[Experimental study on the improvement of Ilizarov transverse tibial bone transport and microcirculation...

Objective: To observe the effect of traditional and modified Ilizarov transverse tibial bone transport on microvascular regeneration of lower limbs in dogs. Methods: After general anesthesia on 10 experimental dogs, traditional and modified transverse tibial bone transport were performed on both tibias respectively. The control group was treated with the traditional method (the periosteum and bone flap were completely isolated), while the experimental group was treated with the modified method (the fibular periosteum of the open window bone flap was retained). All the external fixators were pulled outwards at a speed of 1 mm every day from 5 days after operation;after one week, the external fixators were moved back every 3 days for one week. The situation of wounds and activity of lower limbs were observed. Simultaneously, the angiogenesis was observed by digital subtraction angiography (DSA) through femoral artery at different stages, and the density of vascular endothelial cells measured by local tissue sections. The data before and after the operation were compared with paired t test. Results: The operation was successfully completed in 10 experimental dogs, and all wounds healed about 1 week after the operation. There was no significant abnormality in lower limb movements in all dogs. Peripheral blood vessel area in middle leg of lower limb in 4 weeks and 8 weeks after operation was (5.9±0.4) mm(2) and (6.9±0.6) mm(2) in control group and it was (6.2±0.6) mm(2) and (8.0±0.6) mm(2) in experimental group, respectively; all were significantly improved than those before the operation ((5.0±0.4) mm(2), (4.9±0.4) mm(2), respectively) (F=446.457, 829.192, both P<0.05). There was no significant differences in vessel area between the two groups at the 4th week after operation (t=1.216, P=0.240), but there was significant difference at the 8th week after operation between the two groups (t=4.423, P=0.000). The percentage of vascular endothelial cells in stained cells under endoscopy was 4.42%±0.28% and 5.63%±0.53% in the control group at the 8th week; and in the experimental group, it was 5.35%±0.26% and 7.18%±0.25%, respectively;all were significantly elevated than those before the operation; and there were significant differences between the two groups (t=7.35, 8.30, both P<0.05). Conclusion: Transverse tibial bone transport and microvascular network regeneration technology can reconstruct the microvasculature below the calf of dogs; the method of window-opening osteotomy is improved to "door" type window-opening, it can retain the lateral periosteum of tibial crest and regenerate the microvasculature network more abundantly.