Intermittent hydrarthrosis, unspecified ankle and foot

This code describes a condition characterized by recurrent, temporary swelling of a joint due to an accumulation of synovial fluid, specifically affecting an unspecified ankle or foot. The swelling is intermittent, meaning it comes and goes, and is not associated with a known underlying cause like infection or injury.

Use this code when documentation indicates intermittent joint swelling in the ankle or foot without a specified laterality (right or left) and without an identified etiology. This code is appropriate when the physician has diagnosed "intermittent hydrarthrosis" of the ankle/foot but has not specified which ankle/foot is affected.

• Ensure documentation explicitly states "intermittent hydrarthrosis" and specifies the ankle or foot as the affected site.
• Avoid using this code if a more specific diagnosis, such as traumatic effusion or inflammatory arthritis, is documented.
• If laterality (right or left ankle/foot) is documented, a more specific code (M12.471, M12.472) should be used instead.