Osteoarthritis of the trapeziometacarpal joint (TMJ), also called rhizarthrosis is a common disease, mostly affecting post-menopausal women. Intra-articular therapy with hyaluronic acid (HA) was usually recommended as a second-line treatment after failure of non-pharmacological modalities, only in early stages of the disease .Aim of the present observational, retrospective, comparative study is the assessment of the efficacy and tolerability of i.a. injections of an hybrid HA formulation (Synovial H-L®) in comparison to triamcinolone in patients with TMJ Osteoarthritis (OA). We are analyzing the records collected in the departmental archives of outpatients affected by TMJ OA, according to the ACR criteria for the classification for hand OA and who were treated with i.a. Sinovial H-L or triamcinolone acetonide from December 1st, 2015 to December 1st 2016.The patient's assessment of spontaneous hand pain on a 0-100 mm VAS with 0 representing the absence of pain and the FIHOA score validated in Italian language were routinely recorded and documented in our centre prior to the injections (T0), at the time of the second i.a. administration (T1), after one month (T2) and after 3 (T3) and 6 months (T4) following the i.a. therapy.