THIS INVENTION CONCERNS THE TREATMENT OF CARTILAGE DISORDER AND OSTEOARTHRITIS IN PARTICULAR. MORE SPECIFICALLY, IT RELATES TO THE USE OF FGF-18 IN TREATMENT REGIMENS AND FOR THE MANUFACTURE OF A MEDICAMENT FOR THE TREATMENT OF PATIENTS HAVING A CARTILAGE DISORDER SUCH AS OSTEOARTHRITIS, SUCH AS FOR EXAMPLE KNEE OSTEOARTHRITIS OR SECONDARY HIP OSTEOARTHRITIS. SPECIFICALLY PROVIDED IS A PREFERRED TREATMENT SCHEME COMPRISING ONCE WEEKLY ADMINISTRATION OF AN FGF-18 COMPOUND PER TREATMENT CYCLE.