I am working on a research project using Australian hospital administration data. If a patient is diagnosed with "Non-post-traumatic osteoarthritis on the right knee", how is this principal diagnosis coded in ICD-10-AM?

I am aware the following code:

"M17.1 Other primary gonarthrosis

Primary gonarthrosis:

• NOS
• unilateral"

However, I am not sure how the affected knee (left or right) is coded.