Ultrasound-guided peripheral nerve blocks for osteoarthritis pain management: a review of the genicular, suprascapular, PENG and deep peroneal nerve blocks.

Background: Osteoarthritis (OA) is the most prevalent form of arthritis and a leading cause of chronic pain worldwide. A significant proportion of patients experience refractory pain despite optimized conservative treatment, underscoring the need for alternative analgesic strategies. Ultrasound-guided peripheral nerve blocks targeting joint-specific nociceptive pathways have been proposed as a minimally invasive option, yet the evidence across different joints has not been comprehensively appraised. Objective: This narrative review summarizes the available evidence on the therapeutic use of ultrasound-guided peripheral nerve blocks across four targets in OA: the genicular nerves (knee), the suprascapular nerve (glenohumeral joint), the pericapsular nerve group - PENG (hip), and the deep peroneal nerve (ankle/midfoot), examining anatomical rationale, ultrasound-guided technique, clinical efficacy, safety, and current gaps. Results: The genicular nerve block has the most robust evidence base, with multiple placebo-controlled randomized trials (RCTs) and meta-analyses demonstrating significant pain relief sustained for up to 24 weeks, though overall certainty remains low to very low by GRADE criteria. The suprascapular nerve block is supported by one placebo-controlled RCT and a meta-analysis of broader chronic shoulder pain populations showing sustained benefit up to 12 weeks, with ultrasound-guided approaches yielding consistently larger effect sizes. The PENG block has one RCT comparing it with intra-articular injection: the PENG block provided superior pain relief at day 1, whereas the intra-articular group showed better pain and functional outcomes at weeks 4 and 8; both groups achieved significant pain reduction through 8 weeks. Evidence for the deep peroneal nerve block is limited to retrospective case series confirming high rates of immediate pain relief but lacking controlled data. Across all blocks, no serious adverse events or motor deficits were reported, and the role of corticosteroid adjuvants remains uncertain. Substantial heterogeneity in techniques, injectate protocols, and outcome measures limits cross-study comparison. Conclusion: In selected patients with refractory OA pain, ultrasound-guided peripheral nerve blocks may offer analgesic benefit with a favorable safety profile, best considered as part of a multimodal approach. However, well-designed sham-controlled RCTs with standardized protocols and extended follow-up are needed to define their efficacy, optimal technique, and positioning within the OA treatment algorithm.