Ultrasound Measurement of Femoral Articular Cartilage Thickness Before and After Marathon Running

Abstract

Objective: The purpose of this study was to use ultrasonography to measure femoral articular cartilage thickness changes during marathon running, which could support MRI studies showing that deformation of knee cartilage during long-distance running is no greater than that for other weight-bearing activities.

Materials and methods: Participants included 38 marathon runners with no knee pain or history of knee injury, aged 18-39. Ultrasound images of the femoral articular cartilage were taken two hours before and immediately after the race. Femoral articular cartilage thickness was measured at both the medial and lateral femoral condyles.

Results: The maximum change in femoral articular cartilage thickness, measured at the left outer lateral femoral condyle, was 6.94% (P=.006). All other femoral articular cartilage thickness changes were not significant.

Conclusion: A change in femoral articular cartilage thickness of 6.94% supports our hypothesis that long-distance running does not induce deformational changes greater than that of regular daily activities. This study using ultrasonography supports MRI evidence that knee cartilage tolerates marathon running well.

Keywords: articular cartilage; diagnostic musculoskeletal ultrasound; knee ultrasound; long-distance running; sport biomechanics.

Figure 1. Areas of measurement for inner and outer femoral condyles

Used with permission from: Mayo Foundation for Medical Education and Research

Figure 2. Ultrasound measurements

A: Before the marathon. B: After the marathon. A significant decrease in femoral articular cartilage thickness can be seen at the left lateral femoral condyle (arrow).