Interestingly, the bone and immune crosstalk in Osteoarthritis results in apparently opposite outcomes at the same time, albeit in separate compartments: with net bone loss (sclerosis) in the subchondral area under direct mechanical pressure, and new bone formation propagating tangentially (osteophytes).
Perhaps piezoelectric forces may be in interplay with the inflammatory milieu to yield the characteristic OA phenotype. So it's not just mechanical wear-and-tear, nor purely osteo-immunology, that makes for OA and OP. Interesting.
Primary Osteoarthritis of the Hands seems to me a very different animal from Osteoarthritis of the knees and hips. The former has a prominent genetic component and age propensity. Pathologically, OA hands looks very much "outside-in" inflammatory (synovitis, erosions), while OA knees is more "inside-out" mechanical (subchondral bone marrow oedema, cartilage ulceration).
In fact, the "Inflammatory OA hands" described in this sonographic study looks a lot like RA and PsA.
The Arthritis Cure?