Joint Cartilage in Long-Duration Spaceflight

Abstract

This review summarizes the current literature available on joint cartilage alterations in long-duration spaceflight. Evidence from spaceflight participants is currently limited to serum biomarker data in only a few astronauts. Findings from analogue model research, such as bed rest studies, as well as data from animal and cell research in real microgravity indicate that unloading and radiation exposure are associated with joint degeneration in terms of cartilage thinning and changes in cartilage composition. It is currently unknown how much the individual cartilage regions in the different joints of the human body will be affected on long-term missions beyond the Low Earth Orbit. Given the fact that, apart from total joint replacement or joint resurfacing, currently no treatment exists for late-stage osteoarthritis, countermeasures might be needed to avoid cartilage damage during long-duration missions. To plan countermeasures, it is important to know if and how joint cartilage and the adjacent structures, such as the subchondral bone, are affected by long-term unloading, reloading, and radiation. The use of countermeasures that put either load and shear, or other stimuli on the joints, shields them from radiation or helps by supporting cartilage physiology, or by removing oxidative stress possibly help to avoid OA in later life following long-duration space missions. There is a high demand for research on the efficacy of such countermeasures to judge their suitability for their implementation in long-duration missions.

Long-term space missions’ effects on the human organism: what we do know and what requires further research

“…NASA does not currently recognize spaceflight-related changes in joint cartilage as a high health risk for Mars mission since it is not a direct threat to mission success. Although research on human joint cartilage modifications in spaceflight is scarce, data from cell, animal, and human studies suggests that exposure to near weightlessness mixed with radiation is likely to result in joint cartilage thinning, degeneration ( Ganse et al, 2022 ), and eventually osteoarthritis during long-term space missions ( Patel, 2020 ).…”

Organs in orbit: how tissue chip technology benefits from microgravity, a perspective

“…Microgravity additionally eliminates loading force. In orbit, astronauts lose cartilage, muscle, and bone mass due to the drastic decrease in mechanical stimuli ( Ganse et al, 2022 ; Comfort et al, 2021 ; Mu et al, 2022a ; Grimm et al, 2016 ; Willey et al, 2011 ). For instance, bone cells are mechanosensory, sensing and relaying mechanical signals.…”