Comparison of diving experience factors between divers classified as positive and negative for bone cysts.

Official U.S. Navy diving records for enlisted divers who were 35 years of age and older were examined for differences in diving experience between those who were classified as positive or negative for bone cysts. One-third of the divers (n = 31) were classified as positive, and two-thirds (n = 62) as negative, for bone cysts. Diving experience factors included total years of diving experience, frequency of dives between 15 and 31 m, frequency of dives deeper than 31 m, number of saturation dives, number of dives involving decompression, and number of cases of decompression sickness. None of these factors differed significantly between the two groups. While previous findings showed that bone cysts are twice as prevalent among divers as among a comparison group of Navy enlisted men matched to divers for age, rank, and occupational specialty, these results indicate that this high prevalence rate does not appear to be related to specific types of diving exposure. Other environmental factors such as long-bone injury, disease, or exposure to hazardous or toxic substances may account for differences in the prevalence of bone cysts between the two groups.