SAN DIEGO — Bone marrow edema is common in the sacroiliac joints of both amateur and professional young athletes, with damage most frequently seen in the posterior lower ilium, according to research presented at the American College of Rheumatology Annual Meeting.
“There are two problems in spondyl science — one is early recognition of the disease,” Ulrich Weber, MD, a researcher at King Christian 10th Hospital for Rheumatic Diseases in Graasten, Denmark, and a lead author of the study, told attendees. “We have an effective treatment, but that treatment is very expensive. So, how do we allocate this treatment to the right patients?”
He added, “We have a definition about so-called positive MRI in the sacroiliac joints, and this illustrates the difficulty we have, because these joints — the spine and sacroiliac joints — are deep in the body, so we have no clinical ways to diagnose this disorder, and very few lab parameters for what discriminates between what is normal and what is the disease.”
To learn more about the “background noise” in MRIs of sacroiliac joints in healthy athletes with mechanical axial strain, and to determinine the intersection of normal variation and detection of early axial spondyloarthritis, the researchers reviewed data on 20 recreational runners and 22 professional hockey players — all from the Danish Premier League. Forty percent of the runners, and all of the hockey players, were men. The mean age of the runners was 27.2 years, while the mean age of the hockey players was 25.9 years.
The researchers performed MRI scans of all the participating athletes’ sacroiliac joints. The runners were scanned before, and 24 hours after, completing a 6.2-km run, while the hockey players underwent an MRI at the end of their competitive season. According to the researchers, three independent, blinded readers analyzed the MRI scans for bone marrow edema, and paired images of the healthy runners were read blinded to timepoint.
In addition, the readers received seven MRI scans of two paired images of spondyloarthritis patients undergoing anti-TNF treatment. The pretest reader calibration used MRI scans from 11 patients with active sacroiliitis and nine healthy volunteers. The researchers analyzed the mean frequency of sacroiliac joint quadrants with bone marrow edema and their distribution in eight regions: upper and lower ilium and sacrum, each divided into anterior and posterior.
According to the researchers, the mean number of sacroiliac joint quadrants with bone marrow edema in the healthy runners was 3.1, before and after running. Among the hockey players, it was 3.6. The posterior lower ilium was the most affected region in all athletes, followed by the anterior upper sacrum, the researchers said. Bone marrow edema was found in three to four sacroiliac joint quadrants on average in both amateur and professional athletes.
“Our study results inform about frequency, they inform about anatomical clustering, to help discriminate the so-called background noise that may be disassociated from the true disease,” Weber said. “[There are other] studies that deal with the intersection between normal variation and disease because it’s the only measure we have that is halfway reliable to assist in early diagnosis of the disease, because the clinical examination is so limited. On the other hand, we should never use an MRI as the gold standard to diagnose. The gold standard would be using all of the clinical data, inclusive of the MRI.”
Weber U. “Bone Marrow Edema in Sacroiliac Joints of Young Athletes Is Common and Shows Most Frequently in the Posterior Lower Ilium.” Presented at the American College of Rheumatology Annual Meeting, Nov. 3-8, 2017; San Diego, California.
Disclosure: Weber reports no relevant financial disclosures.