Metal debris from bony resection in knee arthroplasty--is it an issue?
BACKGROUND
Metal particles are generated during bone preparation in knee arthroplasty. These particles may produce third-body wear, or may have a role in osteolysis. Knowledge of their characteristics may help in the development of methods to reduce the amount of metal debris during bone cutting procedures.


METHODS
We performed bony resection of the distal femur and proximal tibia on 15 pig knees, simulating a total knee arthroplasty (TKA). Metal debris was collected from the saw blades, cutting blocks and bone surfaces and cleaned for microanalysis.


RESULTS
The average loss of metal from the saw blades was 1.13 mg. The average volume of a wear particle was 3.4 x 10(-16) m(3). From this, it was estimated that approximately 500,000 particles are released from the saw blade alone. Material analysis of the particles indicated that the majority originated from the metallic cutting guides, suggesting that many millions of wear particles would be generated during the surgical procedure. Two particle shapes predominated: platelet shape and ploughed shape.


CONCLUSIONS
Wear particles are produced during resection for a TKA. These may enter the artificial articulation and cause accelerated wear and macrophage activation. Redesign of cutting blocks and saw blades may reduce the amount of debris produced during surgery.
Gotterson
Peter R
PR
School of Engineering Systems, Queensland University of Technology, Brisbane, Australia.
Nusem
Iulian
I
Pearcy
Mark J
MJ
Crawford
Ross W
RW
D000818:Animals; D019645:Arthroplasty, Replacement, Knee / Q000009:adverse effects*; D005269:Femur / Q000601:surgery; D008422:Materials Testing; D008670:Metals; D010014:Osteolysis / Q000209:etiology; D010316:Particle Size; D013525:Surgical Instruments; D013552:Swine; D013977:Tibia / Q000601:surgery
D008670:Metals