Theses and Dissertations

Issuing Body

Mississippi State University


Elder, Steven H.

Committee Member

Liao, Jun

Committee Member

Kent-First, Marijo G.

Committee Member

Butler, R. Allen

Date of Degree


Document Type

Graduate Thesis - Open Access


Biomedical Engineering

Degree Name

Master of Science


James Worth Bagley College of Engineering


Department of Agricultural and Biological Engineering


The ACL is one of the major ligaments in the knee connecting the femur to the tibia which provides stability by resisting shear in sagittal plane. ACL tears occur in 1 out of 3000, and due to inability to heal, reconstructive surgeries are performed at a rate of 200,000/year. Final graft fixation tension during surgery has been shown to wane due to stress-relaxation which has been correlated with negative clinical outcomes. Therefore, preconditioning, which currently is an isometric load (88N), is performed to remove stress-relaxation after the final tension has been applied in vivo. Three preconditioning protocols, creep, stress relaxation, and none, were tested to show significant differences and variance in graft tension after 30 minutes. The results suggest that the current preconditioning protocol may not be efficient enough to remove stress-relaxation after final fixation, and that a creep protocol causes less variability than the other preconditions performed.



ACL reconstructive surgery||stress relaxation||preconditioning