CARPAL TUNNEL SYNDROME
Carpal tunnel syndrome (CTS) is the popular name for a complex of signs and symptoms that results from compression of the median nerve as it passes through the wrist in a narrow, rigid tunnel which is surrounded by the bones of the wrist, filled with tendons, and covered with a tight ligament called the transverse ligament. In the carpal tunnel, the nerve is accompanied by the nine tendons that flex the fingers and thumb. The most common cause of CTS is swelling of the membranes (tendon sheaths or bursae) that normally surround and lubricate the tendons as they glide in the tunnel. The signs and symptoms may be mild, moderate, or severe and usually worsen without treatment.
The syndrome occurs more often in women, typically after age 30. A non-specific inflammatory swelling of tendon bursae (tenosynovitis) is the common cause. Tasks that require rapid, repetitive bending of the fingers, the use of vibratory tools, or a prolonged power grip, are known to hasten the onset of symptoms. Many diseases, some drugs, direct injury, and even pregnancy may increase the fluid (swelling) in the bursae enough to compress the median nerve in the rigid tunnel. The median nerve functions to provide sensation to a significant portion of the palm and fingers. In addition, it also is responsible for providing the motor control of some of the muscles of the palm and thumb.
The most frequent complaint is numbness and tingling of the palmar surface of any of the five digits, except for the little finger. A complaint about “dropping things” is frequent because of this numbness. Occasionally, an accompanying pain radiates into the forearm. Symptoms often first appear, or worsen, at night because of normal fluid shifting to the extremities, and normal wrist flexion during sleep. Prolonged or constant symptoms signal progressive of severe nerve compression, and thumb muscle weakness can follow. ‘Locking’ of the fingers is an associated complaint in 25% of cases of CTS because both can be caused by tenosynovitis.
An accurate medical history and the clinical examination will establish the diagnosis in most cases. Often, the symptoms can be duplicated or worsened by bending the wrist firmly palmward for 60 seconds (Phalen’s test), and/or by tapping the front of the wrist over the nerve (Tinel’s sign). The more uncomfortable (and expensive) electrodiagnostic test which measures nerve function are reserved for the evaluation of questionable diagnoses.
Patients with recent, mild, or intermittent symptoms may be treated successfully with anti-inflammatory drugs and night splints which prevent wrist flexion. However, most cases will recur if the cause of the nerve compression persists. Unless significant improvement is noted early in the treatment phase, non-operative treatment may not be successful.
Surgery is usually the treatment of choice for classic carpal tunnel syndrome. Typically, 80-90% of patients will have permanent relief of their symptoms following division of the wrist ligament (transverse carpal ligament) which covers the carpal tunnel. Release of scar around the median nerve and partial removal of the tendon bursae (sheath) is added in selected cases.
By performing these procedures, it is possible to decrease the pressure on the nerve and to relieve the symptoms. Outpatient surgery, local anesthesia, and an incision limited to the proximal palm comprise the normal surgical approach today. Following surgery, while the complete relief of the nerve compression symptoms may be immediate, it often may take up to three months. Unfortunately, it is possible for the nerve to suffer permanent damage as the carpal tunnel syndrome develops. If this happens, then the likelihood of persistent symptoms, even after surgery, is greater. The annoying ache associated with an underlying tendon bursae disease, like the pains of arthritis, may linger on, without the threat of nerve dysfunction.
In adolescents and young adults, fracture of this bone is the most common fracture around the wrist. Men are ten times more likely to fracture this bone than women. Although the bone is small, it takes a lot to break it. Oddly enough, twice as much force is required to break the scaphoid bone as to break one of the bigger forearm bones. Because of this, most patients who have broken their scaphoid have done it while participating in sports, such as football, basketball, riding a motorcycle or in an automobile accident. Usually the patient falls on the outstretched hand and hyperextends the wrist joint.
What is so special about this fracture?
Because the bone is entirely inside the joint, there are some unique things about this fracture. The patient frequently overlooks the fracture because it feels like “just a sprain.” There is often only a little swelling and a variable amount of pain may be present. Usually, the swelling will go away in a few days. Unlike the forearm, hand, and finger bones, fractures of the scaphoid almost never show any obvious deformity of the wrist. “It doesn’t look broken.” These factors can make it common for the diagnosis to be delayed for weeks, months or occasionally even years after the initial injury because the patient or his doctor thinks it is just a common wrist sprain.
How do I know it is broken?
Often, an x-ray of the wrist can detect a scaphoid fracture. The fracture may occasionally be invisible on the first x-ray, only to show up on an x-ray examination taken weeks or months later. Many patients with a suspected scaphoid fracture will often require a “bone scan” to determine if the fracture is present. This test can be performed 3 days after the injury to assist in the diagnosis, if needed.
What does the bone look like?
