satisfaction, reducing repeated hospital appointments and improving quality of care. Other proponents of ultrasound have pointed to the cost-effectiveness and cost-comparison of ultrasound relative to other forms of imaging, advocating for further integration of diagnostic and therapeutic ultrasound into office-based practice of sports medicine (18).
Through recent advancements in ultrasound, sports medicine clinicians have been endowed with the capacity to diagnose, treat, and manage a broad array of conditions afflicting athletes. A number of these techniques have been studied in the hands of clinicians, in an effort to evaluate utility as a point-of-care diagnostic and therapeutic tool. This review has highlighted a number of applications of ultrasound in athletes that hold promise for use as point-of-care diagnostics and therapeutic tools. Research thus far has focused mainly on applications of point-of-care ultrasound in treating and diagnosing musculoskeletal disease in athletes, although preliminary evidence has been generated for broader applications for ultrasound. Not all techniques have been proven effective in this setting, and further research will be required to validate specific applications of point-of-care ultrasound in the hands of clinicians caring for athletes.
The authors declare no conflict of interest and do not have any financial disclosures.
1. Adhikari S, Marx J, Crum T. Point-of-care ultrasound diagnosis of acute Achilles tendon rupture in the ED. Am. J. Emerg. Med.
2012; 30: e3–4.
2. Adhikari S, Zeger W, Schmier C, et al.. Pilot study to determine the utility of point-of-care ultrasound in the assessment of difficult laryngoscopy. Acad. Emerg. Med.
2011; 18: 754–8.
3. Alfredson H, Masci L, Ohberg L. Partial mid-portion Achilles tendon ruptures: new sonographic findings helpful for diagnosis. Br. J. Sports Med.
2011; 45: 429–32.
4. Archambault JM, Wiley JP, Bray RC, et al.. Can sonography predict outcome in patients with achillodynia? J. Clin. Ultrasound
. 1998; 26: 335–9.
5. Aström M, Gentz CF, Nilsson P, et al.. Imaging in chronic Achilles tendinopathy: a comparison of ultrasonography, magnetic resonance imaging and surgical findings in 27 histologically verified cases. Skeletal Radiol.
1996; 25: 615–20.
6. Atchia I, Kane D, Reed MR, et al.. Efficacy of a single ultrasound-guided injection for the treatment of hip osteoarthritis. Ann. Rheum. Dis.
2011; 70: 110–6.
7. Ault MJ, Rosen BT. Portable ultrasound: the next generation arrives. Crit. Ultrasound J.
2010; 2: 39–42.
8. Ayalin T, Lam SH. Ultrasound-assisted lumbar puncture in infants. Acad. Emerg. Med.
2011; 18: e36.
9. Blankenbaker DG, De Smet AA. Hip injuries in athletes. Radiol. Clin. North Am.
2010; 48: 1155–78.
10. Brown J, Sivan M. Ultrasound-guided platelet-rich plasma injection for chronic patellar tendinopathy: a case report. PM R.
2010; 2: 969–72.
11. Caselli S, Di Paolo FM, Pisicchio C, et al.. Three-dimensional echocardiographic characterization of left ventricular remodeling in Olympic athletes. Am. J. Cardiol.
2011; 108: 141–7.
12. Chen SF, Lu CH, Huang CR, et al.. Ultrasonographic median nerve cross-section areas measured by 8-point “inching test” for idiopathic carpal tunnel syndrome: a correlation of nerve conduction study severity and duration of clinical symptoms. BMC Med. Imaging
. 2011; 11: 22.
13. Chiang YP, Feng CF, Lew HL. Ultrasound-guided examination and injection of the shoulder. Am. J. Phys. Med. Rehabil.
2011; 90: 616–27.
14. Child S, Bryant AL, Clark RA, Crossley KM. Mechanical properties of the Achilles tendon aponeurosis are altered in athletes with Achilles tendinopathy. Am. J. Sports Med.
2010; 38: 1885–93.
