“Medical appointments and elective surgeries that are pre-arranged can only be covered by sick leave if an employee is not able to work because of a personal illness or injury. It will depend on each individual circumstance,” the Fair Work Ombudsman website points out.
https://www.mybusiness.com.au/human-resources/3892-obscure-leave-rule-many-employers-may-not-know
Toms Blog on Life and Livingness