·         Onset time

·         Peak effect

·         Duration of sensory block

2. Motor block :   

·         Onset time

·         Peak effect

·         Duration of motor block

3.Vital parameters:

4. Peri-operative complication

5. Duration of analgesia

6. Number of rescue analgesic required within 24 hrs

Group(P):     (n=48)

In this group patients will be given combined psoas compartment block and sciatic nerve block.

Group(S) :    (n=48)

In this group patients will be given unilateral subarachnoid block.

Psoas compartment block :

·         The block will be given in lateral position. Surgical side leg will be in the nondependent position.

·         Two points will be marked – posterior superior iliac spine (PSIS) and Intercristal line.

·         Line will be drawn from the PSIS parallel to the spine and another line is intercristal line.

·         Point of intersection of the two lines is the point of needle insertion.

·         Under all aseptic precaution 100mm 22 gauze insulated needle connected to nerve locator set at 3mA frequency will be inserted at this point. When the needle enters in the psoas compartment quadriceps motor response will be seen. Adequate proximity to the nerves will be assured by continued twitching after reducing the stimulation to 0.5mA. After negative aspiration 25ml local anaesthetic solution will be injected.

  Sciatic nerve block:

·         The sciatic nerve block will be performed by classical Labat’s approach. The patient with same lateral decubitus position (Sim’s position)

·         Two lines will be drawn: the first from the greater trochanter to the sacral hiatus and second from greater trochanter to the posterosuperior iliac spine (PSIS). A perpendicular will be drawn from the midpoint of the greater trochanter‑PSIS line, caudad that intersected the greater trochanter‑sacral hiatus line, which represent the insertion point.

·         Under all aseptic measures the insulated needle will be connected to nerve stimulator set at 3 mA, and will be inserted at right angles to the skin to elicit a motor response like planter flexion. Adequate proximity to the nerves will be assured by continue twitching after reducing the stimulation to 0.5mA.

·         After negative aspiration 25ml local anaesthetic solution will be injected.

 v  Post-operative Monitoring of Patient:

Effect of Sensory block and post-operative analgesia (Visual Analogue Score – VAS) will be assessed every 1hr for first 6 hours, every 2 hour for next 6 hours and then at 18 and 24 hours.