Primary Care Coding Alert

Question: Our physician wrote "knee pain" and "arthritis left knee" as a diagnosis. Would I use the 715 (Osteoarthrosis and allied disorders) or 716 (Other and unspecified arthropathies) category to code this?

New Mexico Subscriber

Answer: "Knee pain" would be coded as 719.46 (Other and unspecified disorders of joint; pain in joint; lower leg). In general, arthritis (whether acute, chronic, or subacute) is classified as 716.9x, and arthritis in the knee would be coded 716.96 (Other and unspecified arthropathies; Arthropathy, unspecified; lower leg). Assuming the arthritis is a more definitive diagnosis of the "knee pain" also noted, you would simply code 716.96. ICD-9 does not provide a mechanism to specify left versus right knee; you will likely have to wait for ICD-10 to get to that level of detail.