[Impaired Healing after Surgery for Femoral Fractures]. / Poruchy hojení po operacní lécbe zlomenin stehenní kosti.

PURPOSE OF THE STUDY: The aim of the study was to analyse causes of impaired bone healing in femoral fractures and to present options of their management. MATERIAL AND METHODS: This is a retrospective study of the data on complications prospectively collected between 2008 and 2013. The patients admitted for primary treatment at the Trauma Centre of the Faculty of Medicine in Hradec Kralove from January 2008 to December 2013 included 1186 patients with injury severity scores (ISS) > 15 and 1340 patients with new injury severity scores (NISS) >15, all older than 16 years. With the exception of two patients, the primary treatment involved the application of an external fixator as part of damage control surgery. Definitive surgery, regardless of the site of fracture, was performed using unreamed femoral nails (UFN) in 51, distal femoral nails (DFN) in 33, plates in 26, long proximal femoral nail antirotation (PFNA-long) in 14 and nails combined with dynamic hip screw (DHS) plates in five fractures. The analysis revealed both mechanical and biological causes of poor bone healing. RESULTS: Of the 124 patients whose multiple injuries included a fracture of the femur, 11 died within 24 hours in spite of intensive resuscitation. In the remaining 113 patients there were 16 bilateral fractures, 20 fractures of the proximal femur (extraarticular), 72 diaphyseal femur fractures and 26 distal femur fractures. Nine patients sustained segmental femoral shaft fractures. Ten diaphyseal and 14 distal femur injuries were open fractures (13.5% and 54%, respectively). Pseudarthrosis developed in a total of 12 fractures (9.3%); six (7.2%) were diaphyseal fractures, of which three were initially open fractures, and six (21.4%) were distal femur fractures with two initially open injuries. All proximal femur fractures healed completely. DISCUSSION: The frequency of non-union femoral diaphyseal fractures in our patients treated by unreamed intra-medullary nailing is in agreement with the literature data. The frequency of non-union distal femur fractures in our group was slightly higher than is published in the literature. This can be accounted for by the characteristics of our group consisting of patients with multiple severe injuries in whom fractures are due to high-energy trauma; the overall severity of injuries negatively affects the biological potential of a human organism for bone healing. CONCLUSIONS: A successful outcome of femoral fracture repair is based on an understanding of the biomechanical principle, i.e., correct fracture reduction and stable osteosynthesis fitting the morphology of the fracture. Comminuted femoral fractures heal well with the use of a narrow long nail whose working length allows for even distribution of movement at a fracture line amongst the fragments and thus fracture motion load does not exceed 20%. On the other hand, short oblique and transverse fractures are examples of problematic fractures which require maximum possible stability provided by a thick nail with a short working length; this is achieved by reaming the medullary cavity or adding lag screws. In our group of patients these fractures were also the most problematic ones. Generally, nailing remains the golden standard in the management of femoral fractures.