An implantable device designed to treat focal cartilage defects in the posterior surface of the patella by excision of the lesion and cemented fixation of the device in the surgically-prepared defect, with retention of the surrounding healthy articular cartilage. It typically consists of a disc-shaped device with a fixation stem, and is made of synthetic polymer [e.g., ultrahigh molecular weight polyethylene (UHMWPE)] mixed with a microbe-derived (biosynthetic) material [e.g., hyaluronic acid (HA)]. It is available in a range of sizes for treatment of different size lesions.