Use of scintigraphy for assessment of fracture healing and early diagnosis of osteomyelitis following fracture repair in rabbits.
OBJECTIVE
To evaluate use of technetium Tc 99m disodium hydroxymethylene diphosphonate (99m-Tc-HDP) for assessing fracture healing and 99m-Tc-HDP and technetium Tc 99m ciprofloxacin (99m-Tc-CIPRO) for early diagnosis of osteomyelitis in rabbits.


METHODS
32 skeletally mature New Zealand White rabbits.


METHODS
A femoral fracture defect stabilized with bone plates and cortical screws was used. Scintigraphy was performed 4, 8, 12, and 16 weeks after surgery. The 99m-Tc-CIPRO scan was performed 48 hours after the 99m-Tc-HDP scan. The uptake ratio of the experimental limb to the normal limb was calculated by use of multiple regions of interest. Results of radiography performed to determine external callus and lysis grade and percentage defect ossification at 16 weeks were compared with scintigraphy results.


RESULTS
Infected fractures had a higher uptake ratio for 99m-Tc-HDP and 99m-Tc-CIPRO than noninfected fractures. Infected fractures could be differentiated from noninfected fractures late in healing by use of 99m-Tc-HDP. Although 99m-Tc-CIPRO was better than 99m-Tc-HDP for identifying infection, there was a high incidence of false positive and negative results with 99m-Tc-CIPRO. There was an association between 99m-Tc-HDP uptake ratio and callus formation and a good correlation between 99m-Tc-HDP uptake ratio and defect ossification after 4 weeks.


CONCLUSIONS
99m-Tc-HDP and 99m-Tc-CIPRO may be useful for diagnosing osteomyelitis late in fracture healing; however, false positive and false negative results occur. Technetium Tc 99m disodium hydroxymethylene diphosphonate may be useful for evaluating fracture healing.
Southwood
Louise L
LL
Department of Clinical Sciences, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins 80523, USA.
Kawcak
Chris E
CE
McIlwraith
C Wayne
CW
Frisbie
David D
DD
Steyn
Phillip E
PE
D000818:Animals; D002939:Ciprofloxacin / Q000031:analogs & derivatives*; D005260:Female; D005269:Femur / Q000473:pathology*; D017102:Fracture Healing; D015609:Organotechnetium Compounds; D010019:Osteomyelitis / Q000175:diagnosis*; D011817:Rabbits; D011877:Radionuclide Imaging / Q000662:veterinary*; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives*
D015609:Organotechnetium Compounds; C431804:Technetium Tc 99m ciprofloxacin; D002939:Ciprofloxacin; C024226:technetium Tc 99m hydroxymethylene diphosphonate; D013669:Technetium Tc 99m Medronate