Osteo-arthritis or OA is a generic term for inflammation (the -itis) of the joints (-arth) and associated bony structures (-osteo). The cause, by and large, is due to damage to the cartilage of the joint secondary to 1. a direct attack by bugs or chemicals (TB or gout etc), 2. alteration of the structural support of the underlying bone and stabilising ligaments (fractures, infections, loss of blood supply and so on) and 3. direct trauma damage to the cartilage itself due to direct impact trauma or repetitive minor trauma (that can also be caused by joint instability after ligament tears). All cartilage wears out with age and certain activities such as climbing may hasten this degeneration by causing repetitive minor trauma. It is my understanding that there is no substansive proof that physiotherapists have a greater chance of OA of the joints of their thumbs even after years of heavy use. Finger tip OA is common even in non-climbers.
Dear Chalk. To qualify as an Orthopaedic surgeon requires a minimum of 14 years study and experience (of which at least 7 years include 80 hour work weeks) before being let loose on the unsuspecting public . There are few if any careers that takes as long and the training as rigorous and arduous even in the other medical specialties.
At least in my generation the selection process to get to study medicine was also one of the most rigorous academically. Even so nobody scores even close to 100% and yet South African medical standards are still considered to be one of the best in the world. But it then begs the question: if the medical profession is so poor then how bad are the other professions that let loose their members on the public with much less training and experience. Sometimes with as little as 3 or 4 years training and little or no experience?