Pacific Rim Orthopaedic Surgeons

Radial Tunnel Syndrome

Motor functions in the arm are primarily controlled by the radial nerve, including rotating the forearm and straightening the wrist or fingers. When compressed, these simple motions become difficult and painful, a tell-tale sign of radial tunnel syndrome.

What is Radial Tunnel Syndrome?

The radial nerve controls many different arm movements, from rotating the forearm to extending the elbow, wrist, and finger movements. The nerve is one of three in the forearm that travel from the side of the neck, down the back of the arm, through the forearm, and into the hands. This specific nerve is called the “radial tunnel” nerve due to it passing through the radial tunnel, a collection of muscles in the elbow. 

Radial tunnel syndrome occurs when this specific nerve is compressed or pinched as it enters the radial tunnel in the elbow, creating excessive pressure which causes pain. 

The syndrome is rare but is most common in adults between the ages of thirty and fifty years old, and certain factors can put someone at greater risk for developing it:

  • Diabetes
  • Not warming up adequately before playing sports
  • An underactive thyroid gland
  • Tumors or ganglion cysts in the arm
  • Radial nerve inflammation
  • Poor arm and wrist strength, and flexibility

Radial Tunnel Symptoms & Syndrome Causes

The primary symptom of radial tunnel syndrome and tenderness outside the elbow, radiating down to the forearm. The pain itself isn’t usually severe, more of a nagging ache that stays; though, some activities can make the symptoms worse, such as flexing the wrist, extending the elbow too much, or heavy lifting. The pain can get worse while sleeping and will weaken the forearm muscles and wrist over time, sometimes leading to an inability to lift the hand past a certain point. 

The cause of radial tunnel syndrome is excessive inflammation of the nerve and structures within it. 

While inflammation of the nerve is the primary cause, there are specific activities that can result in developing the syndrome:

  • Repetitive motions, such as acts similar to typing or using a screwdriver
  • Constant push and pull activities, such as throwing a football or baseball
  • A direct and hard blow to the outside of the elbow or forearm
  • Excessively gripping, pinching, or bending the wrist

Diagnoses, Radial Tunnel Treatment & Management

Radial tunnel syndrome can’t be diagnosed using imaging tests and because the symptoms mirror tennis elbow, it can be difficult to diagnose. While imaging tests can’t conclusive prove radial tunnel syndrome, a doctor may still order an MRI or X-ray to rule out other potential conditions or injuries. 

During an appointment to diagnose radial tunnel syndrome, a healthcare provider will examine the elbow and forearm while asking questions about the pain felt and other symptoms. They’ll try to locate the exact point where the nerve is being compressed inside the radial tunnel by feeling around it and applying pressure. The doctor will try and identify the source of the pain and compression in two ways:

Turning the palm to be palm down and palm up against resistance.

If pain is felt in the forearm, it is likely radial tunnel syndrome. The other portion of the test is to keep the middle finger straight against resistance, if it’s painful to do so then it’s likely radial tunnel syndrome.

With the arm facing up and the elbow slightly flexed, the doctor will separate the elbow into nine equally sized areas in three rows.

They will lightly apply pressure to each spot and ask whether any pain or discomfort is felt. If pain is experienced on the outermost spots of the top two rows, it’s likely radial tunnel syndrome.

Close-up of doctor hands holding skiagram. Surgeon talking about wrist trauma. Smiling intern listening carefully to traumatologist. Traumatology and health care concept

Treatments

The primary radial tunnel syndrome treatment is ceasing or drastically reducing activities that inflame the condition and severity of the symptoms. Resting the arm and avoiding any painful movements is generally successful for relieving symptoms in three to six weeks, but there are other approaches to help speed recovery along:

1.

Over-the-counter, anti-inflammatory medications

2.

Steroid injections to relieve inflammation and pressure on the radial nerve

3.

Using wrist and/or elbow splints to help reduce movement, especially while sleeping

4.

Physical therapy exercises, such as the wrist extension stretch, wrist flexion stretch, wrist supination, and radial nerve glides. These exercises should be done on both sides of the body and learned from a medical professional, such as a physical therapist.

There is a surgical treatment for radial tunnel syndrome, but it’s only recommended if rest and non-invasive treatments fail. To remove the excessive pressure, a surgeon cuts right below the outside of the elbow and into the forearm to move around muscle tissues in the radial tunnel. Doing this will allow them to see exactly where the nerve is pinched or compressed, which they’ll then cut the parts that are compressing the nerve and expand the tunnel.

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We at Proliance Pacific Rim Orthopedic Surgeons strive to help our patients achieve a return to normal activity through compassionate and exceptional care using evidence-based medicine in a patient-friendly environment. We are committed to bringing you a high standard of care that is patient-focused, with the goal of improving your quality of life.