A customised patient-specific 4-in-1 femoral finishing cutting jig comprising a cutting block (2) which is configured to be placed, in use, in contact with the distal resection surface (sd) of a femur (f)； the jig (1) being characterised in that it comprises a reference means (R； 9； 10) which is connected to said block (2)； wherein the reference means (R； 9； 10) is configured to position, in use, said block (2) relative to the distal resection surface (sd) in a predetermined and patient-specific manner； wherein the reference means (R； 9； 10) comprises a first contact element (9； 10) having a first surface (11； 12) which is configured to face, in use, a first femoral condyle (cfl； cfm) and being customised and patient-specific； said first surface (11； 12) is configured to be placed against a respective portion of a first femoral condyle (cfl； cfm) having a corresponding profile.
