Superolateral Genicular Nerve Block Added to Medial Blocks in Medial Knee Osteoarthritis

We aimed to report the observed analgesic outcomes among patients with advanced medial knee OA who received medial genicular nerve blocks with or without an additional superolateral genicular nerve block during a period-based clinical practice setting, and to explore clinical and imaging features associated with an insufficient response after medial-only blocks in a non-randomized observational cohort.

In this prospective observational cohort study (October 2024-March 2025), patients with Kellgren-Lawrence grade 3 or 4 medial knee OA and baseline walking pain ≥20 mm on a 100-mm Visual Analog Scale (VAS) received genicular nerve blocks as part of their routine clinical care. During two consecutive clinical periods, patients received either medial blocks only (superomedial and inferomedial; "2-nerve") or medial plus superolateral blocks ("3-nerve") (non-randomized allocation by clinical period). Walking VAS and Timed Up and Go (TUG) tests were performed immediately before and after the block (short-term post-block assessment). In the 2-nerve group, patients with <70% pain reduction (non-responders) were compared with responders using the magnetic resonance imaging OA Knee Score (MOAKS) and quantitative sensory testing (QST).

Walking pain VAS changed from 51.9 to 15.8 mm (2-nerve) and from 61.6 to 10.6 mm (3-nerve); between-group difference in pain reduction was observed, with a larger reduction in the 3-nerve group (p = 0.02). TUG results improved in both groups, without between-group differences. Within the 2-nerve group, lateral femoral BML scores were higher in non-responders than in responders (p = 0.03), whereas MOAKS cartilage, osteophyte, meniscus, and QST parameters did not differ.

Adding a superolateral genicular nerve block was associated with greater short-term walking pain reduction in advanced medial knee OA. Lateral femoral BMLs may help identify patients who may warrant consideration for an individualized approach and may inform diagnostic target selection when medial-only blocks provide insufficient analgesia.