Lateral Ligament Sprain

The lateral collateral ligament is a strong collection of fibres that joins the top of the fibula to the thigh bone (or femur). It ensures that the knee joint’s outer surfaces do not open up or form a gap that can lead to instability and knee conditions.

Symptoms by Grade of Injury

The severity of the ligament sprain will usually fall under three grades of injury. These should correspond to the seriousness of your symptoms as follows:

GRADE 1

A grade 1 sprain will cause pain to be experienced while bending the knee approximately 30 degrees, especially with force placed on the inside of the knee. The likelihood of inflammation or tenderness in the area is minimal, and the joint should not feel loose or overly flexible when bent.

GRADE 2

Grade 2 will mimic the above symptoms but with additions. Tenderness will be prominent at a lateral ligament position on the outside of the knee. This is usually accompanied by inflammation. While bending or putting pressure on the knee, definite looseness will be felt. It may be difficult to fully turn the leg and knee out to the side.

GRADE 3

A grade 3 sprain involves a total ligament tear, though the pain symptoms can be deceptive: less pain is often felt than for a grade 2 injury. Pain symptoms will therefore depend on the individual, but when bending and placing stress on the knee there should be major looseness in the joint. A feeling of knee instability is a key factor.

Causes

A direct impact to the inner part of the knee joint is the most common way that the lateral ligament is sprained. This sort of collision can be expected in high speed contact sports that involve aggressive tackling, such as football or rugby. Sports that do not require or facilitate knee protection put you at greater risk. A hard blow to the outer surface of the knee joint is more likely to result in injury to the medial collateral ligament (see our article for further details).

Treatment

The first step is to cease any strenuous activities involving the knee, particularly the sport or activity that lead to the condition. Begin to rest, and ice the area approximately 3 times per day in the event of swelling. Consult your doctor, who can examine the injury and recommend the best course of action depending on the grade of injury. They might use a varus knee test to assess knee laxity, or take an x-ray in more severe cases. Most grade 1 and 2 sprains are treated conservatively with rest, suitable pain medication, massage, and rehabilitation techniques. More serious injuries (in the grade 2 and 3 range) can require measures such as a knee brace and heat retainer to support the knee and increase blood flow to the area. Surgery may also be necessary in order reduce the risk of injury recurrence or knee instability. If this is the case then full recovery can take up to a few months, whereas less serious sprains should be healed much sooner.