Before getting underway, let's clarify some terminology lest it confuse the issue. Specifically, you state that: "I have done some research on the internet in which there are reported cases of dysbaric osteonecrosis in recreational divers who have done deep dives, done the required deco stops but who also report some symptoms that are indicative of mild DCS."
Deep dives that generate deco obligations are not recreational dives; they are technical dives that involve large nitrogen loadings. This is an important distinction for several reasons.
Dysbaric osteonecrosis (DON) has a strong association with large numbers of dives involving large nitrogen loadings over extensive periods of time. Not surprisingly, it is primarily a disorder of commercial divers, distantly followed by technical divers. It is extremely unusual in true recreational divers.
Yes, there have been a very, very few cases of DON reported in recreational divers. Even at that, I'd point out that in several of these cases DON was only a best guess diagnosis after other reasonable explanations had apparently been ruled out.
You ask several specific questions:
Q1. "If a diver gets a mild DCS hit-some discomfort in the hip or shoulder that passes within a couple hours and for which no intervention is done (use of O2 or a chamber ride- is there a significant chance that there will be physiological damage?"
A1. As a point of terminological correctness, DON is caused by a physiological process, but the actual damage is anatomical. Specifically, areas of bone die because blood vessels serving that bone are occluded by nitrogen bubbles coming out of solution.
No. In the otherwise normal and healthy recreational diver the chances of DON are extraordinarily small.
Q2. "Understanding that recreational diving is by definition NDL, is this a problem for the general recreational dive community?"
A2. Based on the overall literature and thinking of most diving medicine and physiology experts, in the true recreational diver who remains within NDL and does conservative ascents, safety stops and surface intervals, it is not.
This is educational only and does not constitute or imply a doctor-patient relationship. It is not medical advice to you or any other individual, and should not be construed as such."