Antimicrobial efficacy of external fixator pins coated with a lipid stabilized hydroxyapatite/chlorhexidine complex to prevent pin tract infection in a goat model.
BACKGROUND
Pin tract infection is a common complication of external fixation. An antiinfective external fixator pin might help to reduce the incidence of pin tract infection and improve pin fixation.


METHODS
Stainless steel and titanium external fixator pins, with and without a lipid stabilized hydroxyapatite/chlorhexidine coating, were evaluated in a goat model. Two pins contaminated with an identifiable Staphylococcus aureus strain were inserted into each tibia of 12 goats. The pin sites were examined daily. On day 14, the animals were killed, and the pin tips cultured. Insertion and extraction torques were measured.


RESULTS
Infection developed in 100% of uncoated pins, whereas coated pins demonstrated 4.2% infected, 12.5% colonized, and the remainder, 83.3%, had no growth (p < 0.01). Pin coating decreased the percent loss of fixation torque over uncoated pins (p = 0.04).


CONCLUSIONS
These results demonstrate that the lipid stabilized hydroxyapatite/chlorhexidine coating was successful in decreasing infection and improving fixation of external fixator pins.
DeJong
E S
ES
Extremity Trauma Study Branch, U.S. Army Institute of Surgical Research, Brooke Army Medical Center, Fort Sam Houston, Texas 78234-6200, USA.
DeBerardino
T M
TM
Brooks
D E
DE
Nelson
B J
BJ
Campbell
A A
AA
Bottoni
C R
CR
Pusateri
A E
AE
Walton
R S
RS
Guymon
C H
CH
McManus
A T
AT
D000818:Animals; D000891:Anti-Infective Agents, Local / Q000494:pharmacology*; D001858:Bone Nails; D016009:Chi-Square Distribution; D002710:Chlorhexidine / Q000494:pharmacology*; D020099:Coated Materials, Biocompatible; D020878:Device Removal; D004195:Disease Models, Animal; D017886:Durapatite / Q000494:pharmacology*; D016267:External Fixators; D005592:Fracture Fixation / Q000295:instrumentation*; D006041:Goats; D008297:Male; D013193:Stainless Steel; D013203:Staphylococcal Infections / Q000517:prevention & control*; D018709:Statistics, Nonparametric; D013978:Tibial Fractures / Q000628:therapy*; D014025:Titanium; D019415:Torque
D000891:Anti-Infective Agents, Local; D020099:Coated Materials, Biocompatible; D013193:Stainless Steel; D017886:Durapatite; D014025:Titanium; D002710:Chlorhexidine