15. Choi SJ, Ahn JH, Lee YJ, et al.. de Quervain disease: US identification of anatomic variations in the first extensor compartment with an emphasis on subcompartmentalization. Radiology
. 2011; 260: 480–6.
16. Cook JL, Purdam CR. Is tendon pathology a continuum? A pathology model to explain the clinical presentation of load-induced tendinopathy. Br. J. Sports Med.
2009; 43: 409–16.
17. Créteur V, Madani A, Brasseur JL. Pronator quadratus imaging. Diagn. Interv. Imaging
. 2012; 93: 22–9.
18. Coris EE, Pescasio M, Zwygart K, et al.. Office-based ultrasound in sports medicine practice. Clin. J. Sport Med.
2011; 21: 57–61.
19. D’Ascenzi F, Cameli M, Zacà V, et al.. Supernormal diastolic function and role of left atrial myocardial deformation analysis by 2D speckle tracking echocardiography in elite soccer players. Echocardiography
. 2011; 28: 320–6.
20. De Jonge S, de Vos RJ, Weir A, et al.. One-year follow-up of platelet-rich plasma treatment in chronic Achilles tendinopathy: a double-blind randomized placebo-controlled trial. Am. J. Sports Med.
2011: 39: 1623–9.
21. de Vos RJ, Weir A, Tol JL, et al.. No effects of PRP on ultrasonographic tendon structure and neovascularisation in chronic midportion Achilles tendinopathy. Br. J. Sports Med.
2011; 45: 387–92.
22. Fleming SE, Kim JH. Ultrasound-guided umbilical catheter insertion in neonates. J. Perinatol.
2011; 31: 344–9.
23. Filippucci E, Gabba A, Di Geso L, et al.. Hand tendon involvement in rheumatoid arthritis: an ultrasound study. Semin. Arthritis Rheum.
2012; 41: 752–60.
24. Finnoff J, Lavallee ME, Smith J. Musculoskeletal ultrasound education for sports medicine fellows: a suggested/potential curriculum by the American Medical Society for Sports Medicine. Br. J. Sports Med.
2010; 44: 1144–8.
25. Fredberg U, Bolvig L, Pfeiffer-Jensen M, et al.. Ultrasonography as a tool for diagnosis, guidance of local steroid injection and, together with pressure algometry, monitoring of the treatment of athletes with chronic jumper’s knee and Achilles tendinitis: a randomized, double-blind, placebo-controlled study. Scand. J. Rheumatol.
2004; 33: 94–101.
26. Fredberg U, Ostgaard R. Effect of ultrasound-guided, peritendinous injections of adalimumab and anakinra in chronic Achilles tendinopathy: a pilot study. Scand. J. Med. Sci. Sports
. 2009; 19: 338–44.
27. Hall BT, McArthur T. Ultrasound diagnosis of a patellar tendon rupture. Mil. Med.
2010; 175: 1037–8.
28. Hashiuchi T, Sakurai G, Morimoto M, et al.. Accuracy of the biceps tendon sheath injection: ultrasound-guided or unguided injection? A randomized controlled trial. J. Shoulder Elbow Surg.
2011; 20: 1069–73.
29. He W, Xiang DY, Dai JP. Sonography in the 29th Olympic and Paralympic Games: a retrospective analysis. Clin. Imaging
. 2011; 35: 143–7.
30. Hirschmuller A, Konstantinidis L, Frey V, et al.. Prognostic Value of Achilles Tendon Doppler Sonography in Asymptomatic Runners. Med. Sci. Sports Exerc.
2011. [Epub ahead of print]. doi: 10.1249/MSS.0b013e31822b7318.
31. Hoksrud A, Bahr R. Ultrasound-guided sclerosing treatment in patients with patellar tendinopathy (jumper’s knee): 44-month follow-up. Am. J. Sports Med.
2011; 39: 2377–80.
