Suggest Remedy For Recurring Knee Cap Dislocation Post Knee Revision

Hi My husband had a knee revision 3 months ago. Prior to this he had not been able to walk or bend the knee for almost a year due to old knee prosthesis removal and a rod inserted due to fractured tibia. In the past 4 weeks he has been doing physio and getting around with a walker. today he noticed the knee popping. Like it came out of the joint and was very painful but when applied pressure it would pop back in and then less pain. This has happened about 3 times today. He is seeing his surgeon on Monday. Is there anything he can do in the meantime to keep from occurring multiple times.