Clinical Reviews: Current Concepts

Diagnostic and Interventional Musculoskeletal Ultrasound: Part 2. Clinical Applications

Jay Smith, MD, Jonathan T. Finnoff, DO

Musculoskeletal ultrasound involves the use of high-frequency sound waves to image soft tissues and bony structures in the body for the purposes of diagnosing pathology or guiding real-time interventional procedures. Recently, an increasing number of physicians have integrated musculoskeletal ultrasound into their practices to facilitate patient care. Techno- logical advancements, improved portability, and reduced costs continue to drive the proliferation of ultrasound in clinical medicine. This increased interest creates a need for education pertaining to all aspects of musculoskeletal ultrasound. The primary purpose of this article is to review diagnostic ultrasound technology and its potential clinical applica- tions in the evaluation and treatment of patients with neurological and musculoskeletal disorders. After reviewing this article, physicians should be able to (1) list the advantages and disadvantages of ultrasound compared to other available imaging modalities; (2) describe how ultrasound machines produce images using sound waves; (3) discuss the steps necessary to acquire and optimize an ultrasound image; (4) understand the difference ultrasound appearances of tendons, nerves, muscles, ligaments, blood vessels, and bones; and (5) identify multiple applications for diagnostic and interventional musculoskeletal ultrasound. Part 2 of this 2-part article will focus on the clinical applications of musculo- skeletal ultrasound in clinical practice, including the ultrasonographic appearance of normal and abnormal tissues as well as specific diagnostic and interventional applications in major body regions.

NORMAL AND ABNORMAL TISSUES The primary clinical utility of musculoskeletal ultrasound is to examine soft tissues in the body for the purpose of diagnosing pathological changes or performing interventional procedures. After obtaining the necessary equipment, knowledge, and skills to perform the examination, physicians must familiarize themselves with the normal and abnormal appear- ances of tissues. Seamless integration of musculoskeletal ultrasound into clinical practice requires skill, time, and patience. Ultrasound can be used to readily identify and differentiate tendons, muscles, ligaments, nerves, and vessels at a resolution of Ͻ1 mm. These tissues generally are described by their echogenicity (isoechoic, hypoechoic, anechoic, hyperechoic), echotexture (internal echo pattern), degree of anisotropy (i.e., occurs when an otherwise-normal but smooth structure appears “dark” on ultrasonographic imaging as a result of the fact that the ultrasound beam did not encounter the structure perpendicular to the plane of that structure), compressibil- ity, and the presence or absence of blood flow on Doppler examination. These features are J.S. Department of Physical Medicine and summarized in Table 1 and Figure 1. Rehabilitation, College of Medicine, Mayo Clinic, 200 First St SW, Rochester, MN Tissue echogenicity is characterized as hyperechoic, hypoechoic, anechoic, or isoechoic. 55905. Address correspondence to: J.S.; Hyperechoic structures are brighter (or whiter) than normal or in relation to surrounding e-mail: [email protected] structures, whereas hypoechoic structures are darker (or blacker) than normal or in relation Disclosure: nothing to disclose to surrounding structures. Anechoic structures are devoid of echoes and appear black. J.T.F. Department of Physical Medicine and Isoechogenic structures are similar in brightness to surrounding structures. These terms can Rehabilitation, College of Medicine, Mayo Clinic, Rochester, MN be used in an absolute sense (ie, tendons are generally hyperechoic, or bright) or in a relative Disclosure: nothing to disclose sense (a tendon affected by tendinopathy often appears darker than expected or relative to Disclosure Key can be found on the Table of surrounding tendons and therefore is hypoechoic). Contents and at www.pmrjournal.org Echotexture refers to the internal pattern of echoes, which can vary depending on Submitted for publication July 10, 2008; whether the structure is imaged transversely or longitudinally. Tendons exhibit a fibrillar accepted September 30.

PM&R © 2009 by the American Academy of Physical Medicine and Rehabilitation 162 1934-1482/09/$36.00 Vol. 1, 162-177, February 2009 Printed in U.S.A. DOI: 10.1016/j.pmrj.2008.09.002 PM&R Vol. 1, Iss. 2, 2009 163

Table 1. Normal ultrasonographic characteristics of soft tissues

Echotexture Appearance Susceptibility Doppler Tissue Echogenicity Transverse Longitudinal to Anisotropy Compressibility Flow Tendon Hyperechoic Broom end Fibrillar ϩϩϩ ϪϪ ϪϪ Ligament Hyperechoic Broom end Fibrillar ϩϩ ϪϪ ϪϪ Nerve Mixed Honeycomb Fascicular ϩϪϪϪϪ echogenicity Muscle Mixed Starry night Pennate ϩϪϪϪϪ echogenicity or “feather like” Vessel Hypoechoic ϪϪ ϪϪ ϪϪ ϩϩa - ϩϩϩv ϩv - ϩϩϩa or anechoic

ϪϪ ϭ absent; ϩϭmildly present; ϩϩ ϭ moderately present; ϩϩϩ ϭ significantly present; aϭ arteries; vϭ veins. pattern when imaged longitudinally and a “broom-end” pat- able to the relative multidirectional nature of their incurred tern when imaged transversely [1-3]. These patterns result stresses. Ligaments appear fibrillar during longitudinal scan- from the compact arrangement of hyperechoic collagen bun- ning. Their echotexture is often not distinguishable during dles within the tendon, separated by the hypoechoic inter- transverse scanning because of their thin size, but when vening ground substance [1-3]. The synovial sheaths or transverse imaging is possible, they have a “broom-end” paratenons of tendons frequently can be visualized with a appearance. Ligaments can easily be distinguished from ten- high-frequency (Ͼ10 MHz) transducer and appear as a thin, dons by tracing the ligament to the bony structures to which hyperechoic tissue layer surrounding the tendon bulk. it attaches. For example, the medial collateral ligament is easily differentiated from the pes anserine tendons by its Tendons anatomic course (adductor tubercle to proximal medial tibia), ligamentous echotexture (Table 1), and deep location Because of the tightly packed arrangement of collagen bun- relative to the overlying pes anserine tendons. Dynamic liga- dles within a tendon, tendons demonstrate significant anisot- ment testing can be performed under ultrasound to facilitate ropy. As solid structures, they are noncompressible and do differentiation of a high-grade partial versus complete liga- not normally exhibit blood flow. Tendons can be examined ment tear or to document joint instability [4,8,9]. dynamically through passive, active, or resisted joint mo- tions, sonopalpation, or transducer compression [1-4]. Most bursa adjacent to tendons are not visualized unless dis- Muscles tended; exceptions include the subacromial-subdeltoid, ret- rocalcaneal, and deep infrapatellar bursae. Fascia and joint capsules have a similar ultrasound appear- ance to ligaments and are easily identified based upon loca- Nerves tion. The mixed hypo- and hyperechogenicity of muscle arises from the regular pattern of hypoechoic muscle fascicles The fascicular longitudinal and honeycomb transverse within the hyperechoic peri- and epimysium [6,10]. Longi- echotexture patterns of nerves are caused by the hypo- tudinally, muscle demonstrates a “feather” or “veins on a leaf” echoic nerve fascicles surrounding by hyperechoic con- pattern, whereas transversely they appear as a “starry night.” nective tissue (external and interfascicular epineurium) Dynamically, compression or muscle contraction can reveal [3,5,6].Nervesarebestexaminedtransversely,during partial thickness strain injuries [6,10]. which long segments of nerves can be traced (eg, ulnar nerve from brachial plexus to the hand). Nerves are differ- entiated from tendons by their echotexture, relative lack of Vessels anisotropy, location, and proximity to vessels. Provocative testing during ultrasound evaluation of nerves may in- Veins and arteries appear as hypo- or anechoic tubular volve a sonographic Tinel’s sign to localize a regenerating structures that are easily compressible and exhibit blood nerve stump or neuroma, range of motion to induce nerve flow on Doppler examination. Because veins and arteries subluxation or dislocation, or muscle or joint motion to are the only tissues that should normally exhibit blood demonstrate dynamic stenosis within a musculotendinous flow, they are easily distinguished from tendons, nerves, or osseofibrous structure, respectively [4,5,7]. and ligaments. In addition, although both veins and arter- ies are generally easily compressible, arteries will remain pulsatile during compression, whereas veins will not. Ligaments Identification of veins and arteries during diagnostic scan- Ligaments appear similar to tendon but are less compact and ning will facilitate locating nerves as these 2 structures contain a more diverse pattern of collagen bundles attribut- often course side by side in the body. 164 Smith and Finnoff MUSCULOSKELETAL ULTRASOUND: PART 2

Figure 1. (a) Transverse view of carpal tunnel, demonstrating mixed echogenicity honeycomb pattern of median nerve (N), in contrast to the hyperechoic, fibrillar appearance of the surrounding finger flexor tendons (T). (b) Longitudinal view of flexor carpi radialis traversing superficial to the scaphoid bone in the wrist. Note the hyperechoic, fibrillar echotexture, which is characteristic of all tendons. (c) Longitudinal view of dorsal wrist, producing a transverse view of the dorsal scapholunate ligament (circled), appearing as a tightly packed, hyperechoic, fibrillar structure. (d) Correlative transverse view of dorsal wrist, producing a longitudinal view of the dorsal scapholunate ligament (arrows). Typical of all ligaments, the ligament is better visualized longitudinally rather than transversely and can be located by placing the transducer across the adjacent bony landmarks (lunate and scaphoid). (e) Longitudinal view of median nerve in the forearm (arrows). Hypoechoic fascicles alternating with hyperechoic epineurium are shown. The fascicular pattern of nerves can be compared with the tightly packed fibrillar pattern of tendon (see b). (f) Transverse view of the calf musculature. Note the “starry night” appearance of the gastrocnemius and soleus muscles in cross-section (Figure 1 continues).

