Repetitive injury syndrome: can imaging help?
ALAN RUSSELL, MD, of Brampton, ON, wonders, "Is there a way to diagnose repetitive injury syndrome using bone scans or other imaging, or is the diagnosis purely clinical?"
Repetitive injury syndrome is often used as a catch-all phrase that can encompass a wide variety of medical conditions. In athletes, these may include overuse injuries that result in stress fractures like shin splints. Baseball and cricket pitchers may present with ligament or tendon damage, e.g. the rotator cuff tendon. Even in non-athletic everyday situations, repetitive use injuries are seen, such as carpal tunnel syndrome, bursitis or other cases of tenosynovitis in secretarial office staff, or first carpal-metacarpal (thumb) joints in children from excesssive playing of video games.
The stress injuries in bone and muscle observed in athletes most commonly involve the tibia, metatarsals and femoral neck, but can involve almost any part of the body depending on the region of overuse femoral shafts in long distance runners, coracoid processes in skeet shooters.
Early recognition of pathology is critical to ensure proper treatment and to avoid exacerbation of the problem, with the aim of returning the patient to full function and activity as soon as possible. In cases where the diagnosis is fairly obvious from clinical history, symptoms and exam, no imaging is required. As many of these injury conditions result in non-specific clinical presentations, however, imaging can play a large role in accurate and timely diagnosis. Plain radiographs are the easiest, simplest and least expensive of the imaging modalities and can still be used as the primary imaging tool in specific cases. Although diagnosis can be made with x-rays in some conditions, i.e. stress fractures, this modality is usually insensitive and the signs often don't become obvious until later in the disease process. X-rays would then delay diagnosis and treatment. Nuclear medicine bone scans have a very high sensitivity for bone and even soft tissue injuries particularly when performed as a three-phase study, with blood flow and blood pool images, along with the delayed bone uptake images. Bone scans, though, are limited by relative poor specificity and lack of anatomic detail. As such, magnetic resonance imaging (MRI) has emerged as the imaging modality of choice in a number of these conditions, providing exquisite sensitivity and anatomic detail. Limited access to MRI in Canada, combined with the significant cost of the studies, may be a deterrent in some cases. I recommend that you discuss difficult cases with your local radiologist to assess which modality would be best for your patient's situation. MM
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