What is radial tunnel syndrome?
The radial nerve is one of three nerves in your forearm, traveling from the side of your neck, down the back of your arm, through your forearm and into your hand. Your radial nerve is responsible for a lot of different arm movements, including forearm rotation, elbow extension, and wrist and finger movement. When the nerve reaches your elbow, it passes through the radial tunnel, which is a collection of muscles.
Radial tunnel syndrome occurs when the nerve is pinched or compressed as it enters the radial tunnel. This creates unwanted pressure on your radial nerve, often causing nagging pain.
Who is most at risk of developing radial tunnel syndrome?
Radial tunnel syndrome is most common in people between the ages of 30 and 50. Women are also much more likely to develop this condition than men. There are also certain factors that may put you at a greater risk of developing radial tunnel syndrome, including:
- Poor arm and wrist strength and flexibility.
- Failing to adequately warm-up before playing sports.
- An underactive thyroid gland.
- Tumors or ganglion cysts (mass or lump) in your arm.
- Swelling or fluid in your arm.
- Radial nerve inflammation.
How common is radial tunnel syndrome?
It’s extremely rare. Each year, only 0.003% of the general population deal with superficial radial nerve compression.
Symptoms and Causes
What are the symptoms of radial tunnel syndrome?
You’ll likely feel pain and tenderness in the area on the outside of your elbow, stretching down to your forearm. The pain is a nagging ache that can stick with you and cause fatigue. Certain activities can make these symptoms worse, including:
- General activities that require extensive use of your forearm and/or wrist.
- Heavy lifting.
- Extending your elbow too much.
- Any forearm rotation.
- Flexing your wrist.
Over time, radial tunnel syndrome can weaken your forearm muscles and your overall wrist strength, making it increasingly difficult to grip or lift certain things. The pain may also get worse while you’re sleeping. Sometimes radial tunnel syndrome can cause wrist drop, meaning you lose the ability to lift your hand past a certain point.
Tennis elbow is also a condition that possesses a lot of similar symptoms, so it’s important to be specific when talking with your doctor about your symptoms.
What causes radial tunnel syndrome?
When your radial nerve goes through the radial tunnel below your elbow, it travels between different muscle bellies and under facial bands (facial bands are tissue fibers that enclose, separate or bind together muscles, organs and other soft structures in your body.) When the radial tunnel, and all the structures inside it, becomes inflamed, it puts too much pressure on the nerve, leading to this condition. But there are several different activities that can cause radial tunnel syndrome, including:
- Repeating certain motions (often at work) over and over again. Typing or using a screwdriver are good examples of these types of motions.
- Constantly putting your arm through push-and-pull activities. Think about throwing a football or baseball — you initially pull your arm back and then push it forward to release the ball.
- A direct, hard blow to the outside of your elbow or forearm.
- Excessively gripping, pinching or bending your wrist.
Diagnosis and Tests
How is radial tunnel syndrome diagnosed?
There are no formal imaging tests that can diagnose radial tunnel syndrome, which makes diagnosing this condition somewhat difficult. Even so, your doctor may order an X-ray, MRI or electromyography test, just to rule out other potential injuries or conditions.
Before examining your elbow and forearm, your doctor will ask you about your specific pain, your medical history and your symptoms. Then they’ll try to find the exact point where the nerve is being compressed inside your radial tunnel by feeling around the outside of your elbow and applying light pressure. There are also two specific tests that your doctor may use to diagnose this condition, which include:
- Physical exam: Your doctor will ask you to turn your palm from a palm down position to a palm up position against resistance. If you experience pain in your forearm, it’s likely a sign of radial tunnel syndrome. The second part of this test requires you to keep your middle finger straight against resistance. If it’s painful to do so, it’s also a sign of radial tunnel syndrome.
- Rule of nine test: During this test, with your arm facing up and your elbow slightly flexed, your doctor will separate your elbow into nine equally sized areas, in three rows. Then they’ll lightly apply pressure to each spot, asking you whether you feel pain, discomfort, or nothing at all. If you feel pain on the outermost spots of the top two rows, it’s likely a sign of radial tunnel syndrome.
Management and Treatment
How is radial tunnel syndrome treated?
The best way to treat this condition is to stop, or drastically reduce, the activity that causes your symptoms. If you can, try to rest your arm and avoid any movements that cause pain. Rest and medical treatment is generally successful in relieving symptoms in three to six weeks for most patients.
