Ligaments connect bone to bone. They’re the tethers or guy-wires that help hold joints together. They also limit or restrict the movement of joints to help prevent damage.
Technically, damage to a ligament is called a sprain, whereas damage to a tendon is called a strain. Yes, it’s a nit-picking difference, but there is a difference! However, for practical purposes the two terms are often used interchangeably.
Ligament sprains are graded on a scale of 1-3, just like tendons. A Grade 1 injury involves over-stretching of the ligament fibers, but no actual, or only microscopic, tears. In a Grade 2 sprain some, but not all, of the ligament fibers are torn. Grade 3 sprains are characterized by a complete tear of the entire ligament. Grade 1 sprains cause mild swelling and pain, but no joint instability. Grade 2 sprains cause moderate swelling, perhaps with some black & blue, and perhaps some mild joint instability. Grade 3 tears have much greater pain, swelling, often moderate bruising, and cause gross joint looseness.
Diagnosing a sprained ligament is based on the history of the injury and the physical exam, and confirmed by ultrasound and/or MRI imaging.
Treating a sprain depends in part on the severity of the injury. The majority of Grade 1 sprains are treated conservatively, typically with modified/protected activity and possibly physical therapy. Grade 2 sprains require more aggressive and formal treatment, starting with physical therapy and perhaps splinting or bracing for a brief period. Grade 3 tears most often require surgical repair. Chronic sprains—those that fail to heal completely and cause recurring or chronic pain and impact activity—usually require Regenerative Medicine treatment, such as Prolotherapy and PRP to stimulate a healing and repair response.