Bone bone or other highly calcified structures, rendering the image The ultrasound appearance of bone is distinctive, manifest- beyond the interface nearly black. This phenomenon is re- ing as a well-defined, linear, smooth, hyperechoic border ferred to as posterior acoustic shadowing. Consequently, (refer to Figure 3, Part 1 of this review) [11-13]. The hyper- ultrasound can only provide information about the superfi- echogenicity of bone is caused by the high reflectivity of the cial portion of visualized bones. With respect to joints, high- acoustic interface. In fact, virtually the entire sound beam is frequency (Ͼ10 MHz) scanners typically can be used to reflected and therefore ultrasound is unable to “see” beyond identify the superficial portions of the constituent bones, a PM&R Vol. 1, Iss. 2, 2009 165

Figure 1. (Continued) (g) Correlative longitudinal view, demonstrating the typical pennate (“feather-like”) arrangement of hypoechoic muscle fibers separated by hyperechoic fibroadipose connective tissue. (h) Transverse view of radial artery and accompanying veins in the wrist. The vessels appear anechoic. (i) Doppler examination confirms the vascular nature of the structures. (j) Correlative longitudinal view with Doppler (Philips iU22, Philips Medical Systems, Bothell, WA).

thin hyperechoic joint capsule, and a small amount of easily from high-grade partial-thickness tears may be facilitated by displaceable anechoic intra-articular fluid [12-15]. Normal muscle activation, passive stretch, or manual compression synovium is not able to be visualized with ultrasound. with the transducer, all of which may reveal the gapping of a full thickness tear [3,4]. Tendon Injuries Tenosynovitis may appear as simple, anechoic, easily dis- placeable fluid surrounding the tendon, or as complex fluid Most tissues in the musculoskeletal system demonstrate a with mixed echogenicity. Synovial hypertrophy may also be similar spectrum of pathological ultrasound changes present and is frequently associated with hyperemia on throughout the body. Tendinosis manifests as tendon en- Doppler examination [2,3]. The ultrasonographic appear- largement, hypoechogenicity, and an increase in the interfi- ance of complex fluid within the tendon sheath is nonspe- brillar distance (Figure 2) [1-3]. These changes are the result cific, and diagnostic aspiration should be completed if infec- of intratendinous edema and an increase in interfibrillar tion is suspected. Intratendinous calcifications appear as ground substance. These changes may be regional or diffuse, linear or ovoid hyperechoic structures with variable amounts and it is important to note that the fibrillar tendon echotex- of posterior acoustic shadowing, depending on their density ture is maintained [2,3]. Partial-thickness tearing demon- (Figure 3) [3,16]. Similar to bone, when calcifications are strates the additional finding of focal regions of anechogenic- dense, ultrasonographic evaluation of structures deep to the ity accompanied by loss of the normal fibrillar pattern, calcification is problematic. confirmed on both longitudinal and transverse images [2,3]. However, tendon continuity is maintained. Ligament Injuries High-grade partial-thickness tearing may demonstrate tendon thinning rather than thickening as the result of to a The manifestations of ligament injury are similar to those loss of tendon substance. Full-thickness tearing manifests as described for tendons. Low-grade injuries manifest as en- a tendon gap occurring in a background of tendinosis-related larged, hypoechoic ligaments with an otherwise-normal changes. Differentiation of nonretracted full-thickness tears echotexture, whereas partial- and full-thickness tears dem- 166 Smith and Finnoff MUSCULOSKELETAL ULTRASOUND: PART 2

Figure 2. (a) Longitudinal view of normal Achilles tendon, exhibiting a typical hyperechoic, fibrillar echotexture. (b) Correlative extended field of view ultrasound image of patient with mid-substance Achilles tendinopathy. Note the focal swelling and hypoechogenicity with maintenance of the fibrillar echotexture. Left screen ϭ inferior (CALC ϭ calcaneus), right screen ϭ superior, top screen ϭ superficial, bottom screen ϭ deep (Philips iU22, Philips Medical Systems, Bothell, WA).

onstrate fiber disruption. Comparison with unaffected liga- Muscle Injuries ments in other areas facilitates detection of more subtle Low-grade muscle strains exhibit subtle regions of hypo- abnormalities. Stress testing may be used to differentiate echogenicity accompanied by obscuration of the normal pen- partial versus complete tears and assess joint stability [4]. nate echotexture; the affected area looks “washed out” [6,10]. Higher grade injuries and contusions demonstrate variable Nerve Injuries degrees of frank fiber disruption and heterogenous fluid typical of a hematoma. Peripheral nerves also can be evaluated for signs of entrap- ment or inflammation. Similar to tendons and ligaments, affected nerves exhibit regional swelling and diffuse hypo- Bone and Joint Disorders echogenicity, often accompanied by a loss in their normal fascicular pattern [3,5,6,17]. Entrapment sites may be local- Irregularities in the otherwise superficial, smooth surface of ized by evaluating for swelling proximal to the entrapment bone may be indicative of periostitis or stress fracture [12]. site and a focal narrowing at that site, that is, a “notch sign” Further evaluation of any suspicious bone disorder is neces- [3,5,6]. Dynamic testing can evaluate for subluxation or sary because of the inherent limitations of ultrasound. Ultra- dislocation [18]. sound is very sensitive for detecting joint effusions through- out the body [19,20]. Simple effusions are anechoic, compressible, and devoid of Doppler flow. Complex, heterogeneous appearing fluid is a nonspecific finding and may be indicative of infection [20]. Aspiration is recommended as clinically indicated. Synovitis appears as noncompressible, echogenic tissue within a joint (or tendon sheath), possibly exhibiting hyperemia on Dopp- ler examination. Periarticular erosions, crystal disease-re- lated deposits, and gouty tophi can all be observed during joint evaluation; however, one should recognize that poten- tially clinically important findings may not be accessible to ultrasound examination deep within a joint [12]. Enlarged bursae typically contain simple anechoic fluid, but complex fluid may be present, similar to joint effusions. Periarticular and peritendinous ganglia appear as multilobulated, ane- choic, noncompressible structures devoid of blood flow [21,22]. Figure 3. Longitudinal view of supraspinatus tendon in a pa- tient with a large intratendinous calcification (arrows) and symptomatic rotator cuff calcific tendinopathy. Note appear- CLINICAL APPLICATIONS ance of calcium deposit, similar to bone in Figure 3. Posterior acoustic shadowing obscures evaluation of structures deep to During the past 10 years, the clinical applications of diagnos- the calcification. Left screen ϭ lateral, right screen ϭ medial, tic and interventional musculoskeletal ultrasound have ex- top screen ϭ superficial, bottom screen ϭ deep (Philips iU22, panded rapidly. Technological advancements and an increas- Philips Medical Systems, Bothell, WA). ing diversity of users have established ultrasound as a clinical PM&R Vol. 1, Iss. 2, 2009 167

problem-solving tool in musculoskeletal medicine. The pre- status of the rotator cuff or biceps tendon, ultrasound may be requisites for successful scanning as well as basic scanning considered as an initial diagnostic test after obtaining appropri- principles have been reviewed in Part 1 of this 2-part article ate radiographs [24,27,33,35,38,39]. [11]. When approaching a regional musculoskeletal disor- For example, with respect to a patient presenting with an der, the physician is reminded to follow a standard examina- appropriate history, shoulder pain, stiffness, passive motion tion protocol to answer a predefined clinical question, eval- loss, and a normal radiograph, an unremarkable ultrasound uating target structures both transversely and longitudinally. would support the diagnosis of adhesive capsulitis, facilitat- ing implementation of appropriate treatment [42,43]. Ultra- sound enables follow-up of partial-thickness or small full- Shoulder thickness rotator cuff tears for signs of structural progression. The high prevalence of rotator cuff disorders coupled with Ultrasound-guided injections into the bicipital tendon sheath ultrasound’s ability to evaluate tendons with high resolution and subacromial-subdeltoid bursa may be performed for have established ultrasound as a front-line diagnostic tool in diagnostic or therapeutic purposes [44-48]. In a subset of many patients presenting with shoulder pain [23,24]. The patients presenting with symptomatic calcific rotator cuff earliest consistent application of musculoskeletal ultrasound tendinopathy, the use of ultrasound can delineate the pres- was the evaluation of rotator cuff and associated soft tissue ence and extent of the calcification, excluded concomitant pathologies [25,26]. Since that time, clinical applications in rotator cuff tears (atypical in this group), and facilitate treat- the shoulder have increased dramatically. ment via ultrasound-guided percutaneous lavage and aspira- The shoulder region can typically be examined with high- tion (Figure 4) [16,49-53]. Examiners are reminded that frequency (Ͼ10 MHz) linear array transducers, although in ultrasound cannot completely investigate the glenohumeral larger patients mid-range frequency (6-10 MHz) transducers labrum or intra-articular regions of the glenohumeral, acro- may be required [23,24,27,28]. Specific guidelines for ultra- mioclavicular, or sternoclavicular joints [24-28]. Conse- sonographic evaluation of the shoulder have been established quently, physicians must rely on alternative diagnostic imag- (see Table 3, Part 1 of this 2-part article [11]). Examiners ing such as radiographs, computed tomography (CT), or MRI should be aware that the curved geometry of the rotator cuff to definitively confirm the presence or absence of pathologies tendons creates anisotropy during most examinations, par- affecting these areas. ticularly at the musculotendinous junction [23,28,29]. Ultrasound can be used to detect loose bodies in the Transducer repositioning, as previously described, should be posterior glenohumeral joint recess and fragmentation of used to differentiate anisotropy from true pathology bony margins consistent with erosive arthritis and synovitis. [23,28,29]. When necessary, ultrasound can facilitate accurate diagnostic Ultrasound can be used to detect and characterize tendon aspiration or therapeutic injection into these joints [44,45]. disorders affecting the biceps and rotator cuff, including Ultrasound also may be used to identify relevant periarticular biceps tenosynovitis, tendinosis, and partial- or full-thick- pathologies, such as spinoglenoid notch cysts associated with ness tearing [23,24,30-33]. In addition, sonography is better posterior labral tears, or acromioclavicular joint cysts associ- tolerated and preferred by patients compared with a mag- ated with massive rotator cuff tears [23,54]. Ultrasound netic resonance imaging (MRI) scan [34]. Physicians must recognize that fluid around the biceps tendon may represent tenosynovitis or an extension of a glenohumeral joint effusion, because the bicipital sheath directly communicates with the joint [23,28,31]. In fact, loose bodies arising from the glenohumeral joint may be identified within the biceps sheath. Bicipital tenosynovitis is suggested by the presence of concomitant bicipital tendi- nopathy or tearing, echogenic synovial hypertrophy, pain during sonopalpation, and hyperemia on Doppler examina- tion [23,31]. A dynamic evaluation can reveal bicipital insta- bility during external rotation [32]. In experienced hands, ultrasound can identify the pres- ence and extent of partial-thickness and full-thickness rotator cuff tears with accuracy similar to MRI (see Figure 6b, Part 1 of this 2-part article) [11,24,27,30,33,35-39]. Figure 4. Longitudinal view of supraspinatus tendon. A 22- In addition, ultrasound can be used to identify fluid in the gauge needle (arrows) has been guided into a symptomatic, subacromial-subdeltoid bursa, bursal hypertrophy, and im- hyperechoic, intratendinous calcification. With the use of a pingement of hypertrophied rotator cuff tendons or bursal tis- lavage technique, the hydroxyapatite crystals are aspirated, sue against the lateral acromion during arm elevation (ultra- resulting in an eggshell appearance. Left screen ϭ lateral, right sonographic impingement sign) [33,40,41].Consequently, screen ϭ medial, top screen ϭ superficial, bottom screen ϭ deep (Philips iU22, Philips Medical Systems, Bothell, WA). when clinically relevant information is desired regarding the 168 Smith and Finnoff MUSCULOSKELETAL ULTRASOUND: PART 2