32. Hosey RG, Kriss V, Uhl TL, et al.. Ultrasonographic evaluation of splenic enlargement in athletes with acute infectious mononucleosis. Br. J. Sports Med.
2008; 42: 974–7.
33. Housner JA, Jacobson JA, Morag Y, et al.. Should ultrasound-guided needle fenestration be considered as a treatment option for recalcitrant patellar tendinopathy? A retrospective study of 47 cases. Clin. J. Sport Med.
2010; 20: 488–90.
34. Hunderfund AN, Boon AJ, Mandrekar JN, Sorenson EJ. Sonography in carpal tunnel syndrome. Muscle Nerve
. 2011; 44: 485–91.
35. Jeon IH, Kochhar H, Lee JM, et al.. Ultrasonographic evaluation of the shoulder in elite wheelchair tennis players. J. Sport Rehabil.
2010; 19: 161–72.
36. Katz JF, Yucel EK. Point-of-care ultrasonography. N. Engl. J. Med.
2011; 364: 2075–6.
37. Lee MH, Cha JG, Jin W, et al.. Utility of sonographic measurement of the common tensor tendon in patients with lateral epicondylitis. AJR Am. J. Roentgenol.
2011; 196: 1363–7.
38. Lopez-Ben RR. Assessing rheumatoid arthritis with ultrasound of the hands. AJR Am. J. Roentgenol.
2011; 197: W422.
39. Luz KR, Furtado R, Mitraud SV, et al.. Interobserver reliability in ultrasound assessment of rheumatoid wrist joints. Acta Reumatol. Port
. 2011; 36: 245–50.
40. Malliaras P, Cook J. Changes in anteroposterior patellar tendon diameter support a continuum of pathological changes. Br. J. Sports Med.
2011; 45: 1048–51.
41. Malliaropoulos N, Papacostas E, Kiritsi O, et al.. Posterior thigh muscle injuries in elite track and field athletes. Am. J. Sports Med.
2010; 38: 1813–9.
42. Maxwell NJ, Ryan MB, Taunton JE, et al.. Sonographically guided intratendinous injection of hyperosmolar dextrose to treat chronic tendinosis of the Achilles tendon: a pilot study. AJR Am. J. Roentgenol.
2007; 189: W215–20.
43. McCorkle R, Thomas B, Suffaletto H, Jehle D. Normative Spleen Size in Tall Healthy Athletes: Implications for Safe Return to Contact Sports After Infectious Mononucleosis. Clin. J. Sport Med.
2010; 20: 413–5.
44. Migliore A, Massafra U, Bizzi E, et al.. Comparative, double-blind, controlled study of intra-articular hyaluronic acid (Hyalubrix) injections versus local anesthetic in osteoarthritis of the hip. Arthritis Res. Ther.
2009; 11: R183.
45. Minardi JJ, Lander OM. Septic hip arthritis: diagnosis and arthrocentesis using bedside ultrasound. J. Emerg. Med.
2012; 43: 316–8.
46. Mishra A, Collado H, Fredericson M. Platelet-rich plasma compared with corticosteroid injection for chronic lateral elbow tendinosis. PM R.
2009; 1: 366–70.
47. Mishra A, Pavelko T. Treatment of chronic elbow tendinosis with buffered platelet-rich plasma. Am. J. Sports Med.
2006; 34: 1774–8.
48. Moayyeri A, Adams JE, Adler RA, et al.. Quantitative ultrasound of the heel and fracture risk assessment: an updated meta-analysis. Osteoporos. Int.
2012; 23: 143–53.
49. Morvan G, Vuillemin V, Guerini H, et al.. Recent advances in imaging of hip and knee prostheses. Bull. Acad. Natl. Med.
2011; 195: 613–26.
50. Ocguder DA, Tosun O, Bektaser B, et al.. Ultrasonographic evaluation of the shoulder in asymptomatic overhead athletes. Acta Orthop. Belg.
2010; 76: 456–61.
