204 patients affected by knee osteoarthritis will be included in a double-blinded randomized controlled trial. Patients in the experimental group will be treated with a single intra-articular injection of collagen (solution of low molecular weight peptides derived from hydrolyzed collagen) instead patients in the control arm, will be treated with a single intra-articular injection of placebo (saline solution). All patients will be evaluated by clinical examination before the infiltrative procedure and they will follow-up at 1,3,6 months. During the follow-up visits ,will be evaluated the inflammatory status of the knee by thermographic assessment and questionnaires, filled out by patients, will be utilized for clinical evaluations. After 6 months, patients in the control arm (saline solution injection), have the possibility to cross-over into the treatment arm (collagen) in which case they will be followed for an additional 6 months.
The aim of the study is to compare the 6 months clinical outcome of the treatment with a single intra-articular collagen injection versus a single placebo (saline solution) infiltration in the infiltrative treatment of knee osteoarthritis. The evaluation will be performed through clinical, subjective and objective assessments.