The authors examined the association between smoking and failure of non-vascularized bone grafting and screw fixation for scaphoid non-unions and delayed unions in a retrospective cohort study of 64 patients. The median follow-up time after surgery was 42 weeks, with scaphoid healing defined as the presence of trabecular continuity on at least 2 of 4 radiographic views. Union occurred in 47 patients, of whom 3 were smokers, whereas union failed in 17 cases, of whom 13 were smokers (p = 0.005). Proximal pole fractures, long injury-grafting intervals, and non-compliance were similar between smokers and non-smokers.
The authors draw attention to the potential adverse effect of smoking on healing of non-vascularized scaphoid bone grafts. Smoking has been associated with delayed and/or failed union of ankle and spinal fusions, tibial fractures, and ulnar shortening osteotomies and partial wrist fusions. In rabbit studies, nicotine has demonstrated inhibitory effects on healing of tibial osteotomies and on revascularization of autografts (Raikin et al, Clin Orthop, 1998; Daftari et al, Spine, 1994). With the available evidence to date, a patient with a delayed or un-united scaphoid fracture might benefit from counseling and assistance to discontinue smoking prior to attempted surgical repair and grafting.