Juvenile arthritis, unspecified, knee

• arthropathic psoriasis (L40.5-)
• certain conditions originating in the perinatal period (P04-P96)
• certain infectious and parasitic diseases (A00-B99)
• compartment syndrome (traumatic) (T79.A-)
• complications of pregnancy, childbirth and the puerperium (O00-O9A)
• congenital malformations, deformations, and chromosomal abnormalities (Q00-Q99)
• endocrine, nutritional and metabolic diseases (E00-E88)
• injury, poisoning and certain other consequences of external causes (S00-T88)
• neoplasms (C00-D49)
• symptoms, signs and abnormal clinical and laboratory findings, not elsewhere classified (R00-R94)

Use an external cause code following the code for the musculoskeletal condition, if applicable, to identify the cause of the musculoskeletal condition

Disorders affecting predominantly peripheral (limb) joints

• arthropathy in Whipple's disease (M14.8)
• Felty's syndrome (M05.0)
• juvenile dermatomyositis (M33.0-)
• psoriatic juvenile arthropathy (L40.54)

• any associated underlying condition, such as:
• regional enteritis [Crohn's disease] (K50.-)
• ulcerative colitis (K51.-)

juvenile rheumatoid arthritis, unspecified (M08.0-)