Because strenuous sports put a lot of stress on the knees, athletes often fall victim to ACL tears and sprains. About half of the time, patients with such conditions also suffer damage to other knee ligaments, the articular cartilage or the meniscus. Injured ligaments are considered “sprains” and are graded on a severity scale. A Grade 1 ACL sprain is the least severe, typically just an over-stretched ligament that does not impair normal knee function. A Grade 2 sprain involves a ligament stretched to the point that it is loose. This is sometimes called a “partial tear.” A complete tear, when the ligament is severed and the joint is unstable, is a Grade 3 sprain. According to the American Academy of Orthopaedic Surgeons, ACL injuries are caused by:
- Changing direction rapidly
- Stopping suddenly
- Slowing down while running
- Landing from a jump incorrectly
- Direct contact or collision, such as a football tackle.
Research indicates that women are particularly prone to ACL injuries. Certain sports, like football and basketball, are more of a threat to the knees than other physical activities. Symptoms include:
- A popping noise in the joint
- The knee giving out from under you
- Pain and swelling
- Loss of full range of motion
- Tenderness along the joint line
- Discomfort while walking.
A torn ACL does not heal on its own. Surgery is required to regain full function of the knee. Because the two sections of a severed ligament cannot be sutured back together, the ACL must be reconstructed by replacing it with a tissue graft on which a new ligament can grow. Graft material is taken from the patellar tendon, between the kneecap and the shin bone; the hamstring tendons, at the rear portion of the thigh; or the quadriceps tendon, which runs from the kneecap into the thigh. Surgeons sometimes graft tissue from cadavers. They perform the procedure by using an anthroscope to make small incisions. The operation involves less pain, shorter hospital stays and faster recovery times than more invasive surgery.