The effect of therapeutic ultrasound on metallic implants: a study in rats.
OBJECTIVE
To investigate whether therapeutic ultrasound (US) use over metallic implants has the potential for adverse effects as a result of greater temperature increases at the tissue-metal interface.


METHODS
A randomized controlled trial.


METHODS
A research laboratory.


METHODS
Sprague-Dawley rats (N=40; weight, 230-300g) were used and divided into 3 study groups.


METHODS
In group 1, both limbs of 10 rats were used for evaluation of temperature changes. Metal pins were placed into the femur of the left limb, and the right limbs were used as controls. A thermal sensor was placed into the medulla to record the elevation of tissue temperature during US application. In groups 2 and 3 with 15 rats in each, a midshaft femoral fracture was produced, and intramedullary fixation was performed with metal pins. Group 2 received US treatment for 5 minutes daily and continued for 27 days. Group 3 served as controls.


METHODS
The rats in groups 2 and 3 were killed on postoperative day 30. The specimens were evaluated by radiology, histopathology, and biomechanics.


RESULTS
The presence of metal in bone did not cause an increased temperature rise. US application did not increase or decrease callus formation, and there was no tissue necrosis. The average removal torques of pins in groups did not show a significant difference.


CONCLUSIONS
Internal fixation with metallic implants may not be a contraindication for therapeutic US treatment.
Department of Orthopaedics and Traumatology, Acibadem University Faculty of Medicine, Istanbul, Turkey. bariskocaoglu@gmail.com
Barış
B
Kocaoğlu
Cengiz
C
Cabukoglu
Nadire
N
Ozeras
Mustafa
M
Seyhan
Mustafa
M
Karahan
Selim
S
Yalcin
D000818:Animals; D001696:Biomechanical Phenomena; D001831:Body Temperature; D001858:Bone Nails; D017102:Fracture Healing; D050723:Fractures, Bone / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D011859:Radiography; D051381:Rats; D017207:Rats, Sprague-Dawley; D013016:Sound