Posterolateral Corner

Posterolateral Corner Injury

John Miller Physiotherapist

Article by John Miller

What is a Posterolateral Corner Injury?

Injuries to the posterolateral corner (PLC) of the knee are most commonly associated with athletic traumas, motor vehicle accidents and falls. PLC injuries account for 16% of all knee ligament injuries and often occur with other cruciate injuries.

PLC provides both static and dynamic stabilisation to the knee joint. The static structures include the lateral collateral ligament (LCL), popliteus tendon, popliteofibular ligament and posterolateral capsule. Together these structures prevent varus collapse at the knee and external rotation of the tibia on the femur. The PLC’s Dynamic structures play similar roles to the static structures but through movement. These structures include the popliteus muscle, iliotibial band, bicep femoris and lateral gastrocnemius tendon.

Your PLC is the outside of your knee that extends from the bottom of your femur (thigh bone) to the heads of your tibia & fibula (lower leg bones).

Ligaments and joint capsules surrounding the joint provide stability during movement and weight-bearing.

Importantly, the common peroneal nerve (a nerve that supplies the lower leg and toes) wraps around the top of the fibula. It can become compromised if there is an injury to the PLC of the knee.

What Causes a Posterolateral Corner Injury?

A combined hyperextension and varus force to the knee can injure the posterolateral corner of the knee. An example of this could be a blow to the inside of your knee with a straight knee.

Other mechanisms include coupled hyperextension and external rotation of the tibia or external rotation of the tibia and a large varus force.

What are the Symptoms of a Posterolateral Corner Injury?

Injuries affecting the PLC may or may not occur in conjunction with injuries to other structures in the knee. Symptoms of a PLC injury commonly include:

  • Pain or swelling over the posterolateral surface of the knee.
  • Pain is aggravated by weight-bearing activities, especially high loads going through the lower limb, such as walking up a hill, quick direction changes or jumping.
  • A feeling of weakness or ‘giving way’ around the knee.

If you have an injury to the PLC and the peroneal nerve is affected, you may also experience pins and needles or numbness in the lower leg and foot. You may also experience foot or ankle weakness.

How is a Posterolateral Corner Injury Diagnosed?

On examination, your physiotherapist or sports doctor will look for signs of a PLC injury. Palpation and a series of knee ligament stability tests on physical examination confirm or deny damage to the PLC. They will be graded accordingly based on severity. An MRI may be required to confirm the diagnosis.

What is the Treatment for a Posterolateral Corner Injury?


Most patients with a mild posterolateral injury start to recover within a few weeks of the damage with the appropriate rehabilitation.

Your physiotherapy treatment will aim to:

  1. Reduce pain and inflammation
  2. Normalise joint range of motion
  3. Strengthen the muscles of your lower limb
  4. Improve patellofemoral (knee cap) alignment
  5. Normalise your muscle lengths
  6. Improve your proprioception, agility and balance
  7. Improve your technique and function walking, running, squatting, hopping and landing
  8. Minimise your chance of reinjury

We advise that you discuss your knee injury with a knee injury practitioner such as a sports physiotherapist, sports physician or knee surgeon. They will provide the most accurate information about your injury and rehabilitation program.


Most grade I PLC injuries resolve entirely with conservative treatment. Surgery may be required in severe cases, depending on the number of structures within the PLC involved. Risks of surgery include infection, persistent instability and pain, stiffness, and difficulty returning to the previous activity level. Operations are determined case by case and the severity of the injury.

Functional instability is a problem with PLC injuries. Your sports physiotherapist, sports doctor or knee surgeon should professionally guide your return to sport.

Post-Surgical Rehabilitation

Post-operative knee rehabilitation is one of the most important yet too often neglected aspects of knee surgery. The most successful and quickest outcomes result from the guidance and supervision of an experienced physiotherapist.

Your rehabilitation following knee surgery focuses on restoring full knee motion, strength, power and endurance. You will also require individualised balance, proprioception and agility retraining towards your specific sporting or functional needs.

Your physiotherapist has extensive knowledge in this field. We suggest you contact them for the best advice in your circumstances.

How to Prevent a Posterolateral Corner Injury?

You can do several things to reduce your risk of sustaining a PLC injury.

These include:

  • Correcting poor biomechanics of the knee or ankle joints
  • Adequate warm-up and stretching program before and after exercise
  • Correcting muscle imbalances in the lower limb
  • Adequate footwear during exercise
  • Avoid sudden increases in training frequency or intensity.
  • Strengthening muscles of the lower limb

Return to Sports with a Posterolateral Corner Injury

An inadequate rehabilitation regime often renders the athlete to experience difficulty when returning to their sport after sustaining a PLC injury. It is crucial to complete your specialised rehabilitation program as your physiotherapist prescribes to enable a return to competition as quickly and safely as possible.

