Review Question - QID 219432

This patient presents with a segmental femoral shaft fracture. The use of unreamed intramedullary nails for the treatment of femoral shaft fractures is a risk factor for delayed union and non-union (Answer 4).

Femoral shaft fractures are high-energy injuries that are generally treated successfully with intramedullary nailing. The overall union rate of diaphyseal femur fractures is greater than 95%. Several factors have been investigated as potential risk factors for femoral shaft non-union. Both antegrade and retrograde nailing are routinely used in treatment. Several factors including concomitant injuries, the patient’s body habitus, and the surgeon’s preference can influence the choice of implant and operative approach. As discussed below, two retrospective studies published in 2020 evaluating closed versus open reduction of these fractures showed no difference in union rate or infection. The use of unreamed nails has been shown in several publications to be an independent risk factor for non-union and delayed union. Although reaming does disrupt the endosteal blood supply, it stimulates the periosteal blood supply to the fracture, deposits intramedullary autograft into the fracture site, and allows for larger nails to be placed. Recent studies report nails sized 10mm, 11mm, or 13mm in diameter had equivalent union rates.

Telgheder et al. performed a retrospective trial involving 107 patients undergoing intramedullary fixation of nonpathologic femoral shaft fractures (AO/OTA type 32). They evaluated the union rates between open versus closed reduction prior to intramedullary nailing. At a mean follow-up of 14 months, there was no reported difference in union rates or time to union between the two cohorts.

Ghouri et al. performed a retrospective analysis of 110 isolated femoral shaft fractures. 73 patients underwent closed reduction and 37 underwent open reduction prior to intramedullary nailing. The overall non-union rate was 5.5% with no difference observed between the two groups. There was also no difference in infection rate. The operative time was shorter in the closed group. The authors recommend open reduction if closed reduction maneuvers are not successful after 15 minutes.

Duan et al. performed a systematic review on the effect of unreamed versus reamed femur intramedullary nails on union rates and reoperation rates. They included seven trials with 965 fractures. In this study, reamed nails had lower reoperation and non-union rates. There was no difference between the two groups when comparing implant failure, mortality, or acute respiratory distress syndrome. The authors recommend reamed intramedullary nailing over non-reamed nails.

Figures A & B: Plain films of a right diaphyseal segmental femur fracture. Illustration A: Plain film of the same fracture 6 weeks post-op.

Incorrect Answers:
Answer 1: Multiple studies have found similar union rates between open and closed reduction techniques.
Answer 2: Retrospective studies have shown no difference in union rates when cerclage wires are added to the construct.
Answer 3: Antegrade and retrograde intramedullary nails have similar reported union rates.
Answer 5: Staged external fixation has no reported difference in union rates.