The Acute Effect of Running on Knee Articular Cartilage and Meniscus Magnetic Resonance Relaxation Times in Young Healthy Adults

Abstract

Background Understanding the acute response of healthy knee cartilage to running may provide valuable insight into functional properties. In recent years, quantitative magnetic resonance (MR) imaging techniques (T1ρ and T2 relaxation measurement) have shown tremendous potential and unique ability to noninvasively and quantitatively determine cartilage response to physiologic levels of loading occurring with physiologic levels of exercise. Purpose To measure the short-term changes in MR T1ρ and T2 relaxation times of knee articular cartilage and meniscus in healthy individuals immediately after 30 minutes of running. Study Design Descriptive laboratory study. Methods Twenty young healthy volunteers, aged 22 to 35 years, underwent 3T MR imaging of the knee before and immediately after 30 minutes of running. Quantitative assessment of the cartilage and menisci was performed using MR images with a T1ρ and T2 mapping technique. After adjusting for age, sex, and body mass index, repeated-measures analysis of variance was used to determine the effects of running on MR relaxation times. Results The post-run T1ρ and T2 measurement showed significant reduction in all regions of cartilage except the lateral tibia when compared with the pre-run condition. The medial tibiofemoral (T1ρ: 9.4%, P < .0001; T2: 5.4%, P = .0049) and patellofemoral (T1ρ: 12.5%, P < .0001; T2: 5.7%, P = .0007) compartments experienced the greatest reduction after running. The superficial layer of the articular cartilage showed significantly higher change in relaxation times than the deep layer (ΔT1ρ: 9.6% vs 8.2%, P = .050; ΔT2: 6.0% vs 3.5%, P = .069). The anterior and posterior horns of the medial meniscus (9.7%, P = .016 and 11.4%, P = .001) were the only meniscal subregions with significant changes in T1ρ after running. Conclusion Shorter T1ρ and T2 values after running suggest alteration in the water content and collagen fiber orientation of the articular cartilage. Greater changes in relaxation times of the medial compartment and patellofemoral joint cartilage indicate greater load sharing by these areas during running.

The immediate effect of long-distance running onT2andT2* relaxation times of articular cartilage of the knee in young healthy adults at 3.0 T MR imaging

“…A recently published analysis of T 2 of the hyaline cartilage in a healthy study population revealed mean values of 20-30 ms in the deep layer and 40-50 ms in the superficial layer of the femoral condyle with an arthroscopically normal articular cartilage. 14 In comparison with our results, Subburaj et al 19 found similar T 2 values with a mean T 2 relaxation time of 31.7 ms (63.9 ms) in 20 young healthy volunteers (age 28.7 years; 22-35 years).…”

“…For the assessment of the immediate influence of athletic loading on cartilage relaxation times, only T1rho and T 2 have been applied and investigated so far. 19,20,27 One previous investigation of Subburaj et al 19 The authors observed a slight increase of relaxation times immediately after the run, but they returned to approximately prerun values after 2 h. As an explanation, the authors argue that they analyzed actual running in an in vivo study design instead of passive knee bending. These findings are contrary to our results and to the above-mentioned publications, although the study designs are comparable.…”

“…In contrast to previously published studies, we did not perform a separate investigation of the superficial and deep cartilage layers in each cartilage segment. 19,22 In some areas, e.g. the lateral anterior condyle, the cartilage appeared to be too thin (1-3 mm) to safely and reproducibly integrate a sufficient amount of pixels in a single ROI and hence to generate robust results.…”

“…17,18 T1rho and T 2 have also proven to be reliable in the detection of acute effects on the articular cartilage of the knee after physical loading. 19,20 To the best of our knowledge, no comparison of the immediate effects on T 2 and T 2 * relaxation times after running has been published. Hence, the purpose of the presented feasibility study was to analyze the acute effects of long-distance running on T 2 and T 2 * relaxation times in young, active adults and to investigate the correlation between these two biomarkers.…”

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“…One such type is deep water running (DWR), otherwise known as aqua jogging, which consists of simulated running in deep water. DWR is utilized for a variety of populations including the elderly, obese individuals, individuals with orthopaedic injuries, athletes, healthy individuals, as well as many persons with various clinical conditions (Subburaj et al, 2012;Killgore, 2012;Cuesta-Vargas et al, 2012;Azevedo, Lambert, Zogaib, & Barros Neto, 2010;Kaneda, Sato, Wakabayashi, Hanai, & Nomura, 2008;Broman, Quintana, Lindberg, Jansson, & Kaijser, 2006). Aqua jogging is used as low-impact training modality for individuals with compromised joints, during rehabilitation, weight bearing restriction, or when land exercise is not tolerated.…”