What is Radial Tunnel Syndrome?
Radial tunnel syndrome (RTS) is a set of symptoms that occur due to pinching of the radial nerve as it travels through a very narrow tunnel called that radial tunnel near the outside of the elbow surrounded by muscles, their tendons, and bones. This tunnel is one of the very common spots where the radial nerve can get squeezed. Moreover, within the tunnel, there are a few potential sites where the nerve gets compressed.
The radial nerve starts at the neck and runs to the back of the upper arm. Then crossing the outside of the elbow, the nerve enters the radial tunnel. It finally goes down to the forearm and hand. During its course, the radial nerve gives off two branches. The branch that travels through the radial tunnel supplies the muscles of the forearm and the back of the hand but doesn’t carry any sensory signals (sensations). This preserves the sensation of the areas supplied by this branch of the radial nerve.
What are the Signs and Symptoms of Radial Tunnel Syndrome?
Radial tunnel syndrome causes pain at the back of the forearm, the outside of your elbow, and/or the back of the hand especially when trying to straighten your wrist and fingers. The pain which can be a dull ache, or felt like a cut, stab, or pierce, also weakens the ability to straighten the affected wrist, hand and fingers.
As compared to the cubital or carpal tunnel syndromes, numbness and tingling do not occur with radial tunnel syndrome. These symptoms are typical of damage to the nerves that transmit sensory signals unlike the pinching radial nerve’s branch here that only supplies the muscles.
Common Causes of Radial Tunnel Syndrome
The condition appears to be more common amongst women aged 30 to 50 years old. Other factors that increase the risk of RTS include:
- Fracturing your upper arm bone
- Previous surgical treatments for carpal tunnel syndrome or cubital tunnel syndrome
- Elbow or forearm trauma
- Overusing your arm such as during heavy pulling or pushing as in heavy manual workers can irritate the nerve and cause RTS
Treatment of Radial Tunnel Syndrome
Your doctor will diagnose RTS based on the clinical examination. Conservative/medical therapy is tried at first.
Conservative measures include:
- Resting the arm and hand
- Taking over-the-counter medicines to reduce pain
- Using a wrist brace or splint to limit forearm movement and prevent the nerve from pinching
- Using ice or cold packs to reduce pain and inflammation
- Radial nerve block — your doctor injects a medicine through the radial tunnel to numb the affected site
- Work modifications — avoiding heavy-lifting as well as activities that require keeping your elbow straight with the palm facing downward and wrist in a bent position for long periods
If your symptoms fail to respond to conservative measures, your doctor will recommend surgically releasing the pressure on the pinching radial nerve — a procedure called radial tunnel release.
Radial tunnel release is usually done as an outpatient procedure and you do not need to stay in the hospital overnight.
During this surgery, the surgeon cuts all the potential sites of radial nerve compression sites within the tunnel. This widens the tunnel, providing more space for the squeezed radial nerve.
What to expect during the Recovery period?
Although non-surgical treatment yields good results, surgical therapy for RTS is more promising.
After surgery, you’ll be required to wear an elbow splint to help heal the operated site faster. In about a week, your doctor shall recommend a gentle exercise program to help you get back on track gradually. Alternative therapies like icing, stretching, and soft-tissue massage also increase the range of motion.
During the recovery period, it is best to avoid lifting and other activities that require bending the arm at your elbow. In about 6 to 8 weeks, your therapist will start exercises to strengthen the muscles and ligaments of your elbow, forearm, wrist, and hand.
How long it takes to recover after surgery depends on the extent of nerve damage before surgery. Complete recovery occurs in about 67% to 93% of patients and can take 6 to 8 months. However, if your symptoms fail to resolve completely over a period of 9 months, the surgery is likely to be unsuccessful.