Ethics committee approval was taken on October 22, 2019, numbered 19/342. 120 adult patients who will undergo spine stabilization surgery between October 2019 and January 2020 in "Gülhane Training and Research Hospital" were planned to be included in the study. Patients will be randomized to 30 patients with MTP block (Group MTP) and ESP block (Group ESP) and no block (Group K) in addition to patient-controlled analgesia (PCA). Postoperative pain scores, analgesic use, number of PCA button presses, total amount of opioid administered and complications due to opioids will be recorded. The obtained data will be compared statistically.

Ethics committee approval was taken on October 22, 2019, numbered 19/342. 120 adult patients who will undergo spine stabilization surgery between October 2019 and January 2020 in Gulhane Training and Research Hospital were planned to be included in the study. Appropriate patients will be informed about the study and their written consent will be obtained. All patients were scheduled for ASA I-III. Exclusion criteria for patients are as follows: ≤18 or ≥81 years old, body mass index (BMI) ≥30 or ≤18 kg / m2, skin infection where the needle is punctured, allergic drugs to any of the study, pre-existing pain syndromes, pregnancy, severe liver diseases), kidney diseases (serum creatinine greater than 2 mg / dL, oliguria, anuria or hemodialysis) or cardiovascular disorders (functional class of the New York Heart Association greater than III). During the preoperative visit, all patients will be instructed on how to assess their pain using a numerical analogue pain scale (0 = no pain, 10 = maximum pain to be considered) and patient-controlled analgesia (PCA). Patients will be randomized according to a computer-generated random number table, in addition to patient-controlled analgesia (PCA) with MTP block (Group MTP) and ESP block (Group ESP) and no block (Group K). Nerve blocks will be made at the end of the operation after the surgical site is sutured and intact before the dressing is done. The linear ultrasound probe will be applied in the prone position bilaterally in the region of the transverse process corresponding to the center of the incision line by the same three experienced senior doctors with ultrasound guidance covered with sterile probe sheath. In the ESPB group, a high-frequency 15 6 MHz (Megahertz) linear ultrasound probe will be placed vertically about 3 cm laterally from the midpoint of the incision line in the midline. Once the erector spinae muscle and transverse projections have been identified, the peripheral nerve blockage needle (50 mm 22 Gauge) will be advanced from caudal to cranial between the fascia of the erector spina muscle and the transverse process. After 1 ml normal saline injection, this plane will open. Twenty milliliters of 0.25% bupivacaine will be given for the block. The same procedure will be applied 3 cm later than the incision line. In the MTP Group, a high frequency HFL-50 15-6 MHz linear ultrasound probe will be placed vertically approximately 3 cm laterally from the midpoint of the incision line in the midline. Using the parasaggital scan, the block needle (50 mm 22 Gauge) will be advanced from the caudal to the cervical target of the paravertebral cavity. When the needle tip reaches the midpoint between the transverse process and the pleura, 1 ml normal saline is performed. Once the needle tip has been confirmed, 20 ml of 0.25% bupivacaine will be given to the block. The same procedure will be applied 3 cm later than the incision line.

No regional plan block will be applied to the control group. All groups will receive analgesia in the postoperative period using patient-controlled analgesia (PCA), and the pain will be evaluated three days postoperatively using a numerical grading scale (NRS) ranging from 0 (painless) to 10 (worst imaginable pain). The number of PCA button presses, the total amount of opioids applied, and complications associated with opioids will be recorded. The obtained data will be compared statistically

Inclusion Criteria:

• 18-80 years old
• ASA (American Society of Anesthesiologists) score between I-III.

Exclusion Criteria:

• ASA (American Society of Anesthesiologists) score >III,
• emergency surgery,
• secondary surgery,
• receiving chronic pain treatment