Expected age or activity related epidemiological findings in musculoskeletal MRI
| Body part | Prevalence |
| Neck | Up to 87% of asymptomatic individuals may have bulging discs,107 with 58% of younger, asymptomatic athletes showing cervical disc degeneration.108 |
| Shoulder | 60% of asymptomatic older adults show subacromial bursitis on MRI and around half have rotator cuff tears,109 110 whilst up to 72% of middle-aged individuals have asymptomatic superior labral tears.111 In younger, asymptomatic athletes, 65% can have rotator cuff tears and 88% rotator cuff tendinosis.112 52% of pre-teen athletes demonstrate asymptomatic activity-related ‘abnormal’ shoulder MRIs.113 With the exception of large rotator cuff tears, systematic review suggests little-to-no correlation between shoulder imaging findings and shoulder symptoms.28 114 |
| Low back | At age 60, 88% of asymptomatic adults will have disc degeneration, 70% will show disc bulges, 50% will show facet degeneration and 23% spondylolisthesis.115 Lumbar stenosis is seen in upto 20% of those under the age of 40.116 Moderate or severe spinal stenosis is seen in up to 64% of those in their 50s and 93% in those in their 80s. The majority are asymptomatic, as only 17.5% of those with severe central stenosis may have symptoms.117 In younger, asymptomatic adolescent sports players, up to 85% may show MRI changes including disc bulges, facet arthropathy as well as pars lesions.118 Even 22% of asymptomatic children can show disc degeneration on MRI.119 |
| Hip | Labral tears are seen in up to 69% of asymptomatic adults,120 or even 89% of asymptomatic athletes121 and labral cysts in 50% of dancers.122 Acetabular dysplasia is seen in around 15% of asymptomatic people, with bilaterality in up to 39.5% of cases.123 124 Cartilage defects may be seen in 12% of asymptomatic individuals.125 |
| Knee | The majority of people with meniscal tears have no recent symptoms.126 Meniscal tears are seen in around a third of middle-aged asymptomatic individuals, where 97% of knees will show incidental ‘abnormalities’, including bucket-handle tears.127 Above the age of 40, MRI shows osteoarthritis features in up to 43% of asymptomatic individuals128 |
| Ankle and Foot | Tibial stress fractures have been seen in 41% of asymptomatic runners.129 In ankle MRI of asymptomatic amateur marathon runners, up to 80% may show tendon changes, 48% ligament injuries and 27% achilles tendinopathy.130 Up to 37% of people may have incidental ‘abnormal’ anterior talofibular ligaments.131 132 Achilles tendon changes may be seen in up to 63% of asymptomatic individuals, and retrocalcaneal bursal changes in 68% of runners.133 Morton Neuroma’s is present in 26%–33% of asymptomatic individuals.134 135 |