guidance can facilitate cyst aspiration for temporary symp- tom control as clinically indicated [54]. Ultrasound provides significant advantages over MRI and CT scans to evaluate the postoperative shoulder [55]. Diag- nostic evaluation is most commonly performed to exclude rotator cuff tear after rotator cuff repair or total shoulder arthroplasty [55]. Examination of the postoperative shoulder is one of the most challenging diagnostic musculoskeletal examinations and should only be performed by experienced practitioners [54].

Elbow Figure 5. Longitudinal view of the lateral elbow and common extensor tendon in a patient presenting with refractory “lateral The superficially located structures about the elbow are ame- epicondylitis.” Arrows denote a focal region of hypoechoge- nable to ultrasound examination with high-frequency (Ͼ10 nicity accompanied by obscuration of the normal fibrillar MHz) transducers. With respect to the lateral elbow, ultra- echotexture of the tendon. These changes are consistent with sound provides excellent imaging of the common extensor high-grade tendinopathy with focal intra-substance partial thickness tearing. RH ϭ radial head, CAP ϭ capitellum. Left tendon. Although not typically required for initial diagnosis, screen ϭ distal, right screen ϭ proximal, top screen ϭ superfi- ultrasound can assist in management of refractory cases cial, bottom screen ϭ deep (Philips iU22, Philips Medical Sys- lateral epicondylosis (also called tennis elbow) by character- tems, Bothell, WA). izing the extent of tendon tearing and identifying the pres- ence of concomitant radial collateral ligament injury (Figure 5) [56,57]. As clinically indicated, the radial nerve may be Identification of ulnar nerve subluxation may influence traced as it passes through the supinator to identify focal the approach to therapeutic injection in this region, as well as swelling and stenosis suggestive of radial tunnel syndrome the distance measurements used to calculate nerve conduc- [7]. Nerve examination may be supplemented by visualiza- tion velocity across the elbow [69]. The medial collateral tion during pronation-supination. The radiocapitellar artic- ligament (also known as ulnar collateral ligament) can be ulation may be examined for osteoarthritic changes or a plica, evaluated to reveal partial or complete tears [9,70]. Valgus and effusion or loose bodies may be seen in the annular recess stress testing during ultrasound visualization can reveal adjacent to the radial neck [19,20]. A comprehensive articu- asymmetric increases in ulnohumeral joint laxity as an indi- lar assessment would require radiographs, CT, or MRI. cator of instability, thus assisting in diagnosis and triage Ultrasound guidance may be used to aspirate effusions, [9,71]. Finally, the median nerve can be identified in the diagnostically block the radial nerve at the supinator, or mid-arm and traced distally as it traverses through the pro- guide corticosteroid injection into the common extensor nator teres, identifying potential entrapment sites in patients tendon region [20,58,59]. Because of the inconsistent and presenting with proximal median neuropathies [3]. often marginal long-term results of corticosteroid injections For most physicians, applications in the anterior elbow to treat common extensor tendinopathy/lateral epicondylo- are limited. Imaging the distal bicep tendon is technically sis, in recently described procedures, researchers have at- challenging, and MRI remains the test of choice in most cases. tempted to more directly stimulate a healing response Loose bodies may be identified in the anterior recesses, but [58,59]. Ultrasound-guided percutaneous tenotomy, plate- CT scan is much more sensitive when the primary indication let-rich plasma injection, sclerosing therapy, and autologous for diagnostic testing is a search for loose bodies throughout blood injections have all produced promising short-term the elbow [20]. In comparison, the triceps tendon is easily improvements in refractory cases, although prospective ran- examined using ultrasound, revealing tendinopathy, partial domized studies and longer-term follow-up are currently tearing and, in rare cases, full-thickness tearing. Elbow effu- lacking [60-64]. sions are best visualized posteriorly when the elbow is flexed, Ultrasound has similar applications on the medial elbow, within the olecranon fossa [19,20]. Loose bodies may also be particularly with respect to the management of flexor-prona- detected in this location (Figure 6). Ultrasound can be used tor tendinopathy or medial epicondylosis (also called Golfer’s for diagnostic elbow joint aspiration and injection via a elbow) [65,66]. In addition, ultrasound can readily trace the posterior approach when clinically indicated [20]. ulnar nerve from the mid-humerus to mid-forearm, provid- ing anatomic localization of ulnar nerve compression about Wrist-Hand the elbow [67,68]. Thus, ultrasound can supplement elect- rodiagnostic testing by demonstrating the location of struc- Ultrasound can provide exquisitely detailed images of ten- tural nerve changes, as well as potentially identifying under- dons, nerves, vessels, joint capsules, retinacula/pulleys, and lying causes such as loose bodies, synovitis, osteophytes, some ligaments in the wrist-hand [72-74]. The superficial tumors, subluxation or dislocation, or a snapping triceps location of these structures allows interrogation with high- tendon [3,18,67,68]. frequency linear transducers (12-17 MHz), providing resolu- PM&R Vol. 1, Iss. 2, 2009 169

ure 1d) [72]. The ligament is located by scanning in an anatomic transverse plane just distal to Lister’s tubercle on the dorsal radius. This is a common location for periarticular ganglion cysts, which are readily identified by ultrasound as well-defined, noncompressible, anechoic structures devoid of internal blood flow [21]. Ultrasound-guided aspiration, with or without corticosteroid injection, may provide short- or intermediate term relief (Figure 7) [22]. The superficial radial nerve can be imaged as it emerges from beneath the brachioradialis tendon and courses distally and dorsally over the first extensor compartment tendons, facilitating identifi- cation of focal neuropathy or post-traumatic neuroma. Similar to the dorsal wrist, all volar wrist tendons may be Figure 6. Longitudinal view of the posterior elbow, demon- traced proximal to distal, allowing the physician to identify strating a calcified loose body in the olecranon fossa (arrows) the presence and extent of tendinopathy and associated teno- in a patient with elbow pain, stiffness, and normal radiographs. synovitis [72,75]. The volar radiocarpal joint recesses may be Left screen ϭ proximal, right screen ϭ distal, top screen ϭ superficial, bottom screen ϭ deep (Philips iU22, Philips Medical investigated for effusion and synovitis [72]. The volar-radial Systems, Bothell, WA). wrist is the second most common location for periarticular ganglia, usually arising from the scaphotrapeziotrapezoidal articulation [21]. These ganglia typically are located between tion of less than a millimeter. If available, small footprint the flexor carpi radialis ulnarly and the radial artery radially. linear array transducers allow greater maneuverability and Ultrasound guidance may be used to aspirate/inject any of may be particularly useful during ultrasound-guided proce- these areas as clinically indicated, although the operator dures. Clinically, ultrasound is a powerful tool to differenti- should exercise appropriate caution because of the proximity ate among multiple potential pain generators in patients of neurovascular structures [21,22]. presenting with regional wrist-hand complaints and can fa- The role of ultrasound in the evaluation of carpal tunnel cilitate therapeutic aspiration or injection. syndrome continues to evolve [80,81]. When abnormal, the On the dorsal wrist, the tendons within all 6 wrist exten- median nerve will appear enlarged and hypoechoic, and will sor compartments may be traced from their musculotendi- demonstrate some obscuration of its internal fascicular struc- nous junctions to their distal insertions [72]. Ultrasound can ture when imaged transversely (Figure 8) [82]. The severity be used to identify the presence of tendinopathy, partial- of ultrasonographically documented anatomic changes cor- thickness tearing, or full-thickness tearing, thus assisting in relates closely with electrophysiologic abnormalities [81]. triage and management [75]. Associated tenosynovitis or intrasynovial pannus can be accurately identified, particu- larly with the use of power Doppler [75,76]. Dynamic exam- ination may reveal symptomatic snapping of tendons as they cross other tendons, joint, bony prominences/osteophytes, or synovial pannus [4]. Provocative supination-pronation testing during ultra- sonographic visualization can objectively document extensor carpi ulnaris subluxation in patients presenting with dorso- ulnar wrist pain and snapping [4,77]. All dorsal wrist tendon sheaths are accessible to ultrasound-guided aspiration/injec- tion. Within the first dorsal extensor compartment, ultra- sound can readily identify fibrous or fibroosseous septae between the abductor pollicis longus and extensor pollicis brevis tendons, the presence of which have been implicated in suboptimal injection responses to injections in cases of DeQuervain’s tenosynovitis [72,78-80]. In these cases, ultra- sound guidance can ensure injectate distribution into both subcompartments. Figure 7. Transverse view of dorsal wrist in an athlete present- ing with a symptomatic, complex, dorsal wrist ganglion asso- The dorsal radiocarpal and distal radioulnar joint recesses ciated with the scapholunate ligament. Using ultrasound guid- can be assessed for effusion or synovitis [72]. Ultrasound- ance, a 19-gauge needle (arrows) is safely advanced guided aspiration/injection can proceed as clinically indi- between tendons into the cyst for therapeutic aspiration and cated. In most patients the dorsal scapholunate ligament may injection. Left screen ϭ radial, right screen ϭ ulnar, top screen be identified as a fibrillar, hyperechoic structure spanning the ϭ superficial, bottom screen ϭ deep (Philips iU22, Philips Med- ical Systems, Bothell, WA). dorsal osseous margins of the scaphoid and lunate (Fig- 170 Smith and Finnoff MUSCULOSKELETAL ULTRASOUND: PART 2

