Differences in Trochlear Surface Damage and Wear Between Three Different Total Knee Arthroplasty Designs.

Area of Science:

• Orthopedic surgery
• Biomaterials science
• Wear analysis

Background:

• Patellofemoral kinematics are influenced by trochlear design in total knee arthroplasty (TKA).
• Limited data exists on comparative contact properties of contemporary TKA femoral components.

Purpose of the Study:

• To evaluate and compare patellofemoral joint contact properties.
• To identify surface damage and wear patterns in retrieved femoral components from three modern TKA designs.

Main Methods:

• Analysis of 18 retrieved femoral components (Triathlon, SIGMA, GENESIS II) matched for key patient factors.
• Assessment of wear and surface damage via visual inspection, light microscopy, and light profilometry.

Main Results:

• All implant types showed surface damage upon visual inspection; no significant visual differences were noted.
• Light profilometry revealed significantly increased roughness in retrieved Triathlon and SIGMA components versus reference.
• SIGMA components demonstrated significantly greater roughness than Triathlon or GENESIS II, particularly in the proximal trochlear groove and medial trochlea.

Conclusions:

• Increased patellofemoral joint understanding is crucial given rising TKA demands.
• Retrieved SIGMA components exhibited higher roughness compared to Triathlon and GENESIS II.
• The causes and clinical implications of increased trochlear roughness require further research.