Biocompatibility Beyond Polymers

Absorbable materials have been used extensively in the manufacture of fixation devices for cruciate ligament reconstruction. The growth in the use of these materials has been based on their satisfactory performance, coupled with the promise of ultimate absorption. These materials, however, have shortcomings, such as the extended period over which they absorb and reported late foreign body reactions.

Bilok^® composite material was developed over many years of research to address these shortcomings. The Bilok material is a composite of low molecular weight PLLA and synthetic β Tricalcium Phosphate. Both PLLA and Tricalcium Phosphate have long histories of implantation and biocompatibility in a human environment.^1,2 These components are combined in a matrix optimized to achieve a material which is physically and biologically superior for implantation when compared with polymers and co-polymers.

The First Material of its Kind

The Bilok composite material was the first material to combine Calcium Phosphate with an absorbable polymer, resulting in a product that addresses the issues with polymer-only screws, by offering surgeons:

• Osteoconductive PLLA/Tricalcium Phosphate composite material
• Unequalled clinical follow-up over 6 year period
• Improved biocompatibility compared with Polymer-only screws

Diagram (a) below shows new bone formation within the central driver recess cavity, indicating the osteoconductive nature of the Bilok material. Diagram (b), under high magnification, shows full integration of the implant-to-bone interface with no evidence of fibrous encapsulation.³

(a) 12 week low magnification dog femur		(b) 12 week high magnification dog femur