【Abstract】 Objective To observe the effect of fasciocutaneous flap with peroneal nerve trophic vessels in repairing soft tissue defects in different parts of the lower limb. Methods From July 2004 to May 2010, 39 patients with soft tissue defects in different parts of the lower limbs were repaired with fasciocutaneous flaps with peroneal nerve trophic vessels. According to the intact condition of the soft tissue of the ipsilateral calf and the range of the flap, the ipsilateral or contralateral cross leg flap was selected for surgery. Results The flaps in 39 cases were all viable and followed up for 2 to 36 months, with excellent texture, satisfactory appearance and function, no secondary ulceration, and resistance to abrasion. Conclusion: Fasciocutaneous flap with peroneal nerve trophic vessels is easy to cut, rich in blood supply without sacrificing the major arteries, and can effectively repair various soft tissue defects from the knee to the forefoot. Wang Weiguo, Department of Orthopedic and Trauma Surgery, Jinan General Hospital, Jinan Military Region 【Keywords】 Fasciocutaneous flap of peroneal nerve, soft tissue defects of lower limb, cross leg flap, peroneal nerve trophic vascular flap, has the characteristics of not sacrificing the main blood vessels, flexible design, easy operation, hidden donor area, and high viability, especially when accompanied by main blood vessel injury. With the flexible fixation of the external fixation bracket, the healthy peroneal nerve trophic vascular flap can be used to repair the defects of the ipsilateral flap that are difficult to complete the repair mission. Since 2004, we have used the peroneal nerve trophic vascular fasciocutaneous flap to repair the soft-tissue defects in different parts of the lower limb in a retrograde or retrograde fashion, and the flaps are all viable and the results of the treatment are satisfactory. Clinical data: 28 cases of male and 11 cases of female, minimum age 6 years old, maximum age 71 years old, average age 28 years old. The average age of this group was 28 years old, the minimum age was 6 years old, the maximum age was 71 years old, the average age was 28 years old, and the defects were as follows: dorsalis pedis in 2 cases, forefoot in 6 cases, hallux valgus in 5 cases, mid- and lower calf in 5 cases, ankle in 7 cases, heel in 9 cases, and below the knee and anterior tibia in 5 cases. The maximum flap area was 19 cm x 12 cm, and the minimum was 4 cm x 3 cm. Surgical points: 1. When repairing dorsal foot, heel and ankle defects, the point of rotation: 5-7 cm above the outer ankle. axis: the line between the midpoint of the Achilles tendon and the midpoint of the N fossa in the outer ankle. 2. the width of the skin tip was not less than 2.5 cm. The width of the flap should not be less than 2.5 cm, and the area of the designed flap should exceed the area of the defect by 10% to 20%. 2. When repairing knee or upper tibial defects, the axis of the flap is the same as the above, and the point of rotation should be 5-6 cm below the midpoint of the N fossa at the highest point in the middle and lower lower part of the lower leg, the flap site is determined according to the size and shape of the wound, and the procedure is similar, but the peroneal nerve should be included into the fascia as much as possible. The width of the fascial tip can be increased appropriately. If the width of the donor area is less than 6.0 cm, it can be closed directly, and if it is more than 8 cm, it can be implanted with medium-thickness skin.3 When there is extensive contusion of the skin and soft tissues of the posterior and lateral sides of the ipsilateral calf, or when it is estimated that the maximal area of the ipsilateral area of the cut can not be completed the task of repair, it should be repaired by the fascial flap with the nutrient blood vessels of the peroneal nerve of the contralateral side.4 There were 28 cases of acute and serious cases in the present group, and there were 11 cases of second-stage or elective surgery. The former were mostly multiple injuries and most of them were combined with complex fractures, and 5 cases were on the verge of amputation, which required simple and effective internal and external fixation of the fractures at the same time or later, and then used the peroneal nerve trophic vascular flap of the ipsilateral side or the healthy side to repair the defective soft tissue wounds. RESULTS: In this group, there were 39 cases, 28 cases of retrograde, 5 cases of cis-legged, and 6 cases of cross-legged, and all the flaps survived after surgery. Three cases of retrograde flap showed local tension blisters and epidermal necrosis at the distal skin edge of the flap, which healed after dressing change, and the flap was normal in color and elasticity without bloat and had good appearance in 2-36 months of postoperative follow-up. The donor area healed well and had no minor good effects on function. Discussion 1. Anatomical basis of the flap The peroneal nerve is formed by the confluence of the medial peroneal cutaneous nerve of the tibial nerve and the lateral peroneal cutaneous nerve of the peroneal nerve. The cutaneous nerve has multiple and constant blood sources, with arteries in a phasic