Comparative evaluation of short vs. long needles in deep ultrasound-guided pharmacopuncture for acute low back pain: study protocol.

BACKGROUND/

OBJECTIVES

Acute Low Back Pain (LBP) commonly shows rapid symptom improvement during the early phase; however, delayed or inadequate treatment may increase the risk of recurrence and chronicity. Ultrasound-guided pharmacopuncture has demonstrated promising analgesic effects, yet the optimal needle length for deep interfascial targeting remains unclear, particularly in procedures involving the Quadratus Lumborum-Psoas-Iliocostalis (QPI) space. This study aims to compare the short-term clinical response, procedural feasibility, and safety of short versus long needles used for QPI-guided pharmacopuncture in patients with acute LBP.

METHODS

This prospective, multicenter, comparative observational study includes adults aged 20-65 years presenting with acute LBP within 7 days of onset. Participants undergo a single session of ultrasound-guided Polydeoxyribonucleotide (PDRN) pharmacopuncture targeting the QPI interfascial plane using either a short needle (26G × 60 mm) or a long needle (25G × 100 mm). Group assignment is based on pre-designated site-level data extraction rather than randomization. The primary outcome is the change in the Numeric Rating Scale (NRS) score immediately after treatment. Secondary outcomes include changes in lumbar range of motion (ROM), patient-reported percentage pain reduction (PRPPR), and procedural usability. Safety is monitored immediately post-procedure and again during a telephone follow-up 24-36 h later. Statistical analyses will compare between-group effects and explore potential associations with procedural characteristics.

DISCUSSION AND

CONCLUSION

This study aims to provide preliminary feasibility evidence on whether needle length affects procedural performance and immediate analgesic response during ultrasound-guided interfascial pharmacopuncture for acute LBP. By evaluating both clinical and procedural metrics, the results may contribute to establishing standardized needle-selection criteria and support future randomized controlled trials designed to optimize deep pharmacopuncture techniques within Korean medicine primary care settings.

CLINICAL TRIAL REGISTRATION: https://cris.nih.go.kr/cris/search/detailSearch.do?seq=32507&search_page=L&search_lang=&class_yn=.