Good news indeed for both the patient and his worried dad!
There are all sorts of interesting things that the orthopaedic surgeons are getting up to these days to stave off joint replacement in young patients. Joint drilling, resurfacing....
IS your son on glucosamine and chondriotin? There are a couple of interesting studies going on at the moment where they are looking at prevention of cartilage loss (as distinct from evidence of repair in previous studies) in 'reasonably healthy' joints. Part 1 of the biggest glucosamine trial is in:
Those with mild hip / knee symptoms reported little reduction in pain or improvement in function.... but they have little evidence of degeneration. Those in the moderate and severe categories reported a statistically significant reduction in joint pain and improvement in joint function. Those in the placebo group reported little improvement in either. (some evidence to suggest worsening in some individuals but not to a 0.5 level of confidence yet...)
AT the end of 2012 / early 2013 Part 2 of this study will close and data will be collected and analysed..... They are hypothesising that those in Rx G1 (mild) will still be in G1 after 10 years of glucosamine, whereas as those in Control G1 (placebo) will have progressed on to find themselves now in G2 (moderate pain and dysfunction) thanks to the effects (or not...) of glucosamine therapy.
I'm awaiting the publication of this with baited breath.