The knee is a complex joint which consists of bone, cartilage, ligaments and tendons that make joint movements easy and at the same time more susceptible to various kinds of injuries. Knee problems may arise if any of these structures get injured by overuse or suddenly during sports activities. Pain, swelling, and stiffness are the common symptoms of any damage or injury to the knee. Common causes of knee injury include:
- Fracture of the femur (thigh bone) or tibia and fibula (leg bones)
- Torn ligament (either anterior or posterior cruciate ligament)
- Rupture of blood vessels following a trauma that leads to accumulation of extra fluid or blood in the joint
- Dislocation of knee cap (patella)
- Torn quadriceps or hamstring muscles
- Patellar tendon tear
An ACL injury is a sports related injury that occurs when the knee is forcefully twisted or hyperextended. An ACL tear usually occurs with an abrupt directional change with the foot fixed on the ground or when the deceleration force crosses the knee. Changing direction rapidly, stopping suddenly, slowing down while running, landing from a jump incorrectly, and direct contact or collision, such as a football tackle can also cause injury to the ACL.
The medial collateral ligament (MCL) is the ligament that is located on the inner part of the knee joint. It runs from the femur (thigh bone) to the top of the tibia (shin bone) and helps in stabilizing the knee. Medial collateral ligament (MCL) injury can result in a stretch, partial tear, or complete tear of the ligament. Injuries to the MCL commonly occur as a result of a pressure or stress on the outside part of the knee.
PCL injuries are very rare and are difficult to detect than other knee ligament injuries. Cartilage injuries, bone bruises, and ligament injuries often occur in combination with PCL injuries. Injuries to the PCL can be graded as I, II or III depending on the severity of injury. In grade I the ligament is mildly damaged and slightly stretched, but the knee joint is stable. In grade II there is a partial tear of the ligament. In grade III there is a complete tear of the ligament and the ligament is divided into two halves making the knee joint unstable.
The PCL is usually injured by a direct impact, such as in an automobile accident when the bent knee forcefully strikes the dashboard. In sports, it can occur when an athlete falls to the ground with a bent knee. Twisting injury or overextending the knee can cause the PCL to tear.
Meniscal tears often occur during sports. These tears are usually caused by twisting motion or over flexing of the knee joint. Athletes who play sports such as football, tennis and basketball are at a higher risk of developing meniscal tears. They often occur along with injuries to the anterior cruciate ligament, a ligament that crosses from the femur (thigh bone) to the tibia (shin bone).
Various types of meniscal tears that can occur are longitudinal, bucket handle, flap, parrot -beak and mixed or complex.
The symptoms of a meniscal tear include:
- Pain over the inner or outer side of the knee, where the tear occurred
- A “popping “or “clicking” may be felt at the time of injury
- Tenderness when pressing on the meniscus
- Swelling and stiffness of the knee
- Inability to move your knee through its complete range of motion
- Joint locking can occur if the torn cartilage gets caught between the femur and tibia preventing straightening of the knee
Knee sprain is another common injury that occurs from overstretching of the ligaments that support the knee joint. A knee sprain occurs when the knee ligaments are twisted or turned beyond its normal range causing the ligaments to tear.
Some of the common causes of a knee sprain include forceful twisting of the knee, sudden stopping while running, direct blow to the knee, and fall that results in landing on your knees. The factors that increase the risk of knee sprain include participation in sports activities such as skiing, poor coordination, poor balance, and inadequate flexibility and strength in muscles and ligaments.
The most common symptoms include pain, swelling, bruising, warmth and redness of the skin, and restricted movements. Pain will occur soon after injury and may increase upon moving the knee.
Patellar dislocation is a condition that occurs when the kneecap or the patella completely shifts out of the groove towards the outside of the knee joint. Normally, the kneecap fits in the groove, but uneven groove can cause the kneecap to slide off resulting in partial or complete dislocation of the kneecap. It may occur as a result of a direct blow to the outside of the knee.
Patellar tendon tear
Patellar tendon tear most commonly occurs in middle-aged people who participate in sports which involve jumping and running. Patellar tendon can be ruptured by several reasons such as by a fall, direct blow to the knee, or landing on the foot awkwardly from a jump. It can be a partial or a complete tear. In partial tear, some of the fibers in the tendon are torn, but the soft tissue is not damaged. In complete tear, the soft tissues are disrupted into two pieces.
Immediately following a knee injury before being evaluated by a doctor, you can initiate the R.I.C.E. method of treatment:
- Rest: Rest the knee as more damage could result from pressure on the injury
- Ice: Ice packs can be applied to the injured area to reduce swelling and pain. Never place ice directly over the skin. Ice should be wrapped in a towel and applied to the affected area for 15-20 minutes four times in a day for several days
- Compression: Wrapping the knee with an elastic bandage or compression stocking can help minimize the swelling and support your knee
- Elevation: Elevating the knee above the heart level will also help reduce swelling and pain.
It is important to seek your doctor’s advice if you hear a popping noise or feel as if your knee has given way at the time of injury and if you are unable to move your knee because of severe pain.