Snapping Knee – Causes & Management

Knee pain, particularly when accompanied by a snapping or popping sound, can disrupt daily activities. While some knee sounds are normal, persistent or painful snapping can indicate an underlying issue. At Complete Orthopedics, we specialize in identifying the causes of knee pain and implementing effective treatment plans, whether surgical or conservative, to alleviate discomfort and restore knee function.

How Common It Is and Who Gets It? (Epidemiology)

Snapping knee syndrome is relatively common, especially in athletes or individuals who engage in repetitive knee movements, such as runners, dancers, and military personnel. This condition can occur in people of all ages but is most frequently observed in those who engage in high-impact activities or have a history of knee injury.

Why It Happens – Causes (Etiology and Pathophysiology)

The snapping sound in the knee can result from several factors, both intra-articular (inside the joint) and extra-articular (outside the joint). Intra-articular causes include meniscal tears, loose bodies (fragments of cartilage or bone), and discoid meniscus (an abnormally shaped meniscus). Extra-articular causes involve conditions like iliotibial band syndrome, hamstring tendon snapping, and biceps femoris tendon subluxation. When these structures are injured or overstressed, they can cause friction, leading to snapping or popping sounds.

Intra-Articular Causes:

Meniscal Tears: The menisci act as shock absorbers in the knee. Tears in this cartilage can lead to a catching sensation.

Discoid Meniscus: An abnormally shaped meniscus that is more prone to injury.

Loose Bodies: Small pieces of bone or cartilage that float within the joint space can cause snapping.

Extra-Articular Causes:

Iliotibial Band Syndrome: Tightness of the iliotibial band, usually from overuse, where it snaps over the outer knee.

Hamstring Tendon Snapping: The tendons at the back of the knee can snap over the bones of the knee joint.

Biceps Femoris Tendon Subluxation: This rare condition involves the lateral knee pain due to the tendon slipping over the head of the fibula.

MRI of the knee in the coronal section showing various structures.

How the Body Part Normally Works? (Relevant Anatomy)

The knee joint is formed by the femur (thigh bone), tibia (shinbone), and the patella (kneecap). Ligaments, tendons, and cartilage provide stability and facilitate smooth movement. The meniscus acts as a cushion between the femur and tibia, while the iliotibial band and other tendons help control knee movement. When these structures are disrupted, they can cause abnormal sounds during knee motion.

What You Might Feel – Symptoms (Clinical Presentation)

The primary symptom of snapping knee syndrome is an audible snap, pop, or click during knee movement. This is often accompanied by pain, swelling, or a sensation of instability. The pain can range from mild to severe, depending on the underlying cause, and may worsen with movement. Some individuals also experience a feeling of something being “caught” inside the knee joint, especially with meniscal tears or loose bodies.

How Doctors Find the Problem? (Diagnosis and Imaging)

Diagnosis begins with a thorough physical examination, including tests to assess knee stability and alignment. The physician will check for tenderness, swelling, and abnormal movement. Imaging studies such as X-rays and MRIs are commonly used to observe the knee structures in motion and confirm the cause of the snapping sound. An MRI is particularly useful for visualizing soft tissue damage like meniscal tears or ligament injuries.

Classification

Snapping knee syndrome can be classified based on the underlying cause:

• Meniscal Tears: Tears in the cartilage that cushion the knee joint, often leading to a catching or popping sensation.

• Loose Bodies: Small fragments of bone or cartilage that float within the joint, causing mechanical interference.

• Iliotibial Band Syndrome: Tightness in the iliotibial band, causing it to snap over the outer knee.

• Tendon-related Snapping: Conditions such as hamstring tendon snapping or biceps femoris tendon subluxation that cause tendons to move abnormally over the knee joint.

Other Problems That Can Feel Similar (Differential Diagnosis)

Other conditions that may present with similar symptoms to snapping knee syndrome include:

• Patellofemoral Pain Syndrome (Runner’s Knee): Softening of the cartilage under the kneecap, causing pain and occasional popping sounds.

• Arthritis: Degeneration of the joint cartilage, leading to pain, swelling, and crepitus (a grinding sensation).

• Knee Instability: Due to ligament damage, causing abnormal knee movement and snapping sounds.

