Thermal properties of first metatarsal osteotomies.

UNLABELLED: Heat is generated whenever osteotomies are created, Kirschner wires are inserted, holes are drilled, and when bone is reduced with a burr. Although previous investigators have determined the combination of time and temperature necessary to cause bone injury, to our knowledge, no one has yet specifically studied whether the heat generated when osteotomies are performed in the foot reaches sufficient levels to damage osseous tissue. Toward that end, the authors designed an experiment to measure the change in cadaveric first metatarsal temperature, and the time associated with the rise and fall of the bone temperature, in response to osteotomies performed with and without concomitant saline solution irrigation of the saw blade. The study was conducted on matched pairs (contralateral limbs) of cadaveric bone, with one side being irrigated with normal saline solution and the other side being osteotomized without saline solution irrigation. Osteotomies were created dorsally and plantarly at 3 sites in the first metatarsal specimens, specifically at the head, mid-diaphysis, and base; and a total of 112 osteotomies were included in the analyses. Regardless of whether saline solution irrigation was used, none of the bone specimens reached a temperature known to be associated with thermal injury during osteotomy. The use of saline solution irrigation did, however, provide a reduction in peak bone temperature during osteotomy, and the duration of sustained temperature elevation was also shortened with the use of irrigation. LEVEL OF CLINICAL EVIDENCE: 5.