Ru JY, et al. - Authors sought to identify the risk factors in the development of re-nonunion following primary revision inclusive of exchanging reamed nailing (ERN) and augmentative compression plating (ACP) with intramedullary nailing (IMN) in situ for femoral shaft nonunion subsequent to failed IMN. A higher likelihood of developing re-nonunion was seen in the patients with excessive tobacco use, body mass index (BMI) ≥30 kg/m², bone defect ≥5 mm, primary revision with ERN, and no adjuvant ABG procedure. Out of these risk factors, two strongest risk factors were the primary revision with ERN and no adjuvant ABG procedure.

Methods

• Experts conducted a retrospective study for 63 cases (61 patients) of femoral shaft nonunion subsequent to failed IMN, who were made primary revision with either ERN or ACP from June 2007 to June 2015.
• Based on the speculation that they would contribute to the outcome, following set of variables were selected: sex (male or female), age, body mass index(BMI), smoking, alcohol abuse, cause of injury, fracture type, type of IMN (antegrade or retrograde), use of IMN locking screws(dynamic or static), site of nonunion, primary nonunion time, pathological type of nonunion, bone defect (mm), primary revision method (ERN or ACP), and adjuvant autogenous bone grafting (ABG) (yes or no).
• They used univariate analysis and multiple regression in order to identify risk factors in the development of re-nonunion after primary revision with either ERN or ACP for femoral shaft nonunion subsequent to failed IMN.
• They noted 1.5 years to be the minimum follow-up time (standard deviation [SD]=1.2, range 1.5–8 years).

Results

• As per data, out of 63 cases (61 patients) of femoral shaft nonunion subsequent to failed IMN, primary revision with ERN was performed in 33 (52.4%) cases and primary revision with ACP was performed in 30 (47.6%) cases.
• They under took adjuvant ABG procedure in 39 (61.9%) cases during primary revisions.
• After primary revision with either ERN or ACP, re-nonunion was diagnosed as in 18 (28.6%) cases.
• Results demonstrated a significant difference in time to union between patients treated with primary ERN and those with primary ACP (log-rank,p=0.006).
• Moreover, a statistically significant difference was seen between patients with adjuvant ABG procedure and those without it (log-rank,p=0.009).
• Smoking, BMI, site of nonunion, bone defect, primary revision method, and adjuvant ABG procedure were included in the relative risk factors.
• Nonetheless, multiple logistic regression analysis suggested the primary revision method and adjuvant ABG procedure to be 2 independent risk factors.