Knee Pain Causes

A Comprehensive Guide

Knee pain is often a symptom of underlying issues ranging from acute injuries to systemic health conditions. Identifying knee pain causes is essential for effective treatment. This guide offers an overview of potential culprits, providing a pathway to understanding and addressing your knee discomfort.

Knee Pain Causes
Knee Pain Causes

Knee Ligament Injuries

Ligament injuries, such as ACL and PCL tears, are significant knee pain causes. They can lead to instability and severe discomfort, requiring prompt medical evaluation.

ACL Injuries

An ACL injury is a common sports-related knee injury that can lead to long-term knee pain and require surgical intervention.

Knee Meniscus Injuries

Meniscus tears, often caused by twisting or turning quickly, are prevalent knee pain causes, with treatment options varying based on severity.

Kneecap Pain

Pain in the kneecap can arise from various conditions, affecting your ability to engage in daily activities comfortably.

Knee Arthritis

Arthritis is a leading cause of knee pain, particularly in older adults, with symptoms that can significantly impair quality of life.

Knee Tendon Injuries

Tendon injuries can result from overuse or sudden, high-impact activities, contributing to ongoing knee pain.

Muscle Injuries

Muscle strains and related conditions are common knee pain causes, especially among athletes and active individuals.

Knee Bursitis

Inflammation of the bursae can cause significant knee pain, often requiring targeted treatment to reduce symptoms.

Children’s Knee Conditions

Young athletes can experience specific knee conditions related to growth and activity levels.

Other Knee-Related Conditions

Various other conditions can lead to knee pain, necessitating a broad understanding of potential knee pain causes.

Knee Surgery

In some cases, surgical intervention may be the best option to address certain knee pain causes effectively.

Seek Professional Advice

For tailored information regarding your knee pain, consult a healthcare professional with experience in knee conditions, such as a knee physiotherapist, sports physician or knee surgeon. They can provide a personalised assessment and treatment plan to address your specific needs.

Knee Pain Products & FAQs

A variety of products can support knee pain management. Browse our selection and read our FAQs to learn more about how to alleviate knee discomfort. More info: Knee Pain Products & FAQs

With this guide, you’re better equipped to understand the various knee pain causes and take the first step towards recovery. Remember, early intervention by a skilled physiotherapist can significantly improve your outcomes and assist in returning you to a pain-free, active lifestyle.

Knee Pain FAQs

Knee pain is a widespread issue, impacting individuals of varying ages and lifestyles. Causes range from injuries and wear and tear to conditions like arthritis. This FAQ section aims to provide insights into knee pain, covering diagnosis, ligament issues, ACL injuries, meniscal injuries, age and arthritis concerns, and pain relief methods through exercise and treatment.

Feel free to click on the questions to for deeper discussions into each topic.

knee pain faqs
Knee Pain Faqs

Diagnosis Related

How Can I Determine If My Knee Injury Is Serious?

  • Learn to assess the severity of your knee injury based on symptoms and situations.

How Can I Identify The Type Of Knee Injury I Have?

  • Discover how different knee injuries manifest and what signs to look for.

When Should I Seek a Physiotherapist or Doctor for My Knee Injury?

  • Find out the right time to consult professionals for your knee concerns.

Is Knee Clicking a Sign of a Serious Condition?

  • Understand what knee clicking indicates about your joint health.

When Should I Consider Getting a MRI for My Knee?

  • Learn about the circumstances when an MRI becomes necessary.

Why Has My Knee Suddenly Started Hurting?

  • Explore potential reasons behind sudden knee pain.

Why Does My Knee Hurt On The Inner Side?

  • Identify causes of inner knee pain and when to seek help.

Knee Ligament Related

What Are The Common Symptoms of a Torn Ligament in the Knee?

  • Recognise the signs of a torn knee ligament.

Can I Walk With A Torn Ligament In My Knee?

  • Understand the feasibility and risks of walking with a torn ligament.

ACL Related

What are the Consequences of Not Getting Surgery for an ACL Injury?

  • Learn about the long-term effects of untreated ACL injuries.

What Are The Symptoms Of An ACL Tear?

  • Identify the key signs of an ACL tear.

Meniscus Related

Is Surgery Necessary for a Meniscal Injury?

  • Discover when surgery is essential for meniscal injuries.

Can a Torn Meniscus Heal Without Surgery?

  • Find out if meniscal tears can heal naturally.

Age & Arthritis Related

At What Age Do Knee Problems Typically Begin?

  • Learn about the onset age for common knee problems.

What are the Common Symptoms of Arthritis in the Knee?

  • Identify arthritis symptoms in the knee.

Running Related

What are Some Ways that Runners Can Reduce Knee Stress?

  • Explore methods for runners to minimise knee stress.

Knee Treatment & Exercise Related

Is Walking Good For Knee Pain?

  • Understand the benefits of walking for knee pain.

What are Some Effective Ways to Relieve Knee Pain?

  • Discover various methods to alleviate knee pain.

How Much Walking is Recommended for Individuals with Knee Pain?

  • Learn the ideal walking duration for those with knee pain.

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