Foot and ankle sonography

Normal and Injured Ankle Ligaments on Ultrasonography With Magnetic Resonance Imaging Correlation

Ultrasonography (US) has been increasingly used in the evaluation of ankle ligamentous injuries given its advantages as a dynamic, efficient, noninvasive, and cost-effective imaging method. Understanding the anatomy of the ankle ligaments is critical for correct diagnosis and treatment. This pictorial essay describes and illustrates the US scanning technique and potential pitfalls in evaluating the ankle ligaments and also provides an overview of the US appearance of normal and injured ankle ligaments with magnetic resonance imaging correlation. Highlighted structures include the lateral complex, medial/deltoid complex, spring (calcaneonavicular) ligament complex, and syndesmosis.

Imaging Techniques and Indications

This article evaluates the utility of radiography, ultrasonography, and MRI in diagnosing Achilles tendon injuries. It reviews the pertinent anatomy of the Achilles and associated structures, and signs of disorder with each imaging technique. The economics of use ultrasonography and MRI are discussed. They should serve as complementary diagnostic tools, with ultrasonography the first choice because of its ease of use, ability to view dynamic function, and cost. However, clinical examination is often best for diagnosis; MRI and ultrasonography often should be considered only when the diagnosis is confounding or a patient does not respond to recommended conservative care.

Sonographic Evaluation of Fibromatosis (Aggressive Type) Using Color Doppler Interrogation

Fibromatosis refers to formation of a fibrous or tumor-like nodule or nodular swelling arising from fascia or connective tissue. The behavior of fibromatosis ranges from a self-limiting benign condition to the aggressive or recurrent type. No articles at this time have reported cases of aggressive fibromatosis emphasizing the use of color Doppler sonography for preoperative planning. The authors report two cases of aggressive fibromatosis interrogated with color Doppler imaging and magnetic resonance imaging that correlate with surgical findings.

Lower limb complications of diabetes mellitus: a comprehensive review with clinicopathological insights from a dedicated high-risk diabetic foot multidisciplinary team

Diabetic complications in the lower extremity are associated with significant morbidity and mortality, and impact heavily upon the public health system. Early and accurate recognition of these abnormalities is crucial, enabling the early initiation of treatments and thus avoiding or minimizing deformity, dysfunction and amputation. Following careful clinical assessment, radiological imaging is central to the diagnostic and follow-up process. We aim to provide a comprehensive review of diabetic lower limb complications designed to assist radiologists and to contribute to better outcomes for these patients.

Pictorial essay: USG of lumps and bumps of the foot and ankle

USG is a cost-effective and dynamic way to interrogate superficial lumps and bumps. We present a pictorial review of the USG findings in various “lumps and bumps” of the foot and ankle.

Musculoskeletal sonography of the normal foot

Traumatic, degenerative and rheumatological injuries of the foot are common and can be managed by an ever increasing number of treatments and surgical interventions. High-frequency sonography is inexpensive, portable and is unique in allowing true dynamic assessment of the ligamentous, muscular and tendinous structures. The ultrasound technique demonstrates a steep learning curve and requires detailed knowledge of the foot anatomy. Ultrasound assessment plays an important role in the diagnosis and management of injuries of these structures by guiding rehabilitation and surgical intervention without delay. However, intimate knowledge of the ultrasound appearances of the foot anatomy and normal variants is paramount to correctly identify pathological conditions. We describe the normal sonographic appearances of the foot musculoskeletal structures with MR correlation including joints and their ligaments, dorsal and plantar surfaces of the foot, and the arches of the foot and their supporting structures.