distribution with extensive anastomosis to each other, and its proximal portion emanates from a well-known artery with accompanying arteries. The trophic artery of the peroneal nerve is the superficial peroneal artery, a dense vascular plexus with transcutaneous branches supplying the skin of the lower middle 2/3 of the posterior calf. The medial peroneal cutaneous nerve and the peroneal nerve transport branch are supplied by arteries from five arteries: the musculocutaneous branch of the carotid artery, the musculocutaneous branch of the posterior tibial artery, the cutaneous branch of the tibial artery, and the medial and lateral peroneal arteries, etc. Masquelet et al. suggested that although these small arteries have a limited range of blood supply on their own, the longitudinal network of small perforating arteries that anastomose through their branches expands the range and distance of the supply, and that the longitudinal network of interwoven arteries formed by the anastomosis of the branches. Nutrition to long segments of the cutaneous nerve and skin. The peroneal nerve trophic vascular flap has four sets of blood supply systems: (1) peroneal nerve trophic vessels; (2) saphenous vein trophic vessels; (3) peroneal artery perforating branches; and (4) peripheral ankle vascular network. It is most suitable for reconstruction of skin and soft tissue defects in the distal third of the lower leg and foot. Because the peroneal nerve perforators are located as low as 5 cm above the ankle, the flap can be lifted distally to form a cross-legged flap with a venous return: retrograde flap venous return is mainly through the superficial venous network of the deep fascia and the perforator veins back into the deep venous network. Peroneal nerve and small saphenous vein around the rich vascular network and the flap and fascia within the superficial and deep multilayered vascular network of the traffic branch blood flow can be bi-directional. Studies have shown that the venous blood in the superficial veins does not flow back in the reverse direction. When venous blood enters but does not leave, stasis occurs in the flap, venous pressure rises, and the pressure difference between the arteries supplying blood to the tip decreases, resulting in arterial crisis, embolism, and necrosis of the flap distal to the flap or all of the flap. 2. The following points should be noted in the treatment of flap accidents: ① If the postoperative stasis and swelling of the flap is obvious, the sutures in the tip can be removed for a few stitches and generally recovered. If the effect is poor in its distal incision and bleeding; ② if a venous crisis, the flap in a timely manner, the small saphenous vein (the tip is not ligated) and the affected area of the saphenous nerve or the proximal branch of the saphenous nerve anastomosis; ③ intraoperative to avoid tension suture, so the design of the flap than the affected area of the trauma of 10% to 20%, the needle distance can be a little larger, design of the tip of the tip should be with a sufficiently wide tip of the skin, suture is not easy to cause the embedded peroneal nerve nutrient vascular fascia! The skin flap should be placed under negative pressure drainage or half-tube drainage to prevent blood accumulation, swelling, pressure and infection; ⑤ Elevate the affected limb after surgery, and carry out three antitoxic treatments according to the finger reimplantation for one week after surgery, and resolutely avoid circular bandaging of the skin flap or pressure bandaging, and the skin flap should be able to be observed directly under the observation of blood circulation; ⑥ The blood circulation of cross-legged flap has a close relationship with the stability of the external fixator that fixes the legs and the loosening will cause the skin flap to be twisted and folded, which will cause the skin flap to be twisted and folded, which will cause the flap to be twisted and folded. The loosening will cause distortion and folding of the skin, which will seriously affect the blood circulation of the flap, and its stability should be ensured and adjusted in time after the occurrence. 3. Cross-legged flap disadvantages and advantages: to do cross-legged flap repair needs about three weeks will be forced to fix the patient’s legs the patient’s physical and mental destruction is greater, the elderly or frail people should be used with caution. Due to the patient’s limited mobility, nursing care needs to be strengthened. Cross-legged flap of the tip of the skin is only transposed about 90 degrees compared with the retrograde repair of peroneal nerve trophoblastic vascular flap of the tip of the peroneal nerve needs to be reversed 180 degrees obvious advantages, less likely to occur in the blood circulation crisis, cross-legged flap surgery is safer than the unilateral surgery. Cross-legged flap can be used to repair the forefoot or hallux valgus with more soft tissues, expanding the scope of peroneal neurotrophic vascular flap repair. When the ipsilateral calf is extensively injured or even in danger of amputation, it is no longer feasible to use the ipsilateral peroneal neurotrophic vascular flap, and the cross-leg flap can be used to bring the leg back to life.