Knee Injuries

The knee joint is a very important hinge joint of the body. Although its movement is confined to simple flexion and extension, its function is vital in the mobility of an individual such as for standing, walking, running, squatting, and gliding. The importance of the knee joint is best appreciated in athletes whose careers have been put to a temporary or a permanent halt due to knee injuries.

The knee joint is the part of the body where the thigh bone (femur) meets the leg bones (tibia and fibula). In front of the knee joint is the kneecap (patella), which serves to protect the knee joint. The knee joint is stabilized by four ligaments:

  • Anterior cruciate ligament otherwise known as ACL
  • Posterior cruciate ligament otherwise known as PCL
  • Lateral collateral ligament otherwise known as LCL
  • Medial collateral ligament otherwise known as MCL

Within the knee joint are strips of cartilages that are positioned on top of the tibia. These cartilages, or menisci, serve as cushions that absorb shock in the knees. There are two menisci in each knee: the medial meniscus and the lateral meniscus.

Any part of the knee can be injured with abrupt movement, sudden twisting motion, sudden stops or change in direction, fall, collision, and even overuse. The most common knee injuries are:

  • Patellar Fracture—this commonly happens when a person trips and falls on his knees
  • Ligament tear—this usually happens during sudden twisting motions or sudden stops such that the ligaments are stretched beyond their limit. The ACL is the knee ligament that is most frequently torn.
  • Meniscal tear—this happens when there is too much pressure on the cartilage like in weight-lifting exercises or in sudden twisting motion.

Signs and symptoms

Injury to the knees is very easy to detect. It is often preceded by a history of trauma that is accompanied by the following signs and symptoms:

  • Pain in the knees, either with movement or without movement
  • Swelling of the knees (fluid due to inflammation or bleeding)
  • Redness
  • Difficulty in ambulation and weight-bearing on the affected knee
  • Laxity of the joint (or the ability to overextend the joint beyond normal limits)
  • A history of a popping sound heard or felt in the knees before the other symptoms occurred

First aid

If injury to the knees is suspected, the following are the recommended intervention that will relieve the pain or prevent further damage to the knees:

  • Immobilize the injured knee with a bandage and splint.
  • Avoid using the knee until a serious injury is ruled out. Do not try to work against the pain because it may worsen the injury.
  • Apply cold compress to decrease the swelling and relieve the pain.
  • Elevate the knee.
  • Avoid manipulating the knees (for example through a massage) because it might do more harm than good to the injured knee.
  • Over the counter painkillers may be taken to relieve the pain.


Knee injuries that lead to severe pain and immediate swelling of the knees require a visit to the doctor to rule out serious conditions like torn ligaments or fractures. A doctor will do a thorough history of the mechanism of injury and a comprehensive physical examination of the knees. Based on the history and physical exam, a doctor might request for the following:

  • Knee X-rays—to rule out bone fracture. X-rays do NOT show ligament or meniscal injury
  • Knee MRI—to better assess the anatomy of the knees and rule out conditions like ligament or meniscal tears


Treatment of knee injuries depends on the specific part of the knee that is damaged. For minor injuries that involve only bruising of soft tissues, RICE—rest, ice, compression, and elevation of legs—may be sufficient. These injuries can heal on their own even without intervention. However, for severe injuries like fractures, ACL tear, or meniscal tear, surgical intervention might be necessary. Fractured bones might require plating or fixation; torn ligaments might require repair; and torn meniscus might need to be taken out. In addition to surgery, physical rehabilitation of the knees to strengthen it and help it regain its function can be helpful.


Knee injuries are very common in athletes and in ordinary people alike. The following are recommendations that can help prevent knee injuries:

  • Wear protective equipment for the knees when playing sports.
  • Do stretching before a game.
  • Avoid heavy weight lifting.
  • Invest in good footwear to minimize the impact to the knees when you jump or run.
  • Avoid abrupt turns, twists, or stops.