Overview

Peroneal nerve injury, a common yet often overlooked condition that can lead to significant long-term complications, including chronic pain, muscle weakness, and instability. The peroneal nerve controls important lower leg functions such as foot dorsiflexion and sensation in the outer leg and foot. When damaged, either by trauma, compression, or surgery, it can result in issues like foot drop, impaired balance, and altered gait. Left untreated, these complications can reduce mobility and quality of life. Early diagnosis, targeted rehabilitation, and supportive therapies are crucial for minimising damage and improving recovery outcomes.

What is a peroneal nerve injury?

The common peroneal nerve, commonly known as the common fibular nerve, wraps around the fibular neck just below the knee. This location near the specific bony surface makes it vulnerable to injury. Alongside this, trauma, compression and surgical injury can also occur.

In simple words, peroneal nerve injury usually occurs when the peroneal nerve is compressed, severed or stretched. This causes the disruption of its ability to transmit signals between the brain and muscles or skin in the lower leg and foot. Depending on the severity and type of damage, this injury can affect the body's motor and sensory functions. So the person may lose their muscle control along with feeling. Causes may include:

• Squatting or prolonged leg crossing
• Knee dislocations or fractures
• Surgical complications (e.g., hip or knee surgeries)
• Compression from casts or braces
• Neurological diseases like diabetes

Injury can be partial or complete and may involve motor, sensory, or both components of the nerve.

Common causes of peroneal nerve injury

Several factors can contribute to damage or dysfunction of the peroneal nerve:

• Keeping your legs in a squat or crossed position for a long time can apply pressure to the peroneal nerve and can compress the nerve at the fibular neck, leading to permanent or temporary injury if maintained for a longer period of time
• Any type of trauma or injury that affects a person’s knee, like knee fractures or dislocations, can damage the nerve directly because of its close proximity to the bone
• Other objects like splints, tight and compressed casts, and braces can easily apply pressure to the peroneal nerve, which can lead to damage. Therefore, they are recommended to be worn with proper padding and monitoring
• Orthopaedic surgeries such as total knee replacement, hip surgery, or arthroscopic procedures may inadvertently stretch or compress the peroneal nerve
• Chronic conditions like peripheral neuropathy, diabetes and other conditions such as multiple sclerosis can alter the nerve health and make it more susceptible to injury due to a lesser blood supply

Chronic pain

Chronic pain that is often associated with peroneal nerve injury is a kind of neuropathic pain, often felt as burning, sharp, tingling pain or an electric shock-like pain. This pain can be caused by multiple reasons, including inflammation of the nerve, damage to nerve fibres that often cause misfiring pain signals and sensitisation of the central nervous system.

Symptoms

Symptoms include tingling sensation, also known as paresthesia, constant pain in the outer leg or top of the foot, any type of pain often triggered by movement or prolonged standing, shock like sensation that radiates down the leg, sensation of coldness or unusual temperature changes often felt in affected area, also pain that become worse at night or during periods of rest and hypersensitivity to certain objects.

Management

It is difficult at times to manage this pain due to its intensity and location, but certain methods can improve the condition. Using medications such as pregabalin, duloxetine, and gabapentin helps to manage pain. These medications should only be taken as per the advice of healthcare professionals. Other topical agents such as lidocaine patches and capsaicin creams can also be used to manage pain. For desensitisation, certain physical therapies can also be done. Many healthcare professionals also recommend injections or nerve blocks.

Muscle weakness

Peroneal nerve injury is the root cause of muscular weakness, due to the fact that this nerve is responsible for the control of several muscles in the lower leg that are important for food movement and stability of the ankle. Due to this injury, the motor branches are damaged, leading towards loss of nerve supply, which can cause weakness due to lack of muscular stimulation and loss of balance due to poor muscle control. The muscles that are most affected include the Tibialis anterior, the Extensor digitorum longus and Peroneus longus and brevis.

