A perforator flap is a flap with a small diameter (0.5-0.8 mm) skin penetrating vessel for blood supply, which belongs to the category of axial vascular flaps and is a new development in microsurgical flap transplantation [1, 4]. “From June 2007 to November 2008, 13 cases of soft tissue defects in the calf, foot and ankle were repaired with the use of posterior tibial artery perforator flaps in our department, and satisfactory results were obtained, which are reported below. 1, Clinical data 1, 1 General information The group of 13 cases, 9 males and 4 females. The age ranged from 16 to 45 years old, with an average of 31,2 years old. Among them, 3 cases applied to repair soft tissue defect of lower leg, 5 cases of soft tissue defect of heel, 2 cases of soft tissue defect of dorsal foot and 3 cases of soft tissue defect of inner ankle. Causes of injury: 4 cases of wheel crushing injury, 4 cases of stone and other heavy object smashing injury, 2 cases of machine crushing injury, and 3 cases of plate exposure after lower tibial fracture surgery. The flaps were cut from 5 cm×3 cm to 15 cm×6 cm, and all of them were transferred with the tip. 1.2 Surgical methods Before surgery, each penetration point was marked one by one along the posterior tibial artery with color ultrasound Doppler, and the appropriate one was selected as the nutrient vessel according to the location of the trauma, and the penetration point was the flap rotation point and marked with a marker. The skin on one side was firstly incised, and the skin was carefully separated in the superficial fascial layer, and the skin was retracted to find the preoperative localized perforating vessels, observe their travel direction, and determine their entry into the skin. Then the skin on the other side is incised, and the flap is released from far to close to the deep fascial layer toward the penetrating vessel, and if the patient does not have thick subcutaneous fat, a clear vessel can be seen to travel within the superficial fascia of the skin. When the flap is free to 1 cm from the penetrating vessel, the deep fascia is cut to ensure that there is a certain amount of deep fascia continuous with superficial fascia around the penetrating vessel through the deep fascia, and then the deep fascia around the penetrating point is retracted, and the required length of the tip of the penetrating vessel is traced and free in the gap between the medial edge of the gastrocnemius muscle and the long toe flexor muscle, and the flap is free with only the penetrating vessel attached to the limb, and the flap is rotated to cover the wound with this penetrating branch as the axis, and the donor area is The flap was rotated to cover the wound and the donor area was packed with skin implants. All flaps were viable, 12 cases healed in one stage, and one case had small necrosis of the distal part of the flap, which healed in the second stage after drug exchange. From March to December after surgery, 10 patients were followed up, the flaps were soft, the flaps were not bloated, the appearance was beautiful, the donor area implants were all viable, there were no complications, and the patients were satisfied with the surgical results. 3. Discussion The blood supply of the lower and middle skin of the calf mainly comes from the penetrating branch of the posterior tibial artery. The upper part of the posterior tibial artery is located in the deep surface of the flounder muscle, and the lower part is located in the gap between the medial edge of the gastrocnemius muscle and the long toe flexor muscle, which is not deep and easy to reveal. The posterior tibial artery emits five to seven intermuscular penetrating branches, of which two to four branches account for the majority (70%) [7]. The middle 1/3 and lower 1/3 of the calf account for 55% of these branches and 45% for the lower 1/3 [7]. The penetrating branches are usually divided into thick and long descending branches, short and thin ascending branches, and horizontal branches, and the adjacent penetrating branches communicate with each other, with a diameter of 0.5-2.0 mm and a tip length of 0.5-2.0 cm [7], which is the basis of the blood supply of the posterior tibial artery penetrating flap flap. The posterior tibial artery perforator flap was developed on the basis of the medial calf fascia flap. The medial calf fascial flap is cut in the deep subfascial plane during surgery, and the flap is often cut into the saphenous vein and saphenous nerve that enter the flap. In contrast, the main excision plane of the posterior tibial artery perforator flap is superficial to the deep fascia, allowing the saphenous vein and saphenous nerve to be isolated and protected. The small amount of deep fascia around the access point of the flap is mainly to avoid damage to the access point during dissection, and this part of the deep fascia is completely free, unlike the fascial flap, which is continuous with the limb, and can sometimes be completely free of deep fascia. The author has the following experience with the application of posterior tibial artery perforator flaps in 13 patients. The main advantages of the posterior tibial artery perforator flap are: (1) the flap does not cut the deep fascia, which causes little damage to the donor area; (2) the flap is relatively thin, and the shape of the repair is more satisfactory; (3) the flap tip only carries the perforator vessels, which makes the flap rotation more convenient and flexible; (4) the flap tip contains less tissue, and there are no bumps and skin folds due to skin and deep fascia folding, which are relatively less likely to be stuck and less prone to postoperative vascular crisis and more It is safer and more reliable. The main disadvantages of the posterior tibial artery flap are: (1) the variability of the perforator is high, which requires preoperative positioning of the perforator and more adequate preparation (2) the perforator must be found before the final decision on the flap design is made, and the design may be changed at any time, which requires a higher clinical resilience of the operator (3) the microsurgical technique of the operator is more demanding, and the surgical operation requires more delicate operation. (4) the tracking of the dissected vessel tip is laborious and the operation time is relatively long. A problem that remains to be solved is that the maximum area of flap area to be cut is still based on the operator’s personal experience, i.e., there is no quantitative study on how large an area of flap can be fed by different diameter penetrations. In one case, the flap area was too large and resulted in partial necrosis of the distal end. Clinically, when repairing soft tissue defects in the foot and lower leg, most of the wounds are superficial and require only a thin layer of superficial skin fascial tissue to cover the exposed tendon, bone or plate, and only a few wounds require a larger volume of tissue for deep filling. The deep fascia is the interface between the deep and superficial tissues of the body and has an important protective effect on the deeper tissues. The traditional medial calf flap removes the deep fascia from the donor area and often also removes the saphenous vein and saphenous nerve, but such removal is not meaningful for the repair of the recipient area and is a “waste”, and it also increases the thickness of the flap and affects the aesthetics of the recipient area. However, this kind of flap is not meaningful for the repair of the recipient area, which is a kind of “waste”. When repairing superficial soft tissue defects in the lower leg, foot and ankle, the posterior tibial artery perforator flap is an ideal procedure.