This little bone is about the size of a peanut shell and is almost completely covered in articular cartilage. It functions much like a ball bearing in your wrist joint. Because of this, its’ blood supply is very fragile, and sometimes the fracture leaves part of the bone without any blood flow. (Unfortunately, the blood supply is “backwards,” supplying the top of the bone better than the base). This is very important. Although our bones are as hard as wood, they are alive and need blood coursing through them in order to function normally. Sometimes when a scaphoid bone breaks and loses its blood flow, it undergoes a process called avascular necrosis. This may cause the bone to crumble, and the wrist joint may be destroyed.
What happens if my scaphoid bone does not heal?
When a scaphoid fracture fails to heal, the patient may initially get better for a while until the pieces of broken bone, which are loose inside the wrist joint, cause a deterioration of the wrist joint called traumatic arthritis. In this condition, the joint becomes painful and stiff, decreases grip strength and limits a person’s ability to carry out even moderate activities. The time required for the arthritis to develop is variable depending upon how heavily the wrist is being used. Traumatic arthritis is different from rheumatoid or osteoarthritis. This process only occurs in the injured joint and does not spread to other joints if the body.
What about ligament injuries in addition to a scaphoid fracture?
Since it takes such a violent injury to fracture the scaphoid bone, additional injuries to the surrounding ligaments of the wrist often occur along with a scaphoid fracture. When this happens, it is much more difficult to obtain healing of the scaphoid in just a cast. If the wrist is not stabilized surgically, collapse of the wrist bones occurs causing deterioration and permanent stiffness of the wrist joint.
What is the difference between a fresh fracture and fracture nonunion?
The word “nonunion” means something special to an orthopedic surgeon. It means that the bone has failed to heal. A nonunion may occur for a number of reasons. Simple immobilization in a cast will not lead to healing of the bone. This scaphoid bone is particularly prone to this for several reasons: there is the possibility of the fracture being missed at the initial injury leading to a delay in treatment; secondly, the bone has a poor blood supply. The fact that it is inside the joint and is constantly being bathed by synovial fluid also contributes to the development of a nonunion. A nonunion, in other words, is a failure on the part of the patient’s bone to complete the healing process. A “false joint” occurs at the nonunion since the ends of the broken scaphoid are attached to ligaments at each end of the bone, further separating the fracture and preventing healing. The term “fresh fracture” is used when the injury is less than two to four weeks old. Although this is the optimum time for treating scaphoid fractures, frequently the patient is not seen during this period.
How should my fractured scaphoid be treated?
The answer to this question depends on the type of fracture, the presence of any associated ligament damage, and the severity of the ligament damage. The location of the fracture in the bone is also important since fractures of some parts of the bone statistically heal better in a cast than others.
When should the fracture be treated in a cast and when does it need an operation?
The best results from cast treatment are in those patients who have a fracture that is incomplete or does not extend all the way across the bone. “Nondisplaced” fractures treated in a cast less than 28 days after the injury have a good chance of healing. Fractures that are complete, particularly if they are displaced to any degree, take a much longer time in a cast to heal and may not heal at all. The average time for a fracture of the waist of the scaphoid of a bone that is not displaced is three months in a cast. Since this is only an average, there are many patients who take much longer to heal than this. Studies have shown improved rates of healing in a long arm cast (thumb included), for up to 6 weeks, followed by a short arm thumb spica cast. Approximately, 10% take over six months in a cast to heal. A careful discussion with your orthopedic surgeon may result in a decision to operate and stabilize the bone with a special screw. These patients usually are allowed out of a cast within three weeks to begin flexibility exercises, but full use in sports is not allowed until motion and strength are restored and the x-ray shows that the bone has healed (usually 8 to 12 weeks after the operation).
Are there any fractures that should not be treated in a cast?
Yes. Any fresh fracture that is displaced or unstable should be treated with an operation to reduce and/or stabilize this type of fracture with the fixation device. If it is not stabilized, the bone usually will not heal in a cast; and if it does, the wrist is stiff and usually develops traumatic arthritis leading to pain and loss of use. Also, nonunions of the bone or old fractures require special treatment.
How is a nonunion or an old fracture of the bone treated?
A nonunion of the scaphoid bone requires a bone graft to stimulate the old fracture to begin the healing process again. This small piece of bone is taken from the patient’s pelvis. If you need to have a bone graft taken from the iliac portion of your pelvic bone, it will be sore for a few days when you walk. Occasionally, fresh fractures require a bone graft when they are in many pieces (comminuted).
After the bone graft, how long do I have to wear the cast?
This depends on several factors: the type of bone graft and the quality of blood flow in your scaphoid bone.
