Transient synovitis, multiple sites

This code represents a temporary, non-infectious inflammation of the synovial membrane affecting multiple joints. It is characterized by joint pain, swelling, and limited range of motion, typically resolving spontaneously without long-term sequelae.

Apply this code when documentation indicates transient synovitis affecting more than one joint, such as bilateral hips or a combination of hip and knee involvement. Supporting documentation should specify the transient nature of the inflammation and the multiple sites affected.

• Ensure the documentation explicitly states "multiple sites" or lists more than one affected joint.
• Distinguish from other forms of synovitis (e.g., M65.8- Other specified synovitis and tenosynovitis) which may have different etiologies or chronicity.
• Do not use if a specific infectious or autoimmune cause for the synovitis is identified; code the underlying condition instead.