Saline Lavage X Saline Lavage and Osteonil® Mini in Rizarthritis

Patients with multiple osteoarthritis (including carpometacarpal joint of the thumb, stages I to III - Eaton et al.) in treatment at the Institute of Orthopedics and Traumatology fo the Clinics Hospital - University of São Paulo (IOT-HC-FMUSP) will be invited to participate in this study. All patients are obliged to participate in a two-day education course on OA. During the program they are instructed about OA, metabolic syndrome, comorbidities and importance of diet, and daily exercise (including specific exercises for the hand). After inclusion, 40 joints will be randomized in one of two treatment options, i.e., Lavage with saline solution and final injection of 1mL of saline solution, or lavage with saline solution followed by injection of 10mg of hyaluronic acid with mannitol (5mg). After the procedure patients will receive naproxen 500mg twice daily for 5 days. Patients will be instructed to exercise at least 180 minutes/week and if possible daily exercise for the hand (5 to 10 minutes daily). Patients will be instructed to write down when and what they exercised as well as their daily medication intake (for co-morbidities and pain). All patients will be submitted to pain (VAS), range of motion (ROM), Quick DASH, Sollermand Test and functional (palmar grip strength and lateral and pulp-pulp pinch strength) evaluations immediately prior to the procedure and after 1, 3 and 6 months of each joint. As the assessments of pain, range of motion and strength will be compared with measurements of the same limb at inclusion, each hand involved of the patient will be considered as a case. The "n" was calculated to obtain a statistical power of 80% and a level of significance of 5%. To do this, we considered the mean and standard deviation of the pulp-pulp pinch (our primary outcome) found in previous study of the prevalence of hand OA in individuals with knee osteoarthritis submitted to our educational program. A sample size was used to detect a variation of 1 point on the two-tailed pulp-pulp pinches. The sample size calculated by group was 16. Considering also possible faults and abandon of about 20% of the patients, the value of 20 patients per group was obtained.