gms | German Medical Science

Objectives/Interrogation: Previous studies have suggested that outcomes following scaphoid non-union surgery are affected by factors including smoking, fracture location or chronicity, and graft donor site or vascularity. These studies are limited by low numbers, differing definitions of non-union, and variable follow up. This study investigates the outcome of scaphoid non-union surgery with bone graft across 19 United Kingdom centres.

Methods: This study was defined as a multicentre retrospective evaluation of service. Non-union was defined as a failure to unite within 12 weeks of acute injury. The minimal interval between surgery and data collection was 2 years with a minimum of 12 weeks radiological follow up following non-union surgery. The outcome of the "non-union" surgery was union status. Descriptive statistics are provided as frequencies with percentages (%). Proportional differences were examined using the Chi squared or Fisher's exact tests as appropriate. Logistic regression was used to estimate the odds ratio (OR) and 95% CI for persistent non-union following surgery. To adjust for known confounders, multivariable logistic regression was used with pre-selected co-variables.

Results: Data was collected for 806 individuals (n=462 following exclusions). 93% of patients were male with a mean age of 27yr (SD 10). Overall union rate was 69%. The choice of bone graft differed significantly depending on the fracture site (p<0.001). Smoking at the time of surgery doubled the odds of non-union (adjusted OR 1.8, 95% CI 1.0, 3.1). Separate analysis of proximal pole and waist fractures suggested that smoking may particularly affect the outcome of proximal pole fracture non-unions (union rates for non-smokers v smokers = 77% v 43%: p=0.01); Surgical delay of 1 or 2 years was independently associated with 40% (adjusted OR 1.4 (0.7, 2.8)) and 140% (2.4 (1.2, 4.8)) higher odds of non-union respectively. Age, graft vascularity, and fixation method had no association with outcome. Comparison of assessments of union by the treating surgical team and the investigators showed excellent agreement (90%, k=0.8, p< 0.001).

Conclusions: This study suggests that in the United Kingdom healing rates following surgery are less than previously published (>80%). Our findings support the hypotheses that smoking and the time interval between acute fracture and non-union surgery influence the outcome of bone graft surgery.