Hand Nerve Transposition

Cubital Tunnel Syndrome, also known as ulnar nerve compression, occurs when the ulnar nerve, which runs along the inside of the elbow, is compressed. This compression can lead to pain, numbness, and weakness in the hand and arm. When non-surgical treatments fail, surgical intervention is often considered. Anterior subcutaneous transposition of the ulnar nerve is a common surgical technique used to treat recurrent cubital tunnel syndrome.

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

Cubital tunnel syndrome affects individuals of various ages, but it is most commonly seen in those aged 40-60 years. It can occur in both active individuals and those with sedentary lifestyles. Occupational factors, such as prolonged elbow flexion or repetitive movements, may contribute to the development of ulnar nerve compression. Athletes or manual laborers are also at higher risk due to repetitive stress or trauma to the elbow.

Why It Happens – Causes (Etiology and Pathophysiology)

Cubital tunnel syndrome occurs when the ulnar nerve is compressed, usually at the medial epicondyle (the “funny bone” area) of the elbow. This compression can result from prolonged elbow flexion, trauma, repetitive stress, or anatomical abnormalities. In some cases, previous surgical procedures, such as decompression or partial epicondylectomy, may fail and lead to recurrent symptoms. When compression persists, nerve damage may result, leading to tingling, weakness, and potential atrophy in the hand.

How the Body Part Normally Works? (Relevant Anatomy)

The ulnar nerve runs from the neck down the arm, passing through the cubital tunnel at the elbow. It supplies sensation to the pinky and half of the ring finger, as well as motor function to certain muscles in the hand and forearm. The cubital tunnel is a narrow passage formed by bone, muscle, and ligament at the elbow. Compression of the ulnar nerve within this tunnel disrupts its function, leading to the symptoms associated with cubital tunnel syndrome.

What You Might Feel – Symptoms (Clinical Presentation)

Patients with cubital tunnel syndrome often report numbness, tingling, and weakness in the hand, particularly in the ring and little fingers. Symptoms are often aggravated by elbow flexion, such as during phone use or resting the elbow on a hard surface. Weakness may be noted in hand grip strength or difficulty with fine motor tasks. In advanced cases, muscle atrophy in the hand can occur, particularly in the intrinsic muscles that control finger movement.

How Doctors Find the Problem? (Diagnosis and Imaging)

Diagnosis is based on a thorough clinical examination, which includes a history of symptoms and activities that may contribute to nerve compression. Physical tests, such as Tinel’s sign and the elbow flexion test, are used to assess nerve irritation. Electromyography (EMG) and nerve conduction studies are often performed to measure nerve function and assess the extent of compression. In some cases, ultrasound or MRI may be used to evaluate the ulnar nerve and surrounding structures.

Classification

Cubital tunnel syndrome is generally classified based on its severity and whether it is a primary or recurrent case. The stages include:

• Mild: Symptoms are intermittent, and nerve function remains intact.

• Moderate: Symptoms are more persistent, with some evidence of nerve dysfunction.

• Severe: Symptoms include persistent pain, numbness, weakness, and possible muscle atrophy.

Other Problems That Can Feel Similar (Differential Diagnosis)

Conditions such as cervical radiculopathy, thoracic outlet syndrome, or wrist issues like Guyon’s canal syndrome can mimic the symptoms of cubital tunnel syndrome. A careful physical examination, combined with diagnostic tests, is necessary to rule out these other conditions.

Treatment Options

Non-Surgical Care

Initial treatment often involves conservative measures, such as:

• Rest and activity modification to avoid positions that exacerbate symptoms.

• Splinting of the elbow to prevent excessive flexion.

• Physical therapy focusing on strengthening and nerve gliding exercises.

• Anti-inflammatory medications to reduce pain and swelling.

Surgical Care

If conservative measures fail, surgery may be considered. The goal of surgical treatment is to relieve the compression on the ulnar nerve. Options include:

• Anterior subcutaneous transposition: Moving the nerve to a new position to prevent further compression.

• Medial epicondylectomy: Removing part of the bone that is compressing the nerve.

• Decompression: Creating more space in the cubital tunnel.

Surgical Technique

Positioning: The patient is placed in the lateral decubitus position, which provides optimal visualization of the ulnar nerve. This positioning allows the surgeon to access the posterior and medial aspects of the elbow, facilitating a better dissection and reduction of nerve entrapment.

Procedure: The surgical incision is made just anterior to the medial epicondyle, extending proximally and distally. The procedure includes the careful dissection of the ulnar nerve, which is exposed by releasing several structures including the medial intermuscular septum and the flexor-pronator fascia. Z-plasty is performed on the flexor-pronator fascia to lengthen it and relieve pressure on the nerve.

Once the nerve is mobilized, it is transposed anterior to the medial epicondyle and positioned to prevent any future compression. The fascia is then reapproximated to hold the nerve in place, ensuring it remains tension-free and protected.

