M25.66 Stiffness of knee, not elsewhere classifiedNon-billable header with 3 child codes.
M25.661 Stiffness of right knee, not elsewhere classifiedM25.662 Stiffness of left knee, not elsewhere classifiedM25.669 Stiffness of unspecified knee, not elsewhere classifiedM24.6 Ankylosis of joint ("stiffness of joint without ankylosis (M25.6-)")M25.649 Stiffness of unspecified hand, not elsewhere classifiedM25.65 Stiffness of hip, not elsewhere classifiedM25.651 Stiffness of right hip, not elsewhere classifiedM25.652 Stiffness of left hip, not elsewhere classifiedM25.659 Stiffness of unspecified hip, not elsewhere classifiedM25.66 Stiffness of knee, not elsewhere classified (this code)M25.661 Stiffness of right knee, not elsewhere classifiedM25.662 Stiffness of left knee, not elsewhere classifiedM25.669 Stiffness of unspecified knee, not elsewhere classifiedM25.67 Stiffness of ankle and foot, not elsewhere classifiedM25.671 Stiffness of right ankle, not elsewhere classified