Osteolysis is an active
resorption of
bone matrix by
osteoclasts and can be interpreted as the reverse of
ossification. Although osteoclasts are active during the natural formation of healthy bone the term "osteolysis" specifically refers to a pathological process. Osteolysis often occurs in the proximity of a
prosthesis
In medicine, a prosthesis (plural: prostheses; from grc, πρόσθεσις, prósthesis, addition, application, attachment), or a prosthetic implant, is an artificial device that replaces a missing body part, which may be lost through trau ...
that causes either an immunological response or changes in the bone's
structural load. Osteolysis may also be caused by pathologies like
bone tumors, cysts, or chronic inflammation.
Joint replacement
While
bone resorption is commonly associated with many diseases or joint problems, the term ''osteolysis'' generally refers to a problem common to artificial joint replacements such as
total hip replacements, total knee replacements and total shoulder replacements. Osteolysis can also be associated with the radiographic changes seen in those with bisphosphonate-related
osteonecrosis of the jaw.
There are several biological mechanisms which may lead to osteolysis. In total hip replacement, the generally accepted explanation for osteolysis involves wear particles (worn off the contact surface of the artificial
ball and socket joint
The ball-and-socket joint (or spheroid joint) is a type of synovial joint in which the ball-shaped surface of one rounded bone fits into the cup-like depression of another bone. The distal bone is capable of motion around an indefinite number o ...
). As the body attempts to clean up these wear particles (typically consisting of plastic or metal), it triggers an
autoimmune reaction which causes resorption of living bone tissue. Osteolysis has been reported to occur as early as 12 months after implantation and is usually progressive. This may require a revision
surgery
Surgery ''cheirourgikē'' (composed of χείρ, "hand", and ἔργον, "work"), via la, chirurgiae, meaning "hand work". is a medical specialty that uses operative manual and instrumental techniques on a person to investigate or treat a pat ...
(replacement of the prosthesis).
Although osteolysis itself is clinically
asymptomatic
In medicine, any disease is classified asymptomatic if a patient tests as carrier for a disease or infection but experiences no symptoms. Whenever a medical condition fails to show noticeable symptoms after a diagnosis it might be considered asy ...
, it can lead to implant loosening or bone breakage, which in turn causes serious medical problems.
Distal clavicular osteolysis
Distal clavicular osteolysis (DCO) is often associated with problems weightlifters have with their
acromioclavicular joints due to high mechanical stresses put on the
clavicle as it meets with the
acromion. This condition is often referred to as "weight lifter's shoulder".
[ ]Medical ultrasonography
Medical ultrasound includes diagnostic techniques (mainly medical imaging, imaging techniques) using ultrasound, as well as therapeutic ultrasound, therapeutic applications of ultrasound. In diagnosis, it is used to create an image of internal ...
readily depicts resorption of the distal clavicle as irregular cortical erosions, whereas the acromion remains intact.[Arend CF. Ultrasound of the Shoulder. Master Medical Books, 2013. Sample chapter available a]
ShoulderUS.com
/ref> Associated findings may include distended joint capsule, soft tissue swelling, and joint instability.
A common surgery to treat recalcitrant DCO is resection of distal clavicle by removing a few millimetres of bone from the very end of the bone.
See also
* Osteolytic lesion
* Biomineralization
References
External links
{{Musculoskeletal physiology
Geriatrics
Orthopedic surgical procedures
Musculoskeletal disorders
Arthritis