The effect of surgical dissections on blood flow to the tibial tubercle.

Tibial tubercle transfer is often used for the treatment of patella maltracking. Because the periosteum of both sides of the tibia is stripped off along the tibial tubercle and then the bilateral cortices are transferred, this procedure may disturb the blood supply to the tibial tubercle. However, the blood supply to the tibial tubercle has not yet been clearly elucidated. The purpose of this study is to investigate the effect of surgical dissection on blood flow to the tibial tubercle in an animal model using a hydrogen washout technique. Eleven knees of nine mongrel dogs weighing from 7.0 to 19.1 kg were utilized. The blood flow was measured using a hydrogen washout technique. Before performing the surgical procedures, the control blood flow rate of the tibial tubercle averaged 19.6 ml/min per 100 g of tissue. The blood flow rate did not significantly decrease after transecting the periosteum on the lateral side of the tibia alone (P > 0.05). After completing the tibial tubercle osteotomy, the blood flow rate averaged 11.5 ml/min per 100 g of tissue, which is a 25.3% decrease as compared with the value after transecting the periosteum on the lateral side of the tibia alone (P < 0.05). The blood flow rate significantly decreased to 3.4 ml/min per 100 g of tissue after the distal periosteal transection and osteotomy of the distal cortex of the tibial tubercle (P < 0.05). The addition of a medial periosteal transection caused a complete arrest of the blood flow in 10 out of 11 knees, or a 91.2% decrease as compared with the value after a distal periosteal transection and osteotomy of the distal cortex of the tibial tubercle (P < 0.05).