Sheppo -
Blew my knee (3degree MCL tear) in March skiing. Took a good 6wks of physio to get back up skiing, but what helped was a Don Joy knee brace. Physios will be able to source them and reccomend models.
Mine has adjustments to limit the extension from 30degrees down to 5 degrees. They are EXCELLENT but expensive.
Just had a knee reco 3 wks ago, so will be using the Don Joy again for kiting, as they are waterproof. Physio is the key mate, good luck.
MikeEP