Outcomes and complication rates of different bone grafting modalities in long bone fracture nonunions: a retrospective cohort study in 182 patients

Background: Novel bone substitutes have challenged the notion of autologous bone grafting as the 'gold standard' for the surgical treatment of fracture nonunions. The present study was designed to test the hypothesis that autologous bone grafting is equivalent to other bone grafting modalities in the management of fracture nonunions of the long bones. Methods: A retrospective review of patients with fracture nonunions included in two prospective databases was performed at two US level 1 trauma centers from January 1, 1998 (center 1) or January 1, 2004 (center 2), respectively, until December 31, 2010 (n = 574). Of these, 182 patients required adjunctive bone grafting and were stratified into the following cohorts: autograft (n = 105), allograft (n = 38), allograft and autograft combined (n = 16), and recombinant human bone morphogenetic protein-2 (rhBMP-2) with or without adjunctive bone grafting (n = 23). The primary outcome parameter was time to union. Secondary outcome parameters consisted of complication rates and the rate of revision procedures and revision bone grafting. Results: The autograft cohort had a statistically significant shorter time to union (198 +/- 172-225 days) compared to allograft (416 +/- 290-543 days) and exhibited a trend towards earlier union when compared to allograft/autograft combined (389 +/- 159-619 days) or rhBMP-2 (217 +/- 158-277 days). Furthermore, the autograft cohort had the lowest rate of surgical revisions (17%) and revision bone grafting (9%), compared to allograft (47% and 32%), allograft/autograft combined (25% and 31%), or rhBMP-2 (27% and 17%). The overall new-onset postoperative infection rate was significantly lower in the autograft group (12.4%), compared to the allograft cohort (26.3%) (P < 0.05). Conclusion: Autologous bone grafting appears to represent the bone grafting modality of choice with regard to safety and efficiency in the surgical management of long bone fracture nonunions.