What is the role of body mass vis a vis osteoarthritis? Why might we think that this not be a pure mechanical phenomenon? (hint: Framingham)
Intuitively, excess load should cause excess wear:
Excess body mass increases the load placed on joints which increases stress and accelerates the breakdown of cartilage.
However, OA may not be a pure mechanical phenomenon because being overweight has also been associated with higher rates of hand OA --this suggests that a circulating systemic factor may also play a role.
Basal thumb (C-MC) arthritis is more common among the obese; yet unless these people are doing a lot of handstands, this joint should not be excessively loaded by body mass