If your injury is minor, you may only need to put ice on your knee, elevate your leg, and stay off your feet for a while. You can reduce swelling by wrapping an ace bandage around your knee

One of the most common ways of hurting knees is through ACL (anterior cruciate ligament). This generally occurs during heavy sports, which involves sudden stops or changes in direction, jumping and landing such as soccer, basketball, football and downhill skiing. There is a pop sound in the knee when an ACL injury occurs following which your knee may swell, feel unstable and become too painful to bear the bodyweight. Depending on the severity of your ACL injury, treatment may include rest and rehabilitation exercises to help regain strength and stability or surgery to replace the torn ligament followed by rehabilitation. A proper training program may also help reduce the risk of an ACL injury.

Symptoms: The ‘pop’ sound doesn’t come from everydody’s knee when they met with an injury. Some other common symptoms are:

• Pain: If you have a minor injury, you may not feel pain. You may feel sore along your knee’s joint line. Some people have trouble standing or putting pressure on the hurt leg.
• Swelling: This is most likely to happen during the first 24 hours. You can reduce swelling by putting ice on your knee and elevating your leg by propping it up on a pillow.
• Trouble walking: If you’re able to put pressure on your hurt leg, you may notice that it’s harder than normal to walk. Some people find that the knee joint feels looser than it should.
• Less range of motion: After you damage your ACL, it’s very likely that you won’t be able to bend and flex your knee like you normally would.

Causes: Ligaments are strong bands of tissue that connect one bone to another. The ACL, one of two ligaments that cross in the middle of the knee, connects your thighbone (femur) to your shinbone (tibia) and helps stabilise your knee joint. ACL injuries often happen during sports and fitness activities that can put stress on the knee and that results in:

• Suddenly slowing down and changing direction (cutting)
• Pivoting with your foot firmly planted
• Landing awkwardly from a jump
• Stopping suddenly
• Receiving a direct blow to the knee or collision, such as a football tackle

When the ligament is damaged, there is usually a partial or complete tear of the tissue. A mild injury may stretch the ligament but leave it intact.

Treatment: Treatment depends on how badly you’ve been hurt. Here are some of the options your doctor may give you:

First aid: If your injury is minor, you may only need to put ice on your knee, elevate your leg, and stay off your feet for a while. You can reduce swelling by wrapping an ace bandage around your knee. Crutches can help to keep weight off your knee.

Medications: Anti-inflammatory drugs can help to reduce swelling and pain. Your doctor may suggest over-the-counter medications or prescribe something stronger. For intense pain, your doctor may inject your knee with steroid medication.

Knee brace: Some people with a damaged ACL can get by with wearing a brace on their knee when they run or play sports. It provides extra support.

Physical therapy: You may need this a few days a week to get your knee back in working order. During your sessions, you'll do exercises to strengthen the muscles around your knee and help you regain a full range of motion. You may be sent home with exercise to do on your own.

Surgery: Your doctor may tell you that you need this if your ACL is torn badly.

The writer Dr Vivek Logani,Chief of Joint Replacement & Sports Injury Centre Paras Hospitals, Gurugram