TITLE:
A Scoping Review of the Effectiveness, Safety, and Technical Considerations of Hydrodissection in Lumbar Facet Joint Interventions
AUTHORS:
Harry McGrath, Eoin Cashman, Dominic Harmon
KEYWORDS:
Hydrodissection, Lumbar Facet Joint, Medial Branch Block, Chronic Low Back Pain, Interventional Pain Management, Evidence Gap
JOURNAL NAME:
Pain Studies and Treatment,
Vol.14 No.2,
March
25,
2026
ABSTRACT: Background: Chronic low back pain affects 15% - 45% of adults, with facet joint pathology contributing substantially to this burden. Current interventional treatments—including intra-articular corticosteroid injections and medial branch blocks—demonstrate highly variable success rates (13% - 74% for ≥50% pain relief). Hydrodissection, a technique using larger volumes of injectate (5 - 30 mL) to mechanically release entrapped nerves from adhesions, has shown promising results for peripheral nerve entrapments and select spinal applications. However, its application to lumbar facet joint interventions remains unexplored. Objective: To map and characterize the existing evidence base regarding the application of hydrodissection to lumbar facet joint interventions and medial branch blocks, identify the extent, range, and nature of available evidence (or its absence), and establish a research agenda to address identified gaps, following established scoping review methodology (PRISMA-ScR/JBI framework). Methods: A comprehensive literature search was conducted across PubMed, Embase, Cochrane Library, and Web of Science databases from inception through January 2026. Search terms included hydrodissection, lumbar facet joint, medial branch block, and related terminology. Two independent reviewers screened titles, abstracts, and full texts. Reference lists of relevant articles were manually searched. Results: No published studies—randomized controlled trials, observational studies, or case series—specifically applied hydrodissection technique to lumbar facet joint injections or medial branch blocks. While extensive literature exists for standard facet interventions (Levels I - II evidence from multiple systematic reviews and guidelines), and hydrodissection has been successfully applied to related structures (superior cluneal nerve with 80% response rates, caudal epidural space, cervical nerve roots), the translation to facet joint interventions represents a complete evidence gap. Technical challenges include ultrasound visualization accuracy (11% - 13% incorrect needle placement versus fluoroscopy) and volume considerations that may compromise diagnostic specificity. Conclusions: The complete absence of evidence for hydrodissection in lumbar facet joint interventions represents a significant research opportunity. Given the theoretical mechanistic rationale (nervi nervorum release, vasa nervorum restoration), successful applications in anatomically related structures, and limitations of current treatments, systematic investigation is warranted. We propose a staged research pathway: 1) cadaveric feasibility studies establishing ultrasound visualization parameters, 2) pilot case series documenting technical success and short-term outcomes, and 3) randomized controlled trials comparing hydrodissection to standard approaches in selecting patient populations.