Effects of gelatin sponge implantation in cancellous bone defects in dogs.

Reports from oral surgeons suggested that packing bone defects with cellulose or collagen stimulated cancellous bone replacement. The study reported here was designed to evaluate a similar method for augmenting the remodeling of cancellous bone defects and graft donor sites. Gelatin sponge was implanted into bony defects created in the proximal humeral metaphysis of 5 adult Beagles after collection of cancellous bone. A similar defect created in the contralateral humerus was left unpacked. Four months after creation of the defect, the dogs were euthanatized, and the surgical sites were evaluated by use of correlated microradiographic and histologic examination. Unpacked sites had filled completely with loosely woven trabecular bone. Remodeling had not taken place in sites packed with gelatin sponge. Gelatin sponge did not elicit any reaction in the surrounding bone, but remained in situ and obstructed new bone formation. Gelatin sponge blocked rather than augmented cancellous bone replacement.