Cruciate ligament injury
What is a cruciate ligament injury?
Cruciate ligament injury is one of the most common knee ligament injuries. At first there is a popping sound and a tearing sensation, followed by swelling and pain at the injured site. After a few days the swelling and pain subside and daily life is unaffected, which makes early treatment difficult. If a cruciate ligament injury is not treated in time, bleeding and inflammation develop at the torn site. Over time this can progress to degenerative arthritis and cause further damage to the other ligaments, the cartilage and other structures supporting the knee joint, so early treatment is important.
Classification of cruciate ligament injuries
A small number of fibers are torn, with almost no joint laxity; there is swelling and tenderness over the ligament but no limitation of joint motion
About 2/3 of the ligament is torn, with moderate joint laxity; pain on movement makes the patient avoid using the knee and limits activity
Both the superficial and the deep layer of the medial collateral ligament are torn, with severe pain, severe swelling and marked restriction of movement
Symptoms
When the cruciate ligament is injured, severe pain rises from deep inside the knee.
- 1
- A ‘pop’ sensation followed by severe knee pain
- 2
- Leg weakness or unsteadiness
- 3
- Knee pain worsens when walking or running
- 4
- The knee swells
Anterior cruciate ligament injury
The anterior cruciate ligament stabilizes the knee joint by keeping the shin bone from sliding forward, and acts as the central axis of rotation to prevent the leg from twisting excessively. It is thinner and less resistant to impact than the posterior cruciate ligament, however, so it tears more easily, and when it does the damage is extensive. The anterior cruciate ligament is usually injured by trauma: landing from a jump, stopping suddenly or changing direction while running, colliding with an object or another person, falling onto the knee, falling while skiing or skating, or an impact in a traffic accident.
Posterior cruciate ligament injury
The posterior cruciate ligament prevents the tibia from moving backwards relative to the femur. Injury commonly occurs when the knee joint protrudes excessively, when the tibia shifts backwards, or when falling with the knee bent. In 80% of posterior cruciate ligament injuries another ligament is also injured, so care is needed.
Diagnosis and Treatment
Diagnosis can be made through history taking, physical examination, MRI and joint endoscopy. If the detailed examination (MRI) shows severe damage, reconstruction is performed using joint endoscopy. Patients can be discharged after about 2-3 days in hospital, and a period of rehabilitation is required.