|Case 9 :|
|A young weight-lifter comes with wrist pain since a month. MRI was performed. What is the diagnosis?|
|__________SCROLL FOR ANSWER__________|
findings reveal loss of marrow fat of lunate bones on these sequences.
is Avascular necrosis of lunate (Kienbock’s disease).
the case of avascular necrosis of the carpal lunate, the condition
frequently occurs during adult life. Secondary to an injury, and as a
result of the injury, the blood supply is often permanently lost. This
condition has been referred to in the literature as "Kienbock's
necrosis occurs in other bones too, particularly:
head, Femoral head &
condyles, tibial plateau, talus, and scaphoid
sickness (embolization with nitrogen bubbles)
cause of Kienbocks disease is unknown. The disease sometimes begins with a
simple fracture or multiple compression fractures caused by repeated
stresses across the wrist. Trauma may or may not precede symptoms. The
loss of blood supply to the lunate has been attributed to many factors,
including traumatic interference with circulation, ligament injury with
degeneration and collapse, primary circulatory or vascular problems, and
solitary or chronic injuries resulting in vascular impairment.
disease is commonly associated with negative u1nar variance, in which the
ulnar head lies more proximal than the radial head on posteroanterior
x-ray. (Neutral ulnar variance means the distal surfaces of the radius and
ulna are level.)
of the wrist
help to determine the presence of avascular necrosis and u1nar variance.
X-rays in early Kienb6ck-'s disease may be completely normal. The earliest
indication of avascular necrosis on plain radiographs is increased lunate
density ac-companied by flattening, but chronic pain may be present before
x-ray findings appear.
has gained wide acceptance in the early diagnosis and evaluation of
scintigraphy using Tc-99m phosphate
is a highly sensitive, albeit nonspecific, modality for identifying
metabolic bone changes. It has a role as a screening tool in patients who
have wrist pain of unknown origin and normal radiographs.
MRI very effectively helps detect early avascular necrosis in various
bones, including the lunate, by revealing loss of bone marrow fat. It can
detect abnormalities in the lunate when plain radiographs are normal.
2 is characterized by increased radiographic density in the lunate
relative to the other carpal bones. The lunate retains its size, shape,
and anatomic relationship to the other carpal bones.
3 Kienbock's disease is characterized by lunate collapse and proximal
migration of the capitate. Scapholunate dissociation is a prominent
feature on anteroposterior radiographs.
4 disease is characterized by established osteoarthritis of the wrist,
with degenerative cysts, subchondral scle-rosis, and joint space
with negative ulnar variance may benefit from an equalization of the
distal articular surfaces of the radius and ulna. Excellent results have
been reported with ulnar-lengthening and radial-shortening osteotomies.
These operations should not be used when the lunate has collapsed, as in
stage 3 or 4 disease.
stage 3 disease, triscaphe (scaphoid-trapezium-trapezoid) and
procedures for stage 4 disease include proximal row carpectomy and wrist