What does it mean if you injure your knee and you hear a pop? Usually it means that you really injured something, but what that something is really depends on where one feels the pain and what actually happened to cause the injury.
The classic knee injury where you hear a pop is an ACL tear. This can occur when an athlete changes direction suddenly playing a cutting sport, such as soccer or basketball, or gets their ski caught on an edge and the binding doesn’t release.
Occasionally you can hear or feel a pop on the inside or outside of your knee due to a meniscal tear; this isn’t always due to a trauma, it can occur just walking at times.
A third cause of a pop in your knee is an MCL tear, this occurs with a valgus or knock-kneed type force directed at your knee. This Lakers player was likely hit from the outside, forcing his knee inward and popping his MCL.
The last common cause of a pop in the knee is rupture of a baker’s cyst. This occurs without any trauma and can be accompanied by significant bruising and swelling in the calf.
None of these are an actual emergency, but most will lead to some difficulty walking and most patients would benefit from crutches at least for a few days until they get evaluated by a doctor.
Read about Anthony Davis’s left knee injury.