The Problem
Nerve compression problems behind the elbow are called cubital
tunnel syndrome. The ulnar nerve passes through the cubital tunnel
which is a bony passageway. When you "hit your funny bone"
and have tingling in the small and ring fingers, you are hitting the
ulnar nerve at the cubital tunnel.
The tunnel has a bone passageway on both sides and the base. A ligament
holds the nerve into the tunnel by crossing from one bone to the other.
The ulnar nerve controls muscles used for gripping, primarily of the
little, ring, and sometimes middle fingers. It also controls muscles
in the hand used for strong pinch, and other muscles that coordinate
fine movements. This includes most of the muscles in the hand except
two muscles that lift the thumb up and out of your palm, turning the
thumb into a better position for pinching. The ulnar nerve also receives
feeling from the small and ring fingers from both the palm and backside
of your hand.
Your complaints may result from either sensory or motor (muscle)
nerve compression. For example, 
your
symptoms may primarily involve numbness and tingling in the little
and ring fingers, the side and back of the hand. These complaints
occur or worsen when the elbow is bent, as when: 1) holding a telephone
in the hand, 2) resting the head on the hand, 3) crossing the arms
over the chest, 4) curling the arm under the body during the night.
Your hand may also become cold or numb when it is on top of a steering
wheel. The other group of symptoms involves motor functions of the
nerve. You may be aware that the hand has become weaker, resulting
in trouble opening jars. You may drop things, or your hand may not
perform quite as easily as it did before. For example, you may have
difficulty coordinating your fingers while typing or playing the violin,
guitar, or piano. The problems usually worsen with extended activities.
Frequently there are both sensory and motor symptoms present. Often
we do not know the cause of this problem. Often, the patient experienced
some injury to the region of the elbow: Examples include fractures,
dislocations, direct blows, and severe twisting of the elbow. The
nerve can also be injured with a sudden forceful flexion and extension
of the elbow as may occur when the hands are on the wheel of a car
in a rear ended automobile accident. Occupations requiring significant
elbow flexion throughout the day, such as typing, computer data or
assembly line work may contribute toward problems with pressure on
this nerve. Nerve compressions are more common in people with arthritis,
diabetes, thyroid problems, and those who consume a great deal of
alcohol.
Nonoperative Treatment
With elbow bending, the nerve is pulled up between bones into the
bony groove, causing increased pressure on the nerve. Every time the
elbow is bent the nerve is tightened and the blood supply to the nerve
is reduced. A straight elbow has less pressure on the nerve. You may
be able to avoid surgery by keeping the elbow straight as often as
possible. Clearly this cannot be done throughout the day because you
need to bend your elbow to do many tasks. Regular daily activities
must be altered. Avoid crossing your arms across your chest. When
talking on the telephone, watch how much your elbow is bent. Those
who need to use the telephone frequently should get a cradle attachment
or headset. You may have to alter your sleeping position with pillows.
Adjust your chair and desk so that when writing, working at a typewriter
or a computer keyboard, the elbow is flexed no more that 30 degrees
and the wrist is in a neutral position. You may need a night stand
for bedtime reading so that the book is not always held with the elbow
bent. Most of these changes are common sense and require you to pay
attention to your daily activities. We can make a splint to keep the
elbow straight or slightly (30 degrees) flexed. I often suggest that
you fabricate your own elbow extension splint with soft toweling or
use hockey elbow pads, which prevent elbow flexion. In addition before
considering surgery, we will need to manage contributing medical conditions
such as arthritis and diabetes.
The Operation
The operation is designed not only to take pressure off the
nerve, but also to move the nerve to a position to reduce compression
during common daily activities. There are many operations for compression
of the ulnar nerve at the elbow. We will concentrate on the procedure
to move the ulnar nerve to the front of the elbow. The nerve will
no longer have the added pressure of being pulled into the bony groove
when bending the elbow. Placing the nerve beneath a muscle layer prevents
it from slipping back in the bony groove and provides an increased
blood supply to help heal the nerve. The placement under the muscle
also protects the nerve from injury. With a new location, The nerve
can become compressed or pinched by the new anatomic structures the
nerve must pass through. The operation is also designed to remove
these potential sites.
This operation is called an anterior submuscular transposition of
the ulnar nerve. The incision is made behind the elbow. The length
of the incision varies, depending on the thickness of the arm, the
size of the arm, the amount of fat tissue, and the presence of any
unusual anatomic arrangements. A longer incision gives a better view
of the delicate structures Dr. Bermant is trying to protect. A nerve
crosses the area of the incision. This is a small nerve that supplies
the skin behind the elbow and in part of the forearm. This nerve and
others may become injured during the operative procedure. After surgery,
pain in the scar and loss of sensation are possible despite Dr. Bermant's
care to protect these nerves at the time of surgery. Magnifying glasses
(operating microscope or loupes) show detail during the operation
to reduce the chances of injury. The ulnar nerve is identified in
the bony tunnel and the bands causing pressure on it are released.
The muscles that start from the elbow and cross down the forearm are
called the flexor - pronator muscle mass. They turn the forearm, bend
the wrist, and bend some of the fingers. These muscles are lifted
from the bone. The strong tissue that covers this mass is lengthened
to reduce compression in the nerve's new position. The areas above
and below the elbow that the nerve passes through are treated to diminish
future nerve compression. Patients who have constant numbness, severe
weakness, or muscle wasting may have scar tissue inside the nerve.
In these cases, microsurgical release of scar tissue in the nerve
is performed with magnifying glasses or microscope. The outer wrapping
of the nerve is opened and the scar tissue within the nerve is freed.
Care is taken to limit any injury to the small connections between
the nerve fibers.
Recovery Phase
The recovery process occurs generally in two phases. The operation
releases pressure on the nerve and blood flow improves in the nerve
immediately. Frequently, by the time the sutures are removed, you
will note some improvement in the numbness and tingling in the fingers.
Nerves that scar or degenerate do not recover this quickly. Actual
degeneration of nerve fibers may result in muscle wasting or inability
to discriminate fine points with the ends of the fingers. Nerve fibers
must regenerate from the elbow, the site of the nerve injury, through
the forearm and hand to the fingertips. Gripping strength (muscles
in the forearm) takes about 4 to 5 months to start improving. The
small muscles of the hand take 1 to 1 1/2 years for this to occur.
Sensation in the small and ring fingers may take as long to regenerate.
The process slows for older individuals. There is no way to hurry
this neural regeneration process. In some patients with a very severe
degree of nerve compression, recovery may be incomplete.
If the scar becomes painful during healing, this may improve by massaging
with a cortisone-containing cream. If sensory loss is due to injury
to small nerves, the areas affected frequently diminish in size over
time. The loss may be permanent. Nerve regrowth may be associated
with pain, similar to that experienced when your leg and foot "come
back to life" after falling asleep. The pain may progress down
the side of the forearm to the wrist and finally into the little finger.
Such pain may last more than six weeks and require additional postoperative
medication, massage, and therapy.
This information should be reviewed with Dr. Bermant. We hope that
this information helps you better understand the operation, its potential
benefits, risks, and complications.
If you have any questions, please call our office.
version 4/24/96
Cubital Tunnel Syndrome
Hand 
