Regional anesthesia and analgesia technics are widely and securely used during orthopedic surgery. Interfascial plane blocks are the latest used ones for analgesia. There are studies in literature indicating that bupivacaine cause myotoxicity. We aimed to examine plasma CPK(creatine phosphokinase) levels to see whether myotoxicity occurs or not after suprainguinal fascial plane block is applied to patients undergoing knee artroplasty surgery.

During 2 months period all elligible patients undergoing knee artoplasty surgery will be included in the study. Different postoperative analgesic modalities will be used according to the anesthesists experience. During routine blood sample tests plasma CPK levels will be tested 3 times of all patients.(preoperative, postoperative 6th hour, postoperative 24th hour) this data will be recorded for 2 months. After this period of time data will be analysed and patients will be grouped according to the analgesic modalities used.

Inclusion Criteria:

• ASA 1-3
• knee artoplasty patients
• under spinal anesthesia

Exclusion Criteria:

• local anesthetic allergies
• myopathies
• coagulopathies
• Obstructive sleep apne syndrome
• hearth diseases
• liver diseases
• kidney diseases
• thyroid-parathyriod dieseas
• hiperlipidemias using Statins(HMG-CoA reductase inhibitors)
• pregnancy

Patients undergoing knee artroplasty surgery of ASA status 1-3. aged between 18-75years.