The Acute Effect of Running on Knee Articular Cartilage Post Menisectomy on MRI T2 Mapping

Background: Running has many benefits; it has been shown to control blood pressure, levels of lipids and cholesterol as well as improving cardiovascular endurance. Despite all the positive attributes of running, the loading of the joints during running may have a deleterious effect on the joint cartilage leading to osteoarthritis. This effect has been the subject of several studies without a conclusive result. Partial menisectomy is the most common orthopedic surgical procedure performed with more than 850,000 performed annually in the USA. It has been shown that partial menisectomy causes abnormal joint loading and is a risk factor for development of knee osteoarthritis. The majority of patients undergoing partial meniectomy are young and active adults and seeking to return to sporting activities. The effect of running on the knee joint articular cartilage in the post menisectomy state has yet to be investigated.

Methods: 12 young healthy volunteers, who underwent medial partial menisectomy, 1-4 years prior, underwent 3T MR imaging of the knee, before and immediately after 30 minutes of running. The exam included the operated knee and the healthy knee as a control. Quantitative assessment of the articular cartilage and the menisci was performed using a T2 mapping technique. Regions of interest (ROI)analysis was performed on the T2 maps of the operated knee and the healthy knee, each pre and post run. Thus immediate effect of running on the joint cartilage was assessed as well as comparisonbetween the operated and the control knee.

Results: ROI divided Paired T-test revealed significant reduction in T2 post-run in the anterior-superior-medial femoral condyle of the operated knee, in two sequential slices (mean T2 pre-run: 22.18ms, post- run: 19.76ms, p=0.004, p=0.037) compared to the control knee.
ANOVA analysis found no significant difference between the groups.

Conclusion: As hypothesized, running, in the post menisectomized knee, subjects the articular cartilage to excessive loads.