OrthoWertz
Ken Wertzberger, M.D
Shane Alford, P.A.
MRI
Magnetic resonace imaging or MRI, has become a valuable tool utilized to see more
than the bony surfaces of the joint. Plain regular x-rays are good for seeing
bony abnormalities and arthritis. MRI is excellent for seeing things we can't see
on plain xray, like cartilage, ligaments, edema, muscle, and tendon.
So, it will show cartilage and ligament tears in the knee, and tendon
tears(rotator cuff) tears in the shoulder.
MRI can be ordered when symptoms of a chronic problem linger, or if there is an
acute injury that needs more thorough evaluation.
MRI is not a perfect test, nothing is of course, and will have false-positives
and false-negatives. A false-negative is when there is a problem in the joint,
but it doesn't show up on MRI.
A false-positive is when the sensitivity of MRI so great, that it implies there
may be a problem in an area, when there is not.
That said, MRI is very good in 2011.
References:
Editorial - "Indications for Magnetic Resonance Imaging", Journal of Bone and
Joint Surgery, Vol. 73-A, No. 1, January 1991, Page 1.
Bodden, Scott, M.D., et al, "Abnormal Magnetic Resonance Scans of the Lumbar
Spine in Asymptomatic Patients", Journal of Bone and Joint Surgery, Vol. 72-A,
No. 3, March 1990, Page 403.
Fischer, S.P., M.D., et al, HAccuracy of Diagnosis for Magnetic Resonance
Impaging of the Knee: A multi-center analysis of 1,014 patients", Journal of Bone
and Joint Surgery, Vol. 73-A, No. 1, January 1991, Page 2.
Iannotto, Joseph, Ph.D., et al, "Magnetic Resonance Imaging of the Shoulder:
Sensitivity, specificity, and predictive value", Journal of Bone and Joint
Surgery, Vol. 73-A, No. 1, January 1991, Page 17.
Kriegsman, Jack, M.D., "Negative MRI Findings in Knee Injury: Clinical
Implications", Journal of Contemporary Orthopaedics, Vol. 22, No. 5, May 1991,
Page 549.
Raunest, J., M.D., et al, "The Clinical Value of Magnetic Resonance Imaging in
the Evaluation of Meniscal Disorders", Journal of Bone and Joint Surgery, Vol.
73-A, No. 1, January 1991, Page 11.