Perioperative Radiographic Predictors of Non-Union in Infra-Isthmal Femoral Shaft Fractures after Antegrade Intramedullary Nailing: A Case–Control Study

Abstract

Antegrade intramedullary (IM) nailing is the gold standard treatment for femoral shaft fractures; however, the non-union rate of infra-isthmal femoral shaft fractures is still high after antegrade IM nailing. This retrospective case–control study aimed to determine the association between perioperative radiographic factors and the non-union of infra-isthmal femoral shaft fractures after antegrade IM nailing. Univariate and multivariate analyses were used to evaluate the radiographic risk factors of non-union. Ninety-three patients were included, with thirty-one non-unions and sixty-two matched controls between 2007 and 2017. All were regularly followed up for 2 years. Receiver operating characteristic analysis revealed that a ratio of the unfixed distal segment >32.5% was strongly predictive of postoperative non-union. The risk factors for non-union were AO/OTA type B and C (odds ratio [OR]: 2.20), a smaller ratio of the distal fragment (OR: 4.05), a greater ratio of the unfixed distal segment (OR: 7.16), a higher ratio of IM canal diameter to nail size at the level of fracture (OR: 6.23), and fewer distal locking screws (OR: 2.31). The radiographic risk factors for non-union after antegrade IM nailing for infra-isthmal femoral shaft fractures were unstable fractures, shorter distal fragments, longer unfixed distal fragments, wider IM canal, and fewer distal locking screws. Surgeons must strive to avoid non-union with longer and larger nails and apply more distal locking screws, especially for unstable, wider IM canal, and shorter distal fragment fractures.

Development and validation of predictive nomogram for postoperative non-union of closed femoral shaft fracture

“…Santolini et al 22 concluded that complex fractures and high initial fracture displacement increased the risk of non-union in long bone fractures. Similarly, Hung et al 23 showed that the risk factors for non-union of femoral shaft fractures were types B and C according to AO/OTA classification, consistent with the results of this study. According to a study on the factors of non-union of shaft fractures by Jensen 24 , type B fractures have a more significant effect on non-union than type A fractures.…”

Advances in Musculoskeletal Imaging and Their Applications

“…Antegrade intra-medullary (IM) nailing remains the typical treatment for femoral shaft fractures, yet non-union rates remain high for infra-isthmal femoral shaft fractures based on this approach [32]. Thus, a retrospective case-control study aimed at identifying perioperative radiographic factors linked to non-union in these cases after antegrade IM nailing was performed.…”