There are a few different approaches you can take if you’re still feeling pain after avoiding these movements, including:
- Taking over-the-counter, anti-inflammatory medications.
- Taking steroid injections to relieve inflammation and pressure on the radial nerve, if necessary.
- Wearing a wrist and/or elbow splint to reduce movement and irritation on your radial nerve (this is particularly common at night, while you’re sleeping).
You can also utilize different physical therapy exercises to help stretch out and loosen the tight muscle/tissue around the radial nerve, some of which include:
- Wrist Extension Stretch: Put your affected arm out straight in front of you, with your hand up and your fingers facing toward the sky. Use your other hand to pull back on your fingers, until you feel a stretch in your forearm.
- Wrist Flexion Stretch: Put your affected arm out straight in front of you, with your hand down and your fingers facing toward the ground. Use your other hand to pull back on the back of your palm until you feel a stretch in your forearm.
- Wrist supination: Place your affected arm by your side at a 90-degree angle, with your forearm and hand facing up. Put your other hand on your wrist and rotate your forearm inward, toward your body, without moving the other parts of your arm.
- Radial nerve glides: Standing straight, drop your shoulders slightly and rotate your arms into your body. Flex your wrist on one side and raise your arm up to waist level as you tilt your head the opposite way. Once you feel the stretch, hold the position for three to five seconds.
You should do all of these exercises on both sides of your body, even though you’ll likely only be dealing with radial tunnel syndrome in one arm.
The goal of treatment is to eliminate your symptoms and prevent them from ever coming back. If your job is causing your symptoms, you may need to change your work site or talk about getting more breaks during the workday. Try to avoid any heavy push-and-pull movements if possible.
For athletes, practice strength and flexibility exercises and always remember to adequately warm-up before playing or practicing.
Can surgery treat radial tunnel syndrome?
There is a surgical treatment for this condition, but your doctor will likely only recommend it when rest and non-operative therapy fails.
The goal of the surgical decompression is to take the unwanted pressure off your radial nerve as it passes through the radial tunnel. Your surgeon will begin this procedure by making a cut right below the outside of your elbow and into your forearm. After moving around muscle tissues in the radial tunnel, they’ll be able to see where exactly the nerve is being pinched or compressed. Once they find the exact spot, your surgeon will simply cut the parts of the radial tunnel that are compressing the nerve, expanding the tunnel in the process. Once the procedure is done, they’ll stitch the cut back together.
This surgery is uncommon, and it can be performed as an outpatient surgery, meaning you won’t stay in the hospital overnight. This procedure can be performed with general anesthesia (you’ll be asleep) or local anesthesia, which will only numb the arm that is being operated on. You’ll remain awake on local anesthesia.
What happens after surgery for radial tunnel syndrome?
After your surgery, you will be given an elbow splint to wear home that will immobilize your arm. About a week-and-a-half after the procedure, you’ll return to your doctor’s office so that they can remove your stitches and give you a removable splint. Around this time, you can also begin certain activities that will improve your range of motion, including:
- A gentle exercise program.
- Soft-tissue massages.
Six weeks after your procedure, you can begin practicing strength-building exercises for your forearm and hand, like squeezing silly putty, under a therapist’s supervision. During this recovery phase, you need to avoid lifting and other activities that require you to bend your arm at the elbow. In the final stage, your therapist will add exercises to stabilize and strengthen your wrist, elbow and shoulder, and to improve fine motor control in your hand.
Your recovery timeline depends on a few different factors, including:
- Your specific medical history/condition.
- How damaged your radial nerve was before the surgery.
You should expect to be fully recovered from this procedure in four to six months, but it can sometimes take even longer.
Outlook / Prognosis
Does radial tunnel syndrome go away?
If you don’t actively seek treatment for this condition, it won’t go away. In fact, it will only continue to get worse, making certain activities harder and harder over time. If you don’t treat this condition at all, and don’t actively avoid activities that cause pain and symptoms, you could end up with chronic pain in your forearm.
What is the outlook (prognosis) after treatment for radial tunnel syndrome?
Medical treatment is typically successful with this condition, provided you carefully follow instructions and avoid any future injuries to your radial nerve. For those who don’t have success with medical treatment, surgery is an option that has worked very well in improving symptoms. There are some patients who do continue to experience mild pain, even after surgery.
Your primary goal after you’ve recovered, whether it be after surgery or non-surgical treatment, should be to avoid any sort of re-injury to your radial nerve.