At a Glance: Identifying a Cruciate Ligament Tear The "Pop": A loud, audible sound at the moment of injury is a primary indicator. Rapid Swelling: The knee often "balloons" within 1 to 6 hours due to internal bleeding. Instability: A feeling that the knee is "giving way" or cannot support your weight. Loss of Motion: Inability to fully straighten or bend the leg. Immediate Action: Seek a specialist assessment to prevent long-term joint damage. A cruciate ligament tear, most c