Permanent vs. Temporary embolic agents in genicular artery embolization for knee Osteoarthritis: A systematic review and Meta-Analysis.

PURPOSE: To systematically describe the observed safety and pain outcomes of genicular artery embolization (GAE) for symptomatic knee osteoarthritis (KOA), compare embolic agent classes, and critically appraise the methodological quality of available evidence, including sham-controlled randomized controlled trial (RCT) design.

METHODS

Adults with radiographic KOA who underwent transcatheter GAE and reported ≥ 1 patient-reported outcome measure were eligible. The primary outcome was VAS pain reduction at 12 months. Secondary outcomes included WOMAC and KOOS scores, technical success, and adverse events. Random-effects meta-analysis with REML estimation was used; prediction intervals were computed. Pre-specified subgroup analysis compared imipenem/cilastatin versus permanent microspheres.

RESULTS

22 studies (3 RCTs, 19 single-arm or comparative cohorts) comprising 633 patients and 719 knees were included. Pooled within-group VAS WMD at 12 months: -39.6 mm (95% CI, -47.1 to - 32.1; 95% prediction interval [PI], -58.4 to - 20.8; I2 = 76%; p < 0.001). IPM/CS and permanent microspheres produced equivalent observed outcomes (between-subgroup p = 0.73). Technical success: 98.7%. Pooled minor adverse event rate: 18.3%. RCT-pooled between-group SMD versus sham: -0.23 (95% CI, -0.71 to + 0.25; p = 0.34; I2 = 38%).

CONCLUSIONS

GAE is consistently associated with large within-group pain reductions; however, these pre-post estimates are descriptive and do not establish procedure-specific causal efficacy. Three sham-controlled RCTs did not demonstrate significant between-group benefit, representing the highest-quality evidence currently available. Embolic agent class does not significantly influence pain-reduction outcomes; however, safety profiles are not equivalent-focal asymptomatic osteonecrosis was reported exclusively with permanent microspheres, warranting prospective imaging surveillance and explicit patient counseling. Adequately powered RCTs with pharmacologically inert controls, standardized technique protocols, and systematic safety imaging are required before definitive conclusions can be drawn.