High-field magnetic resonance imaging assessment of articular cartilage before and after marathon running: does long-distance running lead to cartilage damage?
BACKGROUND
There is continuing controversy whether long-distance running results in irreversible articular cartilage damage. New quantitative magnetic resonance imaging (MRI) techniques used at 3.0 T have been developed including T1rho (T1ρ) and T2 relaxation time measurements that detect early cartilage proteoglycan and collagen breakdown.


OBJECTIVE
Marathon runners will demonstrate T1ρ and T2 changes in articular cartilage on MRI after a marathon, which are not seen in nonrunners. These changes are reversible.


METHODS
Cohort study; Level of evidence, 2.


METHODS
Ten asymptomatic marathon runners had 3-T knee MRI scans 2 weeks before, within 48 hours after, and 10 to 12 weeks after running a marathon. The T1ρ and T2 MRI sequences in runners were compared with those of 10 age- and gender-matched controls who had MRI performed at baseline and 10 to 12 weeks.


RESULTS
Runners did not demonstrate any gross morphologic MRI changes after running a marathon. Postmarathon studies, however, revealed significantly higher T2 and T1ρ values in all articular cartilage areas of the knee (P < .01) except the lateral compartment. The T2 values recovered to baseline except in the medial femoral condyle after 3 months. Average T1ρ values increased after the marathon from 37.0 to 38.9 (P < .001) and remained increased at 3 months.


CONCLUSIONS
Runners showed elevated T1ρ and T2 values after a marathon, suggesting biochemical changes in articular cartilage, T1ρ values remain elevated after 3 months of reduced activity. The patellofemoral joint and medial compartment of the knee show the highest signal changes, suggesting they are at higher risk for degeneration.
Luke
Anthony C
AC
Anthony C. Luke, University of California, San Francisco, Department of Orthopaedics, 500 Parnassus Ave, MU-320W, San Francisco, CA 94143-0728, USA. lukea@orthosurg.ucsf.edu
Stehling
Christoph
C
Stahl
Robert
R
Li
Xiaojuan
X
Kay
Terry
T
Takamoto
Stephen
S
Ma
Benjamin
B
Majumdar
Sharmilla
S
Link
Thomas
T
D000222:Adaptation, Physiological; D000293:Adolescent; D000328:Adult; D001265:Athletic Injuries / Q000209:etiology*; D002358:Cartilage, Articular / Q000293:injuries*; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000295:instrumentation* / Q000379:methods; D008297:Male; D012307:Risk Factors; D012420:Running / Q000293:injuries* / Q000502:physiology; D013312:Stress, Physiological; D013997:Time Factors; D055815:Young Adult