The Effect of Chilled vs Room-Temperature Irrigation on Thermal Energy Dissipation During Minimally Invasive Calcaneal Osteotomy of Cadaver Specimens

Background: Minimally invasive (MIS) calcaneal osteotomy has grown in popularity in recent years to address hindfoot deformity. A potential complication is thermal bone necrosis secondary to heat generation from the burr that may lead to osteotomy nonunion. Irrigation is commonly employed to reduce this risk. The effect of irrigation on reducing heat accumulation remains an understudied area. The purpose of this study was to evaluate the effect of cooled vs room-temperature irrigation on thermal energy dissipation during calcaneal osteotomy using a Shannon burr. Methods: Fourteen cadaveric limbs at room temperature (68 °F) were randomized to receive either cooled saline (7 limbs) or room-temperature (7 limbs) irrigation during MIS calcaneal osteotomy. Two thermocouple probes were inserted 5 mm away from the plane of the osteotomy, on the proximal and distal sides, respectively. A 3 × 30-mm Shannon burr was used to perform the osteotomy. The burr was run continuously with continuous irrigation using either room-temperature (68 °F) or chilled (37 °F) irrigation, until the osteotomy was completed. Temperature was recorded at 0, 15, 30, 45, and 60 seconds for the 2 groups and used as a measure of thermal energy accumulation. Results: Both room-temperature and chilled irrigation were effective in minimizing temperature change. On the proximal side, an overall mean increase of 2.5 °F with room-temperature irrigation and a mean decrease of 1.0 °F with chilled irrigation were observed at the 60-second interval ( P = .004). On the distal side, there was a mean increase of 1.3 °F with room-temperature irrigation and a mean increase of 0.5 °F with chilled irrigation ( P = .05). Conclusion: For the duration of an MIS calcaneal osteotomy, both continuous room-temperature and chilled irrigation can minimize temperature increases and potentially reduce the risk of an osteotomy nonunion. Clinical Relevance: Both room-temperature and chilled irrigation can minimize bone temperature increases during MIS calcaneal osteotomy.