Inclusion Criteria:  patients undergoing knee surgery i.e. arthroscopy, total knee replacement, ACL repair. ASA physical status I to III Sex (males and females) Age 21-70 years.  Exclusion Criteria:  Hypersensitivity to local anesthetics. Preexisting peripheral neuropathy. Infection near site of infections e.g. osteomyelitis, septic knee joint. Etc. Patient refusal. PAny contraindications for spinal anesthesia. ( eg: coagulopathy, use of anticoagulants