Recovery and What to Expect After Treatment

Postoperative care includes:

• Elevation of the arm to reduce swelling.

• A bulky dressing to protect the surgical site.

• Restriction from heavy lifting for 12 weeks.
  Physical therapy is often required to restore elbow and hand function. Patients may be advised to start range-of-motion exercises early to avoid stiffness.

Possible Risks or Side Effects (Complications)

Potential complications from ulnar nerve transposition surgery include:

• Postoperative bleeding leading to hematomas or seromas.

• Infection at the surgical site.

• Nerve damage or recurrence of ulnar nerve symptoms.

• Scar hypertrophy, which may require desensitization therapy.

Long-Term Outlook (Prognosis)

The prognosis for patients undergoing ulnar nerve transposition is generally positive. Most patients experience significant relief from symptoms, including decreased numbness and improved hand strength. However, recovery time can vary, and some patients may experience residual symptoms or complications.

Out-of-Pocket Cost

Medicare

CPT Code 64718 – Anterior Subcutaneous Transposition of the Ulnar Nerve: $144.77

Under Medicare, 80% of the approved amount for this procedure is covered once the 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—generally cover this 20%, meaning most patients will have little to no out-of-pocket expenses for Medicare-approved ulnar nerve transposition surgeries. These supplemental plans work directly with Medicare to provide full coverage for the procedure.

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

No-Fault Insurance
If your ulnar nerve condition requiring surgery is the result of a motor vehicle accident, No-Fault Insurance will cover the full cost of the procedure. The only possible out-of-pocket cost may be a small deductible depending on your individual policy terms.

Example
Sarah, a 55-year-old patient with cubital tunnel syndrome, underwent anterior subcutaneous transposition of the ulnar nerve (CPT 64718) to relieve her symptoms. Her estimated Medicare out-of-pocket cost was $144.77. Since Sarah 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 surgery.

Frequently Asked Questions (FAQ)

Q. How long does it take to recover from anterior subcutaneous transposition surgery?
A. Recovery time typically takes 8 to 12 weeks. Full recovery, including physical therapy, can take several months.

Q. Will I need physical therapy after the surgery?
A. Yes, physical therapy is essential to restore strength and range of motion in the elbow and hand.

Q. Can cubital tunnel syndrome come back after surgery?
A. While surgery is effective in most cases, there is a small risk of recurrence, especially if the nerve is not properly repositioned or if the underlying cause of compression is not fully addressed.

Clinical Insight & Recent Findings

A recent study compared the force loss in the flexorepronator mass between two types of ulnar nerve transposition techniques—modified subcutaneous and submuscular—using cadaveric specimens.

The study found that submuscular transpositions resulted in significantly higher force loss (average 7.68%) compared to modified subcutaneous transpositions (average 2.16%), a difference of 4.67 times. This suggests that the modified subcutaneous approach, which involves less muscle disruption, may be preferable, especially in overhead athletes where preserving the flexorepronator mass is critical for performance.

These findings are important for surgical decision-making in athletes, aiming to balance symptom relief with minimal impact on muscle force production. (“Study of ulnar nerve transposition in overhead athletes – See PubMed.“)

Who Performs This Treatment? (Specialists and Team Involved)

Anterior subcutaneous transposition of the ulnar nerve is typically performed by orthopedic surgeons specializing in hand or upper extremity surgery. The procedure may be carried out by surgeons with additional expertise in nerve compression syndromes.

When to See a Specialist?

You should see a specialist if you experience persistent symptoms of cubital tunnel syndrome, such as numbness, tingling, or weakness in the hand, particularly if these symptoms do not improve with conservative treatments like rest and splinting.

When to Go to the Emergency Room?

Emergency care is needed if you experience sudden, severe pain, loss of hand function, or worsening symptoms that suggest nerve injury, such as inability to move the fingers or thumb.

What Recovery Really Looks Like?

Recovery from anterior subcutaneous transposition surgery involves managing swelling and pain initially, followed by a period of rehabilitation to restore hand and elbow function. Most patients regain full or near-full function, although some may experience mild residual symptoms.

What Happens If You Ignore It?

Ignoring cubital tunnel syndrome can lead to progressive nerve damage, muscle atrophy, and permanent weakness in the hand. Early intervention is essential to prevent long-term disability.

How to Prevent It?

Preventing cubital tunnel syndrome involves avoiding prolonged elbow flexion, especially during sleep or repetitive tasks. Elbow padding or ergonomic adjustments can also help reduce stress on the ulnar nerve.

Nutrition and Bone or Joint Health

Maintaining healthy bone and joint function is critical for preventing nerve compression. A diet rich in calcium and vitamin D supports bone health, while regular exercise can improve joint flexibility and reduce the risk of repetitive stress injuries.

Activity and Lifestyle Modifications

For patients recovering from ulnar nerve surgery, it’s important to gradually return to normal activities while avoiding excessive use of the elbow or hand. Occupational modifications may be needed for individuals whose jobs involve repetitive elbow motion.