Background
Traumatic bone defects may be primary, following open fractures, or secondary to an aseptic or septic nonunion. The traditional procedures to bridge segmental bone defects include autogenous bone grafting, the open bone grafting (Papineau) technique, posterolateral bone grafting of the tibia, transplantation of allograft bone, and fibula protibia procedures. However, these procedures usually require multiple surgical procedures, no weight bearing during treatment, and have limited extent of bone defect reconstruction. Vascularized bone grafts and bone transport according to the Ilizarov technique show much better results. However, each has its advantages and disadvantages.
Patients and methods
Between April 2001 and September 2008, we treated 32 patients with post-traumatic tibial bone defects at the El-Hadra University Hospital. The patents were divided into two groups: group 1 consisted of 17 patients who were treated using the Ilizarov bone transport technique; group 2 consisted of 15 patients who were treated by vascularized fibular grafting. The average age of the patients at the time of the surgery was 39.9 years in group 1 and 29.7 years in group 2. The mean length of the bone defect was 4.1 cm in group 1 and 7.6 cm in group 2. The site of the bone defect was proximal in six and two patients and middle in eight and 13 patients of group 1 and group 2, respectively. The distal tibia was affected in six patients of group 1. All patients had undergone surgeries previously (one to four operations). The results were divided into bone and functional results. The bone results were based on five criteria: union, infection, deformity, lower limb deformities, and the cross-sectional area of union of the regenerated bone and docking site. The functional results were based on five criteria: pain, need for walking aids or braces, ankle or knee deformity or contracture, loss of range of ankle and knee motion compared with the preoperative range, and ability to return to normal activities of daily living and/or work.
Results
The mean amount of the filled defect was 4.1 cm with Ilizarov bone transport and 7.6 cm with vascularized fibular grafting. The external fixator time in group 1 was 6.9±1.39 months. The average time to achieve union in group 2 was shorter than that in group 1 (4.8 months, range 3–9 months), whereas the average time to full weight bearing is 8.7 months (range 5–15 months). The average follow-up period was 10.9 months (range 6–24 months) in the bone transport group and 17.6 months (8–24 months) in the vascularized fibular graft group. The bone results and functional results of Ilizarov bone transport were excellent in 64.7 and 29.4%, good in 17.6 and 41.2%, fair in 5.9 and 17.6%, and poor in 11.8 and 11.8% of the patients in groups 1 and 2, respectively, whereas those of vascularized fibular grafting were excellent in 73.3 and 6.7%, good in 13.3 and 73.3%, fair in 6.7 and 13.3%, and poor in 6.7 and 6.7%, respectively. The main problems in Ilizarov bone transport were patient compliance, pin tract infection (all patients), residual deformity in seven patients, and skin sloughing in one patient who was treated using a skin flap. Stress fracture of the transported fibula (eight patients) and need for secondary procedures (10 procedures) were the main problems in the vascularized fibular graft group.
Conclusion
Ilizarov bone transport is a good method for management of post-traumatic tibial defects, especially short bone defects; in addition, bone grafting of the docking site is necessary in all cases to achieve union and to shorten the time of external fixator application. Although the vascularized fibular graft yielded better results in longer bone defects with shorter time for union, non-weight-bearing is mandatory until graft hypertrophy to avoid stress fractures, which were the main problem in our series.