Use of Knee Magnetic Resonance Imaging by Primary Care Physicians in Patients Aged 40 Years and Older

Abstract

Background:Criteria are needed for primary care providers such that they can evaluate age-related knee pain in a cost-effective manner. This study examined (1) in what percentage of patients are appropriate radiographic views of the knee ordered before magnetic resonance imaging (MRI) for knee pain, (2) specialists’ retrospective evaluation for appropriate utilization of MRI in knee pain, and (3) in what manner would the MRIs have altered diagnosis and management of knee disorders.Hypothesis:Primary care providers underuse appropriate radiographs—especially, flexion weightbearing posteroanterior films—and overuse MRIs when evaluating older patients with knee pain.Study Design:Case control.Methods:The authors performed a retrospective analysis of 100 patients older than 40 years with knee MRIs. Patient encounters with primary care physicians were reviewed. Given available information, specialists then formulated a pre- and post-MRI diagnosis and treatment plan and indicated whether the MRI would have altered their treatment.Results:Only 12 of 100 MRIs would have been ordered by an orthopaedist given the documented data. No MRIs would have been ordered in the 19 patients aged 60 years or older. Among 44 radiographs ordered, only 7 were flexion weightbearing. The most common pre-MRI diagnoses made by primary care providers were joint pain (22%) and meniscus injury (24%); the most common post-MRI diagnoses were osteoarthritis (40%) and degenerative meniscus injury (23%). In contrast, the 2 most common pre- and post-MRI diagnoses by specialists were osteoarthritis (28% and 37%, respectively) and degenerative meniscus injury (23% and 24%, respectively). Also, referrals to specialists increased from 9% pre-MRI to 76% post-MRI.Conclusion:Primary care providers may be overusing knee MRIs and underusing flexion weightbearing posteroanterior radiographs in patients older than 40 years with knee pain.Clinical relevance:Primary care providers should strongly consider not ordering knee MRI in patients with radiographic evidence of degenerative changes.

MRI of the Knee and Shoulder Performed Before Radiography

“…When the initial radiographs are noncontributory, a shoulder MRI without contrast or an MR arthrography is appropriate [13]. In a previous retrospective analysis of 100 knee MRIs ordered by primary care physicians, only 44 had corresponding radiographs, and only 12 of 100 would have been ordered by a specialist [20]. Lehnert et al demonstrated in a single-center study that 14% of knee and 37% of shoulder MRIs did not follow the AC, and inappropriate examinations had significantly higher odds of having negative results [21].…”

EULAR recommendations for the use of imaging in the clinical management of peripheral joint osteoarthritis

“…The role of imaging in clinical practice for OA diagnosis, management and follow-up has not been clearly defined. Despite this limitation, the increased availability of modern imaging has expanded its use, with possible excesses1 leading to increased costs. A European League Against Rheumatism (EULAR) task force was therefore created to develop evidence-based recommendations on the use of imaging in the management of symptomatic, peripheral joint OA, for clinicians who treat OA in their clinical practice.…”

Trends in knee magnetic resonance imaging, arthroscopies and joint replacements in older Australians: still too much low‐value care?

“…From 2013, general practitioners (GPs) could request MBS‐subsidized knee MRIs for specific indications (acute knee injury; see MBS item descriptors in Box ). Access to MBS‐funded MRI in primary care may be one driver for the increase in its use, with findings that a large number of MRIs ordered in primary care are considered unnecessary by specialists presented with the same information . An increase in the use of MRI in middle‐aged and older adults with knee pain may also increase inappropriate use of arthroscopy and/or appropriate or inappropriate use of joint replacement.…”