Prescription-grade Crystalline Glucosamine Sulfate Therapy in Erosive Hand Osteoarthritis

The objective of this study is to evaluate the efficacy of prescription-grade Crystalline Glucosamine Sulfate (pCGS), as an add-on treatment to conventional therapy, compared to usual therapy alone, in patients with erosive osteoarthritis of the hand (EHOA). This is a 6-months retrospective study including patients with concomitant gonarthrosis and EHOA, defined as the presence of central erosion in at least two interphalangeal joints. Eligibility criteria are symptoms duration for at least 3 months, with a global hand pain score ≥40 mm on a 0-100 Visual Analogue Scale (VAS) and a Functional Index for Hand Osteoarthritis (FIHOA) score ≥6. The participants are stratified into two groups based on whether or not pCGS, at the daily dose of 1500 mg, was added to the conventional therapy for hand osteoarthritis (HOA). The latter consists of education and training in ergonomic principles, exercise and the use on-demand of acetaminophen or oral non-steroidal anti-inflammatory drugs. Patients are evaluated at baseline, after 3 and 6 months. Primary outcome measures are the change from baseline to month 6 in VAS and in FIHOA score. Secondary outcomes are duration of morning stiffness, health assessment questionnaire (HAQ), medical outcomes study 36-item short form (SF-36), symptomatic drugs consumption and percentage of treatment responders, according to the OMERACT/OARSI criteria.