Hand & Wrist Conditions
Carpal Tunnel Syndrome
Carpal tunnel syndrome, or CTS, is a very common disorder that occurs more commonly in women than in men. Most patients complain of numbness of their thumb, index, and/or middle fingers (and sometimes part of their ring finger). In the early stages of this disorder, the numbness comes and goes; patients often wake up in the middle of the night with their fingers numb and need to shake their hands to "wake them back up". As the disease progresses, the numbness stays around longer and some patients have constant numbness. In addition, sometimes it can cause pain in the wrist that can also travel up the forearm. People with carpal tunnel syndrome will frequently complain of dropping things, such as their coffee cups. When it gets worse, this weakness becomes more pronounced.
Carpal tunnel syndrome is caused by a pinching of the median nerve. This nerve passes through a "tunnel" in the wrist called the carpal tunnel; several other tendons that control the flexion of your fingers are also located in this tunnel (flexor tendons). The "roof" of this tunnel (closest to the skin of the palm) is called the transverse carpal ligament. Some people are just born with a ligament that is too tight or tunnel that is too small. Other patients acquire carpal tunnel syndrome after years of repetitive use of their wrists/hands that effectively shrinks the size of the tunnel and pinches the median nerve.
Carpal tunnel syndrome is relatively easy to diagnose. First, your doctor will discuss your history of symptoms — frequently just talking to the patient is adequate to strongly suggest the diagnosis. A physical examination is then performed. This includes some simple tests (placing your hands/wrists in certain positions) that can also help diagnose CTS. X-rays are often obtained, mostly to rule out other disorders of the bones of the wrist that may be causing the symptoms (carpal tunnel syndrome itself does not show up on X-rays). A new test for CTS is an ultrasound to measure the size of your median nerve — this can often be predictive of CTS. Patients are often sent for a test called an electromyelogram (EMG) and nerve conduction velocity test (NCV) that are often very helpful in establishing the diagnosis. In some cases, the EMG and NCV are negative for carpal tunnel syndrome, but that does not mean the patient does not have the disorder. In the earlier stages of CTS, these tests can often be negative, yet we still will proceed in treatment based on a clinical diagnosis.
The initial treatment of carpal tunnel syndrome is with bracing. A removable velcro wrist brace is recommended to be worn at night. Often patients will respond to this treatment, and after several months, may be able to stop wearing the brace. The purpose of the brace is to allow the nerve and other tendons in the carpal tunnel to rest and recover from the activity of the day. By resting, their swelling will decrease, and that will then create more room in the carpal tunnel (and therefore less pinching of the median nerve). It is important to have a splint that is comfortable (if not, it may make symptoms worse; or if it is not comfortable, you will not be likely to wear it).
If symptoms progress, other treatment options include physical therapy (mildly successful), activity modification (stop doing things that aggravate the symptoms, if possible), and steroid injections (in most cases, they only provide temporary relief). If those fail, then carpal tunnel surgery is an option.
Carpal Tunnel Surgery
Surgery for this problem is quite simple: we release (cut) the transverse carpal ligament. By doing so, this creates more space for the median nerve and symptoms usually subside. The ligament may grow back, but if so, it grows back in a looser, thinner version of its old self that does not cause similar irritation. Otherwise, cutting the ligament does not cause significant dysfunction or weakness.
There are three types of carpal tunnel surgery
- Open — utilizing a larger incision,
- Mini-open — utilizing a single smaller incision (approx 1 inch), and
- Endoscopic — utilizing one or two smaller incisions and a specialized scope system.
Numerous studies have shown that outcomes are similar between these techniques, however, there is an increased risk of complications with the endoscopic technique. The scar with the mini-open technique is barely visible once it is completely healed.
Most often, the surgery will be done under local anesthesia with sedation. You will be made sleepy by medications, then the wrist area will be numbed with local anesthetic medications. Most people do not remember the surgery at all. Typically the procedure takes about 15 minutes. You will be sent home when you are awake and alert.
What to Expect After Surgery
Typically, there is very little pain associated with the procedure. Expect some numbness in your hand/wrist for about a day. In some patients, their carpal tunnel symptoms improve almost immediately after surgery; other patients take weeks.
Different surgeons have different protocols for what type of dressings they use after surgery and whether they will place their patients in a splint (partial cast). This determines how much function you will have after surgery.
Risks of Surgery
Risks of carpal tunnel surgery include infection, stiffness, nerve or vascular injury. These risks are fortunately very rare. The biggest risk, in our opinion, is the risk that your symptoms may not improve. This is also unlikely, but increases if you have severe carpal tunnel syndrome (for that reason, it is better to undergo the surgery before the disease has become too severe), or are elderly. Smoking has an effect as well; the less you smoke, the quicker your nerve will heal.