Thermal Damage Done to Bone by Burring and Sawing With and Without Irrigation in Knee Arthroplasty

BackgroundHeat from bone resecting tools used in knee surgery can induce thermal osteonecrosis, potentially causing aseptic implant loosening. This study compared oscillating saws to burrs in terms of temperature generation and histologic damage. Use of irrigation to reduce bone temperature was also investigated.MethodsTemperatures were recorded during sawing and burring with or without irrigation (uncooled or cooled). Histologic analyses were then carried out. Differences between groups were tested statistically (α = 0.05).ResultsOn average, burring produced higher temperatures than sawing (P < .001). When uncooled irrigation was used, bone temperatures were significantly lower in sawed bone than in burred bone (P < .001). Irrigation lowered temperatures and thermal damage depths and increased osteocyte viability (P < .001).ConclusionThese results suggest that irrigating bone during resection could prevent osteonecrosis onset.