Effect of interposed periosteum in an animal physeal fracture model

To study the effect of interposed periosteum on physeal fracture healing, 5 2 skeletally immature female Harlan Sprague-Dawley rats, 4 to 5 weeks of ag e, were randomized to one of three cohort groups. All animals underwent sur gical dissection of the left proximal medial tibia; dissection consisted of superficial exposure and incision of a standard periosteal flap. Animals i n Group I (fracture alone) underwent physeal fracture; those in Group II (f racture and periosteum) underwent physeal fracture with interposition of pe riosteum in the fracture site, and those in Group III (positive control) un derwent physeal fracture, excision of 1/2 of the growth plate, and interpos ition of periosteum in the defect. After histologic examination of serial s ections, fracture alone resulted in physeal injury frequently associated wi th small bar formation without a reduction in leg length. With the addition of interposition of periosteum into the fracture site, a small, but statis tically significant, increase in leg length discrepancy frequently associat ed with small histologic bar formation occurred when compared with fracture alone.