Transient synovitis, right knee

This code signifies a self-limiting inflammatory condition affecting the synovial membrane of the right knee joint, characterized by joint effusion and pain without evidence of infection or other underlying pathology. It is most commonly observed in children and typically resolves spontaneously.

Apply this code when documentation confirms a diagnosis of transient synovitis specifically affecting the right knee. This diagnosis is often made after excluding other causes of knee pain and swelling, such as septic arthritis or traumatic injury, and is supported by clinical examination findings and sometimes imaging (e.g., ultrasound showing effusion).

• Ensure the laterality (right knee) is clearly documented.
• Do not confuse with other forms of synovitis (e.g., M65.861 for other specified synovitis, right knee) or septic arthritis (M00.061).
• This code is typically a primary diagnosis, as it represents the main reason for the encounter.