Summary

Among recreational marathon runners, the LTC, cMFC, and anterior angle of the meniscus were the most vulnerable sites to repetitive loading.

Abstract

Introduction

Long-distance running can overload knee cartilage and meniscus, which may have significant impact on the biochemical and microscopic components on these structures and therefore lead to deformation. The purpose of this study was to investigate the impact of half-marathon running on knee cartilage and meniscus in recreational marathon runners, and to detect the time needed for recovery using MRI T2* mapping, a technique known to be sensitive for microscopic changes in tissue.

Methods

MRI scans of the knee were performed before (t0), immediately after (t1), 3 days after (t2) and 7 days after (t3) half-marathon running using a 1.5T scanner and T2* mapping sequence. One-way repeated ANOVA was used to compare T2* values at t1, t2, t3 with the baseline T0.

Results

Fifteen recreational marathon runners participated this study. A significant increase in T2* was observed at t1 for the superficial layer of the lateral tibial cartilage (sLTC) and the lateral and medial meniscus (LM and MM, respectively; all p < 0.05). At t2, there was a significant increase in T2* for dLTC, LM and MM (all p < 0.05). Further subregion analysis showed significant increase in T2* at both t1 and t2 for the posterior part of the sLTC (both p < 0.05). T2* increased at t1 for the deep center of the medial femoral cartilage (cMFC) and all angles of meniscus (all p < 0.05) except for the lateral-posterior angle. T2* also increased at t2 for the middle part of the sLTC and all meniscus areas (all p < 0.05). T2* of all cartilage and meniscus areas returned to baseline level at t3 (all p > 0.05).

Conclusion

The LTC, cMFC and anterior angle of meniscus were the most sensitive areas to repeated loading in recreational marathon runners. The recovery time of T2* value of knee cartilage after a half marathon was 3 to 7 days. It can be concluded that a half-marathon would not exert irreversible effects on the knee cartilage and meniscus in recreational runners.