Advances in contemporary imaging techniques have led to more widespread use of this modality for the management of osteoarthritis (OA). However, in the absence of evidence-based guidelines, imaging is often used in circumstances where it does not change management. To ensure the optimal, appropriate, cost-effective use of imaging in patients with OA, the European League Against Rheumatism (EULAR) recently drafted 7 key recommendations for clinicians (Sakellariou G, et al. Ann Rheum Dis. 2017 Apr 7. Epub ahead of print).
“In a rapidly ageing world where the demand for diagnostics for joint pain is increasing, these recommendations should provide confidence for clinicians to explain to patients what the clinical diagnosis [of osteoarthritis] is without imaging, and also defend the need for imaging where a differential diagnosis would be excluded through imaging,” said co-investigator Philip Conaghan, MD, Professor, Musculoskeletal Medicine, Leeds Institute of Rheumatic and Musculoskeletal Medicine, Chapel Allerton Hospital, United Kingdom, in an interview with Value-Based Care in Rheumatology.
In general, the recommendations pertain exclusively to symptomatic OA, and were developed with the understanding that imaging abnormalities of OA are seen commonly, particularly with increasing age.
The recommendations clearly cite circumstances in which imaging should and should not be used. For example, routine imaging is not required to make the diagnosis of OA in typical presentations, and routine follow-up is not recommended. Furthermore, imaging should not be used to predict response to nonsurgical interventions.
“The main message is to be sensible about the use of imaging for osteoarthritis. For most people with typical short-duration morning stiffness and weight-bearing pain, imaging does not add to diagnosis above history and clinical examination,” Dr Conaghan stated.
“We don’t really know how much imaging is done to confirm a diagnosis of osteoarthritis or for its monitoring, but given it’s the most common cause of joint pain, its likely to be considerable. Anecdotally there is considerable overuse, that is, imaging that would not lead to change in management, or worse, might lead to inappropriate management. For example, meniscal tears are common in osteoarthritis if an MRI [magnetic resonance imaging] scan is done, but only if there is a clinical symptom of true joint-locking should arthroscopic surgery be considered. So it’s the clinical symptoms, not imaging, that often guide therapy,” he explained.Development Process
A multidisciplinary task force that included rheumatologists, radiologists, methodologists, primary care physicians, and patients from 9 countries defined 10 key questions on the role of imaging in OA. Joints of interest were the knee, hip, hand, and foot, and imaging modalities included conventional radiology, MRI, ultrasonography, computerized tomography, and nuclear medicine. A systematic literature review identified 390 relevant studies out of 17,011 potential journal articles, and searches were performed separately for each joint of interest.
The task force met several times and developed 7 key recommendations, which were graded according to level of agreement, using a scale from 0 (fully disagree) to 10 (fully agree).Use of Routine Imaging
The 7 recommendations had high levels of agreement, ranging from 8.7 to 9.6.
- Recommendations 1 and 2. Imaging is not required to make the diagnosis in patients with typical OA. The caveat is that imaging is recommended in atypical presentations to provide additional information for the diagnosis of OA or added diagnoses
- Recommendation 3. Routine imaging for follow-up of OA is not recommended, unless there is unexpected rapid progression of symptoms or change in clinical characteristics. In such a case, it would be recommended to determine whether this relates to OA severity or an additional diagnosis
- Recommendation 4. The task force agreed that conventional radiography should be the imaging method of choice if imaging is needed. If soft-tissue imaging is required, ultrasound, MRI, or bone computerized tomography are suggested
- Recommendation 5. Review of radiographic views is important for enhancing detection of OA features; for the knee, weight-bearing and patellofemoral views are especially recommended
- Recommendation 6. At present, imaging features do not predict nonsurgical treatment response, and imaging cannot be recommended for this purpose
- Recommendation 7. Intra-articular injection precision depends on the joint and the skillset of the practitioner, and imaging may improve accuracy. Imaging is particularly recommended for joints that are difficult to access with an intra-articular injection because of factors such as site, degree of deformity, and obesity.
These are the first recommendations on the use of imaging in OA in clinical practice, and they have some limitations. There were very few studies on foot pain, which the authors attribute to the search terms used—they searched “osteoarthritis” but not “pain,” which may have restricted their results. Furthermore, only a small proportion of the articles they identified were relevant for clinical practice.
Therefore, the task force proposed a fairly long list of future research priorities. Studies are needed to establish the added value of imaging to clinical findings when making the diagnosis of OA, and in the management and follow-up of the disease.