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Background and Aims There is concern regarding the optimal block site, volume and diffusion of injectate and involvement of nerves in the femoral and adductor canal, for postoperative analgesia in TKA. Simultaneous injection with different colored dyes in the proximal femoral triangle (PFT), proximal (PAC) and distal adductor canal (DAC) Objectives: 1. Evaluate the maximum dye capture rate of each nerve at each level of injection 2. Evaluate the dye spread towards the sciatic nerve posterior to femoral shaft.Methods Six soft embalmed cadavers (12 specimens) in supine position, all injections were performed at PFT; PAC and DAC, under ultrasound and latex solutions (10 ml) were injected over 10seconds. 1. At the level of inguinal ligament (PFT), PURPLE dye was injected at the point where the facia-iliaca split open to engulf the FN. 2. At the interface of the medial borders of the sartorius and the adductors longus (PAC), BLUE dye was injected anterior-lateral to the femoral artery. 3. The adductor canal was scanned distally and GREEN dye was injected proximal and superior to bifurcation of the femoral artery (DAC). After 30 minutes, all dissections were carried out and the sciatic nerve was also explored posterior to the femoral shaft and was evaluated for stain pattern.Results The stain pattern in all 12 specimens were observed during dissection and the capture rate of each nerve was measured as a percentage, examined by descriptive analysis. Purple dye stained FN, ACN, NVM and im-NVM. Blue dye stained ACN, SN, NVM, VAM, SSC, ON and anastomosis between SN/b-AON. Green dye stained the SN, im-NVM, VAM, SSC, ON, SN/b-AON anastomosis and popliteal artery. There was no sciatic nerve involvement.Conclusions Considering our cadaveric injection trials, we believe that the PAC would be a suitable technique, given the involvement of the SN, NVM, and b-AON, which supplies the Anterior knee capsule.