Does urinary cotinine level correlate with post-operative complications in elective foot and ankle surgical patients?

A. Salandy, K. Malhotra, A. Goldberg, N. Cullen, D. Singh

Introduction: Smoking is associated with adverse post-surgical outcomes. Cotinine is a nicotine metabolite and raised levels have been associated with increased complications in head and neck surgery. However, to date no clinical study has investigated the link between cotinine levels and complications following orthopaedic surgery.

Method: A single centre prospective study was conducted between September 2013 and July 2014 on 127 patients undergoing an osteotomy or fusion of the foot or ankle. Patients were followed up post operatively at weeks two, six, twelve, twenty-four, fifty-two or until union. Non-unions, delayed unions, deep surgical site infections and wound complications were recorded. Urinary cotinine level was measured on the day of admission using the Concateno Urine Cotinine enzyme-linked immunosorbent assay (ELISA).

Results: 20 (15.8%) patients reported being a current smoker. 26 (20.5%) of 127 patients had a complication. The mean cotinine value for patients with complications was 353.8 +/- 1035.6. This was not statistically different from those without complications, 1168.3 +/- 4953 (p=0.41). Spearman rank order correlation demonstrated no statistical significance between assay level and complication rate at weeks 2, 6, 24 or overall. There was a statistically significant but negligible correlation at weeks 12 (r=0.194, p=0.29) and 52 (r=0.237, p=0.007).

Conclusion: Our results did not demonstrate a correlation between cotinine level and post-operative complications following elective foot and ankle surgery.