Rib fracture healing in experimental flail chest.

Sixteen dogs were placed under general anesthesia and flail segments of the left chest were created by transecting ribs 7,8,9, and 10 anteriorly and posteriorly. Fractures were 10 cm apart so that a 10-cm flail segment encompassing four ribs was created. In Group I, the control (N = 5), the chest wall muscles were closed without any stabilization of the fractures. Group II (N = 5) had stabilization of both anterior and posterior fracture sites by polypropylene sutures. Group III (N = 6) had stabilization of the fractures in ribs 7 and 8 with 2.5-cm bone grafts taken from the left fourth rib. Ribs 9 and 10 were stabilized by polypropylene sutures. The study established a canine model for flail chest. It also showed that strut stabilization of rib fractures with bone grafts promotes better healing than suture stabilization. It suggests that using bone grafts taken from another rib to stabilize flail segments may be unsatisfactory since the rib used as a donor showed no signs of regeneration at 30 days.