| Osteolysis | |
|---|---|
| Specialty | Orthopedics |
Osteolysis is an activeresorption ofbone matrix byosteoclasts and can be interpreted as the reverse ofossification. 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 aprosthesis that causes either an immunological response or changes in the bone'sstructural load. Osteolysis may also be caused by pathologies likebone tumors, cysts, or chronic inflammation.
Whilebone resorption is commonly associated with many diseases or joint problems, the termosteolysis generally refers to a problem common to artificial joint replacements such astotal hip replacements, total knee replacements and total shoulder replacements. Osteolysis can also be associated with the radiographic changes seen in those with bisphosphonate-relatedosteonecrosis of the jaw.[citation needed]
There are several biological mechanisms which may lead to osteolysis. In total hip replacement, the generally accepted explanation[1] for osteolysis involves wear particles (worn off the contact surface of the artificialball and socket joint). As the body attempts to clean up these wear particles (typically consisting of plastic or metal), it triggers anautoimmune 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 revisionsurgery (replacement of the prosthesis).[citation needed]
Although osteolysis itself is clinicallyasymptomatic, it can lead to implant loosening or bone breakage, which in turn causes serious medical problems.[2]
Distal clavicular osteolysis (DCO) is often associated with problems weightlifters have with theiracromioclavicular joints due to high mechanical stresses put on theclavicle as it meets with theacromion. This condition is often referred to as "weight lifter's shoulder".[3]Medical ultrasonography readily depicts resorption of the distal clavicle as irregular cortical erosions, whereas the acromion remains intact.[4] Associated findings may include distended joint capsule,soft tissueswelling, andjoint instability.[citation needed]
A common surgery to treat recalcitrant DCO isresection of distal clavicle by removing a few millimetres of bone from the very end of the bone.[3]