Sorry to here about you and your Dads wait. Hope the new hip does its job well.
Sadly my NHS track record for surgery means my notes come their own trolley these days, Lol.
When told in the morning I can go home today, this I have learnt means "By the time your discharge letter completed by the ward secretary", with information by all concerned making the Discharge Letter, i.e. Consultants comments, Physiotherapists, Occupational Therapists and one weeks worth of prescription meds sorted, I can then leave. Normally by teatime when this has been completed. My surgery has mainly been for Orthopaedics reasons too.
Still believe this should be explained better to us patients and not left to personnel experiences, or OpEx.
My last surgery was last year and sadly no change with the few different hospitals or hospital departments, but they are getting better explaining why's and were for's of surgery these days, especially in Orthopaedics for my health area.