The operational characteristics of ultrasonography for the diagnosis of plantar intermetatarsal neuroma

A retrospective study was carried out on 48 patients to correlate preoperative ultrasound findings with postoperative histopathology findings and to assess the sensitivity, specificity, positive predictive values, and negative predictive values of ultrasound in the diagnosis of Morton's interdigital neuroma. All case sheets of 48 patients operated on between 1997 and 2005 were reviewed in the medical record section of Ninewells Hospital, Dundee, Scotland, so that preoperative ultrasound reports were compared with the postoperative histopathological reports. A statistical analysis of the results was performed. Ultrasonography showed 43 true-positive cases, 1 true-negative case, and 4 false-negative cases out of 48 cases. Histopathology showed 47 true-positive cases and 1 true-negative case; statistical analysis performed on the results showed a sensitivity of 91.48%, a specificity of 100%, and 100% positive and 20% negative predictive values, respectively. In our analysis, the probability that ultrasound will confirm the presence of plantar intermetatarsal neuroma is 91.67%.

Percutaneous ultrasound-guided injections in the musculoskeletal system

Ultrasound guidance is an accurate method for the delivery of therapeutic injections in the musculoskeletal system. The visualization of the needle in real time allows for reliable placement of the needle tip in the tendon sheath, bursa, or joint of interest. Both superficial and deep articulations and tendon sheaths can be targeted for diagnostic or therapeutic interventions. In addition, intratendinous calcifications, the plantar fascia, and interdigital (Morton's) neuromas can also be visualized and injected directly under real-time guidance. Performing percutaneous interventions with ultrasound ensures accurate needle tip placement and helps direct the needle away from other regional soft-tissue structures such as nearby neurovascular bundles.

Regional musculoskeletal conditions: foot and ankle disorders

Foot pain is very common, especially in women, owing to inappropriate footwear. Overuse, repetitive strain and minor, easily forgettable injuries may result in chronic foot and ankle pain. Rheumatoid arthritis, spondyloarthropathies and gout frequently affect the foot, often as a first presentation. Charcot's joints and foot infections are not rare in diabetes. The rheumatologist should be familiar with foot disorders, either localized or as manifestations of generalized disease. History taking, physical examination, identification of the source of pain by intra-articularly given local anaesthetics and imaging methods should be used to reveal the underlying disorder. Correct diagnosis and efficient therapy-including local steroid injections, physiotherapy, orthoses, surgery-are necessary not only for treatment but also for preventing biomechanical chain reactions. This chapter gives an overview of the epidemiology, diagnosis and treatment of foot pain and foot disorders caused by both local and generalized diseases.

The value of ultrasound in sports medicine

Musculoskeletal ultrasound is increasingly being used in the evaluation and treatment of sports-related injuries. This technique is widely available, rapid, and has a high patient acceptance. Its multiplanar capability and dynamic real-time imaging can be correlated with clinical symptoms and compared to contralateral asymptomatic structures.

Introduction to ultrasonography of ankle tendons

Medical technology is constantly improving, giving the physician more options to aid in diagnosis and treatment of ailments. Ultrasound (US) technology is one area that has made great improvements. Increased resolution and availability are two reasons why ultrasound is now being used to image the musculoskeletal system. This article discusses ultrasound technology, instrumentation, basic exam of ankle tendons, and some of the recent uses. The objective is to make the physician aware of this modality and possibly add it to their diagnostic armementarian.

Ultrasonography for the evaluation of forearm interosseous membrane disruption in a cadaver model

Recognition of interosseous membrane disruption associated with radial head injury and Essex-Lopresti injury is important, especially if radial head excision is contemplated. Because a widely accepted method to diagnose interosseous membrane disruption does not exist, we evaluated the accuracy of ultrasonography to diagnose this injury in a cadaver model. Nine pairs of cadaver forearms were randomized into 2 groups. The central third of the interosseous membrane of forearms of group 1 was cut, whereas it was visualized but not cut in group 2. A dynamic ultrasound examination was performed to determine interosseous membrane integrity, and static images were made. The static images were evaluated by 2 other radiologists and interpretations were recorded. One radiologist incorrectly interpreted 1 pair of forearms; the other 2 radiologists were 100% accurate. The accuracy of ultrasonography in detecting interosseous injuries was 96% with our methods.

