Ultrasonography was performed using the Mindray DP-10 system with a linear transducer positioned at the inguinal fold to identify and visualize the femoral nerve, 10 ml mixture of local anesthetics ( Marcaine® [bupivacaine HCl] 0,5% and Xylocaine® [Lidocaine HCL] 2% = 2:1) were injected in-plane around the femoral nerve. For popliteal sciatic nerve blocks, linear transducer was placed transversally on the distal thigh to visualize Sciatic nerve just before branching, followed by the injection of 20 ml of the same mixture of local anesthetics through a 50 mm block needle in-plane

Patients may assume either a sitting or lateral decubitus position, and subsequent to aseptic procedures, a G27 spinal needle will be introduced into the L3-4 interspinous space until clear cerebrospinal fluid visualization, followed by the injection of 2-2.5 ml of 0.5% hyperbaric Bupivacaine

Marcaine® (bupivacaine HCl) 0,5% and Xylocaine® (Lidocaine HCL) 2% = 2:1 Given in Femoropopliteal block group (Group F)

The primary outcome of this study is the percentage increase in tissue oxygen saturation (StO2) following the administration of femoropopliteal nerve blocks and spinal anesthesia. StO2 will be measured at two locations below the knee (Points A and B) at different heights. Measurements will be taken at four time points: 10 minutes before the intervention (TI), and 5, 15, and 30 minutes after the intervention (T2, T3, T4). The goal is to assess and compare the changes in StO2 induced by each type of anesthesia.