Other chondrocalcinosis, unspecified knee

This code signifies the presence of calcium pyrophosphate dihydrate (CPPD) crystal deposition disease, also known as pseudogout, affecting an unspecified knee joint. It indicates a form of arthritis characterized by the accumulation of these crystals within the cartilage and synovial tissues, leading to inflammation and joint pain.

Use this code when documentation confirms chondrocalcinosis in a patient's knee, but the specific laterality (right or left) is not documented or is unknown. This diagnosis is typically supported by imaging studies (e.g., X-rays showing chondrocalcinosis) and/or synovial fluid analysis revealing CPPD crystals.

• Ensure the documentation explicitly states "chondrocalcinosis" and specifies the knee as the affected joint.
• Avoid using this code if laterality (right or left knee) is clearly documented; instead, select the more specific M11.261 or M11.262.
• This code is for "other" chondrocalcinosis, meaning it's not primary, familial, or due to trauma. If those etiologies are documented, use the appropriate subcategory.