Thermal Osteonecrosis Caused by Bone Drilling in Orthopedic Surgery: A Literature Review.

Thermal osteonecrosis is the in situ death of bone tissue as a result of excessively high temperatures. While the exact temperature at which thermal osteonecrosis occurs has not yet been determined, 50°C is the accepted critical value, as bone regeneration is almost completely impaired from this point on. Thermal osteonecrosis is a significant concern in orthopedic surgery, as it can compromise the bone-implant interface in fracture fixation, which, by definition, is a complication. A literature review was undertaken of the pertinent literature concerning heat generation from bone drilling and how this heat affects bone tissue. The Pubmed, ScienceDirect, and secondary (Cochrane Library) databases were searched up to December 2017 using keywords with the appropriate use of Boolean operators. Both simple text word searching and thesaurus searching were used to maximize the number of relevant articles retrieved. Reference tracking was performed via the retrieved articles to further extend the boundaries of the search. The level of evidence was Level V. It was identified that factors affecting heat generation during bone drilling were multifactorial and did not act independently of each other. Good quality evidence exists that both bone drilling parameters and the drill itself affect heat generation in bone during bone drilling. However, external irrigation is the most important variable and should always be used to keep the bone temperature below the critical value of 50°C. Future studies should focus on how the parameters of bone drilling interact with each other and how this influences heat generation in bone drilling. There is also a lack of in vivo studies on the human bone; this too should be further investigated.