Introduction:
This study evaluated the efficacy of ultrasound-guided erector spinae plane block (ESPB) and pericapsular nerve group (PENG) block under spinal anesthesia for postoperative analgesia in elderly patients undergoing total hip arthroplasty.

Material and methods:
In this randomized, controlled, double-blind study, 90 elderly patients (aged 67-89 years, ASA II and III), scheduled for total hip arthroplasty under spinal anesthesia were randomly allocated to three groups: PENG block (n = 30), ESPB (n = 30), and Control group (n = 30). Ultrasound-guided blocks were administered using 20 mL of 0.2% ropivacaine. The primary outcome was total opioid consumption over 48 hours. Secondary outcomes included pain scores, time to first rescue opioid analgesia, quadriceps muscle strength, neutrophil-to-lymphocyte ratio (NLR), and platelet-to-lymphocyte ratio (PLR).

Results:
Opioid consumption within 48 hours was significantly lower in both the PENG (3.5 ± 4.0) and ESPB (3.4 ± 3.8) groups compared to the Control group (16.07 ± 3.8 ), with P < 0.001, and no significant difference between PENG and ESPB groups (P = 1.0). Time to first rescue analgesia was longer in the PENG (12.3 ± 3.2) and ESPB (11.2 ± 2.9) groups relative to the Control group (4.2 ± 1.1), P < 0.001. Pain scores remained consistently lower in both intervention groups at all time points compared to the Control group. Quadriceps strength was lower in the PENG group at 6 hours postoperatively compared to ESPB. NLR and PLR values were lower in both block groups than in the Control group.

Conclusions:
Ultrasound-guided PENG and ESPB are effective for postoperative analgesia in elderly patients undergoing total hip arthroplasty, significantly reducing opioid requirements and enhancing recovery quality.