ment of joint stability. Ultrasound can image the ulnar col- lateral ligament of the thumb, and identify the presence or absence of a Stener lesion with acceptable accuracy [8,87]. Very high-frequency linear transducers (Ͼ12 MHz) can readily identify the A1, A2, and A4 pulleys in most patients [73]. Disruption of the A2 pulley (Climber’s finger) is mani- fested as pulley discontinuity and can be confirmed ultra- sonographically when active finger flexion results in volar subluxation of the flexor tendon as demonstrated ultrasono- graphically [74,75]. Patients with stenosing tenosynovitis (trigger finger) usually demonstrate thickening of the A1 pulley and dyskinetic tendon movement during active or passive finger flexion-extension [75]. Most cases are clinically obvious and do not require confirmatory imaging. However, Figure 8. Transverse view of the proximal carpal tunnel during when nonguided injections fail to alleviate symptoms, ultra- ultrasound guided injection in a patient with refractory carpal sound guidance will ensure injectate placement and may tunnel syndrome failing to improve after previous non-guided reveal additional underlying pathologies of clinical impor- injection. Needle is depicted by arrows and passes just deep to a swollen, hypoechoic median nerve with obscuration of its tance [88]. normal fascicular pattern. Left screen ϭ radial, right screen ϭ The ability of ultrasound to image the collateral ligaments, ulnar, top screen ϭ superficial, bottom screen ϭ deep (Philips flexor and extensor tendons, and volar plate allow ultrasound iU22, Philips Medical Systems, Bothell, WA). to provide potentially useful diagnostic information in the setting of finger dislocations. Ultrasound can be used to clearly identify the involved structures, facilitate stability The most useful indicator of median neuropathy at the carpal assessment, and identify radiographically occult fractures. In tunnel is an increased in the cross-sectional area at the carpal patients presenting with atraumatic finger joint complaints, tunnel entrance, delineated by the pisiform ulnarly and the ultrasound can be used to detect occult effusion and synovitis scaphoid tubercle radially. A cross-sectional area of Ͼ15 with better sensitivity than clinical examination, potentially mm2 is clearly abnormal, whereas 10-15 mm2 is equivocal revealing an underlying inflammatory arthropathy [14]. and Ͻ10 mm2 is normal [83]. The carpal tunnel ultrasound Early detection is relevant because of the emerging emphasis examination may provide useful information when electro- on early aggressive treatment with disease modifying agents diagnostic studies are equivocal, or secondary causes of car- [14]. The role of ultrasound guidance to aspirate/inject finger pal tunnel syndrome are suspected (eg, ganglia, flexor tendon joints has been well established in the literature [13,89]. tenosynovitis) [84]. Anatomic variants such as a bifid median Although ultrasound is a powerful clinical tool when nerve and and/or persistent median artery are readily identi- appropriately applied in the wrist-hand region, it is not fied [72,85]. Ultrasound guidance can be used to safely direct without limitations. Currently, ultrasound cannot ade- carpal tunnel injections as well as facilitate percutaneous quately evaluate the triangular fibrocartilage complex or in- treatment of underlying pathologies, such as periarticular tercarpal joints and ligaments with sufficient diagnostic ac- ganglion cysts or synovial pannus (Figure 8) [22,86].In curacy for clinical use. In addition, like other body regions, a patients presenting with symptoms referable to Guyon’s ca- variety of tumors, most commonly giant cell tumors, may nal, ultrasound examination may reveal ulnar nerve struc- manifest in the wrist-hand regions [90]. Although ultrasound tural changes indicative of neuropathy, as well as secondary can assist in localizing, characterizing, and biopsying soft causes of ulnar nerve compression such as pisotriquetral tissue tumors, it is frequently not the optimal imaging mo- ganglia, ulnar artery aneurysms, or anomalous muscles dality for soft tissue mass evaluation. Physicians performing [3,72]. ultrasound should be aware of these limitations to avoid Within the hand, ultrasound can image the flexor and misdiagnosis. extensor tendons in their entirety, identifying tendinopathy, partial-thickness tearing, or full-thickness tearing [3,75]. Hip Region Passive or active motion may facilitate differentiation of high- grade partial-thickness tears from full-thickness tears [4,75]. Ultrasound examination of the hip region is relatively chal- The collateral ligaments may be imaged at the metacarpopha- lenging because of the deep location of the target structures, langeal and interphalangeal joints and appear as moderately complex anatomy, and extensive investigation area. Large thick, hyperechoic, fibrillar structures [72]. Low-grade footprint medium-high frequency (7-10 MHz) linear trans- sprains appear as enlarged, diffusely hypoechoic ligaments, ducers or low-medium frequency (2-6 MHz) curvilinear whereas partial or complete fiber disruptions indicate higher transducers are required, providing increased imaging depth grade injuries. Radial or ulnar stress testing during ultra- at the expense of resolution. sound examination will differentiate high-grade partial- from The hip joint can be readily examined for effusion or full-thickness sprains, as well as provide a functional assess- synovitis, and techniques for ultrasound-guided hip aspira- PM&R Vol. 1, Iss. 2, 2009 171

ultrasound guidance may be used to accurately guide ischial bursa aspiration/injection or proximal hamstring peritendi- nous injections [101]. Ultrasound-guided techniques for piriformis sheath and sacroiliac joint injections have been described and may be useful alternatives to fluoroscopically guided procedures, particularly when radiation is contrain- dicated (eg, pregnancy) [102,103]. Although the diagnostic role of ultrasound continues to evolve with respect to the hip, physicians should exercise caution when considering using ultrasound as a primary imaging modality for regional hip pain. The technical limita- tions of ultrasound favor CT or MRI for diagnostic purposes in most cases. Ultrasound may be considered when specific information is desired about superficial structures (eg, ad- ductor tendons, iliopsoas tendons, lateral femoral cutaneous Figure 9. Ultrasound-guided intra-articular hip injection. Nee- nerve), with the understanding that the small field of view dle (arrows) has penetrated the anterior hip capsule at the provided by the ultrasound exam limits the ability to exclude femoral head (FH)-neck junction, entering the anterior joint significant findings beyond the examined region. On the recess. From this position, the hip joint can be injected. Note contrary, once pathology is identified, ultrasound may be the curved image geometry created by the 5-2 MHz curvilin- effectively used to guide needles to virtually any target loca- ear array transducer used for the procedure. A ϭ acetabulum, left screen ϭ distal, right screen ϭ proximal, top screen ϭ tion within the hip region. superficial, bottom screen ϭ deep (Philips iU22, Philips Medical Systems, Bothell, WA). Knee Region Diagnostic examination of the knee can typically be per- tion and/or injection are well described (Figure 9) [91-94]. formed with high-frequency (Ͼ10 MHz) linear transducers Although acetabular labral tears may be observed during the because of the superficial location of most target structures. examination, ultrasound is not capable of completely evalu- The primary indications for ultrasound in the anterior knee ating the labrum or the intra-articular space. Within the are to evaluate the extensor mechanism and to identify and anterior hip region, ultrasound may also help to identify aspirate knee effusions. The echogenic, fibrillar trilaminar iliopsoas tendinopathy, iliopsoas bursitis, and adductor ten- structure of the distal quadriceps tendon is readily revealed dinopathy or tears. with the use of high-frequency transducers, facilitating as- Dynamic ultrasonographic examination during provoca- sessment of tears in native or postarthroplasty knees tive maneuvers is the diagnostic test of choice for symptom- [104,105]. Although patellar tendinopathy is typically a atic snapping iliopsoas tendons at the level of the pelvic brim straightforward clinical diagnosis, structural changes are or femoral head [95,96]. Ultrasound-guided iliopsoas peri- more likely to be observed on ultrasound than MRI in symp- tendinous injection may confirm the diagnosis of symptom- tomatic patients [106]. Tendon neovascularization as de- atic snapping iliopsoas tendons, or iliopsoas tendinopathy in tected by power Doppler examination appears to correlate native or post-arthroplasty hips [96-98]. Although the diag- with clinical symptoms, although the relationship is not nostic role of ultrasound with respect to the lateral femoral absolute (Figure 10) [106,107]. cutaneous nerve remains undefined, most high-resolution Initial experience with ultrasound-guided sclerosis of scanners can readily identify the nerve at the level of the neovessels and dry needling coupled with autologous blood anterior superior iliac spine, facilitating diagnostic or thera- injections has produced favorable results [108,109]. Further peutic ultrasound-guided blockade in patients presenting prospective investigation of these promising therapeutic in- with burning anterolateral thigh pain consistent with meral- terventions is warranted. Ultrasound examination may assist gia paresthetica [99]. in triage and rehabilitation progression by differentiating In the lateral hip, ultrasound may be used to differentiate tendinosis from high-grade partial thickness tearing, as well greater trochanteric bursitis from gluteal tendinopathy and as determining the presence of associated superficial or deep can identify gluteal tears in native or postarthroplasty hips infrapatellar bursopathy. Identification of these latter condi- [100]. The greater trochanteric (ie, subgluteus maximus) tions as pain generators with the use of sonopalpation may bursa is not visualized during ultrasonography unless abnor- lead to therapeutic ultrasound-guided injection. Knee effu- mal. When clinically indicated, ultrasound can precisely sions are best detected in the suprapatellar pouch by using guide diagnostic/therapeutic injections into hip bursae or sagittal views and appear as anechoic fluid collections gluteal peritendinous regions. The diagnostic role of ultra- [15,110,111]. Doppler examination may reveal hyperemia sound in the posterior hip region is limited. Ultrasound may consistent with synovitis. When clinically indicated, ultra- help to identify moderate-to-severe hamstring tendinopathy sound guidance may be used to aspirate effusions and inject and tears but is not likely as sensitive as MRI scan. However, therapeutic agents [110,111]. 172 Smith and Finnoff MUSCULOSKELETAL ULTRASOUND: PART 2

Figure 10. (a) Longitudinal view of the proximal patellar tendon in an athlete with chronic, refractory proximal patellar tendinopathy. Note marked tendon thickening, diffuse hypoechogenicity, extensive neovascularization on Doppler examination. (b) Extended field of view (ie, panoramic) imaging of the same patient, providing a more global view of the tendon. This image allows a better appreciation of the extent of tendon thickening relative to normal (denoted by arrows). Left screen ϭ distal, right screen ϭ proximal, top screen ϭ superficial, bottom screen ϭ deep (Philips iU22, Philips Medical Systems, Bothell, WA).

