| Note |
| This block comprises arthropathies due to microbiological agents. Distinction is made between the following types of etiological relationship: |
| a) direct infection of joint, where organisms invade synovial tissue and microbial antigen is present in the joint; |
| b) indirect infection, which may be of two types: a reactive arthropathy, where microbial infection of the body is established but neither organisms nor antigens can be identified in the joint, and a postinfective arthropathy, where microbial antigen is present but recovery of an organism is inconstant and evidence of local multiplication is lacking. |
| M00 |
| Pyogenic arthritis |
| M01 |
| Direct infections of joint in infectious and parasitic diseases classified elsewhere |
| M02 |
| Postinfective and reactive arthropathies |
