REAMER IRRIGATOR ASPIRATOR (RIA) VERSUS AUTOGENOUS ILIAC CREST BONE GRAFT (AICBG) FOR THE TREATMENT OF NONUNIONS: A MULTICENTRE RANDOMIZED TRIAL

The long-standing gold standard treatment for nonunions and bone defects is autogenous iliac crest bone grafting (AICBG). However, there has recently been significant interest in the use of the Reamer Irrigator Aspirator (RIA) for harvesting bone graft from the intramedullary canal. Potential benefits of RIA include decreased pain, lower rates of harvest site complications, larger graft volumes, and biologic superiority. Such purported benefits are based on retrospective analyses, with a paucity of prospective comparisons available. Accordingly, we conducted a multi-centre, randomized control trial (seven Level 1 trauma centres) of RIA vs AICBG for the treatment of long bone non-unions. We hypothesized that RIA bone graft would demonstrate a clinically significant reduction in post-operative pain and harvest site complications, while providing equivalent union rates. Patients aged 18-65 with a long bone non-union or bone defect requiring bone grafting were eligible for inclusion. Non-unions were defined by six months duration of a non-united fracture with no evidence of progressive healing over the previous three months. Bone defects were defined by the presence of a bone defect that, in the opinion of the treating surgeon, would not go on to heal without further intervention. Enrolled patients were randomized to either RIA bone graft or AICBG for the treatment of their non-union and were followed to one year post-operatively. Bone grafts were obtained in a standardized fashion in both groups. In the RIA group, bone graft was collected from the femoral intramedullary canal via an antegrade or retrograde technique. In the AICBG group, graft was harvested from the anterior or posterior iliac crest. All patients received standardized local anesthesia intra-operatively to the graft site following collection. The primary outcome was the visual analog score (VAS) for pain at the harvest site. Secondary outcomes were volume of graft obtained, union rates, reoperation rates, functional outcomes, and complications. This was a registered randomized controlled trial (NCT01382485). Ninety-three patients were randomized over a nine-year period (RIA = 44 patients, AICBG = 49 patients). The primary outcome of harvest site pain was significantly lower in the RIA group versus the AICBG group at one day post-surgery (RIA=4.0±2.5, AICBG=5.5±2.7, p=0.02), but equivalent at all other time points (see Figure 1). Graft volume obtained was significantly higher in the RIA group vs the AICBG group (RIA=37.8 ml, AICBG=19.3 ml, p The use of RIA bone graft significantly reduces early harvest site pain and provides larger graft volumes relative to AICBG, while resulting in equivalent union rates, complications, and functional outcomes. RIA bone graft is a safe and effective treatment for long bone nonunion and is particularly useful in the larger, challenging bone defects. For any figures or tables, please contact the authors directly.