[Causes and treatment of long bone fracture nonunion after allogeneic bone grafting surgery]

To analyze the causes and managing methods of long bone fracture nonunion after allogeneic bone transplantation.

From December 1995 to December 2000, 43 cases of postoperative nonunion of long bone fracture were treated. These cases included 31 males and 12 females at the age of 19-57 years (40 years on average). The locations were femur in 11 cases, tibia in 21 cases, humerus in 8 cases and forearm in 3 cases. Bone nonunion after allogeneic bone transplantation was caused by extensive soft tissue contusion and poor cover around bone fracture site in 6 cases, by incomplete debridement in 8 cases of osteomyelitis (including 6 without continual lavage and 4 only skin flap transfer), by secondary infection of wounds in 3 cases, by severe primary injury or secondary scar covering bone in 12 cases, instable internal fixation in 7 cases, and by earlier weight bearing in 7 cases. According to Weber classification, there were 4 cases of hypertrophic type and 39 cases of atrophic type. Basing on the type of nonunion, the methods such as refixation, bone retransplantation and transferring tissue flap were chosen to manage the cases.

Incision healed by first intention in 37 cases, superficial infection occurred and cured after 2 weeks of dressing change in 5 cases, and sinus formed and cured after 2 months of dressing change and drainage in 1 case. All transferring tissue flap survived, and partial necrosis occurred at flap edge in 4 cases and cured after dressing change. All patients were followed up for 38-91 months with an average of 54.6 months. All the nonunion cases achieved bone union 5-11 months with an average of 7.6 months. But low extreme shorten monstrosity occurred in 4 cases, malunion in 2 cases, functional limitation near joints in 7 cases, and rotational limitation of forearm in 1 case.

Fracture nonunion after allogeneic bone transplantation mainly shows atrophic type with overall or partial absorption of the allograft bone. The preconditions to guarantee fracture nonunion healing include stability of fracture fixation, using transferring tissue flaps, controlling infection, and adequate bone transplantation.