Lennard Funk is a consultant shoulder and upper limb surgeon and honorary clinical lecturer at Salford Royal Hospitals and the University of Manchester. He is also an upper limb surgeon and co-director of the Manchester Sports Medicine Clinic, a private practice that he runs together with a sports physician and two other orthopaedic surgeons. He specialises in arthroscopic (keyhole) and minimally invasive surgery of the shoulder and elbow, as well as general upper limb surgery and trauma. His particular interests include shoulder dislocations, frozen shoulder, arthritis, stiff elbows and sports injuries of the shoulder.
Nearly six million people a year in the UK visit a doctor because of shoulder sprain, strain, dislocation or other shoulder problem. The shoulder joint's mobility makes it prone to injury and frequent overhead movements or sudden trauma can damage tissues within the shoulder, causing pain, tenderness, weakness, instability and limitation of movement in the joint.
The most common shoulder injuries seen at the Manchester Sports Medicine Clinic (MSMC) are impact and contact injuries, usually in rugby players. Chronic shoulder injuries are also very common, specifically in swimmers, overhead athletes such as tennis and badminton players, and wheelchair athletes. Many of these injuries involve damage to the rotator cuff, a sleeve of muscle that surrounds the shoulder joint and is primarily responsible for most shoulder movements. With age, the rotator cuff tendons degenerate and become more prone to acute injury after an impact. It is currently believed that it is better to repair rotator cuff tears as soon as possible in order to maximise restoration of function.
Ultrasound is a particularly useful imaging tool when examining muscle and tendon injuries, particularly of the shoulder. By performing 'office' shoulder ultrasound during clinical examinations, patients can be instantly scanned at the first clinic appointment, providing an immediate, one-stop diagnosis and assessment that allows quicker treatment and recovery. It also helps surgeons to plan their patient management, and reduces costs, such as those incurred by a radiology report, by the patient taking additional days off work and the cost of clinicians' time. Traditionally, ultrasound of the shoulder has been carried out by radiologists in the UK and USA, although in mainland Europe it has been done by surgeons and clinicians. However, recent advances in ultrasound technology, particularly the development of small, portable ultrasound instruments with rapidly improving resolutions, and the increasing awareness and availability of training courses, have made the approach more accessible for clinicians.
Figure 1: Ultrasound scans of full thickness rotator cuff tear (supraspinatus) |
Ultrasound helps to diagnose a number of rotator cuff pathologies in the shoulder, especially complete rotator cuff tears, which can be well visualised (Fig 1). Rapid assessment and diagnosis of these injuries is critical, since rotator cuff tears generally get bigger with time, so the longer a patient waits for repair, the more difficult the surgery might be and the longer the projected recovery time. Direct signs of complete tears include flattening of the superficial border of the tendon (the normal tendon is convex); a hypoechoic zone separating the tendon edges; absence of the normal tendon, replaced by a thin hypoechoic line representing the hypertrophic bursa surrounding the greater tuberosity; and flattening of the tendon in response to a compression test (the intact cuff cannot be compressed). A number of indirect signs of rotator cuff tears can also be seen, such as effusion around the long head of the biceps tendon; double effusion where joint effusion is seen around the biceps tendon and subacromial subdeltoid bursitis; deltoid herniation, where the deltoid muscle bulges deeply into the gap of the rotator cuff; and muscle atrophy. Partial rotator cuff tears can also be depicted with ultrasound, but the accuracy is lower than that for complete tears. An audit of the MSMC's ultrasound use in 2006 demonstrated 92 per cent sensitivity for complete rotator cuff tears and 86 per cent sensitivity for partial tears, in 64 patients.
Figure 2: Ultrasound scans of intact rotator cuff six months post-repair |
Ultrasound can also detect calcifications in the rotator cuff. Although these are almost always seen by x-ray, they can be missed due to their location or the direction of the x-ray beam. Furthermore, visualising the appearance of calcifications using ultrasound can predict their symptomatology. For example, long and thin calcifications are often asymptomatic, while thick and rounded or irregular calcifications give rise to symptoms. The amount of posterior attenuation can also predict the calcification's hardness, which is useful when arthroscopic removal of the calcium deposits is being considered for treatment. Ultrasound-guided barbotage can also be used to treat the problem, where a needle is inserted to aspirate the calcium while scanning the area by ultrasound. Subacromial bursitis can also be seen with ultrasound when the bursa is more than 2 mm thick (or clearly thicker than that of the uninjured shoulder) and, again, ultrasound is particularly useful for guiding injections such as anti-inflammatory treatments into the area.
Figure 3: SonoSite MicroMaxx ultrasound system |
The MSMC currently uses three different hand-carried ultrasound machines, the SonoSite MicroMaxx®, TITAN® and 180 PLUS™ ultrasound systems with a 38 mm linear array transducer. The portability of these systems combined with their long-life rechargeable batteries make them easy to transfer between rooms and patient cubicles. The speed with which the systems start up and shut down and ease of use are also important, as well as certain functions such as measurement tools and the ability to save images and videos from scans with accompanying patient data.
The MSMC was one of the first places in the UK to acquire the MicroMaxx ultrasound system, which is the highest resolution portable ultrasound machine on the market. Its new features allow quantitative measurement, enhanced image quality and versatility in a compact and lightweight device. When a patient presents with a suspected rotator cuff tear, examining the patient with the MicroMaxx ultrasound system and making a diagnosis literally adds just three to
Figure 4: Lennard Funk |
five minutes to the physical examination. A quick pre-surgical scan instantly shows whether or not there is a tear to the cuff, and how big it is, which is all that is initially required to plan management of the patient's injury. If additional information is needed then patients are sent to a musculoskeletal radiologist with greater skill and higher resolution machines to provide the necessary details.
A number of orthopaedic ultrasound training courses are available for clinicians, including courses specialising in shoulder ultrasound, which are designed for participants to gain hands-on scanning experience, with plenty of opportunity to practise using the instruments and get a feel for the procedures. For more information on the use of office ultrasound for the shoulder see the Education section of www.shoulderdoc.co.uk.
Useful web links:
www.shoulderdoc.co.uk
www.sonosite.com
www.sonositeusers.com
www.sportsmedclinic.com
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