Knee condition
The collateral ligaments are the straps down the sides of your knee — the MCL on the inside, the LCL on the outside — and they stop it folding sideways. Here is the good news most people don’t expect: the inner ligament heals remarkably well on its own, so even a complete MCL tear is usually treated without surgery. The outer side is a different story, and telling the two apart properly — along with what else may have torn alongside — is what this page is for.
Tap any that apply to you — this is guidance, not a diagnosis, but it tells you how quickly to act.
One or more warning signs deserve prompt attention. A foot that won’t lift can mean nerve involvement, and a knee that felt out of place or feels loose in several directions suggests more than one ligament has failed — both need urgent assessment rather than watchful waiting.
Good news — nothing urgent on that list. A tender, sore side of the knee without those features fits a straightforward collateral sprain — the injury type with the most reliable natural healing in the knee. An assessment grades it properly so the brace and the timeline are right.
These ligaments fail when the knee is forced sideways — usually with the foot planted and the body still travelling. Which side tears depends on which way the force pushed:
The anatomical fact behind this page’s optimism: the inner ligament has a generous blood supply and sits where healing tissue can knit — which is why it mends reliably. The outer side is less forgiving, and treated with correspondingly more caution.
Two principles carry collateral healing: protect the ligament, but keep the knee moving. Early on, settle things with relative rest, elevation, cold for comfort and simple pain relief from your pharmacist; use crutches while weight-bearing is painful. A hinged brace is often the centrepiece — it blocks the sideways forces the healing ligament can’t yet resist while allowing the bending and straightening that keeps the knee from stiffening. That combination is why immobilising the leg rigidly is the wrong instinct: motion guides healing tissue and preserves the muscle you’ll need later. Start strengthening as soon as comfort allows, and let a proper grading decide your timeline rather than guesswork — mild sprains settle in weeks, complete ones need a couple of months and a plan. And get the outer side looked at properly: LCL and corner injuries are the ones that quietly need more than a brace.
Instability, not pain, is the measure that matters here — tap the one that fits:
The most common and most forgiving picture. A tender ligament in a knee that still feels solid usually means a lower-grade sprain — protect it, keep it moving, strengthen it, and expect steady progress over a few weeks. An assessment confirms the grade so you aren’t guessing at the timeline.
That wobble deserves grading properly. A knee that feels unreliable on turns and kerbs has lost meaningful ligament support — usually the point where a hinged brace, a structured programme and a clear timeline change the outcome. It’s also when we check nothing else tore alongside.
Frank instability needs assessing promptly. A knee giving way or feeling loose points to a complete tear, an injury on the outer side, or more than one ligament involved — and those are the situations where the right plan early genuinely changes what your knee is like in a year. Same-day appointments are usually available.
Treatment is a ladder — and for the inner ligament, most people never leave the lower rungs:
Tap each card to reveal the truth:
The collateral ligaments are the two straps running down the sides of your knee: the medial collateral ligament (MCL) on the inner side and the lateral collateral ligament (LCL) on the outer. They stop the knee buckling sideways. A sprain is a stretch or tear of one of them — graded one to three, from fibres stretched to a complete rupture — usually caused by a blow to the side of the knee or a sideways force with the foot planted.
For the inner ligament, the best collateral ligament sprain treatment is usually not surgery at all: protection in a hinged brace, early controlled movement, and progressive strengthening heal even complete MCL tears reliably well. The outer side behaves differently — LCL and corner injuries heal less predictably and more often need surgical repair or reconstruction, particularly when another ligament is torn alongside. Grading the injury accurately is what decides between the two paths.
Roughly by grade: a mild sprain settles over one to three weeks, a partial tear over about four to six weeks, and a complete tear over eight to twelve weeks with bracing and rehabilitation. Comfort returns well before strength does, which is why return-to-sport is judged by testing rather than the calendar — going back on a healed-but-weak leg is how second injuries happen.
Isolated inner-side tears rarely do — the MCL’s blood supply lets it heal in place, and results with bracing and rehabilitation are excellent. Surgery enters the conversation for outer-side and corner injuries, for combined injuries involving the ACL or other ligaments, and for a knee that stays unstable after a proper trial of rehabilitation. The pattern of your injury, not its severity alone, drives that decision.
Often yes — and that is precisely why these injuries get underestimated. Walking in a straight line asks little of the side ligaments; the trouble appears when you turn, step off a kerb or change direction. Being able to walk does not grade the injury, and it certainly doesn’t exclude a serious one — particularly on the outer side, where nerve involvement and other torn structures need ruling out.
Same-day appointments are usually available. Call or book online — our team will take it from there.
