Metformin Prevents Nonunion after Three-Cannulated-Screw Fixation in Displaced Femoral Neck Fractures: A Retrospective Study

Abstract

Patients aged from 40 to 60 with displaced fractures of the femoral neck (Garden III or IV) who received fixation with three cannulated screws from January 2005 to December 2012 were evaluated retrospectively for the development of nonunion. Plasma HbA1C, a marker for long-term plasma glucose level, anti-T2DM medication, and other potential risk factors were recorded for the purpose of this study. There were no differences between the union and nonunion groups with respect to age, gender, Garden classification, Pauwel's angle, reduction quality, and T2DM presence. There were significant differences in reduction quality and preoperative plasma HbA1C level between patients with and those without union. The odds ratio (OR) for fracture nonunion was 2.659 (95% confidence interval [CI], 1.530–4.620) in subjects with anatomical reduction compared with those without anatomical reduction, 4.797 (95% CI, 1.371–16.778), in subjects with poor blood glucose control (HbA1C > 10%). The metformin usage showed a preventive effect on nonunion development (OR: 0.193 and CI: 0.060–0.616). The nonunion rate of metformin group (6.7%, 6/89) was even much lower than that of patients without T2DM (17.4%, 80/460).

Glucose Metabolism in Osteoblasts in Healthy and Pathophysiological Conditions

“…In a study with over 14,000 patients enrolled, osteoporosis and vertebral fractures are reduced up to 40% under treatment with metformin [ 138 ]. Metformin might contributes to improved fracture healing as well, as the rates of nonunion after femoral neck fractures are significantly lower in diabetic patients treated with metformin, even when compared to healthy subjects [ 139 ]. Overall, numerus osteoprotective characteristics of metformin were confirmed in vitro, in vivo and in clinical studies (for a detailed review, please see Bahrambeigi et al [ 140 ]); however, further mechanistic research is required to decipher direct and indirect effects of metformin on bone cells.…”

Diabetes pharmacotherapy and effects on the musculoskeletal system

“…Biguanide‐related benefits to bone repair have also been reported. Specifically, metformin usage appeared to improve healing of fixated femoral neck fractures in a small retrospective study of patients with T2D and displaced fractures . Additionally, anabolic benefits of metformin have been seen with localized drug delivery for the treatment of intrabony defects in non‐diabetic patients with chronic periodontitis .…”