51. O’Connor TE, Skinner LJ, Kiely P, Fenton JE. Return to contact sports following infectious mononucleosis: The role of serial ultrasonography. Ear Nose Throat J.
2011; 90: E21–4.
52. Ohberg L, Alfredson H. Ultrasound guided sclerosis of neovessels in painful chronic Achilles tendinosis: pilot study of a new treatment. Br. J. Sports Med.
2002; 36: 173–5.
53. Orlik J, McVey J. Deep vein thrombosis and bilateral pulmonary embolism following minor trauma to the popliteal fossa: could this have been avoided? CJEM
. 2011; 13: 122–6.
54. Pedret C, Balius R, Barceló P, et al.. Isolated tears of the gracilis muscle. Am. J. Sports Med.
2011; 39: 1077–80.
55. Pingitore A, Garbella E, Piaggi P, et al.. Early subclinical increase in pulmonary water content 1 in athletes performing sustained heavy exercise at sea level: ultrasound lung comet-tail evidence. Am. J. Physiol. Heart Circ. Physiol.
2011; 301: H2161–7.
56. Reach JS, Easley ME, Chuckpaiwong B, Nunley JA 2nd. Accuracy of ultrasound guided injections in the foot and ankle. Foot Ankle Int.
2009; 30: 239–42.
57. Ryan M, Wong A, Rabago D, et al.. Ultrasound-guided injections of hyperosmolar dextrose for overuse patellar tendinopathy: a pilot study. Br. J. Sports Med.
2011; 45: 972–7.
58. Sánchez M, Guadilla J, Fiz N, Andia I. Ultrasound-guided platelet-rich plasma injections for the treatment of osteoarthritis of the hip. Rheumatology (Oxford)
. 2012; 51: 144–50.
59. Shampo MA, Kyle RA. Karl Theodore Dussik — pioneer in ultrasound. Mayo Clin. Proc.
1995; 70: 1136.
60. Shankar H. Ultrasound-guided hip joint injections: a new scanning routine for easy methodical training. Pain Pract.
2012; 12: 80–1.
61. Sivan M, Brown J, Brennan S, Bhakta B. A one-stop approach to the management of soft tissue and degenerative musculoskeletal conditions using clinic-based ultrasonography. Musculoskeletal Care
. 2011; 9: 63–8.
62. Soh E, Li W, Ong KO, et al.. Image-guided versus blind corticosteroid injections in adults with shoulder pain: a systematic review. BMC Musculoskelet. Disord.
2011; 25: 137.
63. Standaert CJ. Shockwave therapy for chronic proximal hamstring tendinopathy. Clin. J. Sport Med.
2012; 22: 170–1.
64. Tao K, Davenport M. Deep venous thromboembolism in a triathlete. J. Emerg. Med.
2010; 38: 351–3.
65. Tran N, Chow K. Ultrasonography of the elbow. Semin. Musculoskelet. Radiol.
2007; 11: 105–16.
66. Utter AC, McAnulty SR, Sarvazyan A, et al.. Evaluation of ultrasound velocity to assess the hydration status of wrestlers. J. Strength Cond. Res.
2010; 24: 1451–7.
67. Wiegerinck JI, Reilingh ML, de Jonge MC, et al.. Injection techniques of platelet-rich plasma into and around the Achilles tendon: a cadaveric study. Am. J. Sports Med.
2011; 39: 1681–6.
68. Willberg L, Sunding K, Forssblad M, et al.. Sclerosing polidocanol injections or arthroscopic shaving to treat patellar tendinopathy/jumper’s knee? A randomised controlled study. Br. J. Sports Med.
2011; 45: 411–5.
69. Yim ES, Friedberg RP. Case report: Lower extremity deep vein thrombosis following an intense calf workout. Curr Sports Med Rep.
2012; 11: 282–6.
70. Yoong P, Guirguis R, Darrah R, et al.. Evaluation of ultrasound-guided diagnostic local anaesthetic hip joint injection for osteoarthritis. Skeletal Radiol.
2011; 41: 981–5.