The etiology of the osteoarthrosis is a multifactorial causality. Some factors, the preosteoarthrotic deformities, which concur with the recovery, are well known. The factors of the primary osteoarthrosis are still in the dark and require research. It is presented, that by the miner, the co-operation of several preosteoarthrotic deformities, especially the preosteoarthrotic deformity "repeated knee microtrauma" with unknown factors, leads to the high rate of knee wear and tear which makes the osteoarthrosis after occupational knee strain by mineworkers into an occupational disease.