Hello Doctor, I was playing football yesterday and...

Symptomes and management of Locked Knee 
Knee trauma is considered to be a high force trauma to cause bone fracture, but minor trauma could cause significant ligmanet tear, menesceal tear and knee dislocation. among these the most significant and urgent in the knee dislocation which present with signs of knee deformity and inability of moving the koint and this accedent neccitate emergency reduction with post operative check of popliteal artery which locates behind the knee and could be injured during the reduction. Other potential causes of knee pain are the ligament tear that should be identified and treated by an orthopedic surgeon, to releive the pain you should take Etrocoxib 120  mg tab once daily and apply Endomethacin gel over the affected knee in addition to the use of cold packs .
Required Investigations 
After an appropriate physical exam you should do an X ray to check for any bony fractures, MRI to check for ligament and meniscus tear and US  to look for joint collection 
 Causes 

• Knee dislocation 
• Ligament tear 
• meniscus injury 
• Joint blood collection 

Our advice 
You are adviced to take a rest and physciotherapy for the knee after the diagnosis and have a balanced diet, avoid smoing and avoid heacy contact sports