THE DEVELOPMENTAL COURSE OF DON OBTAINED BY SERIAL BONE SCANNING OF A HIGH RISK SEAFOOD DIVING POPULATION IN PUERTO RICO
Wilson MA 1 , Lehner CE1 , Dueland RT1 , Ferrigno M3 , López-Tristani A2 , Hart EM4 , Aponte O 2 , Diaz E5 , Toldt AM1
1Departments of Surgical Sciences and Radiology, University of Wisconsin-Madison, Madison, Wisconsin; 2Departments of Anesthesiology and Radiology, University of Puerto Rico, San Juan, Puerto Rico; 3Department of Anesthesiology, Brigham and Womens Hospital, Harvard Medical School, Boston, Massachusetts; and 4Department of Nuclear Medicine, Hospital Perea, Mayaguez, Puerto Rico; 5Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts.
INTRODUCTION: We have previously reported on a high risk population of 30 Puerto Rican seafood divers and identified a 50% prevalence of technetium-99m diphosphonate bone scan lesions typical of dysbaric osteonecrosis (DON). We now wish to determine the course of DON in these divers.
METHODS: We re-imaged 22 subjects (73%) of the original active 30 divers, about 20 months after initial scanning. Evidence of active DON was sought; and old, new and resolved joint and long-bone lesions were identified from the whole body scans. With the knowledge that long-bone scan lesions do not show improvement within 6 months of initial bone insult, and that 65% of all lesions resolve within 12 months (90% in 24 months, and 95% in 36 months), we evaluated the course of DON in this high risk DON population.
RESULTS: 14 subjects had a total of 44 lesions (mean = 3.14 lesions/person) based on their bone scans. Seven had improvement in prior long-bone scan lesions; 3 had new lesions; and 4 had both new lesions and resolution of some old lesions. Six had normal scans and 2 had no change When individual long-bone lesions were evaluated: 16 improved; 5 were unchanged; and 10 were new or worsened. Most joint lesions were stable (n=7), but some improved (n=2) or developed anew (n=2). Minimal scan change in joint regions may reflect the development of degenerative joint disease (DJD) with involvement of the articular cartilage by DON.
CONCLUSION: This study confirmed that significant DON lesion changes occurred over a 20-month period. Using knowledge of the long-bone scan repair rate, the course of DON can be made from statistical analysis. (Research was funded by the UPR Sea Grant Institute and UW Sea Grant Institute.)
Submitted to the Undersea & Hyperbaric Medical Society for presentation to the 2005 UHMS Annual Scientific Meeting, Las Vegas, NV, June 16-18.