Femoral and tibial blood supply: A trigger for non-union?

A review of the literature was undertaken to investigate the existing evidence of the vascular distribution of the shaft area of both the femur and the tibia in order to assess whether there are any distinct zones of a compromised blood supply predisposing these areas to an increased risk of non-union following a fracture. The review was conducted in a systematic manner following the PRISMA guidelines. The electronic search initially retrieved 2509 manuscripts, but only 21 fulfilled the inclusion criteria. The search through the bibliographies of the original 2509 results, aided in the collection of a further 43 studies, of which five met the inclusion criteria. In total 26 articles formed the basis of this review. Some of the selected papers contained more than one study of interest. Thus, out of 26 articles we were able to analyse 37 studies: 28 anatomical and 9 imaging studies. The overall sample size of the studies which specified the number of specimens was 3577 bones, of which 2243 were femurs and 1382 were tibias. The specimens were aged between 21 and 98 years. According to the existing evidence I the literature, both the femoral and tibial shaft exhibit specific zones of a compromised blood supply. In particular, dividing the topography of the shaft of the bones into sections of thirds, we were able to identify three zones with varying degrees of vascularisation. The upper third of the femur has a moderate degree of vascularisation, the middle third has a high degree of vascularisation and the lower third has a poor degree of vascularisation. In contrast, the upper third of the tibia has a high degree of vascularisation, the middle third has a moderate degree of vascularisation and the lower third has a poor degree of vascularisation. Based on these findings we speculate that these zones could have major implications in the development of non-union following fracture fixation. Clinical studies are desirable to confirm if fractures occurring in these less vascularised zones and direct surgical approaches (potential violation of the existing vascular tree), are more likely to lead to non union.