Multi-site efficacy and safety of transarterial microembolization with imipenem/cilastatin for refractory musculoskeletal pain: a single-centre analysis of hip, knee and shoulder (FIRE-NEM study).

PURPOSE: To report the early safety, feasibility and clinical efficacy of transarterial microembolization (TAME) with imipenem/cilastatin (IPM/CS) for refractory musculoskeletal (MSK) pain.

MATERIALS AND

METHODS

We performed a retrospective analysis of prospectively collected data from 42 patients who underwent 50 TAME procedures between December 2024 and March 2026 for refractory chronic MSK pain. Districts treated were hip (n = 24), knee (n = 15) and shoulder (n = 11). Pain (NRS) and functional scores (WOMAC, KOOS, Quick-DASH and Oxford Shoulder Score) were assessed at baseline, 1, 3 and 6 months. Technical success was defined as complete embolization of all arteries responsible for hypervascular blush. Clinical success was defined as the minimum clinically important difference (MCID), set at ≥ 2-point reduction on NRS or ≥ 10-point improvement on functional scores; substantial clinical benefit (SCB) was defined as ≥ 30% improvement on the relevant functional score from baseline. Inter-district pain reduction and functional score improvement were compared. Complications were graded according to the modified CIRSE classification.

RESULTS

Technical success was 100%. Median NRS decreased from 9.0 (IQR: 8.0-10.0) at baseline to 6.0 (4.0-7.8) at 1 month, 6.0 (3.0-8.0) at 3 months and 6.0 (3.5-7.0) at 6 months (all p < 0.0001 vs. baseline). MCID for pain was reached in 72.0% of procedures at three months and sustained in 71.4% at six months; MCID for functional scores was 82.0% and 85.7%, respectively. SCB was reached in 72.0% at three months and 77.1% at six months. Pain reduction did not differ significantly across hip, knee and shoulder (p = 0.118), although the subgroup sizes do not allow equivalence to be established. Three minor (CIRSE grade 1-2) access-site complications occurred; no skin ischaemia, nerve injury or osteonecrosis were observed.

CONCLUSION

TAME with IPM/CS appeared to be safe and to provide clinically meaningful early pain relief in patients with refractory MSK pain across multiple districts.

LEVEL OF EVIDENCE: Oxford Centre for Evidence-Based Medicine Level 4.