Constitutive Model of PLG 10-90 for Anterior Cruciate Ligament Reconstruction

There are an estimated 100,000 cases of torn Anterior Cruciate Ligaments (ACL) in the United States each year. Although autografts and allografts are approved treatments, they are expensive, labor intensive, cause donor site morbidity, and require a lengthy patient recovery process. Despite decellularization treatments, DNA left in allografts can increase the risk of disease transmission and immunogenic response. Synthetic implants eliminate the harvesting procedure and have great biocompatibility. Understanding the time dependent properties of a synthetic material that closely matches those of native ligaments is imperative for ACL reconstruction innovation. PLG 10-90 (L-lactide -co-glycolide) monofilament is an absorbable biopolymer and strong candidate for ACL reconstruction. The biopolymer sufficiently matches average native ACL tensile strength and percent elongation to fracture. Additionally, the dissolution time of PLG 10-90 is approximately the same as ACL growth time. This inversely proportional relationship offers the potential of scaffold reconstruction procedures. This research will determine a set of evolutionary equations which predicts failure under a variety of conditions. Specimens are stored under an assortment of loads at in-vivo conditions. A specimen is then subjected to one of several tensile tests, including a jump test, to determine the properties at different time points. These tests illustrate the time dependent properties in terms of rate of dissolution and strain rate. This data will show a relationship between the strength of PLG 10-90 and its dissolution which is required to build a constitutive model and determine the viability for ACL reconstruction.