What is Carpal Tunnel Syndrome (CTS)?
Carpal tunnel syndrome is a compressive neuropathy affecting the median nerve. Compressive neuropathy is characterized by a progressive injury to a nerve caused by pressure—either constant or intermittent—typically from surrounding soft tissues like muscles, ligaments and tendons. The median nerve relays nerve impulses from the hand and wrist along the arm, and it is commonly compressed at the carpal tunnel, which is formed at the wrist by the transverse carpal ligament. When this happens, the outer covering of the nerve, called the myelin sheath, is injured due to a lack of blood flow, reducing the nerves’ ability to conduct signals
Small nerve fibers, such as those that conduct light touch and temperature, are affected by compression of the median nerve first. If carpal tunnel syndrome progresses, the larger fibers, like those that conduct impulses to muscles, can be affected as well. Unfortunately, this condition is progressive: if left untreated, carpal tunnel syndrome will result in increasing damage to the nerve until it no longer functions.
Who gets CTS?
Carpal tunnel syndrome is the most common hand-related problem we treat. Despite it’s mythical status, the age-old idea that carpal tunnel syndrome is caused by typing has been disproven. Carpal tunnel syndrome is more accurately described as a disorder of aging. As we get older, our tissues become less compliant and therefore are less able to tolerate transient swelling (tendonitis) which can be aggravated by wrist position while sleeping. Sleeping with your wrists bent can cause irritation and swelling of the nerve, which will in turn increase the daytime symptoms of carpal tunnel syndrome. Furthermore, people with comorbidities like diabetes, thyroid disorders, rheumatoid arthritis and obesity are prone to carpal tunnel syndrome. Carpal tunnel syndrome can also present as a swelling-related complication of pregnancy, although it is relatively rare.
What are the symptoms of CTS?
The most common symptoms of carpal tunnel syndrome are numbness and tingling in digits innervated by the median nerve—the thumb, index, long and half of the ring finger. This numbness and tingling may be especially present at night time, and can very often wake you up. Some patients also complain of weakness, loss of dexterity, and repeated instances of dropping objects. Pain can be present, but it is not always there; some people who suffer from carpal tunnel never experience pain outside of the discomfort of numbness and tingling.
How is CTS diagnosed?
A thorough medical history is the most effective way to diagnose carpal tunnel syndrome. Through research, hand surgeons have developed a series of specific questionnaires to aid in diagnosis and inform the follow up treatment of carpal tunnel syndrome. In addition, a physical examination will help your physician diagnosis carpal tunnel syndrome and assess whether or not there are other issues at play. Sometimes, electrodiagnostic studies called EMGs are ordered. These studies are performed by a physician with specialized training and can help rule out other problems like peripheral nerve disorders, ALS, and other related compressive neuropathies.
Once diagnosed, carpal tunnel syndrome is graded mild, moderate, or severe. What grade your carpal tunnel is given correlates with electrodiagnostic criteria and general clinical guidelines. Generally speaking, mild carpal tunnel syndrome has no weakness, while moderate carpal tunnel syndrome has some weakness present and severe carpal tunnel syndrome sees atrophy and significant weakness.
How is CTS treated?
There are a number of treatment options available to you, depending on how your carpal tunnel syndrome is graded. Mild carpal tunnel syndrome is often treated with night time splinting and reassessment at a later date to ensure there has been no progression of symptoms. Moderate and severe carpal tunnel syndrome often requires surgical intervention, known as a carpal tunnel release (CTR). Unfortunately, there are many studies showing there is no significant benefit from steroid injections, therapy, ultrasound, or any other non-operative treatment for patients with moderate to severe carpal tunnel syndrome. We recently published an article in the Journal of Hand Surgery showing that those with moderate carpal tunnel syndrome have superior outcomes at any given time tested after surgery when compared to patients with severe carpal tunnel syndrome. This study also showed that if a patient has moderate carpal tunnel syndrome and has surgery the outcome is predictable, while those with severe carpal tunnel syndrome have a more unpredictable outcome.
Open vs Endoscopic CTS?
An endoscopic carpal tunnel release is a surgical procedure that requires your surgeon to use an endoscope to visualize the median nerve and release the transverse carpal ligament. Unfortunately, there is no proven benefit from undergoing an endoscopic carpal tunnel release versus a mini open carpal tunnel release. The only proven way to treat carpal tunnel syndrome is to release the transverse carpal ligament with a mini open carpal tunnel release procedure. While there are significant improvements in recovery time with an endoscopic carpal tunnel release, studies have shown there is an increased chance of recurrence with an endoscopic carpal tunnel release. This is usually due to an incomplete release of the transverse carpal ligament. We perform a mini-open carpal tunnel release with local anesthesia for the vast majority of our patients and have found this to be the safest and most predictable procedure for carpal tunnel syndrome by a wide margin.
“Microinvasive” Carpal Tunnel Release
Carpal tunnel syndrome is a neurological condition. The consensus approach for treating carpal tunnel syndrome once it has become progressed to the point that it is moderate in severity is to release the transverse carpal ligament. Doing so requires your surgeon to surgically divide the ligament, which takes time to heal. Furthermore, here is no such thing as a non-invasive surgical procedure. By its very nature surgery requires a trained physician to access, visualize and repair anatomical structures from within your body. In recovery, the median nerve must regenerate its outer covering (the myelin sheath) which has been damaged by the compressive forces of the carpal tunnel, and the divided transverse carpal ligament must repair itself in an elongated position. Until these things occur, you will have symptoms.
After surgery, most patients can go back to clerical work in a day or two, but they will not be able to participate in heavy manual labor for about a month. Return to aggressive activity too early will lead to scar formation instead of healing and may necessitate a more involved surgical procedure to reverse the scarring. Carpal tunnel release surgery is one of the most common procedures performed by hand surgeons. They have additional fellowship training above and beyond a five-year surgical residency (orthopedics or plastic surgery) and should be trusted to correct this condition.