Lateral collateral & medial collateral ligament sprain
A ligament is a strong band of tissue that joins bone to bone. Surrounding the knee joint there are two ligaments that join from the bottom of the thigh bone (femur) to the top of the shin bone (tibia). One runs on the outside of the knee (lateral collateral ligament – LCL) and the other runs on the inside of the knee (medial collateral ligament – MCL). A sprain of a ligament occurs when the tissue is stretched or torn.
A ligament sprain can be classified as below depending on the severity of the sprain:
• grade I sprain: pain with minimal damage to the ligaments
• grade II sprain: more ligament damage and mild looseness of the joint
• grade III sprain: complete tearing of the ligament and the joint is very loose or unstable.
The collateral ligaments can be damaged through twisting motions of the knee. Furthermore a blow to the outside of the knee can damage the (MCL) and a blow to the inside of the knee can damage the (LCL).
At the time of injury you may feel a pop or a snap. In the case of a (MCL) sprain pain and swelling will be on the inside of the knee and alternatively if the (LCL) is sprained then pain and swelling will be on the outside of the knee.
Diagnosis and treatment
Your physiotherapist will be able to diagnose and treat this condition according to the severity of the sprains. At times an x-ray may be done to rule out any bony damage. A scan may also be done to see the damage to the ligament especially in the case of severe sprains as often other ligaments and tissues (e.g. nerves, bones, blood vessels) of the knee joint can be involved.
In the management of a collateral ligament sprain initial physiotherapy would involve reducing pain and swelling. This may involve electrotherapeutic modalities, ice, rest, wearing of a brace, the use of crutches and gentle massage.
Following this treatment would move onto rehabilitation and return to sport. This may involve strengthening of knee stability muscles, stretching and decreasing activity of tight/overactive muscles, proprioceptive (balance) exercises and correction of any abnormal lower limb biomechanics. Your physiotherapist would also guide you in a gradual progression to sport.