[Why do osteosyntheses fail? The problem with biomechanics and biology].

Avoidance of complications in the course of fracture treatment is of essential importance not only for patients but increasingly from an economic point of view. In the past 15 years emphasis has been placed on the development and fine-tuning of minimally invasive reduction techniques with suitable implants. The main objectives were avoidance of surgical site infection and uneventful fracture healing. This facilitated the solving of long-standing problems but created new sources of error. Minimally invasive, dynamic forms of osteosynthesis were found to fail with extensive open reduction or neglect of biomechanics. Additionally, it appeared that some traditional techniques and basic rules of operative fracture treatment fell into oblivion. The majority of complications are determined already preoperatively by the choice of treatment or implant. After exact analysis of the biomechanics and biological etiology, nonunion is dealt with by an imperative increase in mechanical stability. Additional procedures, i.e., bone graft or debridement, are incorporated into the therapeutic regime. Increasing mechanical stability should be attempted with a minimum of added trauma to avoid local biological impairment. Further improvement of outcome depends on innovative and adapted teaching concepts. Training exclusively with one implant, even under the guidance of the producing company, is insufficient to grasp the various fundamentals of operative fracture treatment indispensable for a successful day-to-day routine.