Pilot investigation into osteotome hard surface coating and cutting-edge degradation

BACKGROUND: Osteotomes are bone cutting tools commonly reused in orthopedic surgical procedures. Despite undergoing rigorous cleaning, visual inspection, and sterilization procedures between every use, the condition of the cutting blade edge is commonly not qualitatively assessed. Subjective feedback from surgeons suggests a large variation in osteotome cutting-edge sharpness is found during use. This study seeks to investigate the retention of osteotome cutting-edge sharpness by comparing the wear resistance of as-supplied, electroless nickel, and titanium nitride coated osteotomes following a series of bone cutting tests. METHODS: Changes in edge sharpness were assessed using visual inspection, depth penetration testing that quantified change in the blade sharpness index, and scanning electron microscopy visual analysis. Visual inspection of each osteotome blade edge was then compared to qualitative blade sharpness index measurement. RESULTS: After use, no cutting-edge damage or change in blade sharpness was detected by visual examination of all three osteotomes; however, the as-supplied osteotome demonstrated 50% loss of blade sharpness index compared to 30% and 15% reduction for the electroless nickel and titanium nitride coated osteotomes, respectively. This finding was supported by scanning electron microscopy evaluation that found greater mechanical damage had occurred along the cutting edge of the as-supplied osteotome compared to the two coated with wear resistant materials. CONCLUSIONS: The rapid loss of blade sharpness found in the as-supplied osteotome supports the degradation in cutting performance frequently reported by surgeons. The findings from this study demonstrate blade sharpness index better detects cutting-edge wear compared to visual inspection. Results from this pilot study also suggest the coating of osteotomes in hard-wearing biocompatible materials assists in retaining cutting-edge sharpness over multiple uses. Further study using a larger sample size is required to validate these findings.