Explanation, Treatment, and Prevention of Trigger Finger

by 


Timothy Jameson, D.C., C.C.S.P.



	Finger movement is facilitated by spaghetti like
tendons that extend from the muscles in the forearms to various
attachment points along the front and back of the fingers. 

Along their route to the fingers, these tendons must pass under
a band of tough fibrous material called retinaculums.  A
retinaculum helps to guide the tendon to its insertion point,
and acts as a retaining band and fulcrum that keeps the tendon
in close proximity to the bones of the hand.  The tendons become
surrounded by fluid-filled protective sheaths as they pass under
a retinaculum.  This sheath prevents friction from occurring
between the tendon and the retinaculum.  


	With overuse of the tendon from such activities as
computer use, musical instrument playing, and hobbies such as
crocheting and firing pistols or rifles, the sheath may become
inflamed and the contents will thicken.  This compresses the
tendon as it passes through the sheath.  Because of this
constriction of the tendon, it begins to swell also.  The tendon
swelling tends to occur just before it passes through the sheath
and retinaculum.  In most cases, this involves the flexor
tendons of the hand.  This inflamed and enlarged flexor tendon
will have difficulty passing through the swollen sheath and will
have difficulty passing under the retinaculum.  


The person suffering from this condition will notice
that one or more fingers will get caught up as he/she tries to
straighten them out.  The finger will get stuck midway in a
flexed position.  The afflicted person will have to physically
straighten the finger with the opposite hand.  This procedure
could painful enough to bring the person to tears. When
straightened, the person may hear an audible snapping sound.  

This snapping is caused by the thickened tendon squeezing
through the tunnel of swollen material. 


	Treatment of this condition should begin as soon as
the person begins to notice difficulty moving the fingers.  If
treated early on, conservative measures will be effective to
bring the inflammation down, and normalize tendon movement. 

Conservative measures would include the following: physical
therapy modalities such as pulsed ultrasound, acupuncture to
stimulate healing and microcirculation, chiropractic
manipulation if needed, myofascial release work for the affected
musculature, and nutritional support. 


If the condition is allowed to progress whereby the
finger cannot straighten, conservative measures should still be
considered over a period of two weeks.  If no relief if noticed
in that time frame, then more invasive measures need to be
taken, such as corticosteroid injection, and possibly surgery to
cut open the sheath to give the tendon more space to glide.  


	Several studies have reported an higher incidence of the development
of trigger finger, carpal tunnel syndrome and tenosynovitis in diabetics.
The use of corticosteroids in this population has not been very successful
in remedying this disease, with only a 50% success rate.  It is also noted 
that diabetics tend to have multiple digits involved.  In these cases
it is important to use conservative care initially, since most medically
cared for individuals will usually require surgical intervention.


With any condition of an inflammatory nature, the
key to prevention is education, proper biomechanics, and common
sense.  The biggest mistake people make is trying to work
through the pain.  Those computer users making thousands of
keystrokes and under the pressure of  deadlines are susceptible
to these injuries.  Also in danger is the musician who is under
the gun to perfect a piece for an upcoming recital or gig.  Many
musicians will practice 6 hours per day to learn musical pieces.
 This puts a tremendous amount of strain not just on the
tendons, but also on the musculature of the entire body.  


	An important aspect in prevention is to take
frequent brakes while computing, playing an instrument, or
enjoying your hobbies.  I recommend at least a 10 minute break
every 45 minutes for the health person.  Taking a break does not
mean heading to the coffee machine.  Breaks should be a time for
stretching of the hands, arms, and neck.  If youve been sitting
for the entire time, get up and move around, loosening up your
legs and back.  Give your body the attention it needs to keep
you going throughout the day.  




References:

Channas M, et.al., Dupuytren's disease, Carpal Tunnel Syndrome, Trigger Finger, and Diabetes Mellitus, J Hand Surg [Am], 1995 Jan, 20:109 -114

Griggs, et.al., Treatment of Trigger Finger Patients with Diabetes Mellitus, J Hand Surg, 1995, 20:787 - 789

Pascarelli and Quilter, Repetitive Strain Injury: A
Computer User's Guide, Wiley, New York, 1994

Salter, Robert B., M.D., Textbook of Disorders and
Injuries of the Musculoskeletal System, Williams & Wilkins,
Baltimore, 1983

Robbins, et al, Pathological Basis of Disease, W. B.
Saunders Company, Philadelphia, 1984





Dr. Timothy Jameson is the director and owner of
Bayshore Chiropractic Center for Performing Arts Injuries
located at 3319 Castro Valley Blvd., Castro Valley, CA 94546. 
You can contact him at 510-582-5454, or by email at
chiro4u@aol.com.  Dr. Jameson specializes in the treatment of
repetitive strain injuries to the arms and hands.