Rinsing morselized allografts improves bone and tissue ingrowth

Bone defects in revision hip surgery can be reconstructed with impacted morselized bone grafts. Rinsing these trabecular allografts may enhance graft incorporation by washing out immunogenic factors present in blood, marrow, and fat. However, it has been proposed that impaction of the graft releases biologically active factors, which can provide sufficient activity to stimulate new bone formation. Rinsing before impaction could enhance bone allograft incorporation, but rinsing after impaction could diminish the incorporation process of impacted bone graft. To study the effect of rinsing and impaction of morselized bone grafts on bone ingrowth, a bone chamber study was done in goats. Autografts and allografts were divided into three treatment groups: (A) impacted; (B) rinsed and impacted; and (C) rinsed, impacted, rinsed, and impacted again. Ten goats received three bone chambers in each proximal tibia. The chambers were filled with either allograft or autograft, yielding six different implants per goat. After 6 weeks, histologic analyses were done and bone and tissue ingrowth were measured. New bone and total tissue ingrowth were higher in autografts than in allografts, especially in the nonrinsed group. With rinsing, total tissue ingrowth increased in the allograft group to approach that of autografts. Rinsing after impaction did not additionally alter bone ingrowth. The current findings show that incorporation of allografts can be improved by rinsing the grafts before impaction.