Treatment Options

Non-Surgical Care

Most cases of snapping knee syndrome are managed conservatively:

• Physical Therapy: Exercises to strengthen the muscles around the knee, improve joint stability, and address any muscle imbalances.

• Bracing or Taping: Provides support and reduces stress on the knee joint during activity.

• NSAIDs: Nonsteroidal anti-inflammatory drugs (such as ibuprofen) help reduce pain and swelling.

• Ice and Rest: Applying ice to reduce swelling and taking breaks from activity to allow healing.

Surgical Care

If conservative treatments are ineffective or if there is significant structural damage, surgery may be required:

• Meniscal Repair: If a meniscal tear is causing the snapping, it may need to be repaired through arthroscopic surgery.

• Loose Body Removal: Small bone or cartilage fragments can be removed with arthroscopic surgery.

• Tendon Release: In cases of tendon-related snapping, releasing tight tendons may alleviate symptoms.

• Patellar Realignment: In cases of misalignment, surgery to reposition the kneecap can help reduce abnormal movement.

Recovery and What to Expect After Treatment

The recovery process varies depending on the severity of the condition and the treatment chosen:

• Conservative Management: Typically involves a period of rest, followed by physical therapy to strengthen the knee and prevent recurrence. Most patients can return to normal activities within a few weeks to months.

• Surgical Recovery: After surgery, the knee will require rest and rehabilitation to restore strength and flexibility. Recovery time varies, with arthroscopic surgeries often allowing for a quicker return to activity than more invasive procedures.

Possible Risks or Side Effects (Complications)

Complications from treatment may include infection, bleeding, or stiffness in the knee joint. In cases of surgery, there may be risks related to anesthesia or damage to surrounding tissues. There is also the possibility of incomplete healing or recurrence of symptoms, especially if the underlying cause was not adequately addressed.

Long-Term Outlook (Prognosis)

The prognosis for snapping knee syndrome is generally favorable, particularly with early intervention. Most individuals recover fully with conservative treatment and physical therapy. Surgical outcomes are also typically positive, with patients returning to normal activities, including sports, once they’ve fully healed. However, long-term management may involve maintaining muscle strength and joint stability to prevent future injuries.

Out-of-Pocket Costs

Medicare

CPT Code 29882 – Meniscal Repair: $163.86
CPT Code 29874 – Loose Body Removal (Arthroscopic): $127.98
CPT Code 27305 – Tendon Release (ITB/Other Knee Tendon): $116.25
CPT Code 27418 – Patellar Realignment / Tibial Tubercle Transfer: $193.59

Under Medicare, 80% of the approved amount for these procedures is covered once your annual deductible has been met. The remaining 20% is typically the patient’s responsibility. Supplemental insurance plans—such as Medigap, AARP, or Blue Cross Blue Shield—usually cover this 20%, leaving most patients with little to no out-of-pocket expenses for Medicare-approved knee surgeries. These supplemental plans work directly with Medicare to ensure full coverage for the procedures.

If you have secondary insurance—such as Employer-Based coverage, TRICARE, or Veterans Health Administration (VHA)—it serves as a secondary payer once Medicare processes the claim. After your deductible is satisfied, these secondary plans may cover any remaining balance, including coinsurance or small residual charges. Secondary plans typically have a modest deductible, usually between $100 and $300, depending on the specific policy and network status.

Workers’ Compensation
If your knee surgery is work-related, Workers’ Compensation will fully cover all treatment-related costs, including surgery, hospitalization, and rehabilitation. You will have no out-of-pocket expenses under an accepted Workers’ Compensation claim.

No-Fault Insurance
If your knee injury resulting in surgery is caused by a motor vehicle accident, No-Fault Insurance will cover all medical and surgical expenses, including meniscal repair, loose body removal, tendon release, and patellar realignment. The only possible out-of-pocket cost may be a small deductible depending on your individual policy terms.

Example
Emily, a 45-year-old patient with knee pain and a meniscal tear, underwent meniscal repair (CPT 29882) and loose body removal (CPT 29874). Her estimated Medicare out-of-pocket costs were $163.86 for the meniscal repair and $127.98 for the loose body removal. Since Emily had supplemental insurance through Blue Cross Blue Shield, the 20% that Medicare did not cover was fully paid, leaving her with no out-of-pocket expenses for the surgeries.

