Knee washout for osteoarthritis

Twenty-nine knees in 23 patients with symptomatic osteoarthritis refractory to treatment with medication underwent washout with lactated Ringer's solution made hypertonic with mannitol. Two arthroscopic cannulas were placed under local anesthesia into the knee. Three liters of fluid were run through the knee, varying inflow and outflow to alternately inflate and deflate the knee. Following washout, patients were injected intraarticularly with hyaluronic acid or placebo, patients were blinded as to which injection they received. Patient were followed prospectively with Hospital for Special Surgery (HSS) knee scores, Knee Society (KS) pain and function ratings, visual analog pain scales, and physical examination obtained before and up to 2 years afterwashout. At 1 year, the mean HSS score increased from 72 to 87, KS pain rating from 64 to 89, and KS function from 62 to 82. Visual analog pain score showed significant improvement in rising from a chair, and walking 10 m, 100 m, and 1 km. At 1 year, 25 knees (86%) had a good or excellent result. When 21 of these were observed at 2 years, 17 (81%) had good or excellent results. Overall, 61% of knee washouts had a good or excellent result at 2 years postwashout. Injection with hyaluronic acid gave no additional clinical benefit following washout. This study confirms the value of a fluid washout in an arthritic knee for some patients. This result may explain some of the symptom relief seen with arthroscopic procedures in this condition.