Symptoms

Symptoms of muscle weakness include foot drop, where a person is unable to lift the front part of their foot while walking, toe dragging, inability to stand on one’s heels and muscular atrophy.

Management

To manage the symptoms of muscle weakness, healthcare providers might suggest electrical stimulation therapy, physiotherapy to provide strength to the muscles, ankle foot orthosis, a procedure to support foot drop, in more severe cases the provider may suggest tendon transfer surgery. This is often considered after 12 to 18 months if the nerve function does not return. Furthermore, nutritional support should also be considered to avoid further damage and regain muscular mass and occupational therapies to help with daily activities.

Instability and gait abnormalities

Peroneal nerve injury is a serious trauma that can cause combined effects of muscle weakness, chronic pain and nerve damage that leads to instability and gait abnormalities. The loss of proprioception can cause severe difficulty in adjusting to uneven surfaces. Poor mechanics while walking, running etc can put stress on the joints and ligaments, which leads to instability and gait abnormalities. If left untreated, this can cause chronic joint misalignment, progressive joint damage and fatigue of muscles. 

Symptoms

Instability and gait abnormalities can show signs and symptoms such as balance issues, especially during walking on uneven surfaces or sudden directional changes, frequent tripping and ankle rolling can also occur due to limited control over foot and ankle positioning. To overcome their foot weakness, a person may overuse other joints, which can cause fatigue and strain, making walking a physically exhausting task. 

Management 

In Order to manage instability and gait abnormalities, the best approach is to provide balance training and certain exercises that help the person to control ankle movements. For further assistance, certain devices can also be used, such as walking sticks. Physiotherapists can also assist the patient to perform gait retraining, which can correct abnormal walking patterns. Other precautions might include good and protective footwear to promote a good grip and ankle protection. 

Summary 

Peroneal nerve injury is something that can change the way you spend your life, as it affects the mobility and quality of life. The issues such as chronic neuropathic pain, instability and gait abnormalities and muscular weakness can make daily tasks difficult. Peroneal nerve injury can severely affect walking and other movements, which can be quite painful at times. Muscular weakness, which affects foot dorsiflexion and eversion, can cause foot drop and muscular atrophy. Likewise, weakened muscles can lead to poor control of the foot and ultimately an abnormal gait. Healthcare professionals can manage the symptoms of instability, gait abnormalities and muscular weakness by prescribing a combination of physical therapy, electrical stimulation and surgical interventions. Anyone affected by peroneal nerve injury should never be demotivated, as advanced techniques and interventions can help a lot.

FAQ’s

What is the peroneal nerve, and what is its purpose?

The peroneal nerve is responsible for dorsiflexion, extension of the toe and foot eversion. It is responsible for the sensation to the parts of the lower leg and the top of the foot.

What basically causes peroneal nerve injury?

There are several causes of peroneal nerve injury, such as knee fracture, certain neurological conditions like diabetes, compression of the nerve and surgical complications.

Is it possible that peroneal nerve injury can cause permanent damage?

If a Peroneal nerve injury is left untreated or there is a severe nerve injury, then this can cause permanent damages such as chronic pain, instability, gait abnormalities, foot abnormalities and muscle weakness.

How to diagnose peroneal nerve injury? 

Healthcare professionals usually diagnose peroneal nerve injury by doing physical examination of the area, nerve conduction studies, MRI and EMG.

Is full recovery possible after a peroneal nerve injury?

Recovery usually depends on the severity of the injury; for example, mild to moderate injury can be recovered from in weeks or months, while severe injury can last a long time.

Can a person walk properly again after a peroneal nerve injury?

With positive lifestyle modifications, usage of assistive devices and rehabilitation, one can walk properly again.

How can I prevent further complications from peroneal nerve injury?

Avoid prolonged pressure on the knee, follow a physical therapy plan, wear supportive braces or footwear, and monitor symptoms closely to prevent joint damage or falls.