Patients presenting with lateral knee pain or swelling may High-frequency (Ͼ10 MHz) linear array and small footprint be evaluated for the presence of distal iliotibial band syn- linear array transducers are typically used. drome, lateral perimeniscal ganglion cysts, biceps femoris In patients presenting with posterior ankle pain, ultra- tendinopathy, or common fibular (peroneal) nerve disorders sound can be used to identify Achilles tendinopathy and [110,112-114]. The complex anatomy of this region limits differentiate between tendinosis and partial-thickness tearing the diagnostic utility of ultrasound, but when clinically indi- (Figures 2 and 11) [117]. Doppler examination may reveal cated, ultrasound can be used to guide therapeutic cyst tendon neovascularization, which is typically present in more aspiration and injection, peritendinous injection, or distal severe and symptomatic cases [118]. Associated paratenoni- iliotibial band injection [112]. tis, retrocalcaneal bursitis, and retro-Achilles (superficial In the posterior knee, ultrasound is most commonly used Achilles) bursitis may be identified as primary or contribut- to diagnose and treat popliteal cysts (Baker cysts; see Figure ing conditions [117,119]. Ultrasound-guided bursa and 4, Part 1 of this 2-part article) [11,115]. The use of ultra- paratenon injections may assist in diagnosis and manage- sound can readily detect Baker cysts, can identify cyst leakage ment of these latter conditions, although caution must be or rupture, and can guide therapeutic aspiration and injec- exercised with respect to the use of corticosteroids in the tion [115]. Ultrasonographically, Baker cysts appear as ane- vicinity of the Achilles or other ankle-foot tendons [119- choic or hypoechoic fluid collections located between the 122]. medial gastrocnemius and semimembranosus tendons that clearly communicate with the posterior tibiofemoral joint [15,115]. If the appearance is atypical or a communicative stalk cannot be identified with certainty, clinicians should search for other conditions that may produce posterior knee pain, including popliteal artery aneurysm, semimembrano- sus tendinopathy, or tumors. An MRI scan should be ob- tained as necessary. Although ultrasound may clearly identify the medial col- lateral ligament, ultrasonographic examination does not typ- ically provide additional clinically useful information. Ultra- sound may be used to document pes anserine bursitis and guide therapeutic injection of the saphenous nerve in pa- tients presenting with medial knee pain syndromes. Ultra- sound is not predictably useful for excluding the presence of Figure 11. Longitudinal view of Achilles tendon in former runner with chronic heel pain. The tendon exhibits structural intra-articular knee disorders such as cruciate ligament dis- changes of chronic tendinopathy, including moderate thick- ruption, (osteo-)chondral injury, or meniscal tear [110,116]. ening, diffuse hypoechogenicity, and neovascularization on Doppler examination. In addition, there is an irregular ane- choic region on the undersurface of the tendon, adjacent to the calcaneus, consistent with partial thickness tearing. Left Ankle-Foot screen ϭ cranial, right screen ϭ distal, top screen ϭ superficial, Virtually all tendons and nerves about the ankle and foot bottom screen ϭ deep (Philips iU22, Philips Medical Systems, Bothell, WA). region are amenable to diagnostic ultrasound examination. PM&R Vol. 1, Iss. 2, 2009 173

Recent uncontrolled case series have reported symptom- atic improvement in patients with chronic Achilles tendi- nopathy treated with ultrasound-guided sclerosis of neoves- sels or intratendinous injection of dextrose (prolotherapy) [123,124]. Further research is warranted in this regard. Ul- trasound can be used to readily identify Achilles tendon rupture and assist in triage. In selected patients, tendon apposition during ankle plantar flexion has been associated with a favorable outcome after nonoperative management [125]. Deep posterior ankle pain may be caused by flexor hallu- cis longus tendinopathy or tenosynovitis, posterior ankle joint effusion/synovitis or loose bodies, or os trigonum syn- drome, all of which may be evaluated ultrasonographically on more sophisticated machines [117]. Therapeutic tendon sheath injection or diagnostic/therapeutic os trigonum injec- Figure 12. Transverse view of the peroneus brevis (PB) and tion can be completed ultrasonographically as clinically in- longus (PL) tendons just distal to the fibular tip in a middle aged dicated [122]. runner with lateral ankle pain. Both tendons are surrounded by In the posteromedial ankle, ultrasound can be used to anechoic fluid, which is consistent with tenosynovitis. The per- readily depict the structures within the tarsal tunnel and oneus longus is markedly thickened, diffusely hypoechoic, and exhibits multiple areas of fissuring (arrows), consistent with high adjacent region [126]. Ultrasound can detect and character- grade tendinopathy with longitudinal split tears. Left screen ϭ ize posterior tibial tendon disorders as accurately as MRI for cranial, right screen ϭ caudal, top screen ϭ superficial (lat- clinical decision making [117,127]. Although uncommonly eral), bottom screen ϭ deep (medial) (Philips iU22, Philips performed, ultrasound guidance can be used to inject the Medical Systems, Bothell, WA). posterior tibial tendon sheath for diagnostic or therapeutic purposes [119,122]. The tibial nerve, medial and lateral plantar branches, and medial calcaneal branch can all be pected anterior tibialis tendon rupture [117]. Ankle joint investigated using high-frequency transducers, facilitating effusions are best visualized anteriorly in an anatomical sag- identification of compression, inflammation, or neuroma. ittal plane with the ankle in slight plantarflexion [117]. Ultrasound-guided nerve block can be performed as indi- Effusions are usually simple but may be complex and contain cated. Periarticular ganglion cysts arising from the medial a variable amount of synovitis or loose bodies [117]. Ultra- tibiotalar or subtalar joints may produce ankle pain or true sound-guided aspiration and injection can be performed; one tarsal tunnel syndrome [126]. They appear as anechoic, should take care to avoid the dorsalis pedis artery and deep multilobulated structures and can be therapeutically aspi- fibular (peroneal) nerve [20,122]. In the appropriate clinical rated using ultrasound guidance, although improvement is setting, hyperechoic debris in the anterolateral gutter would often temporary [117,122]. It is important to recognize that support a clinical diagnosis of anterolateral impingement ultrasound cannot adequately evaluate the joint structures syndrome [130]. Ultrasound-guided injection may be help- from which such a cyst may arise, and MRI would be recom- ful to accurately place the injectate into the meniscoid tissue. mended in such cases. Examination of the anterior talofibular, calcaneofibular, and The peroneal tendons account for the majority of pain posterior talofibular ligaments can be performed but is gen- syndromes in the posterolateral ankle. The use of ultrasound erally of no clinical utility because the ultrasonographic find- accurately identifies and characterizes peroneal tendon dis- ings do not alter management [131]. orders and is the test of choice for demonstrating tendon Within the foot, ultrasound is most commonly used to subluxation or dislocation (Figure 12) [117,128,129]. More confirm a clinical diagnosis of plantar fasciitis and character- recently, symptomatic peroneal tendon snapping within the ize the structural severity [119,132]. Similar to lateral epi- retrofibular groove has been identified as a source of postero- condylosis in the elbow, soft-tissue imaging is not indicated lateral ankle pain as demonstrated by ultrasound in most cases. In refractory or atypical cases, thickening [117,128,129]. Therapeutic and diagnostic peroneus longus (Ͼ4-5 mm), hypoechogenicity, and heterogeneity of the or brevis tendon sheath injections may be performed as plantar fascia would support a clinical diagnosis of plantar clinically indicated [122]. Although uncommon, sural nerve fasciitis [132-134]. The absence of structural findings war- disorders can manifest as posterolateral ankle pain. The nerve rants a search for other causes. can be easily identified just anterior to the Achilles tendon Ultrasound-guided plantar fascia injections have been re- and adjacent to the lesser saphenous vein. From this point, it ported to provide greater therapeutic efficacy compared with can be traced distally in a transverse view to the level of its nonguided injections in a single investigation, although firm bifurcation at the base of the fifth metatarsal in most cases. conclusions in this regard await further study [119,133- Tendon disorders are uncommon in the anterior ankle, 135]. Ultrasound can evaluate all the midfoot joints via a although ultrasound can readily confirm a clinically sus- dorsal approach, identifying arthritis, synovitis, and periar- 174 Smith and Finnoff MUSCULOSKELETAL ULTRASOUND: PART 2

