Augmentative Plating in the Treatment of Femoral Nonunion after Intramedullary Nail Fixation.

Objective: Failure of bone healing after intramedullary nailing (IMN) of a femoral diaphyseal fracture is an uncommon condition, which can cause obvious pain symptoms and seriously affect the daily life of patients. Ununion of femoral fracture requires treatment to promote successful bone union. Augmentative plating (AP) has yielded good results in treating femoral nonunion after IMN. However, there are few large cohort studies and no technical standard for this treatment. To determine (1) the proportion of individuals with femoral nonunion after IMN who achieved radiographic signs of osseous union following the additional treatment of AP and autogenous bone grafting and (2) the factors associated with the failure of this treatment.

Methods: Nonunion after IMN fixation is defined as an unhealed fracture with no radiographic signs of osseous union at least six months after IMN treatment. Osseous union as bridging bone on three of four cortices with the absence of a radiolucent line. Between January 2011 and January 2022, 83 individuals diagnosed with femoral nonunion after IMN fixation underwent AP and an autogenous bone graft.

Results: Seventy-six of the 83 nonunion individuals attained osseous union by 12 months. Six of 36 (16.7%) subjects with mono-cortical plates had non-union. Conversely, one of 47 subjects (2%) with bi-cortical plates had non-union. There were 18 individuals whose AP had ≤6 cortices. Five of these 18 (38.5%) individuals had non-union. Two of 65 with an AP of >6 cortices had non-union. AP with ≤ 6 cortices was a major risk factor for the likelihood of unsuccessful procedures compared to AP with > 6 cortices. Three individuals experienced incision infection at the bone graft harvest site and were treated with local wound care.

Conclusions: A high proportion of individuals with femoral nonunion after IMN fixation were salvaged by AP and an autogenous bone graft. Bi-cortical plate and screw intersection of more than six cortices may increase the treatment effectiveness.

Limitations: There were limitations of this study. First, it was a retrospective study over a 10-year period, and the patients were treated by different orthopedic surgeons. Second, lack of functional evaluation is another limitation of the present work.

Generalizability: The technique of bi-cortical plate and screw intersection of more than six cortices is not difficult for experienced orthopedic surgeons, and no special surgical tools is required.

Closing Statement: Many literature has confirmed the good effect of APP technology in treating femoral nonunion after intramedullary nail fixation, but there are still cases of failure. Our study may enable this technology to achieve better therapeutic effects.