As the body's most complex joints, knees comprise several bones and cartilaginous structures, which are held together tightly by ligaments and tendons. Ligaments are durable strands of fibrous tissue that connect the joint's bones and provide stability.
The knee has 4 primary ligaments that connect the thighbone (femur), shinbone (tibia), and fibula (calf bone):
Damage to the ligaments can occur as a result of vehicle accidents, sports injuries, or falling and landing improperly, with the most common symptoms including:
When diagnosing injured ligaments, physicians will ask patients about any prior joint issues and analyze the ligament damage in a thorough physical examination. They may order X-rays to see if any bones have sustained damage, and MRI imaging is used to observe damage to softer tissues internally. Arthroscopic diagnosis may be performed to confirm imaging test results.
Knee ligament injuries differ for every individual and are classified based on their extent and severity:
Grade 1 injuries usually respond to conservative treatment and don't require surgery. In contrast, grade 2 and 3 knee ligament injuries are more extensive and need surgery to repair or replace the damaged structures.