Have you suffered a
Knee Sprain?

A knee sprain is a common type of knee injury. Whether a seasoned athlete or a weekend warrior, a sprain can keep you on the sidelines. What is a sprain? How do you know if you have one? Is surgery always necessary? What can you do to reduce your knee joint pain?



Knee Anatomy

The knee is made up of the femur above and the tibia below. The knee is supported by a number of ligaments including the medial collateral (MCL), lateral collateral (LCL), anterior cruciate (ACL), and posterior cruciate (PCL). Ligaments function by connecting one bone to another, providing joint stability.

knee anatomy


What is a Knee Sprain?

A sprain is the termed used to describe an injury to a ligament. Ligament sprains are classified as first, second or third degree sprains. A first degree sprain involves a stretch of a ligament. A second degree sprain is a partial tear of a ligament. And a third degree sprain is a complete rupture of the ligament.


How do Knee Ligament Sprains Occur?

Most sprains of the knee occur through some type of trauma. This trauma can be from both contact and non-contact. ACL are common ligament injuries that frequently occur from non contact trauma. A rapid change of direction can allow the knee to buckle inward, putting stress on the ligaments. Of course contact can also cause increased ligament stress. The most common mechanism of injury for direct trauma injuries is contact on the outside or lateral aspect of the knee, causing the knee to buckle inward.


football knee injury


The most common ligament injury of the knee is the ACL. The ACL is injured when the knee is forced medially (a valgus stress), rotated, and/or hyper extended. These injuries occur more often in female athletes that play agility sports such as soccer, basketball, and volleyball. Because of the direction of force, the MCL ligament is also commonly injured along with the ACL. Lateral collateral (LCL) and posterior cruciate (PCL) ligament injuries are less common.


Typical Signs and Symptoms

Ligament injuries of the knee generally cause pain immediately. Swelling also generally occurs fairly quickly. Once the knee becomes swollen, the ability to walk becomes limited as does the range of motion of the knee. The severity of the ligament sprain will determine the amount of pain, swelling, and limited range of motion. In third degree sprains, when the ligament has completely ruptured, a feeling of knee instability can also be felt.


How is a Sprain Diagnosed?

Determining whether you’ve suffered a ligament sprain will be done by a combination of things. Your subjective history will indicated to the doctor whether ligament stress could have occurred. The doctor will then do a physical exam in which the ligaments are put on stress to determine if the test causes pain or if there is ligament instability. Finally, if a possible rupture has occurred, and MRI will be performed to verify if a rupture has occurred.


Typical Treatment

The treatment for a ligament sprain will in part be based on the severity of the sprain. For all sprains, immediate treatment should follow the R.I.C.E protocol: rest, ice, compression, and elevation. Rest can mean avoiding painful activity or, in more significant cases, the use of crutches. Ice should be applied to the knee 10 to 15 minutes at a time, a few times a day. And, as long as you are experiencing pain or swelling, continue to use ice. Compression is best obtained by the use of a compression wrap such as an A.C.E. bandage. And elevation should be performed by elevating the knee above the level of the heart.

First and second degree sprains often benefit from physical therapy. The physical therapist can assist in reducing knee swelling, restoring range of motion, and restoring strength. They can also help to guide you back to function including preparing for returning to sports.


Will Surgery be Necessary?

Most first and second degree sprains heal within six to eight weeks. In cases of third degree knee sprains, when a complete rupture has occurred, surgery may be warranted, depending on which ligament has been injured.

An ACL rupture in a person that participates in agility activities will almost always benefit from ACL surgery. If the ACL is not reconstructed the risk of the knee giving way and causing a meniscus tear increases. ACL reconstruction surgery involves six months of rehabilitation and therefore should not be considered lightly.

For complete MCL injuries, surgery is not necessary. Other structures that assist the MCL will help to provide medial knee stability. Typically with complete MCL tears, a brace is worn for a few weeks and physical therapy begun to help restore normal mobility and strength. Complete lateral collateral and posterior cruciate ligament injuries are rare.

Physical therapy is generally recommended prior to deciding if surgery is necessary. If instability, pain, and swelling continue despite attempting to increase strength, surgery may be required.

Knee sprains are common causes for knee joint pain. If you believe you have sustained a knee sprain, seek out an orthopedic physician to obtain a clear diagnosis and treatment plan.


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