CARTILAGE (CARTILAGE) - 08.20.14
ISS Science for Everyone
Science Objectives for Everyone
The Cartilage experiment is studying to what degree the cartilage of astronauts is effected (weakened) by being in weightlessness for an extended time, focusing on the type of cartilage found in such areas as the knees and elbows. This will help to develop ways to counteract any negative effects which will help to maintain astronaut health and performance and could also be used within prevention/rehabilitation of similar conditions on Earth.
Science Results for Everyone
Sponsoring Space Agency
European Space Agency (ESA)
ISS Expedition Duration
March 2013 - October 2015
Previous ISS Missions
Articular cartilage in synovial joints serves a variety of functions including providing joint congruency, transferring and distributing forces, and allowing joint movement. Healthy cartilage is the prerequisite for proper joint function, and thus for unconfined physical activity. The effects of immobilization on articular cartilage in humans are barely known and cartilage health of the lower limb joints has not been studied in microgravity. Mechanobiological factors cause changes in articular cartilage morphology and biology in a joint throughout life. Healthy articular cartilage tends to be thickest in joints that experience high forces such as the knee. Disuse induces changes in cartilage morphology and biology could be shown in previous studies in animals as well as humans. These data suggest that cartilage thickness in patients is sensitive to unloading.
While in microgravity, the high impact forces are absent, and this potentially could lead to cartilage degeneration or osteoarthritis. The reported changes include decreases in proteoglycan concentration and compressive stiffness, and cartilage softening.
To test the effect of unloading on cartilage thickness and volume, magnet resonance imaging (MRI) of the astronauts’ knees will be performed before and after a stay in microgravity. Blood and urine samples will be taken before, during (Urine samples only if possible) and after a stay in microgravity to investigate the effect of immobilization on biomarkers of cartilage metabolism.
It is expected that:
1. Cartilage volume and thickness will decrease due to microgravity induced unloading.
2. Markers of cartilage biology will show cartilage degradation.
3. Changes in cartilage morphology and muscle volume will be positively correlated.
With articular cartilage (found in such areas as the knees and elbows) being vital to the mobility of humans, understanding the nature of any degeneration occurring in this tissue is vital to the well-being of astronauts in orbit and on their return to Earth. Providing a greater insight into the nature and degree of degeneration in articular cartilage in orbit will help in the development of optimal countermeasures (pharmacological, dietary or exercise-based) in order to alleviate/prevent such adverse effects and hence improve/maintain the health and performance of our astronauts.
Damage to/degeneration of articular cartilage on Earth can be painful and debilitating and have a severe impact on the mobility and performance of humans. Articular cartilage is also extremely slow to regenerate once damaged making this even more significant. By improving our knowledge of the mechanisms behind cartilage degeneration in space we can also draw conclusions to similar degeneration on earth, which could feed into improved rehabilitation/preventative techniques on earth.