It is possible to experience a pinched nerve, known as nerve entrapment or compression, in the area surrounding the knee, though it is less frequent than in the spine or wrist. This condition arises when mechanical pressure from structures like bone, cartilage, muscle, or scar tissue is applied to a nerve, causing irritation and disrupting its function. Understanding this mechanical irritation helps differentiate nerve issues from common joint or soft tissue pain.
Identifying Pinched Nerves Near the Knee
The knee area is traversed by several nerves, but two are most commonly susceptible to compression: the Common Peroneal Nerve and the Saphenous Nerve.
The Common Peroneal Nerve, a branch of the sciatic nerve, is particularly vulnerable as it wraps around the head of the fibula, the small bone on the outer side of the knee. Compression often leads to neuropathic symptoms felt along the outside of the lower leg and the top of the foot. Patients frequently report numbness, tingling, or a burning sensation, sometimes accompanied by sharp, shooting pain. A more concerning symptom is muscle weakness, specifically the inability to lift the front of the foot (foot drop), which causes a person to drag their toes while walking.
The Saphenous Nerve is a purely sensory nerve branching from the femoral nerve, providing sensation to the inner side of the knee and lower leg. Entrapment (saphenous neuralgia) typically causes symptoms along the inner thigh, knee, and calf. The pain is often described as a dull ache, burning, or electrical sensation along the nerve’s path. Unlike peroneal nerve compression, a saphenous nerve issue does not result in muscle weakness or motor deficits, as it does not control any muscles.
Common Causes of Nerve Compression
Nerve compression around the knee occurs when the nerve’s space is compromised by internal or external factors. Direct trauma, such as a fibula fracture or dislocation, can cause immediate injury or entrapment of the Common Peroneal Nerve. Bleeding or significant swelling from a knee ligament injury can also put pressure on surrounding nerves.
External compression is a frequent cause, often related to prolonged positioning or restrictive devices. Habits like frequently crossing the legs (which pressures the peroneal nerve at the fibular head) or prolonged squatting can irritate the nerve. Tight casts, rigid knee braces, or positioning required during certain surgeries can also press against the nerve.
Internal masses or fluid accumulation can also cause entrapment. A Baker’s cyst, tumors, or other cysts can physically compress a nerve. Furthermore, surgical procedures, including knee replacement or arthroscopy, can inadvertently lead to nerve damage or the formation of scar tissue, which may later entrap the Saphenous Nerve as it passes through the adductor canal.
Treatment Approaches
Treatment for a pinched nerve near the knee begins with conservative measures aimed at reducing irritation and inflammation. Initial management involves resting the area, modifying activities that aggravate the symptoms, and using nonsteroidal anti-inflammatory drugs (NSAIDs) to manage pain and swelling. Avoiding positions that cause external pressure, such as not crossing the legs, is an effective modification.
If initial steps are insufficient, physical therapy becomes a central component of recovery. Therapists utilize techniques like soft tissue mobilization to release tension in the muscles and fascia surrounding the nerve. Specific exercises, known as nerve gliding or nerve mobilization, are taught to gently move the affected nerve through its pathway, helping restore its mobility and reduce sensitivity. Bracing or splinting may also be employed to support the limb and prevent movements that stretch or compress the nerve.
When conservative care does not provide adequate relief, interventional procedures are considered. Steroid injections can be delivered directly to the site of compression to reduce inflammation and swelling around the nerve. If symptoms persist despite these efforts, surgical decompression may be necessary to permanently relieve the pressure. This involves physically freeing the nerve by removing the source of compression, whether it is scar tissue, a cyst, or a restrictive band of fascia.