ticular ganglia [136]. Dorsal osteophytic lipping resulting in (3) establish a method of documenting competency among neuritis or tendinopathy can be depicted with static ultra- physiatrists who choose to integrate musculoskeletal ultra- sound and confirmed with dynamic testing. Diagnostic or sound in their practices, and (4) continue to explore and therapeutic ultrasound-guided joint aspirations and injec- document cost-effective clinical applications of musculoskel- tions may be performed for these conditions as clinically etal ultrasound in physiatric practice. These actions are nec- indicated [122,136]. essary to establish physiatrists as credible users of musculo- Investigation of the plantar aspect of the midfoot remains skeletal ultrasound as viewed by our patients, our colleagues challenging because of the complex anatomy and similar in other medical specialties, and third-party payers. To our echogenicity of multiple layers of crossing tendons. The advantage, we have walked down this path before, as our primary indication for ultrasound in this region is to confirm field successfully managed the evolution of electrodiagnostic a clinically suspected plantar fibroma, appearing as a focal, and spinal injection techniques during the 20th century. The hypoechoic fusiform swelling located within the plantar fas- 21st century now presents a similar challenge with the pro- cia along its medial border [137]. A mass lesion presenting liferation of diagnostic and interventional musculoskeletal with any other appearance warrants further evaluation with ultrasound. CT or MRI. Within the forefoot, ultrasound can detect effu- Physiatrists share a long and rich history with ultrasound sions and/or synovitis in the metatarsophalangeal and inter- technology and are uniquely positioned to be leaders in the phalangeal joints, plantar plate disruptions, and Morton neu- field of musculoskeletal ultrasound. The information pre- romas in addition to intermetatarsal bursitis, facilitating sented in this 2-part article is relevant to all physiatrists as we identification of potential pain generators in patients present- witness the rapid infiltration of diagnostic and interventional ing with forefoot pain or metatarsalgia [138,139]. ultrasound into musculoskeletal medicine. More impor- Morton neuroma appears as a well defined, noncompress- tantly, the authors hope that this review will inspire inter- ible, hypoechoic mass lesion within the plantar aspect of the ested and motivated physiatrists to integrate musculoskeletal intermetatarsal space at the level of the metatarsal heads, as ultrasound into their practices and participate in the activities visualized from a plantar approach [138,139]. Continuity that will solidify the position of this powerful technology in with the interdigital nerve confirms the diagnosis but is the future. inconsistently visualized even when sophisticated machines are used [18]. Morton neuroma is often accompanied by intermetatarsal bursitis, appearing as an anechoic, compress- REFERENCES ible fluid collection dorsal to the Morton neuroma as visual- 1. Adler R, Finzel K. The complementary roles of MR imaging and ized from a plantar approach [138,139]. Therapeutic joint ultrasound of tendons. Radiol Clin N Am 2005;43:771-807. aspiration and injection, as well as Morton neuroma and 2. Ellis J, Teh J, Scott P. Ultrasound of tendons. Imaging 2002;14:223- intermetatarsal bursa injection, can be performed with the 228. use of ultrasound guidance [122,140]. 3. Martinoli C, Bianchi S, Derchi L. Tendon and nerve sonography. Despite the broad range of clinical applications in the Radiol Clin North Am 1999;37:691-711. 4. Khoury V, Cardinal E, Bureau N. Musculoskeletal sonography: a ankle and foot, ultrasound cannot adequately evaluate the dynamic tool for usual and unusual disorders. AJR Am J Roentgenol intra-articular structures of the hindfoot or midfoot joints 2007;188:W63-W73. and has limited capability to image many deeply located 5. Ellis J, McNally E, Scott P. Ultrasound of peripheral nerves. Imaging structures in the plantar midfoot region. Radiographs are 2002;14:217-222. recommended to supplement any ultrasound examination 6. Walker F. Imaging nerve and muscle with ultrasound. Adv Clin Neurophysiol 2004;57:243-254. and, when clinically indicated, advanced diagnostic imaging 7. Bodner G, Harpf C, Meirer R, Gardetto A, Kovacs P, Gruber H. should be pursued in the form of MRI, CT, or bone scan. Ultrasonographic appearance of supinator syndrome. J Ultrasound Med 2002;21:1289-1293. 8. Ebrahim F, De Maeseneer M, Jager T, Marcelis S, Jamadar DA, Jacob- THE FUTURE OF MUSCULOSKELETAL son JA. US diagnosis of UCL tears of the thumb and Stener lesions: ULTRASOUND IN PHYSIATRY technique, pattern-based approach, and differential diagnosis. Radio- graphics 2006;26:1007-1020. The integration of diagnostic and interventional musculo- 9. Nazarian L, McShane J, Ciccotti M, et al. Dynamic US of the anterior skeletal ultrasound into clinical practice represents a signifi- band of the ulnar collateral ligament of the elbow in asymptomatic cant development in the field of physiatry. Having success- major league baseball pitchers. Radiology 2003;227:149-154. fully prescribed therapeutic ultrasound for more than 50 10. Campbell S, Adler R, Sofka C. Ultrasound of muscle abnormalities. Ultrasound Q 2005;21:87-94. years, physiatrists now have the opportunity to use muscu- 11. Smith J, Finnoff JT. Diagnostic and Interventional Musculoskeletal loskeletal ultrasound as a clinical decision-making tool for Ultrasound: Part 1. Fundamentals. PM&R 2009;1:64-75. the benefit of their patients. With this opportunity comes the 12. O’Conner P, Grainger A. Ultrasound imaging of joint disease. Imaging challenge of creating the future of musculoskeletal ultra- 2002;14:188-201. sound in physiatry. To meet this challenge, physiatrists must 13. Raza K, Lee C, Pilling D, et al. Ultrasound guidance allows accurate needle placement and aspiration from small joints in patients with (1) develop an infrastructure to provide musculoskeletal early inflammatory arthritis. Rheumatology 2003;42:976-979. ultrasound education, (2) implement practice guidelines to 14. Hoving J, Buchbinder R, Hall S, et al. A comparison of magnetic ensure the appropriate application of ultrasound technology, resonance imaging, sonography, and radiography of the hand in PM&R Vol. 1, Iss. 2, 2009 175

patients with early rheumatoid arthritis. J Rheumatol 2004;31: 38. Bachman G, Melzer C, Heinrichs C, et al. Diagnosis of rotator cuff 663-675. lesions: comparisons of US and MRI on 38 joint specimens. Eur Radiol 15. de Miguel Mendieta E, Ibanez T, Jaeger J. Clinical and ultrasono- 1997;7:192-197. graphic findings related to knee pain in osteoarthritis. Osteoarthritis 39. Cullen D, Breidahl W, Janes G. Diagnostic accuracy of shoulder Cartilage 2006;14:540-544. ultrasound performed by a single operator. Australas Radiol 2007;51: 16. Bradley M, Bhamra M, Robson M. Ultrasound guided aspiration of 226-229. symptomatic supraspinatus calcifications. Br J Radiol 1995;68:716- 40. van Holsbeeck M, Strouse P. Sonography of the shoulder: evaluation 719. of the subacromial-subdeltoid bursa. AJR Am J Roentgenol 1993;160: 17. Jamadar D, Jacobson J, Hayes C. Sonographic evaluation of the 561-564. median nerve at the wrist. J Ultrasound Med 2001;20:1011-1014. 41. Bureau N, Beuchamp M, Cardinal E, Brassard P. Dynamic sonography 18. Jacobson J, Jebson P, Jeffers A, Fessell D, Hayes C. Ulnar nerve evaluation of shoulder impingement syndrome. AJR Am J Roentgenol dislocation and snapping triceps syndrome: diagnosis with dynamic 2006;187:216-220. sonography. Radiology 2001;220:601-605. 42. Sheridan M, Hanaffin J. Upper extremity: emphasis on frozen shoul- 19. De Maeseneer M, Jacobson J, Jaovisidha S, et al. Elbow effusions: der. Orthop Clin North Am 2006;37:531-539. distribution of joint fluid with flexion and extension and imaging 43. Lee J, Sykes C, Saifuddin A, Connell D. Adhesive capsulitis: sono- implications. Invest Radiol 1998;33:117-125. graphic changes in the rotator cuff interval with arthroscopic correla- 20. Fessell D, Jacobson J, Habra G, et al. Using sonography to reveal and tion. Skeletal Radiol 2005;34:522-527. aspirate joint effusions. AJR Am J Roentgenol 2000;174:1353-1362. 44. Adler R, Allen A. Percutaneous ultrasound guided injections in the 21. Bianchi S, Abdelwahab I, Zwass A, Giacomello P. Ultrasonographic shoulder. Tech Shoulder Elbow Surg 2004;5:122-133. evaluation of wrist ganglia. Skeletal Radiol 1994;23:201-203. 45. Adler R, Sofka C. Percutaneous ultrasound guided injections in the 22. Briedahl W, Adler R. Ultrasound-guided injection of ganglia with musculoskeletal system. Ultrasound Q 2003;19:3-12. corticosteroids. Skeletal Radiol 1996;25:635-638. 46. Eustace J, Brophy D, Gibney R, Bresnihan B, FitzGerald O. Compar- 23. Middleton W, Reinus W, Totty W, Melson G, Murphy W. Ultrasono- ison of the accuracy of steroid placement with clinical outcome in graphic evaluation of the rotator cuff and biceps tendon. J Bone Joint patients with shoulder symptoms. Ann Rheum Dis 1997;56:59-63. Surg 1986;68:440-450. 47. Naredo E, Cabero F, Beneyto P, et al. A randomized comparative 24. Churchill R, Fehringer E, Dubinsky T, et al. Rotator cuff ultrasonog- study of short term response to blind injection versus sonographic raphy: diagnostic capabilities. J Am Acad Orthop Surg 2004;12:6-11. guided injection of local corticosteroids in patients with painful shoul- der. Arthritis J Rheumatol 2004;31:308-314. 25. Crass J, Craig E, Feinberg S. Ultrasonography of rotator cuff tears: a 48. Chen M, Lew H, Hsu T, et al. Ultrasound guided shoulder injections review of 500 diagnostic studies. J Clin Ultrasound 1988;16:313-327. in the treatment of subacromial bursitis. Am J Phys Med 2006;85:31- 26. Bretzke C, Bretzke C, Crass J, Craig E, Feinberg S. Ultrasonography of 35. the rotator cuff. Normal and pathologic anatomy. Invest Radiol 1985; 49. Farin P, Jaroma H. Sonographic findings of rotator cuff calcifications. 20:311-315. J Ultrasound Med 1995;14:7-14. 27. van Holsbeeck M, Kolowich P, Eyler W, et al. US depiction of partial 50. Aina R, Cardinal E, Bureau N, Aubin B, Brassard P. Calcific shoulder thickness tear of the rotator cuff. Radiology 1995;197:443-446. tendinitis: treatment with modified US guided fine needle technique. 28. Rutten M, Jager G, Blickman J. US of the rotator cuff: pitfalls, limita- Radiology 2001;221:455-461. tions, and artifacts. Radiographics 2006;26:589-604. 51. Chiou H, Chou Y, Wu J, et al. The role of high resolution ultrasonog- 29. Teefey S, Middleton W, Payne W, et al. Detection and measurement of raphy in management of calcific tendinitis of the rotator cuff. Ultra- rotator cuff tears with sonography: analysis of diagnostic errors. AJR sound Med Biol 2001;27:735-743. Am J Roentgenol 2005;184:1768-1773. 52. Chiou H, Chou Y, Wu J, Hsu CC, Huang DY, Chang CY. Evaluation of 30. Teefey S, Hasan S, Middleton W, Patel M, Wright RW, Yamaguchi K. calcific rotator tendinitis of the rotator cuff: role of color Doppler Ultrasonography of the rotator cuff. A comparison of ultrasono- ultrasonography. J Ultrasound Med 2002;21:289-295. graphic and arthroscopic findings in one hundred consecutive cases. 53. delCura J, Torre I, Zabala R, Legórburu A. Sonographically guided J Bone Joint Surg 2000;82A:498-504. percutaneous needle lavage in calcific tendinitis of the shoulder: 31. Ptasznik R, Hennessy O. Abnormalities of the biceps tendon of the short- and long-term results. AJR Am J Roentgenol 2007;189:W128- shoulder: sonographic findings. AJR Am J Roentgenol 1995;164:409- W134. 414. 54. Hashimoto B, Hayes A, Ager J. Sonographic diagnosis and treatment 32. Farin P, Jaroma H, Harju A, Soimakallio S. Medial displacement of the of ganglion cysts causing suprascapular nerve entrapment. J Ultra- biceps brachii tendon: evaluation with dynamic sonography during sound Med 1994;13:671-674. maximal shoulder external rotation. Radiology 1995;195:845-848. 55. Prickett W, Teefey S, Galatz L, Calfee RP, Middleton WD, Yamaguchi 33. Jacobson J, Lancaster S, Prasad A, van Holsbeek M, Craig J, Kolowich K. Accuracy of ultrasound imaging of the rotator cuff in shoulders that P. Full thickness and partial thickness supraspinatus tears: value of US are painful postoperatively. J Bone Joint Surg 2003;85A:1084-1089. sings in diagnosis. Radiology 2004;230:234-242. 56. Connell D, Burke F, Coombes P, et al. Sonographic examination of 34. Middleton W, Payne W, Teefey S, et al. Sonography and MRI of the lateral epicondylitis. AJR Am J Roentgenol 2001;176:767-773. shoulder: comparison of patient satisfaction. AJR Am J Roentgenol 57. Levin D, Nazarian L, Miller T, et al. Lateral epicondylitis of the elbow: 2004;183:1449-1452. US findings. Radiology 2005;237:230-234. 35. Iannotti J, Ciccone J, Buss D, et al. Accuracy of office-based ultra- 58. Nimgade A, Sullivan M, Goldman R. Physiotherapy, steroid injec- sonography of the shoulder for the diagnosis of rotator cuff tears. tions, or rest for lateral epicondylitis? What the evidence suggests. J Bone Joint Surg 2005;87A:1305-1311. Pain Practice 2007;5:203-215. 36. Teefey S, Rubin D, Middleton W, Hildebolt C, Leibold R, Yamaguchi 59. Smidt N, Assendelft W, van der Windt D. Corticosteroid injections for K. Detection and quantification of rotator cuff tears. Comparison of lateral epicondylitis: a systematic review. Pain 2002;96:23-40. ultrasonographic, magnetic resonance imaging, and arthroscopic 60. Connell D, Ali K, Ahmad M, Lambert S, Corbett S, Curtis M. Ultra- findings in seventy-one consecutive cases. J Bone Joint Surg 2004; sound guided autologous blood injection for tennis elbow. Radiology 86A:708-716. 2006: 35:371-377. 37. Swen W, Jacobs JW, Algra P, et al. Sonography and magnetic reso- 61. McShane J, Nazarian L, Harwood M. Sonographically guided percu- nance imaging are equivalent for the assessment of rotator cuff tears. taneous needle tenotomy for treatment of common extensor tendino- Arthritis Rheum 1999;42:2231-2238. sis in the elbow. J Ultrasound Med 2006;25:1281-1289. 176 Smith and Finnoff MUSCULOSKELETAL ULTRASOUND: PART 2

