Surgeons constantly measure the depth of bone defects during orthopedic implant procedures to make sure they remove the least amount of healthy tissue. One way of doing this involves measuring devices with graduated and colored measuring lines. Coloring is traditionally applied using coatings or elastomer-based materials. Unfortunately, these colors eventually wear away.

To overcome these problems, engineers at IonBond AG, Switzerland, (ionbond.com) developed micro-thin biocompatible coatings (0.002 to 0.003 mm) using a high-vacuum PVD (physical vapor deposition), or PA-CVD (plasma-assisted chemical vapor deposition). “These methods use highly ionized metal plasmas,” says IonBond's Iain J. Smith. “High-energy ions create high-purity coatings on surgical instruments that resist wear, corrosion, and multiple sterilizations.” The instruments are then machined to remove some of the surface, leaving the coating only where it is needed, as in the measuring grooves.”

The coating remains in the grooves longer than traditional coloring products. “Instruments can be used without color particles entering or contaminating incisions,” says Smith. Even after extensive prion neutralization (aggressive pH levels), the measuring lines remained clearly visible. Several colors ensures that the users can easily distinguish similar instruments.