Ultrasound in sports medicine—A critical evaluation
Section snippets
Apparatus
Ultrasound equipment varies considerably in its near field image quality. Machines designed for abdominal imaging may be non-diagnostic for musculoskeletal applications. Whilst linear array probes with frequencies over 10 MHz are the normally preferred, there are machines that provide these technical parameters but produce poor images for musculoskeletal applications. The major factor is probe design compounded by different methods of beam focussing and signal processing. When testing a machine
Muscle injury
Ultrasound is useful in assessing muscle injury, as loss of the normal pennate pattern of the muscle fibres can show the nature and location of the damage within muscle. However, in the first 25 h muscle injury can sometimes be difficult to identify using ultrasound. This is because new haemorrhage is echogenic and similar in appearance to normal muscle. This means that fresh haemorrhage can mix with the normal fibro fatty tissue within muscle and be inconspicuous to early ultrasound
Musculotendinous injury
Ultrasound is invaluable in assessing musculotendinous injury. Using dynamic stress of the musculotendinous junction a gap or the presence of a partial tear is easily demonstrated. This observation may make a significant difference to the patients’ management. Dynamic assessment of this nature is not possible with conventional MRI. Surgical management is becoming more aggressive and such differentiation does make significant changes to therapy. For example, Achilles tendon injuries above the
Enthesitis and entheseal injuries
In the young athlete the site of injury is often the enthesis where tendon or muscles insert into the bone. The MR appearances of entheseal injuries can look very aggressive and may be mistaken for a malignant lesion. Ultrasound will show cortical irregularity and increased vascularity and when compared to the normal side this often allows a more precise diagnosis. It also permits Colour Doppler assessment of the adjacent tendon to determine whether there is an active inflammatory reaction. For
Tendon disease
Subtle tendinopathy can be detected using ultrasound examination by the observation of fluid in the tendon sheath. A thin layer of fluid is seen in normal tendon sheaths provided that the ultrasound equipment is of high resolution. Tendinopathy shows more fluid and this is easily assessed by comparison with the normal side. As the tendinopathy progresses then the amount of fluid increases. Intrinsic change within the tendon can be detected earlier in the disease process by ultrasound imaging
Ligamentous disease
Ligaments can be imaged with ultrasound with much greater precision than MR. Using conventional MR systems the line pair resolution is significantly lower than that provided by modern ultrasound probes. Ligaments are fine, thin structures and the smaller ones are seen at best as a single black line using MR. Partial ruptures and neovascularisation due to repetitive injury can be detected using ultrasound which provides better images of their internal structure. The ability to dynamically stress
Avulsion fractures
Small avulsion fractures can be difficult to detect on plain radiographs and impossible to see on MR. To detect small avulsions is important in determining the full extent of an injury and the next step in management. For example, an avulsion of the distal pole of the patella will need surgical reattachment and if there is a bony fragment the nature of surgery and chance of success are materially affected (Fig. 7).
Block to finger flexion following an injury can be due to a ruptured flexor
Stress fractures
Using both MR and ultrasound stress fractures are seen within accessible areas such as the metatarsals or femoral neck before x-ray changes are apparent [3] (Fig. 8). Ultrasound will show defects in the cortex and early periosteal reaction as a layer of oedema. MR will show bone oedema and periosteal fluid. It also demonstrates bone sclerosis as dark lines on the background of oedema and therefore demonstrates the healing fracture line inside the bone. Ultrasound cannot detect internal changes
Foreign bodies [4]
When there is penetrating trauma in contact sports imaging may be required to show foreign material in the soft tissues. This can be metallic or organic (wood, cloth, etc.). Radiographs are the best method of showing metal and fairly effective at showing glass as all but the thinnest glass is radio-opaque. Glass from light bulbs may be missed using radiographs only. MR is a poor method for finding foreign material as it has no signal and merges into normal fascia, ligaments and tendons.
Joint disease and synovitis
Frequently tendinopathy or ligament changes can co-exist with another abnormality such as a synovitis in the adjacent joint. This is common in the ankle where a ligament rupture can lead to instability, tendinopathy and synovial proliferation (Fig. 10). This latter problem may be overlooked on MR as the use of contrast enhancement is not routine and synovitis may be invisible or difficult to identify on conventional MR Images [5]. In addition, chronic synovitis will not be identified by
Therapies
Ultrasound is becoming established as a useful adjunct to a clinician in guiding injections into the tendon sheath rather than into a tendon. This has made steroid injection within the tendon sheath safer once the skill of guiding the needle using ultrasound has been acquired. It is also used in aspirating symptomatic ganglions and cysts, such as those from the popliteal region or the proximal tibio-fibular joint [7] (Fig. 11).
Aspiration of liquefying haematoma under ultrasound guidance has
Disadvantages of ultrasound
Ultrasound will not adequately image joint disease whether it is due to bone disease, cartilage damage, marrow abnormality or microfractures. Deeply sited ligaments such as the cruciates of the knee are difficult to assess with ultrasound. If a pain is deep then ultrasound should not be the first choice of imaging and MRI is preferred.
Ultrasound is only as good as the operator who is performing the examination and the quality of the equipment that is used. Printed images of a patient's
Diseases where ultrasound examination is preferred
- 1.
Hamstring injuries.
- 2.
Quadratus injuries.
- 3.
Assessment of groin injuries.
- 4.
Assessment of the anterolateral gutter of the ankle and ankle tendinopathy.
- 5.
Patella tendonosis.
- 6.
Achilles tendonosis and rupture.
- 7.
Rotator cuff tears.
- 8.
Epicondylitis at the elbow.
- 9.
Tendon abnormalities around the wrist.
Conclusion
In the hands of a properly trained professional with good modern equipment ultrasound examination is often the preferred first line test for patients with muscle, tendon and ligament injuries. On occasion MR is the best first line test and it is often required to resolve issues in problem patients. Neither MR nor ultrasound should be judged in isolation as the most effective and the safest practitioners will use a combination of methods.
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Cited by (47)
The use of ultrasound in athletes
2018, European Journal of RadiologyCitation Excerpt :Ultrasound can be used to follow up treatment and rehabilitation. Although there may be a lag in the imaging improvement as compared to the clinical improvement it can be helpful to reassure the athlete [3]. Elastography may be used to detect subtle changes in a tendon that may not be visible by grey scale examination and may be used for follow up of the patient following treatment [4].
Application of Ultrasound in Sports Injury
2013, Journal of Medical UltrasoundCitation Excerpt :Stress fracture in athletes is often overlooked because a subtle fracture is not always seen in the plain film. In such cases, MRI is better than other image tools because it evaluates not only the bony surface but also the bone marrow [36–38]. In young athletes, fracture of the epiphysis should be examined since it is usually missed in the traditional roentgenogram.
Automated volumetric assessment of the Achilles tendon (AVAT) using a 3D T2 weighted SPACE sequence at 3 T in healthy and pathologic cases
2012, European Journal of RadiologyCitation Excerpt :These degenerative changes consist of loss of collagen structure, increase of proteoglycan and water content as well as neovascularisation leading to an increased tendon thickness [2,8,9]. Commonly used imaging techniques for diagnosis of these pathologic conditions are magnetic resonance imaging (MRI) as well as B-mode ultrasound (US) [10–14]. In comparison to US, MRI is regarded as the superior approach due to its sensitivity in discriminating neighbouring normal from pathological structures.
Point-of-care radiology service at the US Open Tennis Championships
2022, Skeletal RadiologyAn Isometric and Functionally Based 4-Stage Progressive Loading Program in Achilles Tendinopathy: A 12-Month Pilot Study
2022, Translational Sports Medicine