62. Mishra A, Pavelko T. Treatment of chronic elbow tendinosis with 88. Godey S, Bhatti W, Watson J. A technique for accurate and safe buffered platelet rich plasma. Am J Sports Med 2006;34:1174-1178. injection of steroid in trigger digits using ultrasound guidance. Acta 63. Zeisig E, Ohberg L, Alfredson H. Sclerosing polidocanol injections in Orthop Belg 2006;72:633-634. chronic painful tennis elbow—promising results in a pilot study. 89. Balint P, Kane D, Hunter J, McInnes IB, Field M, Sturrock RD. Knee Surg Sports Traumatol Arthrosc 2006;14:1218-1224. Ultrasound guided versus conventional joint and soft tissue fluid 64. Edwards S, Calandruccio J. Autologous blood injections for refractor aspiration in rheumatology practice: a pilot study. J Rheumatol 2002; lateral epicondylitis. J Hand Surg 2003;28A:272-278. 29:2209-2213. 65. Suresh S, Ali K, Jones H, Connell DA. Medial epicondylitis: is ultra- 90. Wang Y, Luo Y. The value of sonography in diagnosing giant cell sound guided autologous blood injection an effective treatment? Br J tumors of the tendon sheath. J Ultrasound Med 2007;26:1333-1340. Sports Med 2006;40:935-939. 91. Koski J, Anttila P, Isomaki H. Ultrasonography of the adult hip joint. 66. Park G, Lee S, Lee M. Diagnostic value of ultrasonography for clinical Scand J Rheumatol 1989;18:113-117. medial epicondylitis. Arch Phys Med Rehabil 2008;89:738-742. 92. Smith J, Hurdle M-F. Office based ultrasound guided intra-articular 67. Park G, Kim J, Lee S. The ultrasonographic and electrodiagnostic hip injection: technique for physiatric practice. Arch Phys Med Reha- findings of ulnar neuropathy at the elbow. Arch Phys Med Rehabil bil 2006;87:296-298. 2004;85:1000-1005. 93. Sofka C, Saboeiro G, Adler R. Ultrasound-guided adult hip injections. 68. Beekman R, Schoemaker M, Van Der Plas J, et al. Diagnostic value of J Vasc Interv Radiol 2005;16:1121-1123. high resolution ultrasonography in ulnar neuropathy at the elbow. 94. Moss S, Schweitzer M, Jacobson J, et al. Hip joint fluid: detection and Neurology 2004;62:767-773. distribution at MR imaging and US with cadaveric correlation. Radi- 69. Kim B-J, Date E, Lee S-H, et al. Distance measure error induced by ology 1998;208:43-48. displacement of the ulnar nerve when the elbow is flexed. Arch Phys 95. Flanum M, Keene J, Blankenbaker D, Desmet A. Arthroscopic treat- Med Rehabil 2005;86:809-812. ment of the painful “internal” snapping hip: results of a new endo- 70. Jacobson J, Propeck T, Jamadar D, Jebson PJ, Hayes CW. US of the scopic technique and imaging protocol. Am J Sports Med 2007;35: anterior bundle of the ulnar collateral ligament: findings in five 770-779. cadaver elbows with MR arthrographic and anatomic comparison - 96. Blankenbaker D, Desmet A, Keene J. Sonography of the iliopsoas initial observations. Radiology 2003;227:561-566. tendon and injection of the iliopsoas bursa for diagnosis and manage- 71. Sasaki J, Takahara T, Kashiwa H, et al. Ultrasonographic assessment of ment of the pain snapping hip. Skeletal Radiol 2007;35:565-571. the ulnar collateral ligament and medial elbow laxity in college base- 97. Adler R, Buly R, Ambrose R, Sculco T. Diagnostic and therapeutic use ball players. J Bone Joint Surg 2002;84A:525-531. of sonography-guided iliopsoas peritendinous injections. AJR Am J 72. Lee J, Healy J. Normal sonographic anatomy of the wrist and hand. Roentgenol 2005;185:940-943. Radiographics 2005;25:1577-1590. 98. Rezig R, Copercini M, Montet X, Martinoli C, Bianchi S. Ultrasound 73. Boutry N, Titecat M, Demondion X, Glaude E, Fontaine C, Cotten A. diagnosis of anterior iliopsoas impingement in total hip replacement. High-frequency ultrasonographic examination of the finger pulley Skeletal Radiol 2004;33:112-116. system. J Ultrasound Med 2005;24:1333-1339. 99. Hurdle M-F, Weingarten T, Crisostomo R, Psimos C, Smith J. Ultra- 74. Martinoli C, Bianchi S, Nebiolo M, et al. Sonographic evaluation of sound-guided blockade of the lateral femoral cutaneous nerve: tech- digital annular pulley tears. Skeletal Radiol 2000;29:387-391. nical description and review of 10 cases. Arch Phys Med Rehabil 75. Jacob D, Cohen M, Bianchi S. Ultrasound imaging of non-traumatic 2007;88:1362-1364. lesions of wrist and hand tendons. Eur Radiol 2007;17:2237-2247. 100. Connell D, Bass C, Sykes C, Young D, Edwards E. Sonographic 76. Teh J. Applications of Doppler imaging in the musculoskeletal system. evaluation of gluteus medius and minimus tendinopathy. Eur Radiol Curr Probl Diag Radiol 2006;35:22-34. 2003;13:1339-1347. 77. Inoue G, Tamura Y. Recurrent dislocation of the extensor carpi ulnaris 101. Kim S, Shin M, Kim K, et al. Imaging features of ischial bursitis with tendon. Br J Sports Med 1998;32:172-174. an emphasis on ultrasonography. Skeletal Radiol 2002;31:631-636. 78. Zingas C, Failla J, Van Holsbeeck M. Injection accuracy and clinical 102. Pekkafali M, Kiralp M, Basekim C, et al. Sacroiliac joint injections relief of de Quervain’s tendinitis. J Hand Surg 1998;23A:89-96. performed with sonographic guidance. J Ultrasound Med 2003;22: 79. Giovagnorio F, Andreoli C, De Cicco M. Ultrasonographic evaluation 553-559. of DeQuervain’s disease. J Ultrasound Med 1997;16:685-689. 103. Smith J, Hurdle M-F, Locketz A, Wisniewski SJ. Ultrasound guided 80. Mahakkanukrauh P, Mahakkanukrauh C. Incidence of a septum in piriformis injection: technique description and verification. Arch the first dorsal compartment and its effects on therapy of de Quer- Phys Med Rehabil 2006;12:664-667. vain’s disease. Clin Anat 2000;13:195-198. 104. Lee J, Robinson G, Finlay K, Friedman L, Winemaker M. Evaluation 81. Bayrak I, Bayrak A, Tilki H, Nural MS, Sunter T. Ultrasonography in of the quadriceps tendon, patellar tendon, and collateral ligaments carpal tunnel syndrome: comparison with electrophysiological stage after total knee arthroplasty: appearances in the early postoperative and motor unit estimate. Muscle Nerve 2007;35:344-348. period. Can Assoc Radiol J 2006;57:291-298. 82. Wiesler E, Chloros G, Cartwright M, et al. The use of diagnostic 105. Bianchi S, Zwass A, Abdelwahab I, Banderali A. Diagnosis of tears of ultrasound in carpal tunnel syndrome. J Hand Surg 2006;31A:726- the quadriceps tendon of the knee: value of sonography. AJR Am J 732. Roentgenol 1994;162:1137-1140. 83. Sernik R, Abicalaf C, Pimentel B, Braga-Baiak A, Braga L, Cerri GG. 106. Warden S, Zoltan S, Malara F, et al. Comparative accuracy of magnetic Ultrasound features of carpal tunnel syndrome: a prospective case- resonance imaging and ultrasonography in confirming clinically di- control study. Skeletal Radiol 2008;37:49-53. agnosed patellar tendinopathy. Am J Sports Med 2007;35:427-438. 84. El Miedany Y, Aty S, Ashour S. Ultrasonography versus nerve conduc- 107. Cook J, Malliaras P, De Luca J, Ptasznik R, Morris ME, Goldie P. tion study in patients with carpal tunnel syndrome: substantive or Neovascularization and pain in abnormal patellar tendons of active complementary tests? Rheumatol 2004;43:887-895. jumping athletes. Clin J Sports Med 2004;14:296-299. 85. Propeck T, Quinn T, Jacobson J, Paulino AF, Habra G, Darian VB. 108. Hoksrud A, Ohberg L, Alfredson H, Bahr R. Ultrasound guided Sonography and MR imaging of bifid median nerve with anatomic and sclerosis of neovessels in chronic painful patellar tendinopathy: a histologic correlation. AJR Am J Roentgenol 2000;175:1721-1725. randomized controlled trial. Am J Sports Med 2006;34:1738-1746. 86. Grassi W, Farina A, Filipucci E, et al. Intralesional therapy in carpal 109. James S, Pocock C, Robertson C, Walter J, Bell J, Connell D. Ultra- tunnel syndrome: a sonographic guided approach. Clin Exp Rheuma- sound guided dry needling and autologous blood injection for patel- tol 2002;20:73-76. lar tendinosis. Br J Sports Med 2007;41:518-522. 87. O’Callaghan B, Kohut G, Hoogewoud H. Gamekeeper’s thumb: iden- 110. Court-Payen M. Sonography of the knee: intra-articular pathology. tification of the Stener lesion with US. Radiology 1994;192:477-480. J Clin Ultrasound 2004;32:481-490. PM&R Vol. 1, Iss. 2, 2009 177

