Effect of injected versus iontophoretic corticosteroid on the rabbit tendon.
BACKGROUND
The etiologic role of corticosteroid therapy in tendon rupture is controversial. This study compared the effects of injected versus iontophoretically delivered corticosteroid on the normal rabbit Achilles tendon.


METHODS
Rabbits were divided into three treatment groups: (1) corticosteroid injections, (2) iontophoretically delivered corticosteroid, and (3) no treatment. One tendon of each rabbit in the treatment groups was treated with either drug injection or iontophoresis; the tendon of the other leg served as a control. Some tendons were used for testing elastic modulus, ultimate load, and ultimate stress, while the remaining tendons were evaluated histologically.


RESULTS
Injections of either corticosteroid or saline into the tendon sheath resulted in short-term changes in tendon biomechanical characteristics and somewhat higher histologic severity scores; however, iontophoretic delivery of corticosteroid or saline did not affect either significantly.


CONCLUSIONS
Iontophoresis using sterile water or corticosteroid resulted in minimal or no biochemical and histologic changes in the tendon compared with injection of either substance. The method of corticosteroid delivery may be as important as the actual drug effects on the biomechanical and histologic properties of tendons.
Martin
D F
DF
Department of Orthopaedic Surgery, Wake Forest University School of Medicine, Winston-Salem, NC 27157-1070, USA.
Carlson
C S
CS
Berry
J
J
Reboussin
B A
BA
Gordon
E S
ES
Smith
B P
BP
D000125:Achilles Tendon / Q000187:drug effects* / Q000473:pathology / Q000503:physiopathology; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage* / Q000633:toxicity; D001696:Biomechanical Phenomena; D003907:Dexamethasone / Q000008:administration & dosage* / Q000633:toxicity; D007273:Injections, Intramuscular; D007478:Iontophoresis; D008297:Male; D011817:Rabbits
D000893:Anti-Inflammatory Agents; D003907:Dexamethasone