• Taran Singh Pall Singh, Abdul Halim Yusoff, and Yap Keat Chian.
• From the Spine and Spinal Cord Rehabilitation Unit, Department of Orthopaedics, School of Medical Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan, Malaysia.
• Spine. 2015 Aug 1; 40 (15): E866-72.

Study DesignIn vitro animal cadaveric study.ObjectiveTo identify the appropriate rotational speed and safe bone distance from neural tissue during bone burring in spinal surgery.Summary Of Background DataBone burring is a common step in spinal surgery. Unwanted frictional heat produced during bone burring may result in thermal injury to the bone and adjacent neural structure. One of the important parameters influencing the bone temperature rise during bone burring is rotational speed.MethodsThis laboratory-based animal study used bovine spine bones, and the tests were conducted using a steel round burr. The bone temperature was measured simultaneously with thermocouple at the distances of 1 mm, 3 mm, and 5 mm from the burring site during the burring process. The bone burring was done with 4 different rotational speeds of 35,000 revolutions per minute (rpm), 45,000 rpm, 65,000 rpm, and 75,000 rpm.ResultsThis study showed that increasing the rotational speed significantly elevated bone temperature. The threshold temperature of 47°C was reached when bone was burred for 10 seconds, with a rotational speed of 45,000 rpm. The mean bone temperature measured at a distance 1 mm from the burring site for all 4 rotational speeds was always higher than that measured at a distance of 3 mm and 5 mm and this difference was statistically significant (P < 0.001). There was no significant difference between the mean bone temperature measured at a distance of 3 mm and 5 mm (P > 0.05).ConclusionTaking 47°C as the threshold temperature for causing significant impairment to the regenerative capacity of bone, a rotational speed of lower than 45,000 rpm is preferable so as to minimize thermal injury to bone tissue. We also concluded that a 3-mm distance between the site of burring and the neural tissue is a safe distance.Level Of EvidenceN/A.

19 keywords...

hide…