Abstract
Cement-induced thermal osteonecrosis is well documented, as is the potential for nerve injury from thermal energy. Cement is often used to augment fixation following excision of humeral metastases. Porcine femurs were used as a model. We sought to find out the maximum temperatures that would be reached in various parts of the bone during the cement setting process, to explore what negative effects this might have on neighbouring bone and nerve.
A 12mm by 12mm window was cut from 12 porcine femoral shafts, and Palacos R+D cement injected into the defect. As cement set, bone surface temperature was measured using infra-red thermal imaging and thermocouples used to measure temperatures at the bone-cement interface, 5mm from the cement bolus, 10mm from cement bolus and an area running around the shaft replicating radial nerve.
Bone surface temperature rose to a maximum of 34.0 C (on average), and 32.9 C in the ‘radial nerve’ thermocouple. Notably, in two bones there were fractures during specimen preparation, and maximum temperatures in these two areas exceeded 41 degrees C.
Average maximum temperatures were 58.1 C, 36.5 C and 30.1 C at the bone cement interface, 5mm and 10mm from the cement bolus respectively.
