Clinical study of bone transport combined with bone graft and internal fixation at the docking site in the treatment of large segmental bone defect in lower limb

Objective To explore the feasibility and clinical value of Ilizarov bone transport technique combined with bone graft and internal fixation at the docking site in the treatment of large segmental bone defect of the lower limbs. Methods Thirty patients with large lower limbs bone defects were prospectively divided into two groups according to the random number table: pure bone transport group (Ilizarov bone transport technique alone, n=15, 10 males and 5 females, average age 34.4±4.6 years old, 2 cases bone defect of femur, 13 cases tibia, and the length of bone defect 6.2±2.4 cm), and combined bone transport group (Ilizarov bone transport technique with bone graft and internal fixation at the docking site, n=15, 12 males and 3 females with the average age of 33.8±5.2 years, 1 case of bone defect and 14 tibia, and the length of bone defect 6.5±2.2 cm). The preoperative hospital for special surgery (HSS) knee functional scores, Baird-Jackson ankle function scores, external fixation time, external fixation index, bone union time, bone union index, postoperative ASAMI scores and incidence of complications were compared between the two groups. Results All patients were followed up for 9 to 24 months (mean 16.2 months). Pure bone transport group was followed up for 9 to 24 months (mean 16.2 months), and combined bone transport group was 10 to 24 months (mean 16.4 months). In pure bone transport group, the external fixation time was 17.6±5.4 months, and the bone union time was 11.2±3.1 months with the average bone union index 42.4±4.6 d/cm. While in combined bone transport group, the external fixation time of group B was 8.4±2.1 months, and the bone union time was 7.2±2.1 months with the average bone union index 21.1±2.7 d/cm. The external fixation index of pure bone transport group was 32.4±2.1 d/cm, while in combined bone transport group it was 32.1±2.5 d/cm, and there was no significant difference between these two groups (t=0.812, P=0.884) . According to the bone and function score of the ASAMI, in pure bone transport group, bone healing: excellent 6 cases, good 6 cases, fair 2 cases, poor 1 case, excellent rate was 80%. While in combined bone transport group: excellent in 8 cases, good 6 cases, fair 1 case, excellent rate was 93.3%. The difference between the two groups was statistically significant (χ2=10.6, P=0.032). The lower limb function in pure bone transport group: excellent in 5 cases, good in 5, fair in 4, poor in 1, excellent rate was 66.7%; while in combined bone transport group: excellent in 6 cases, good in 7, fair in 2, excellent rate was 86.7%. There was also a significant difference in the incidence of complications between the two groups. Conclusion Both the pure Ilizarov bone transport technique and the Ilizarov technique with bone graft and internal fixation at the docking site could satisfactorily treat the large bone defect and shortening of the lower limb. But the latter technique had shorter healing time, higher healing rates, better limb function and fewer complications. Key words: Ilizarov technique; Femur; Tibia; Internal fixators