Improved Porous Coating for Bony Ingrowth
Approved by the FDA in 2005, hydroxyapatite (HA), a naturally occurring, crystalline component of healthy bone is applied into the surface of Stryker press-fit, un-cemented knee implants as a thin plasma coating, improving bone integration into press-fit implants. Wright Medical has developed a bone-inductive porous coat utilizing titanium foam.
What is a gender-specific implant?
Previously, knee implants were designed using combined male and female "average" dimensions even though men and women are usually different. More recently, gender-specific knee implants have been designed and sized for either males or females. Generally speaking, men require broader implants than women.
The advantages of gender-specific knee implants is that they can more accurately crown (cap) and reseal the specific male or female bone structure.
Why Gender-specific Implants?
When male/female differences are not considered, implant designs may not provide optimal bone coverage. Inadequate bone capping may result in atrophy or dissolution of uncovered bone (osteolysis). Overcapping (protrusion beyond normal bone struction) may irritate soft tissues around the knee during activity. Optimizing coverage improves 1. Hemostasis (control of bleeding), 2. Bone integration into implants, 3. Knee stability, and 4. Loading patterns. Figures 9 and 10 show examples of undercoverage and overcoverage, respectively.