Knee Pain After A Twisting Injury

You planted your foot, your body turned and your knee did not follow. A twisting injury usually involves one of three structures in the knee joint: the anterior cruciate ligament (ACL), the meniscus or the medial collateral ligament (MCL). Each leaves different clues in the first few days, and reading them early helps you treat the injured knee the right way.

Key Takeaways

• A twist on a planted foot can injure the ACL, the meniscus, the MCL or more than one at once.
• A pop at the moment of injury and a knee that feels unreliable when turning point towards the ACL.
• Joint-line pain that builds over a day or two and hurts with deep bending points towards the meniscus.
• Inner knee pain after a blow to the outside of the knee points towards the MCL.
• Being able to walk does not rule out a significant injury.

What A Twist Does Inside

When the foot stays fixed and the body pivots, the ligaments and menisci absorb a force they were never designed for. Which structure gives depends on the direction of the twist, the load on the leg and whether anything struck the knee from the side. These structures rarely fail alone, so the injury you feel most may not be the only one, and combined knee injuries are common.

In older people aged 40 to 70, a twist more often involves the meniscus or the MCL than the ACL, and existing wear or arthritis in the joint makes a tear more likely. Non-surgical care is the usual route. At MTP Health, an orthopaedic and physiotherapy clinic on Sydney’s North Shore, the first goal is to work out exactly what has happened so the plan fits the injury.

Signs That Point To The ACL

The ACL sits deep in the centre of the knee and stops the shin bone sliding forward and rotating under the thigh bone. It tends to tear during a sudden change of direction, an awkward landing or a skiing fall, often with no contact at all.

The classic story is a pop or tearing sensation, with significant swelling within an hour or two because the ligament bleeds into the joint. Many people can still walk afterwards, which is why ACL tears get missed. Once the first few days pass the knee may feel vague rather than sore, with only a dull ache, yet untrustworthy when you turn or step off a kerb, and that unreliable feeling is the key ACL clue.

Signs That Point To The Meniscus

The menisci are the two crescent-shaped cartilage cushions between the thigh bone and shin bone. An acute tear usually happens when the knee is bent and loaded as it twists.

The pain is typically localised to the joint line, the horizontal groove on the inner or outer side of the knee. It tends to build over a day or two and is sharpest with deep bending, squatting or kneeling. If the knee physically jams and will not straighten, that needs medical attention promptly rather than a wait-and-see approach.

Signs That Point To The MCL

The MCL runs along the inner side of the knee and resists the knee bending inwards. It is usually injured by a force to the outside of the knee, such as a tackle or a fall that pushes the lower leg outwards. An MCL injury is one of the more common ligament sprains around your knee.

MCL pain sits on the inner knee, often just above or below the joint line, and is tender to press. It hurts when the knee is pushed inwards or when you cut sideways. The MCL has a good blood supply, and most sprains heal with protection and a structured rehabilitation program over a few weeks, so surgery is uncommon unless other structures are also damaged.

The First Seventy Two Hours

The early days are about protecting the knee, not pushing through, and the basic knee pain self-care steps apply. Rest it relative to what it tolerates, elevate the injured leg when you can, and avoid activities that twist, pivot or deeply load the knee.

Ice packs wrapped in a towel help reduce pain and swelling in the first days, applied to the skin with light compression rather than direct ice, and simple pain relief or over-the-counter pain medication can settle discomfort so you keep moving.

Use heat only later, once the acute phase has passed. Walk as comfort allows, using crutches if the knee feels unsafe, and work gently on straightening it fully, because losing extension early makes every later stage harder. The same principles apply to a rolled ankle alongside the knee.

Some signs mean you should seek medical attention promptly rather than waiting: you heard or felt a pop, the knee ballooned within a couple of hours, you are unable to put weight through the leg, the knee jams or gives way when you walk, or you develop a high temperature and a hot, swollen joint. In those cases, see a doctor or other healthcare professional for advice rather than managing it alone.

Assessing A Twisted Knee

A skilled assessment starts with the story: what you were doing, which way the knee went and what it has done since. The examination then tests each structure in turn. Stability tests such as the Lachman test check the ACL, side-to-side stress checks the MCL, and joint-line tenderness with loaded bending points to the meniscus.

Imaging confirms and plans rather than leads. An X-ray excludes a fracture when the mechanism suggests one. An MRI shows the ACL, menisci and MCL directly and picks up combined injuries, so it is usually requested when there is concern about the ACL or a repairable meniscus tear, or when the knee is not settling.

At MTP Health, the physiotherapy and exercise physiology team usually see you first, settle the knee and screen for these symptoms. Where the findings point to a ligament rupture or a repairable meniscus tear, Dr Jonathan Negus assesses the knee and discusses whether surgery has a role. Many people never need that step.

Treatment Pathways And Next Steps

MCL injuries are managed with protection, early movement and progressive strengthening, and most recover without an operation. Many meniscus tears, particularly in older adults over 40, respond well to a structured exercise program that restores movement and builds the muscles and the tendon attachments that unload the joint.

ACL tears offer two reasonable routes. Some people, especially those who do not play pivoting sports, do well with rehabilitation alone if the knee becomes stable enough for their life.

Those returning to netball, football or skiing, or whose knee remains unreliable despite good rehabilitation, may be advised to consider ACL reconstruction, a keyhole surgery to rebuild the ligament. It carries risks, including infection, stiffness and re-injury, and commits you to a long recovery, so it is a decision made together rather than a default.

Timing matters. Meniscus tears in the outer, well-supplied part of the cartilage can sometimes be repaired rather than trimmed, and the research on meniscus tear surgery favours acting early on that opportunity. Whichever route you take, restoring full straightening and quadriceps strength improves the outcome, so the MTP team starts that work early to return you to normal.

Frequently Asked Questions (FAQs)

Can I still walk on a torn ACL?

Often, yes. Walking in a straight line does not load the ligament much, so many people walk reasonably well once the pain eases. The problem shows up when you turn or pivot.

How do I know if it is my meniscus or a ligament?

Joint-line pain that builds over a day or two and is worst with deep bending suggests the meniscus. A pop with rapid swelling and an unreliable knee suggests the ACL, while inner knee tenderness after a blow from the outside suggests the MCL. An examination is the reliable way to tell.

Do I need an MRI after twisting my knee?

Not always. Many MCL injuries and meniscus tears are managed on examination alone. An MRI is usually requested when there is concern about the ACL, a repairable meniscus tear or a combined injury, or when the knee is not settling.

Should I see a physio or a surgeon first?

For most twisting injuries, a physiotherapist is the right first step to settle the knee, examine each structure and identify the signs that warrant an orthopaedic opinion. At MTP Health the two work in the same clinic, so if the findings point to a rupture or a repairable tear, Dr Negus can see you without starting again.

Will a twisted knee heal on its own?

Many will. MCL sprains and a good proportion of meniscus tears improve with protection, time and a progressive exercise program. A torn ACL does not usually heal back to full strength on its own, though some people manage well without surgery.

Conclusion

Most twisted knees settle well, but the structure involved shapes what happens next, and reading the clues early helps you protect the knee and get the right plan, whether that is rehabilitation alone or a conversation about surgery. If your knee has been twisted recently, or it settled but still does not feel like yours, book an assessment with MTP Health on (02) 9437 9794 and let the team work out what has happened and how to move you forward.