Biosteon ACL Screws (Prod 4168)

Bioabsorbable implants which contain polymers such as poly L-lactide have gained increased popularity over the years and are generally preferred over metal screws for internal fixation due to the following: reduced risk of metallic corrosion, reduced stress shielding of the bone, and the elimination of the need to remove the implant during revision procedures or diagnostic imaging. Although these absorbable devices have been shown to provide secure graft fixation while eliminating the above risks, complications associated with absorbable implants can also arise such as tissue incompatibility (related to unbalanced pH levels) during the resorption period and mechanical weaknesses. The introduction of hydroxyapatite into poly L-lactide creates a composite implant with improved strength retention, potential bone bonding capabilities and osteoconductive properties. In addition, hydroxyapatite acts as a pH buffer during the resorption process, decreasing the likelihood of tissue incompatibility. The Stryker Biosteon(r) Wedge Interference Screw combines the advantages of poly L-lactide (PLLA) with the osteoconductive potential of hydroxyapatite (HA), to create an implant that provides superior mechanical and biological properties for use in anterior cruciate ligament reconstruction. HA facilitates bone growth at the implant site through an osteoconductive process where osteons form, contributing to new bone formation to gradually replace the implant. HA also has the potential to chemically bond to host bone. In addition, HA has shown to buffer the PH levels during the resorption process, an important factor influencing tissue response and biocompatibility.