Use of minimally invasive cerclage wiring for displaced major fragments of femoral shaft fractures after intramedullary nailing promotes bone union and a functional outcome

Background: Femoral shaft fractures caused by high energy trauma can be very challenging due to the large variability in fracture morphology and poor functional outcomes. Displaced major fragments of femoral shaft fractures are difficult to manage after closed reduction and intramedullary nailing (IMN). The minimally invasive cerclage wiring (CW) procedure has become an optimal tool for major fragment resetting and stabilization after IMN. However, arguments continue for the potential risk of arterial injury, blood supply disruption, and delayed bone union or non-union with the CW procedure. The surgical algorithm for treating femoral shaft fractures with displaced major fragments remains controversial. Thus, emphasis is placed on whether the CW procedure can promote the bone union rate and improve functional outcomes without significant complications. Methods: We performed a retrospective study on all patients of femoral shaft fractures with displaced major fragments between June 2015 and August 2019 in our trauma centre. Eligible patients were included and stratified into the CW group and IMN group. Demographics, radiological data, callus formation, union time, and functional outcomes were critically compared between the two groups. Results: Thirty-seven patients were included in the present study according to our inclusion/exclusion criteria, of whom 16 (43.2%) were stratified into the CW group, and 21 (56.8%) into the IMN group. The modified radiographic union score for femorae (mRUSH) in the CW group and IMN group was significantly different (11.94 +/- 1.29 vs. 7.95 +/- 0.74, 6 months; 15.88 +/- 0.50 vs. 10.33 +/- 0.91, 12 months) (p < 0.0001). The mean union time was significantly different between the CW and IMN groups (7.9 +/- 3.2 months vs. 20.1 +/- 8.48 months) (p < 0.0001). Bone union at 12 months differed significantly between the CW and IMN groups (15 vs. 5) (p < 0.05). The Harris Hip Score in the CW group was significantly higher than that in the IMN group (88.19 +/- 4.69 vs. 76.81 +/- 5.26, 12 months; 93.19 +/- 4.68 vs. 87.57 +/- 5.38, 24 months) (p < 0.01). The Hospital for Special Surgery Knee Score was significantly different between the CW and IMN groups (78.50 +/- 5.65 vs. 67.71 +/- 4.65, 12 months; 89.50 +/- 5.05 vs. 75.81 +/- 8.90, 24 months) (p < 0.0001). Conclusions: Minimally invasive CW is an optimal supplement for IMN in the treatment of femoral shaft fractures with displaced major fragments. As illustrated, the benefits of CW potentially include promotion of the bone union rate and improvement in functional outcomes.