Onion skin periosteal reaction also known as multilayered periosteal reaction or lamellated periosteal reaction refers to the multi layered concentric layers of new bone adjacent to the bone cortex. It is called onion skin periosteal reaction because it resembles the layers of an onion. These layers are formed due to any pathological process that leads to the variable, excessive growth of the bone. [1] Onion skin periosteal reaction is seen in osteosarcoma, [2] Ewing sarcoma and Langerhans cell histiocytosis. [3] In radiological images, onion skin periosteal reaction is seen as radiolucent areas along the multiple layers of dense bone. [4] The lucent areas may be occupied by tumors or inflammation.
A computed tomography scan is a medical imaging technique used to obtain detailed internal images of the body. The personnel that perform CT scans are called radiographers or radiology technologists.
Bone healing, or fracture healing, is a proliferative physiological process in which the body facilitates the repair of a bone fracture.
A synovial joint, also known as diarthrosis, joins bones or cartilage with a fibrous joint capsule that is continuous with the periosteum of the joined bones, constitutes the outer boundary of a synovial cavity, and surrounds the bones' articulating surfaces. This joint unites long bones and permits free bone movement and greater mobility. The synovial cavity/joint is filled with synovial fluid. The joint capsule is made up of an outer layer of fibrous membrane, which keeps the bones together structurally, and an inner layer, the synovial membrane, which seals in the synovial fluid.
Osteomyelitis (OM) is an infection of bone. Symptoms may include pain in a specific bone with overlying redness, fever, and weakness. The long bones of the arms and legs are most commonly involved in children e.g. the femur and humerus, while the feet, spine, and hips are most commonly involved in adults.
The periosteum is a membrane that covers the outer surface of all bones, except at the articular surfaces of long bones. Endosteum lines the inner surface of the medullary cavity of all long bones.
Endochondral ossification is one of the two essential processes during fetal development of the mammalian skeletal system by which bone tissue is produced. Unlike intramembranous ossification, the other process by which bone tissue is produced, cartilage is present during endochondral ossification. Endochondral ossification is also an essential process during the rudimentary formation of long bones, the growth of the length of long bones, and the natural healing of bone fractures.
Langerhans cell histiocytosis (LCH) is an abnormal clonal proliferation of Langerhans cells, abnormal cells deriving from bone marrow and capable of migrating from skin to lymph nodes.
A leiomyosarcoma, also known as LMS, is a rare malignant (cancerous) smooth muscle tumor. The origin of the word is from leio- + myo- + sarcoma which means malignant smooth muscle tumor. The stomach, bladder, uterus, blood vessels, and intestines are examples of hollow organs made up of smooth muscles where LMS can be located, however the uterus or abdomen are the most common sites.
Blepharoplasty is the plastic surgery operation for correcting defects, deformities, and disfigurations of the eyelids; and for aesthetically modifying the eye region of the face. With the excision and the removal, or the repositioning of excess tissues, such as skin and adipocyte fat, and the reinforcement of the corresponding muscle and tendon tissues, the blepharoplasty procedure resolves functional and cosmetic problems of the periorbita, which is the area from the eyebrow to the upper portion of the cheek. The procedure is more common among women, who accounted for approximately 85% of blepharoplasty procedures in 2014 in the US and 88% of such procedures in the UK.
Calcification is the accumulation of calcium salts in a body tissue. It normally occurs in the formation of bone, but calcium can be deposited abnormally in soft tissue, causing it to harden. Calcifications may be classified on whether there is mineral balance or not, and the location of the calcification. Calcification may also refer to the processes of normal mineral deposition in biological systems, such as the formation of stromatolites or mollusc shells.
A periosteal reaction is the formation of new bone in response to injury or other stimuli of the periosteum surrounding the bone. It is most often identified on X-ray films of the bones.
The enthesis is the connective tissue between tendon or ligament and bone.
Extramedullary hematopoiesis refers to hematopoiesis occurring outside of the medulla of the bone. It can be physiologic or pathologic.
Infantile cortical hyperostosis (ICH) is a self-limited inflammatory disorder of infants that causes bone changes, soft tissue swelling and irritability. The disease may be present at birth or occur shortly thereafter. The cause is unknown. Both familial and sporadic forms occur. It is also known as Caffey disease or Caffey's disease.
A dentigerous cyst, also known as a follicular cyst, is an epithelial-lined developmental cyst formed by accumulation of fluid between the reduced enamel epithelium and the crown of an unerupted tooth. It is formed when there is an alteration in the reduced enamel epithelium and encloses the crown of an unerupted tooth at the cemento-enamel junction. Fluid is accumulated between reduced enamel epithelium and the crown of an unerupted tooth.
Ewing sarcoma is a type of pediatric cancer that forms in bone or soft tissue. Symptoms may include swelling and pain at the site of the tumor, fever, and a bone fracture. The most common areas where it begins are the legs, pelvis, and chest wall. In about 25% of cases, the cancer has already spread to other parts of the body at the time of diagnosis. Complications may include a pleural effusion or paraplegia.
The Codman triangle is the triangular area of new subperiosteal bone that is created when a lesion, often a tumour, raises the periosteum away from the bone. A Codman triangle is not actually a full triangle. Instead, it is often a pseudotriangle on radiographic findings, with ossification on the original bone and one additional side of the triangle, which forms a two sided triangle with one open side. This two sided appearance is generated due to a tumor that is growing at a rate which is faster than the periosteum can grow or expand, so instead of dimpling, the periosteum tears away and provides ossification on the second edge of the triangle. The advancing tumour displaces the periosteum away from the bone medulla. The displaced and now lateral periosteum attempts to regenerate underlying bone. This describes a periosteal reaction.
Mycetoma is a chronic infection in the skin caused by either bacteria (actinomycetoma) or fungi (eumycetoma), typically resulting in a triad of painless firm skin lumps, the formation of weeping sinuses, and a discharge that contains grains. 80% occur in feet.
The in vivo bioreactor is a tissue engineering paradigm that uses bioreactor methodology to grow neotissue in vivo that augments or replaces malfunctioning native tissue. Tissue engineering principles are used to construct a confined, artificial bioreactor space in vivo that hosts a tissue scaffold and key biomolecules necessary for neotissue growth. Said space often requires inoculation with pluripotent or specific stem cells to encourage initial growth, and access to a blood source. A blood source allows for recruitment of stem cells from the body alongside nutrient delivery for continual growth. This delivery of cells and nutrients to the bioreactor eventually results in the formation of a neotissue product.
Mueller–Weiss syndrome, also known as Mueller–Weiss disease, is a rare idiopathic degenerative disease of the adult navicular bone characterized by progressive collapse and fragmentation, leading to mid- and hindfoot pain and deformity. It is most commonly seen in females, ages 40–60. Characteristic imaging shows lateral navicular collapse. This disease had been historically considered to be a form of adult onset osteonecrosis, with blood flow cutoff to the navicular.