ญญญญญญญญญญ_________________________
by: Kendrick E. Lee, M.D.
Osteoarthritis of the hand is a very common
disorder. The joints most commonly affected are the thumb base
joint (the thumb carpometacarpal joint), the middle joint of the
finger, and the distal joint of the finger (closest to the
fingernail). About 75% of autopsy studies will have
osteoarthritis present at the thumb base, or basal, joint.
Osteoarthritis of the thumb basal joint is
more common in women than in men, a ration of about 10 to 1.
Symptoms most often develop in post menopausal woman. For unknown
reasons, thumb base osteoarthritis is more common in patients of
Caucasian heritage than in patients of Asian or African American
heritage.
The primary symptom of thumb base
osteoarthritis is pain at the base of the thumb, near the wrist.
The pain is often aggravated by pinching the thumb too strongly,
like when writing or doing a stroke on a computer keyboard. Other
symptoms can include swelling and deformity. X-rays of the
thumb base joint will usually show osteoarthritis changes,
although the pain and x-ray severity sometimes do not correlate.
Compared to finger osteoarthritis, thumb
basal joint osteoarthritis is more often severely painful or
disabling, and more often requires treatment. Initial treatment
is usually with activity modification and non-steroidal
anti-inflammatory such as aspirin, ibuprofen, or Naproxen. Soft
thumb support or rigid splinting often helps control pain. Rigid
splinting is usually more effective, but also more disruptive to
active life. The hand therapist can often help fit splints and
teach activity modifications.
A steroid or cortisone injection can help
decrease pain, but often relief with injection alone is
temporary.
In severe or disabling cases, thumb
carpometacarpal joint arthroplasty surgery can be very effective.
There are multiple surgical techniques available. Oftentimes,
surgery includes the removal of the trapezium (the carpal bone
which supports the base of the thumb). The space vacated is
then filled with soft tissue, usually a tendon taken from the
forearm. Often, the base of the thumb metacarpal is
stabilized to the base of the index metacarpal bone by a ligament
reconstruction. Surgery is usually
done with general anesthesia in an outpatient surgical clinic.
A splint or cast is worn for approximately five to six weeks,
followed by exercise and therapy. Improvement can continue
for 6 to 12 months following such surgery, which is usually
effective in significantly relieving or eliminating pain, while
maintaining mobility.
In contrast to the hip or knee joint
replacement surgery, plastic and metal artificial joints have
been disappointing in the reconstruction of the thumb base joint.
Although the finger distal and middle joints
are commonly affected, pain is generally less severe than at the
thumb base joint. The involved finger joints are often
stiff and achy, but are seldom disabling or severely painful.
Treatment is usually with anti-inflammatory medications, activity
modifications, and local treatment modalities such as hot
paraffin baths.
The osteoarthritic distal finger joint can
be associated with a painful mucous (or ganglion) cyst. These
tender modules protrude near the fingernail, and can produce a
groove-like deformity of the finger nail itself. Surgery
can be effective at removing the cyst and decreasing the nail
deformity.
Other than surgery to remove the distal
joint ganglion cyst, surgery is seldom required for the
osteoarthritic finger joint. Rarely, severely painful
arthritis of the finger joints is treated with surgical fusion or
joint reconstruction surgery.