Chronic gout due to renal impairment, unsp knee, with tophus

This code signifies a persistent form of gout caused by kidney dysfunction, specifically affecting an unspecified knee joint, and characterized by the presence of urate crystal deposits (tophi). The renal impairment leads to hyperuricemia, which in turn precipitates chronic gouty arthritis.

Apply this code when documentation clearly indicates chronic gout stemming from renal impairment, with evidence of tophi, and the affected joint is an unspecified knee. This diagnosis requires physician documentation of both the chronic nature of the gout and its etiology due to kidney disease, along with the presence of tophaceous deposits.

• Ensure documentation specifies "chronic" gout and explicitly links it to "renal impairment" as the cause.
• Verify the presence of "tophi" is documented; if not, a different code without tophi would be appropriate.
• This code is for an "unspecified knee"; if the laterality (right or left) is known, a more specific code should be used.