CLINICAL EFFECTIVENESS OF PERICAPSULAR NERVE GROUP (PENG) BLOCK IN CHRONIC HIP PAIN: A RETROSPECTIVE OBSERVATIONAL STUDY

Abstract

Background: Chronic hip pain limits mobility and quality of life, and many patients have suboptimal relief or medication intolerance. The pericapsular nerve group (PENG) block targets articular branches to the anterior hip capsule, aiming for motor-sparing analgesia.

Objective: To evaluate real-world effectiveness, opioid/NSAID-sparing impact, and safety of ultrasound-guided PENG block in chronic hip pain.

Methods: Retrospective observational analysis at a tertiary pain clinic. Consecutive adults receiving PENG block for chronic hip pain were included. Demographics, etiologies, and procedural details were abstracted. Outcomes were Numeric Rating Scale (NRS, 0–10) pain scores at baseline, 1 week, 1 month, and 3 months; functional recovery (HOOS domains where available); changes in NSAID/opioid use; patient satisfaction (5-point Likert); and adverse events. Longitudinal comparisons used appropriate parametric/non-parametric tests; significance at p<0.05.

Results: Of 82 screened, 72 were analyzed (mean age 63.8 ± 8.9 years; 58.3% female). Etiologies: osteoarthritis 70.8%, post-arthroplasty pain 18.1%, avascular necrosis 6.9%, greater trochanteric pain 4.2%. Baseline NRS was 8.2 ± 0.9. Mean NRS improved to 3.4 ± 1.1 at 1 week, 2.8 ± 1.3 at 1 month, and 3.1 ± 1.5 at 3 months (all p<0.001 vs baseline; repeated-measures effect size η²=0.71). Clinically meaningful pain relief (≥50%) persisted in 68.1% at 3 months. HOOS domains improved significantly, with median functional gain ~59%. NSAID use decreased from 94.4% to 38.9%, and opioid use from 15.3% to 2.8% by 3 months. Satisfaction was high (very satisfied 70.8%, satisfied 20.8%). No major complications occurred; minor, self-limited effects in 13.9%. No quadriceps weakness was observed.

Conclusions: Ultrasound-guided PENG block provided substantial, durable, and motor-sparing analgesia for chronic hip pain with marked reductions in NSAID/opioid use and excellent safety. These real-world data support integrating PENG block into multimodal, non-surgical management pathways for appropriately selected patients.