Imaging is crucial to the diagnosis and characterisation of musculoskeletal (MSK) injuries. Experts will share their top three tips for using modalities in the wrist, shoulder, hip, knee and ankle in a special focus session. Delegates will learn more than one good trick in this setting, including how to diagnose traditionally unsuspected injuries related to ice hockey, snowboarding and basketball.
MSK imaging can help diagnose many conditions from dysplasia to rheumatologic disease and tumours. But in daily practice, it really boils down to injury.
“One of our major fields is injury – not exclusively in sports or accidents, but also during daily activities, when incidents may cause harm to the bones, muscles, joints, ligaments, joint cartilage or some supporting structures like the menisci in the knee,” said Professor Üstün Aydingoz from Ankara, Turkey, who will chair the session.
MRI is the most commonly used modality in this setting, but the initial x-ray film contains crucial information about the patient. “That would be an important trick: always make a point of looking at the plain films of the patient during the MR examination,” he said.
Radiologists should look at the x-ray results even if the examination occurred weeks or months before, because it will provide information about the anatomy of the patient and other conditions potentially affecting the MSK system.
Aydingoz’s personal tip is to talk with the patient to understand what happened at the time of the injury. “We are usually limited to the information the clinician has given us. We should really talk to our patients to know if what we are doing has an impact. It would be best to see the patient before or after the exam, but that is not always possible, so we could just phone them,” he said.
With MSK imaging, sport is never too far away, and sports-related injuries will feature heavily during the session. Bruce Forster, MD, Professor and Head of the Department of Radiology at the University of British Columbia, in Vancouver, Canada, will reveal his top three tips for injuries located in the foot and ankle.
He will focus on high ankle sprain, also known as syndesmotic injury, which is associated with ice hockey and far less commonly suspected, yet more serious, than low ankle sprain.
“With the low ankle sprain or typical ankle sprains that we see all the time, patients are able to return to their sport within four to five days. With high ankle sprain, it takes them 45 days, so ten times as long. It is quite an important diagnosis to make, to do proper rehab,” Forster said.
The typical ankle sprain involves injury to the anterior talo-fibular ligament. It is the ligament that tears more frequently; the ankle swells, and the patient endures some pain, but recovery time is generally short.
In high ankle sprain, the inferior tibiofibular ligaments are torn, and longer rehabilitation is necessary. Early diagnosis is therefore crucial.
“If someone fails to improve with ankle sprain, you have to think of this injury. MRI is the next step and it shows the tear of this ligament very well. There is a lot of literature supporting the role MRI plays in this diagnosis. You do not need to use contrast, and it is a very routine, 30-minute protocol,” he said.
A second injury that is commonly confused with typical ankle sprain is the fracture of the lateral process of the talus. This fracture represents about 15% of all ankle injuries in snowboarders and is associated with the soft boots that they wear.
These fractures are missed in almost half of x-rays, yet it is vital that they are picked up early. “Between 15% and 20% of these patients do not get better and they go on to develop osteoarthritis involving the subtalar joint, and that is a serious problem,” said Forster, who recommends using CT in this case.
“The ankle sprain is mimicked by that fracture, which is so easily missed on x-ray. My tip is: if your patient is a snowboarder and has a lot of ankle pain and you do not see anything on x-ray, just do CT. Also, do a CT scan if your patient who was diagnosed with ankle sprain does not get better after a week,” he added.
Radiologists in this setting must have knowledge about sports and know which modalities to use in what context. “In acute injuries, imaging can change treatment, so it is really important to highly prioritise imaging examinations,” explained Forster, who was Director of Diagnostic Imaging for the Vancouver 2010 Winter Olympic & Paralympic Games.
His third and final tip is on how to diagnose a stress fracture of the navicular bone, which commonly occurs in basketball or any jumping sport. This is more of a chronic injury among athletes, representing 15% to 30% of all stress fractures. Again, early diagnosis is key for patient prognosis.
“If you do not detect these fractures, due to the poor blood supply of the middle third of the navicular bone, patients can develop avascular necrosis (AVN), meaning that the bone dies. As this bone is the keystone of the foot, right in the middle of it, the whole foot is impacted with serious degenerative change developing over time.”
Furthermore, this type of fracture is virtually impossible to see on x-ray. Again, in a jumping athlete with more foot pain than ankle pain, but with normal x-ray, radiologists should move on to CT. “It is almost always at the proximal dorsal aspect of the bone, and CT is very good at detecting it,” Forster said.
Radiologists have an essential role as consultants in these and other athletic injuries, as imaging will help change treatment when necessary and athletes can recover more quickly.
“These injuries may be poorly assessed in our first line of imaging. You would think x-rays would be quite good at fractures, but they are not always. As a radiologist, you should be suspicious when your patients do not recover as quickly as they should,” he concluded.
Special Focus Session, Tuesday, September 22, 17:00–18:00
SF 15 My top three tips for imaging musculoskeletal injury
- Chairperson’s introduction
Üstün Aydingoz; Ankara/TR
Jean-Luc Drapé; Paris/FR
Klaus Wörtler; Munich/DE
Vasco Mascarenhas; Lisbon/PT
Christian W.A. Pfirrmann; Zurich/CH
Bruce B. Forster; Vancouver, BC/CA
- Live Q&A: My single best tip in improving diagnostic accuracy in musculoskeletal injury
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