What are collateral ligament injuries?

he collateral ligaments are found on the sides of your knee, unlike the cruciate ligaments found within the middle of the knee joint. The medial collateral ligament (MCL) is a fan-shaped structure found on the inner side connecting the thigh bone (femur) and the shin bone (tibia). The lateral collateral ligament (LCL) is a cord-like structure on the outer side connecting the femur to the smaller bone in the lower leg (fibula). The LCL is part of a complex group of structures in that region. The collateral ligaments prevent excessive sideways movement and angulation at the knee. 

Collateral ligament damage usually results from direct contact injuries that push the knee sideways. Direct blows to the outside of your knee that pushes the knee inwards towards the other knee injures the MCL. MCL injuries are the most common knee ligament injury. The LCL is injured when the knee is forced outwards. Isolated LCL injuries are rare and are usually associated with other nearby structures or cruciate ligament injuries.

What are the symptoms of collateral ligament injuries?

At the time of injury, there is pain at the relevant side of the knee. There is often swelling and bruising over the side of the knee and leg. Swelling within the knee itself is less common. Your knee can feel unstable and may give way. Sometimes the symptoms are quite subtle, particularly with partial tears. If there are associated injuries such as an ACL rupture, these symptoms may predominate.

How are they diagnosed?

The symptoms and a careful examination will usually suggest the diagnosis. An x-ray can be useful to look for associated fractures, but an MRI scan is the investigation of choice.

How are they treated?

Fortunately, MCL and isolated LCL injuries rarely require surgery. Injuries heal well with ice therapy, bracing to protect the knee from sidewise forces, and a rehabilitation programme to strengthen the muscles around the knee. Initially, you may be advised to limit the amount of weight put on the leg with the use of crutches. 

Even complete tears of the collaterals can heal without surgery. Surgery may be recommended for certain tear configurations that don’t heal well or when there are associated knee ligament injuries. Persistent instability after non-operative treatment is also an indication for surgery. 

Recent MCL tears can often be repaired but are often augmented with synthetic material (“internal bracing”). Long-standing injuries with persistent instability usually require reconstruction with a tissue graft. This can be taken from another part of your knee or leg (autograft) or from a human cadaver donor (allograft). Repair of LCL injuries is less successful and usually require additional reconstruction with a tissue graft. 

Physiotherapy and rehabilitation play a crucial role in returning to sport and activity, whether you have surgery or not. A knee brace may be recommended during sports activities to add additional stability and prevent re-injury.

If you or someone you know has suffered an injury or is experiencing pain across their lower limbs or difficulty with mobility and would like a consultant-led review, please contact us. Grosvenor Orthopaedics have extensive experience in the treatment of knee-related injuries with excellent patient outcomes.


Grosvenor Orthopaedics have extensive experience in the treatment of knee-related injuries with excellent patient outcomes.


If you would like to learn about other knee conditions click the button below to find out more


If you would like to learn about other knee treatments click the button below to find out more


The Knee Service at Grosvenor Orthopaedic Partners is led by Mr Luke Jones and Mr Chethan Jayadev, both Oxford PhD educated knee surgeons with London Teaching Hospital NHS consultant posts. They provide a comprehensive range of knee procedures as part of a multidisciplinary team of healthcare professionals including highly specialised physiotherapists, all committed to returning you to optimal function.

Our team are well placed to manage and treat a diverse range of knee problems utilising cutting edge diagnostic technology and treatment approaches, both surgical and conservative. Below is an overview of some of the knee conditions we treat but for a more thorough understanding please contact our team here


Consultant Orthopaedic Knee Surgeon

DPhil(Oxon), FRCS(Tr&Orth), MB BS, BSc(hons)
Luke is a Consultant Knee Surgeon practising at Chelsea and Westminster Hospital NHS Foundation Trust, and the Lister Hospital, Chelsea. He runs a high volume bespoke specialist knee practice that deals with all aspects of knee surgery from minor sports injuries to complex joint reconstructions.


Consultant Orthopaedic Knee Surgeon

MA(Oxon) BMBCh DPhil(PhD) FRCS(Tr&Orth)
Chethan is a Consultant Knee Surgeon practising at the world-renowned Royal National Orthopaedic Hospital Stanmore, Spire Bushey Hospital and King Edward VII’s Hospital. His practice encompasses all aspects of knee surgery, from sports injuries and knee preservation to complex and redo joint replacements. He has a reputation as a thorough, meticulous surgeon offering patients a bespoke and personalised service. He is dedicated to providing the most up-to-date and evidence-based care. Chethan is a strong advocate of patient choice and always puts patients first


Consultant Orthopaedic Knee Surgeon

MBBS MSc FRCS (Tr & Orth)
Mark is a Consultant Orthopaedic Surgeon with a passion for sports related injuries. He strives to not only provide excellent surgical treatments but also rounded, bespoke care that allows his patients to get back to the activities they love. This is evident in his specialist training which includes a Master’s degree in Sports Medicine from University College London to help him when treating all levels of athletes. Alongside surgical treatments, Mr. Webb offers non-operative (conservative) options including using orthobiologics, such as PRP and stem cells, to treat the symptoms of early arthritis, as well as tendon injuries. Treatment plans are tailored to the patient’s requirements and expectations using the best evidence available

What some of our patients say

Miss NN

Thank you and please accept my gratitude for a successful knee surgery and overall a very positive experience. This gold medal is for you!