Short-term effects of knee washout for osteoarthritis

Twenty-nine knees in 23 patients with symptomatic osteoarthritis underwent washout with lactated Ringer's solution. Two arthroscopic cannulas were placed into the knee under local anesthetic. Three liters of fluid were run through the knee using varying inflow and outflow to alternately inflate and deflate the knee. We obtained Hospital for Special Surgery knee scores, Knee Society pain and function ratings, and visual analog pain scales before washout and up to 2 years after washout. At 1 year, the mean Hospital for Special Surgery score increased from 72 to 87, the Knee Society pain rating from 64 to 89, and the Knee Society function rating from 62 to 82. Twenty-five knees had a good or excellent result at 1 year. Twenty-one of these were observed at 2 years; 17 had good or excellent results. This study confirms the value of a fluid washout in an arthritic knee for some patients. This may explain some of the symptom relief seen with arthroscopic procedures in this condition.