Reamer-irrigator-aspirator bone graft and bi Masquelet technique for segmental bone defect nonunions: a review of 25 cases.

INTRODUCTION: Segmental bone loss, either from trauma, tumor or infection is a challenging clinical entity. Amputation is a possible outcome and part of the decision making process. Surgical management is almost always needed and can require several interventions to obtain bone union. A staged protocol of obtaining a clean viable soft tissue bed, placement of a PMMA antibiotic impregnated spacer to induce a neovascular and bioactive membrane followed by autogenous bone graft has been reported with good outcomes. Our study attempts to expand on this data by evaluating the use of RIA bone graft for the treatment of segmental bone loss nonunions following trauma and or infection.

METHODS: Following IRB approval, two orthopaedic trauma fellowship trained surgeons used one surgical protocol for the management of segmental bone defect nonunions. Femur RIA bone graft was used as the graft source when possible. We retrospectively evaluated patients with segmental bone loss of the lower extremity over a two year period. Our primary endpoint was clinical and radiographic bone union. A secondary endpoint was RIA related complications. Additionally, by using some known mathematical equations, we show a plausible way of quantifying the amount of bone loss from a long bone based on the shape of the bone, defect shape and the measured length of bone loss on plain radiograph.

RESULTS: 25 patients with 27 segmental bone loss nonunions were evaluated. Nineteen were tibia bone loss and eight were femoral. 15 (56%) nonunions were open fractures with bone loss and 12(46%) were for bone loss related to infection or surgical debridement. The average deficit size was 5.8 cm in length (range 1-25 cm). At six months and 1 year post operative, 70% and 90% nonunions were healed clinically and radiographically respectively. There were no RIA related complications.

DISCUSSION: RIA bone graft has been shown to be a very bioactive material. Several studies support the use of this bone graft for the treatment of nonunion including one recent study evaluating 13 patients with segmental bone loss. Our study expands on this data by evaluating its use as the primary source of bone graft for the treatment of segmental bone loss nonunions in the lower extremity.

CONCLUSION: RIA bone graft for the treatment of segmental bone defect nonunion of the lower extremity appears safe and can yield predictable results when following sound surgical principles. 90% of our nonunions were healed at one year following a single bone graft procedure. Very large defects, once a formidable clinical dilemma can be managed successfully with the use of RIA bone graft.