Ultrasound of the ankle

Because of their size and superficial location the ankle tendons can be well evaluated with ultrasound (US). The excellent definition of the modern high frequency probes allows us to consider US the technique of first choice in their assessment. Basic US appearances correlate well with the MRI findings. Since US can diagnose most tendon disorders including tendinopathies, tears, dislocations and enthesopathies MRI is less often utilized. US can easily depict the main ankle ligaments. The basic US appearance of ligament tears is well known. US can be considered an inexpensive and accurate technique in the evaluation of ankle sprains.

MRI of the foot and ankle: prevalence and distribution of occult and palpable ganglia

The purpose of this study was to evaluate the prevalence and anatomic distribution of occult and palpable ganglia of the foot and ankle as seen by MRI. Within a 7-year period MRI of the ankle was performed on 2813 patients, and MRI of the foot on 2277 patients using a 1.5T magnet. In all, 167 ganglia in 155 patients were detected. MR images of these patients were reviewed retrospectively by two observers with regard to prevalence, imaging characteristics, and exact anatomic location of ganglia. Clinical findings and (when available) surgical reports were also reviewed. One hundred fifty-seven ganglia in 145 patients were present on MR images of the ankle, and 10 ganglia in 10 patients on MR images of the foot, resulting in a prevalence of 5.6% (157/2813) in the ankle, and a prevalence of 0.4% (10/2277) in the foot. The most common location was the tarsal sinus or tarsal canal (57/167 ganglia [34.1%]). However, only four of these (7%) were palpable as a soft-tissue mass. The second most common location was around the Lisfranc joint (23/167 [13.8%]), of which 11/23 [47.8%] were clinically palpable. Palpable ganglia were statistically larger in size than occult ganglia measured in any of three diameters (P = 0.01-0.002). In addition, ganglia of the foot and ankle represented 42% of all clinically suspected soft-tissue masses. Ganglia in the foot and ankle are an infrequent finding on routine MRI of the foot and ankle. When they occur, these ganglia are most frequently located in the tarsal sinus and tarsal canal, where they are occult to clinical palpation. If ganglia are clinically palpable, they are most commonly located around the Lisfranc joint. In addition, palpable ganglia are larger than occult ganglia.

Coded Harmonic Imaging in the Evaluation of Posterior Tibial Tendon Injury

Coded harmonic imaging has excellent contrast resolution and is very advantageous in diagnosing musculoskeletal pathology. In this article, the authors present a case of a posterior tibial tendon tear using coded harmonics to best define the extent and type of injury for better treatment.

Musculoskeletal ultrasound: an update

In summary, musculoskeletal sonography is a rapidly growing field of interest around the world. Outside of America, it is often the first and definitive imaging modality fordisorders of the musculoskeletal system. Musculoskeletal ultrasound offers rapid, inexpensive, real-time examination of the structures of interest with easy comparison to the contralateral side. Principles of one area of musculoskeletal sonography easily generalize to other areas.

US of nerve entrapments in osteofibrous tunnels of the upper and lower limbs

The diagnosis of nerve entrapment at osteofibrous tunnels relies primarily on clinical and electrodiagnostic findings. Recently, the refinement of high-frequency broadband transducers with a range of 5-15 MHz, sophisticated focusing in the near field, and sensitive color and power Doppler technology have improved the ability to evaluate peripheral nerve entrapment in osteofibrous tunnels with ultrasonography (US). In the upper limb, osteofibrous tunnels amenable to US examination include the carpal tunnel for the median nerve and the cubital and Guyon tunnels for the ulnar nerve. In the lower limb, these tunnels include the fibular neck for the common peroneal nerve, the tarsal tunnel for the posterior tibial nerve, and the intermetatarsal spaces for the interdigital nerves. High-resolution US allows direct imaging of the involved nerves, as well as documentation of changes in nerve shape and echotexture that occur in compressive syndromes. A spectrum of extrinsic causes of entrapment, such as tenosynovitis, ganglia, soft-tissue tumors, bone and joint abnormalities, and anomalous muscles, can also be diagnosed with US. With continued experience, it is likely that this technique will be increasingly used to evaluate nerve entrapment syndromes.