Frequently Asked Questions (FAQ)

Q. What causes snapping knee syndrome?
A. Snapping knee syndrome is caused by conditions such as meniscal tears, loose bodies, tendon tightness, or malalignment of the patella.

Q. Can I treat snapping knee syndrome without surgery?
A. Yes, many cases of snapping knee syndrome can be effectively managed with physical therapy, rest, ice, and NSAIDs.

Q. How long does it take to recover from snapping knee syndrome?
A. Recovery time varies depending on the severity of the condition and treatment. Most people recover within a few weeks to months with conservative treatment, but surgical recovery may take longer.

Q. When should I consider surgery for snapping knee syndrome?
A. Surgery is typically considered if conservative treatments fail or if there is significant structural damage, such as a meniscal tear or loose bodies in the knee joint.

Q. Can snapping knee syndrome be prevented?
A. Prevention involves maintaining strong muscles around the knee, wearing proper footwear, and avoiding overuse or sudden increases in activity. Regular stretching and strength training can also help prevent injuries.

Summary and Takeaway

Snapping knee syndrome is a common condition that can cause pain and instability in the knee. It may be due to various underlying causes, including meniscal tears, tendon tightness, or misalignment of the knee joint. Most cases can be effectively treated with conservative methods like physical therapy and rest, but surgery may be required in more severe cases. Early diagnosis and treatment can help alleviate symptoms and prevent long-term issues.

Clinical Insight & Recent Findings

A recent study described a rare case of bilateral snapping knee caused by inflammation from rheumatoid arthritis with Sjögren’s syndrome, where scar-like tissue in the patellofemoral joint created painful impingement that resolved only after arthroscopic removal of the abnormal tissue.

This finding supports the clinical guidance that while many patients experience harmless popping sensations, persistent snapping accompanied by pain, swelling, or mechanical blockage may indicate a deeper structural problem, such as meniscal injury, loose bodies, or tendon impingement as outlined in the overview of snapping knee.

The study reinforces the need for careful diagnostic evaluation, including imaging, when symptoms fail to improve with conservative care, because some cases—particularly those involving inflammatory or degenerative changes—require surgical intervention to restore smooth knee motion and relieve pain. (“Study of bilateral snapping knee in rheumatoid arthritis – See PubMed.“)

Who Performs This Treatment? (Specialists and Team Involved)

Orthopedic surgeons specializing in knee disorders, particularly sports medicine, are typically involved in the treatment of snapping knee syndrome. Physical therapists and rehabilitation specialists also play a crucial role in recovery.

When to See a Specialist?

If knee pain persists or worsens despite rest and conservative treatments, or if there is a noticeable snapping or popping sound associated with pain, it’s important to consult a healthcare provider.

When to Go to the Emergency Room?

Go to the emergency room if you experience severe knee pain, swelling, or if the knee gives way during activity, as these symptoms could indicate a more serious injury, such as a ligament tear or fracture.

What Recovery Really Looks Like?

Recovery typically involves a combination of rest, rehabilitation, and gradual return to activity. Full recovery may take several weeks to months, depending on the severity of the condition and the treatment method used.

What Happens If You Ignore It?

Ignoring snapping knee syndrome can lead to chronic pain, knee instability, and potential long-term damage to the joint. Early intervention and treatment are key to preventing these complications.

How to Prevent It?

Preventing snapping knee syndrome involves maintaining strong muscles around the knee, avoiding sudden increases in activity, wearing proper footwear, and engaging in regular stretching and strengthening exercises.

Nutrition and Bone or Joint Health

A balanced diet rich in calcium and vitamin D supports joint health and can help prevent conditions that lead to snapping knee syndrome. Proper nutrition also aids in muscle recovery and joint function.

Activity and Lifestyle Modifications

Engage in low-impact activities such as swimming or cycling to reduce stress on the knee while maintaining fitness. Regularly incorporate strength training and flexibility exercises to ensure the knee remains strong and stable.

Do you have more questions?