From the surgeons looking at my xrays, the cushion in the joint is worn away; the xray shows the femeral ball hard against my pelvis; my right hip is not quite as bad; 38 years of motorcycle racing takes its toll I guess.
With worn out joints, I came back to MX after 25 years of roadracing, riding at our practise track that has lots of off-camber left-hand corners, I kept sliding-out and stressing the hip joint until now it wouldn't stop hurting.
According to my surgeon, age 52 is the average for a hip replacement in an active person.