Chlorhexidine gluconate cleansing has no effect on the structural properties of human patellar tendon allografts

Purpose: If an anterior cruciate ligament graft somehow becomes contaminated intraoperatively, soaking it in 4% chlorhexidine gluconate has been shown to be the most popular and efficacious method for sterilization before implantation. The purpose of this study was to evaluate the effects of a chlorhexidine soak on the structural properties of human patellar tendon allografts. Methods: Sixteen human patellar tendon allografts were randomly split into 2 groups of 8. Grafts in 1 group were soaked in 4% chlorhexidine gluconate for 30 minutes, and the other grafts were kept moist in normal saline-soaked gauze. Data on preload width, preload thickness, elongation, ultimate tensile load, and stiffness were obtained through measurement and mechanical testing of the grafts. Results: Graft donor ages ranged from 29 to 43 years. There was no difference in the mean values of graft dimensions of the chlorhexidine-exposed group versus the normal saline-exposed group before mechanical testing (width of 9.48 mm v 9.56 mm, P =.89; thickness of 4.01 mm v 4.57 mm, P =.34). Graft elongation was not statistically different between the groups (2.52 mm v 1.43 mm, P =.27). No statistically significant difference was noted between the ultimate tensile load (2,219 N v 1,878 N, P =.36) or stiffness (274.3 N/mm v 297.0 N/mm, P =.63) of the grafts in both groups. Conclusions: Structural properties of human patellar tendon allografts are not significantly affected by soaking in 4% chlorhexidine gluconate for 30 minutes. Clinical Relevance: Surgeons wishing to treat an inadvertently contaminated graft intraoperatively with 4% chlorhexidine may do so without concern that such treatment will impact graft strength.