Sharp pains directly behind knee cap

My partner has been getting sharpe pains behind the knee cap for the past 2 weeks now.  He is fine all the time he is mobile. When he sits down in the evening for a period of time, thats when the pain starts.  He said it is undiscribable pain.  I have told him to go and seek advice, but he is hopeing that it will just go.  He does have weak joints as he has had surgery on both shoulders now through continuas dislications.

Please advise.  Many Thanks

[DrNoopurMD]

Hi,

How are you?
It is possible that the pain behind the knee cap is due to a ligament pull or tear.
Is there any history of knee injury?
Other possibilities can be a bursa or damaged cartilage. It is best if he gets himself evaluated by an orthopedic specialist. In the meantime ice packs and OTC pain killers will help.