Objective:

To argue that the 12-month sham-controlled trial of genicular artery embolization (GAE) for knee osteoarthritis does not establish that GAE is ineffective, given limitations in trial design and execution.

Approach:

• Trial findings: The letter reviews the reported 12-month results, which found no significant between-group difference in pain improvement.
• Methodological critique: It discusses statistical power, incomplete embolization, patient selection and synovitis assessment, and MRI-reader reliability.
• Broader evidence: It cites animal research, other clinical studies, and ongoing randomized trials as context for the developing evidence base.

Key Findings:

• The trial enrolled 29 patients per group and assumed an 8-point sham response on KOOS-Pain, while the observed sham response was 18.4 points.
• The authors estimate that approximately 450 participants per group would have been needed to detect the observed 3.0-point between-group difference with adequate power.
• The reported 95% confidence interval extended to a 28.56-point benefit, above the cited 12-point minimal clinically important difference; the letter says a clinically meaningful benefit therefore remains compatible with the data.
• Embolization was not performed in three of 29 participants assigned to GAE because angiographic blush was absent.
• The letter questions whether participants had sufficient baseline synovitis, notes that contrast-enhanced MRI was performed only at 1 and 4 months, and reports that one reader assessed all MRI scans and clinical outcomes without reliability data.
• The letter cites more than 12 prospective randomized trials involving over 1,700 patients as ongoing.

Interpretation:

The authors contend that a non-significant result in this small, early-phase trial should not be interpreted as proof of equivalence or absence of GAE efficacy. They call for cautious interpretation while the evidence develops.

Limitations:

• This is a letter presenting the authors’ critique and interpretation, not a new clinical study.
• The supplied text ends mid-sentence, so the letter’s final statement is incomplete.
• The source URL was not provided.

Conclusion:

The authors argue that the trial does not establish GAE ineffectiveness and that conclusions should account for its limited sample size, underestimated sham response, and other methodological concerns.