The augment of the stability in leaving original internal fixation with multidimensional cross locking plate through femoral anterior approach for aseptic femoral nonunion

Background:
Intramedullary nail fixation is the gold standard for the treatment of fresh femoral shaft fractures. Although the incidence of nonunion has decreased significantly, it still occurs from time to time, reaching 1-10%. The main reason was thought as the insecure anti-rotational stability. A lateral locking plate (LP), leaving the nail in situ, was applied to the fracture site to counter the rotational instability. To achieve much more stability, massive surgical exposure was needed for a longer plate or more uni-cortical screws fixation. To solve this problem, a new designed Multidimensional Cross Locking Plate (MDC-LP) was designed. The purpose of this study is to investigate its clinical advantage compared to lateral LP.
Methods: In this retrospective study, forty-nine consecutive aseptic femoral nonunion from January 2015 to October 2019 were randomly assigned to treatment with MDC-LP (group A) and lateral LP (group B) and were analyzed after a minimum 1-year follow-up. The demographic data and surgical information were all compared. Functional outcomes were evaluated by Lower Extremity Functional Scale (LEFS) at last follow-up.
Results: There are no significant differences in the mean age, gender, BMI, time since injury, initial fracture (close/open), nonunion type or location between groups. A 2-months advantage in the time to union was seen in the patients treated with MDC-LP (4.09 months versus 6.8 months in the lateral LP: p= 0.000). All the patients in group A at 9 months postoperatively have bone union but 91% in group B (p=0.449), but all the patients in group A at 6 months have bone healing but 63.6% in group B (p=0.001). More bicortical screw fixation was seen in the treatment with MDC-LP (7 versus 2 in the lateral LP: p= 0.000). Less blood transfusion during hospitalization in group A (222ml versus 745ml in group B: p=0.000). In addition, smaller incision and shorter plate was used in group A compared to those in group B. Better functional outcome in the LEFS was seen in the patients treated with MDC-LP (73 versus 62 in group B: P=0.000). In group A, no complications were observed. However, in group B, 5/22 cases suffered superficial infection and 1/22 patients had persistent nonunion.
Conclusions: For the treatment of femoral nonunion, new designed MDC-LP may be a good option to enhance antirotation stability with retention of primary nailing by providing much more bicortical screw fixation and allow to be placed through femoral anterior approach with faster healing, less surgical trauma, and satisfactory functional outcome.