MCL Injury

These two get confused constantly, because both hurt on the inner side of the knee ¹³.

What separates them is where the tenderness sits: over the ligament itself with an MCL sprain, along the inner joint line with a medial meniscus injury, which can also hurt at the extremes of bending or straightening and make the knee lock ¹³. A scan isn't usually needed at first: an MRI is a reasonable next step if symptoms haven't settled after a few weeks ¹³.

People often ask which is worse. No good evidence puts one above the other; it depends on the grade and on what else was injured at the same time. The more useful point is that they often travel together: a medial meniscus tear is commonly seen alongside an MCL injury ⁵. If your knee catches, locks or won't fully straighten, start from Meniscus Tear.

You may not need a scan. For a knee injury, the story of what happened plus a physical examination can be enough ¹, and most ligament injuries can be diagnosed from a thorough examination of the knee ⁸. You'll be asked how it happened, whether the knee twisted, whether you heard a pop or saw it swell, where it hurts, and whether you've injured this knee before ¹. Then the clinician checks the injured knee against your other one, structure by structure ⁸.

If imaging is ordered, each scan has its own job. An X-ray can't show the ligament, but it will show whether the ligament pulled a small piece of bone away with it. An MRI shows the ligament itself, along with the rest of the knee ⁸.

Getting a knee injury assessed promptly increases the chance of a full recovery ³, as true of a Grade I as of anything bigger.

Rehabilitation for an MCL injury follows The Well Motion Recovery Path™. You move up a phase when the knee shows it can cope, not when the weeks run out.

• Reset: the first days. Protection, elevation and compression, with no heat or massage ¹, and a hinged brace if the knee opens on the valgus stress test ^1,5. Gentle movement and weight bearing start here too ⁶. Expect the knee to feel unsteady side to side. We move you on once you walk without limping.
• Rebuild: where most of the time goes. Sports physiotherapy builds strength and control while the brace guards the knee ⁶, and manual therapy comes in if stiffness lingers after the acute phase ¹. Expect straight-line strength to return before you trust the knee on a turn. We move you on when your movement and strength are back ⁸.
• Return: sport, work, or stairs and uneven ground. It builds gradually ⁸, and we test side-on and twisting loads at the speed your sport or job asks for. You leave with a strength program and, for sport, a brace to wear until you feel confident in the knee ⁵.

How long it usually takes. In one cohort of young military-academy athletes, Grade I sprains cost a median of 13.5 days and higher grades 29 days ⁷. Severe sprains can take months ⁴. A complete tear, or one with an ACL injury, may go to a surgeon, who then sets the timeline ^5,6.

A previous knee injury is a recognised risk factor for a collateral ligament injury ⁸. Here's what has been tested, and what you can work on:

• Bracing has been tested, with mixed results. In a randomised study of 1,396 military cadets playing tackle football, knee braces cut MCL injuries, but only for defensive players ¹⁰. A later review of six studies found just one showing a clear benefit, and two where braced players had more knee injuries ⁹. Those were uninjured knees in American football. After a sprain, your doctor may still suggest a brace for sport ⁸.
• Keep your leg strength up. Weak lower body strength is another recognised risk factor ⁸. Nobody has tested strengthening as a way to prevent a second MCL injury, but unlike your injury history, it's something you can change.
• Go back in stages. Return to sport starts once your movement and strength are back, then builds gradually ⁸.