Abstract: Objective   To investigate the clinical effect of retrograde femoral anterolateral composite flaps with double blood supply and fascia on reconstruction of knee extension device and repair of wounds in knee and upper middle leg.  Methods   From July 2018 to March 2022,5 patients with deep burns of knee joint and middle and upper leg were treated in our hospital.The wounds were repaired by double blood supply composite tissue flap,and the knee extensor device was repaired and reconstructed by fascia.Observe and follow up the operation effect.  Results   Five patients underwent double blood supply composite tissue flap to repair knee and leg wounds,and five patients underwent debridement and VSD treatment after admission,and then underwent double blood supply composite tissue flap to repair wounds.The flap survived by using fascia lata flap to repair and reconstruct knee extender device.During follow-up,the skin flap was soft in texture without obvious swelling,and the knee joint function recovered well.  Conclusion   The double blood supply combined tissue flap can reconstruct the knee extension device and restore the function of the knee joint.It is an ideal treatment method to repair the deep wounds of the knee and lower leg.

Key words: burn, surgical flap, rebuild, knee extender