Anatomical Study Of Neurocutaneous Flaps Pedicled With Perforators In Repairing Soft-tissue Defects Around The Knees

Objective: By means of microscopic dissect and blood latex-injected, we hadmajor researched three arteries around the knee, which including descendinggenicular artery and vastus medialis artery and direct popliteal artery, and theirperforatories. Meanwhile, we had observed the courses and distributions of threecutaneous nerves in the thigh. These cutaneous nerves were intermediate femoralcutaneous nerve(IFCN) and medial femoral cutaneous nerve(MFCN) and posteriorfemoral cutaneous nerve(PFCN). We observed their perforators and anatomosisvessles between these perforator arteries and those neuroctutaneous vessles. Base onthe anatomical researches, we wanted to reached two objective:①To provideanatomical basis for neurocutaneous flaps with pedicled perforators in repairingsoft-tissue defects around the knee.②To explore new type flap in Micorsurgery.Methods:30embalmed lower limbs of adult cadavers were used for theanatomic study, they were all perfused with red latex. Followings were observed bymicrosurgical technique;①The origins, courses, distributions and outer diameters ofthe descending genicular artery, vastus medialis artery and direct popliteal artery andtheir perforators;②Courses and distributions of the IFCN, MFCN and PFCN;③Anastomoses between these perforator arteries and nutrient vessels of MFCN, IFCNand PFCN. Three sides of fresh specimen were used for designing and performingmimic operations.Results:①Theprojection on body surface: the line which betweens themidpoint of inguinal ligament and medial femoral condyle can be considered as theprojection on body surface of medial femoral cutaneous nerve(MFCN). The linewhich betweens the midpoint of inguinal ligament and the midpoint of thepatella-adductor tubercle line which is between the midpoint of the patella and adductor tubercle can be considered as the projection on body surface of the anteriorbranch of intermedial femoral cutaneous nerve(IFCN). Posterior femoral cutaneousnerve started from the midpoint of the inferior gluteus maximus edge, and wentdown along the middle line of posterior thigh region, the final trunk of PFCNaccompanied with small saphenous vein down to the middle line of lower leg.②Thelocation of perforator arteries: the nutrient vessels of MFCN, IFCN and PFCN wereplurisegemental and polyphyletic, but the locations of perforator arteries ofdescending genicular artery and vastus medialis artery and the direct popliteal arterywere relatively constant. The perforating branch of descending genicular arterystarted from above the lower-edge of medial femoral condyle about4cm, andpenetrated into the deep fascia in a trangle depression which surrounded by thevastus medialis muscle, adductor tendon and the medial femoral condyle to thesubcutaneous. The location of vastus medialis perforator is near by the midpoint ofthe line which is between the midpoint of patella and the one thirds of theline(between the midpoint of inguinal ligament and the adductor tendon). The directpopliteal artery perforator which started from popliteal artery directly was constantpierced into deep fascia about7～11cm above the knee joint. These perforatorarteries gave off five much more smaller vessles anastomosed with other nutrientvessels of MFCN, IFCN and PFCN. Then these nutrient vessles along MCFN, IFCNand PFCN formed vascular plexus in the middle line of posterior region of thigh.Conclusion:①We had learned that the origin, the outer diameter of theperforators and their courses, distributions of these perforator vessels which comeseparately from descending genicular artery, vastus medialis artery and the directpopliteal artery. We also had learned that and the morphologic characters of MFCN,IFCN and PFCN, and anastomose relations between these vessles were clear anddefinited;②Based on these anatomical researches, we had designded three newflaps which are intermediate femoral neurocutaneous vascular flap pedicled withvastus medialis perforator and medial neurocutaneous vascular flap pedicled withdescending genicular artery perforator and posterior femoral neurocutaneousvascular flap pedicled with direct popliteal artery perforator. All these three flaps can be used to repaire soft-tissue defects around knees;③The neurocutaneous flappedicled with perforator artery has obvious advantages than conventional flaps, thisflap has small pedicle but sufficient blood supply and less wound, and can bedesigned and operated easily and flexibly. These flaps are supplements in repairingsoft-tissue defects around the knee.