Knee Arthroscopy for Osteoarthritis: A $3 Billion Placebo Unmasked by Sham Surgery Trials

Abstract

Is it possible for expert surgeons to distinguish between real effects and placebo when 700,000 patients a year undergo a procedure proven ineffective by ham trials? Sham-Trials compared real knee arthroscopy for osteoarthritis against fake procedures with only skin incisions but no intra-articular intervention. The trials evaluated pain scores, functional outcomes, and patient satisfaction at various follow-ups. Patients improved equally across both groups, with no statistically significant differences in any outcome across multiple independent trials. These findings achieved GRADE high certainty due to well-designed RCTs and consistent results across the studies. Prior to the sham trials, around 700,000 Americans underwent knee arthroscopy annually costing approximately $3 billion, with surgeons consistently reporting patient improvement following the procedure. Uncontrolled clinical observation cannot detect placebo effects regardless of observer expertise, yet insurance coverage and guideline recommendations persisted for years after the sham trial evidence reached high certainty.