111. Qvistgaard E, Kristoffersen H, Terslev L, Danneskiold-Samsøe B, 125. Kotnis R, David S, Handley R, Willett K, Ostlere S. Dynamic ultra- Torp-Pedersen S, Bliddal H. Guidance by ultrasound of intra-articular sound as a selection tool for reducing Achilles reruptures. Am J Sports injections in the knee and hip joints. Ostoarthritis Cartilage 2001;9: Med 2006;34:1395-1400. 512-517. 126. Nagaoka M, Matsuzaki H. Ultrasonography in tarsal tunnel syn- 112. MacMahon P, Brennan D, Duke D, Forde S, Eustace SJ. Ultrasound drome. J Ultrasound Med 2005;24:1035-1040. guided percutaneous drainage of meniscal cysts: preliminary clinical 127. Nallamshetty L, Nazarian L, Schweitzer M, et al. Evaluation of poste- experience. Clin Radiol 2007;62:683-687. rior tibial pathology: comparison of sonography and MR imaging. 113. Goh L-A, Chhem R, Wang S-C, Chee T. Iliotibial band thickness: Skeletal Radiol 2005;34:375-380. sonographic measurements in asymptomatic volunteers. J Clinical 128. Grant T, Kelikian A, Jereb S, McCarthy RJ. Ultrasound diagnosis of Ultrasound 2003;31:239-244. peroneal tendon tears. J Bone Joint Surg 2005;87A:1788-1794. 114. Visser L. High resolution sonography of the common peroneal nerve: 129. Neustadter J, Raikin S, Nazarian L. Dynamic sonographic evaluation detection of intraneural ganglia. Neurology 2006;67:1473-1475. of peroneal tendon subluxation. AJR Am J Roentgenol 2004;183:985- 115. Ward E, Jacobson J, Fessell D, Hayes CW, van Holsbeeck M. Sono- 988. graphic detection of Baker’s cysts: comparison with MRI imaging. AJR 130. McCarthy C, Wilson D, Coltman T. Anterolateral ankle impingement: Am J Roentgenol 2001;176:373-378. findings and diagnostic accuracy with ultrasound imaging. Skeletal 116. Azzoni R, Cabitza P. Is there a role for sonography in the diagnosis of Radiol 2008;37:209-216. tears of the knee menisci? J Clin Ultrasound 2002;30:472-476. 131. Milz P, Milz S, Putz R, Reiser M. 13 MHz high-frequency sonography 117. Fessell D, Vanderschueren G, Jacobson J, et al. US of the ankle: of the lateral ankle joint ligaments and the tibiofibular syndesmosis in technique, anatomy and diagnosis of pathological conditions. Radio- anatomic specimens. J Ultrasound Med 1996;15:277-284. graphics 1998;18:325-340. 132. Sabir N, Demirlenk S, Yagci B, Karabulut N, Cubukcu S. Clinical 118. Richards P, Win T, Jones P. The distribution of microvascular re- utility of sonography in diagnosing plantar fasciitis. J Ultrasound Med sponse in Achilles tendinopathy assessed by colour and power Dopp- 2005;24:1041-1048. ler. Skeletal Radiol 2005;34:336-342. 133. Kamel M, Kotob H. High frequency ultrasonographic findings in 119. Cunnane G, Brophy D, Gibney R, FitzGerald O. Diagnosis and plantar fasciitis and assessment of local steroid injection. J Rheumatol treatment of heel pain in chronic inflammatory arthritis using ultra- 2000;27:2139-2141. sound. Semin Arthritis Rheum 1996;25:383-389. 134. Kane D, Greany T, Shanahan M, et al. The role of ultrasound in the 120. Gill S, Gelbke M, Mattson S, Anderson MW, Hurwitz SR. Fluoroscop- diagnosis and management of idiopathic plantar fasciitis. Rheumatol- ically guided low-volume peritendinous corticosteroid injection for ogy 2001;40:1002-1008. Achilles tendinopathy. J Bone Joint Surg 2004;86A:802-806. 135. Tsai W-C, Hsu C-C, Chen C, Chen MJ, Yu TY, Chen YJ. Plantar 121. Fredberg U, Bolvig I, Pfeiffer-Jensen M, Clemmensen D, Jakobsen fasciitis treated with local steroid injection: comparison between BW, Stengaard-Pedersen K.Ultrasonography as a tool for diagnosis, sonographic and palpation guidance. J Clin Ultrasound 2006;34: guidance of local steroid injection and, together with pressure algom- 12-6. etry, monitoring of the treatment of athletes with chronic jumper’s 136. D’Agostino M-A, Ayral X, Baron G, Ravaud P, Breban M, Dougados M. knee and Achille’s tendinitis: a randomized, double-blind, placebo- Impact of ultrasound imaging on local corticosteroid injections of controlled study. Scand J Rheum 2004;33:94-101. symptomatic ankle, hind-, and mid-foot in chronic inflammatory 122. Sofka C, Adler R. Ultrasound guided interventions in the foot and diseases. Arthritis Rheum 2005;53:284-292. ankle. Semin Musculoskelet Radiol 2002;6:163-168. 137. Griffith J, Wong T, Wong S, Wong MW, Metreweli C. Sonography of 123. Lind B, Ohberg L, Alfredson H. Sclerosing polidocanol injections in plantar fibromatosis. AJR Am J Roentgenol 2002;179:1167-1172. mid-portion Achilles tendinosis: remaining good clinical results and 138. Quinn T, Jacobson J, Craig J, van Holsbeeck MT. Sonography of decreased tendon thickness at 2-year follow-up. Knee Surg Sports Morton’s neuroma. AJR Am J Roentgenol 2000;174:1723-1728. Traumatol Arthrosc 2006;14:1327-1332. 139. Gregg J, Marks P. Metatarsalgia: an ultrasound perspective. Australa- 124. Maxwell N, Ryan M, Taunton J, Gillies JH, Wong AD. Sonographi- sian Radiol 2007;51:493-499. cally guided intratendinous injection of hyperosmolar dextrose to 140. Hughes R, Ali K, Jones H, Kendall S, Connell DA. Treatment of treat chronic tendinosis of the Achilles tendon: a pilot study. AJR Am J Morton’s neuroma with alcohol injection under sonographic guid- Roentgenol 2007;189:W216-W220. ance. AJR Am J Roentgenol 2007;188:1535-1539.