Response from our HR Expert says:
“If the medical certificate states that the employee was unfit to attend work, the company needs to make a decision.
Option 1: take the medical certificate at face value and agree to the paid personal leave.
Option 2: hold the view that the surgery was elective; that they aren't technically injured (unless the surgeon botched the surgery), and don't have an illness, and aren't entitled to paid personal leave. However if you choose this option, be prepared to defend the position.”