There are two primary types of scaphoid bone grafts being used today in wrist surgery. Both of these are named after the surgeon that invented them. The first type is the Russe graft. Here the bone is hollowed out much like a “twice baked potato” and then the bone graft if packed into the hollowed out scaphoid cavity. The average healing rate is somewhere between 80 and 90% if the bone has good blood supply. If the blood supply is poor, this method rarely, if ever, works. After a Russe type bone graft the average time that you will have to wear a cast is between five and six months. Some surgeons will use other types of screw fixation with bone grafting as an alternative to the Herbert screw.
The other type of bone graft uses the Herbert scaphoid screw (or a similar device using the same concept) and a solid block of bone between the two ends of the scaphoid. Assuming the bone graft can be stabilized with the screw, the patient is allowed out of the cast in three weeks. This is can be a big advantage in the ability to rehabilitate the wrist more completely and quickly. The healing rate of this operation is at least as good, if not better, than the Russe type graft.
Another advantage of the screw fixation of the scaphoid comes in patients whose bones have a poor blood supply. In the Russe bone graft, if the blood supply is poor, very few, if any, of these patients heal their scaphoid fractures after surgery. With the Herbert screw or other devices, a significant number of these patients do obtain healing, but the patient’s cast must be kept on for a period of three months instead of three weeks.
After surgery, when can I resume playing sports or heavy work?
You may not resume contact sports or heavy activities until the bone has healed completely. The screw is not a substitute for healing of the bone. It is merely a substitute for wearing the cast and allows earlier rehabilitation of the wrist. As a rule, after a fresh fracture is stabilized with the screw, the patient may return to sports in eight weeks. After a nonunion and bone grafting, this period is three months unless the blood flow is poor in which case the period of activity restriction may be longer.
If I decide to have my scaphoid operated on, how long do I have to stay in the hospital?
If you do not have a bone graft, about half of the patients go home the same day as the surgery and about half spend one night in the hospital. If you have a bone graft from your pelvis, most of the patients spend the night after surgery in the hospital and are sent home the following day.
What type of anesthesia is used?
Usually an auxillary block or local anesthesia is used to numb the arm. The patient does not require general anesthesia unless a bone graft is required. In this case, the patient usually has a block of the arm and then a short period of light general anesthesia lasting approximately 20 minutes or less while obtaining the bone graft.
In summary, getting this tiny bone healed and the wrist restored to function is the goal. Although challenging and somewhat complicated, working together with your hand/wrist surgeon, you have an excellent chance of maintaining a functional wrist joint that will last you a lifetime. This is often a complicated problem and it is important to understand the treatments thoroughly. If you have questions, do not hesitate to ask.
Trigger Finger and Trigger Thumb AND deQuervain’s Disease
At the wrist and in the palm, tendons glide beneath a system of ligaments and pulleys in a tunnel that increases their mechanical efficiency. Where the tendons cross joints, they are sheathed in thin membranes known as synovium, which provide lubrication to decrease friction.
Inflammation of a synovial tendon sheath is called tenosynovitis (tendonitis). When the associated swelling of the sheath severely narrows the space normally required for a tendon to pass freely through its tunnel and beneath the pulleys and ligaments, the condition is known as stenosing tenosynovitis.
The disease gradually narrows the tendon passageway beneath pulleys and ligaments and interferes with smooth gliding of the tendon. The resulting increase in friction is accompanied by increasing pain. Literally, the lubricating fluid can thicken or dry out around the tendon. Nodules or thickening of the tendon may appear near the entrance to the tunnel (pulley), much as thread may bunch with repeated attempts to pass it through a small eye of a needle. The enlarged tendon can cause more friction and the pain often worsens. As the disease progresses, the thickened tendon nodule may “pop” out of the tunnel. This is usually very painful and can be the source of apprehension when gripping and grasping with the fingers. At times, the finger “locks,” and it is necessary to straighten the finger with the other hand. When the irregularity becomes too large to pass beneath the pulley or ligament, motion ceases, usually with a digit locked in a bent position. This can cause a contracture (inability to fully extend or straighten the finger) of the finger.
Like carpal tunnel syndrome, this disease is more common in women, typically over age 30. This disease is very common in diabetics. Repetitive bending of the fingers, thumb and wrist, gripping and grasping, often related to work, can aggravate or even cause stenosing tenosynovitis. Direct injury and a variety of medical diseases can increase vulnerability, and occasionally the disease is present from birth.
Prolonged splinting, anti-inflammatory drugs and precise steroid injections are more helpful for deQuervain’s disease than for trigger digits. One cortisone injection in the tendon sheath may be very useful in the early treatment of deQuervain’s and may save time and money spent on prolonged therapy or splinting. No more than 1-3 cortisone injections should be considered to treat deQuervain’s or trigger digits unless there are unusual circumstances. Numerous cortisone injections can lead to tendon and soft tissue damage. Surgical release, when necessary (~25%) can offer prompt and reliable relief when properly performed.