'non-ankylotic' is formed from the prefix 'non-' (from Latin 'non', meaning 'not') combined with 'ankylotic' (relating to 'ankylosis').

'ankylotic' derives from medical New Latin 'ankylosis' which traces back to Greek 'ankylos' meaning 'crooked' or 'bent'; over time 'ankylosis' came to denote joint stiffness/fusion and English adopted the adjective form 'ankylotic', to which the negative prefix 'non-' was attached to form 'non-ankylotic'.

Originally Greek 'ankylos' carried the sense 'crooked' or 'bent', but in medical usage it evolved into 'ankylosis' meaning 'stiffness or fusion of a joint'; 'ankylotic' and therefore 'non-ankylotic' reflect this medical sense.