28 Hours of No Fly Time?

[John C. Ratliff]

??? Stay away from NDL's. I had never been "in deco" but often pushed the limits. Now I dive nitrox if I can, and this lets me stay further away from NDL's. I consider that a good thing but others think nitrox is a waste if the dive can be done while not exceeding NDL's. Mind you, I have no proof that my necrosis was from diving, but it fit.

This appears to be correct. Here's an abstract of a scientific paper from PubMed:

Undersea Hyperb Med. 2014 Nov-Dec;41(6):579-87.
Dysbaric osteonecrosis among professional divers: a literature review.
Uguen M1, Pougnet R, Uguen A, Loddé B, Dewitte JD.
Author information
1
Occupational and Environmental Diseases Center CHRU Morvan, Brest, France. marie.guillou-uguen@chu-brest.fr
Abstract
AIM:
Dysbaric osteonecrosis (DON) continues to be a significant occupational hazard that has significant medical and social consequences for professional divers. This review aims to evaluate the prevalence and risk factors of DON among professional divers and to summarize the scientific knowledge regarding distribution of the lesions as well as disease prognosis and treatment.

METHOD:
A literature review using the Medline database.

RESULTS:
The prevalence of DON varies between 0 and 70.6% in professional divers, and its prevalence is highest in Turkey, Hawaii, Korea and Japan but is dependent on activity and medical monitoring. The risk of DON is very low for military divers who strictly obey the decompression rules and who undergo periodic medical examination. DON pre- dominately occurs in the proximal part of the femur and humerus. In a majority of cases, DON will progress despite the absence of further dysbaric exposure.

CONCLUSION:
The pathophysiology of the disease is incompletely understood and other etiological factors are perhaps being overlooked.

PMID:

25562949