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The locomotor system
Published in C. Simon Herrington, Muir's Textbook of Pathology, 2020
In osteoarthritis, changes are seen within the articular cartilage, the underlying bone, and, secondarily, within the synovium. An early change is loss of proteoglycan from the superficial zone of articular cartilage. Disruption of the smooth surface of cartilage follows, initially tangential to the surface (flaking) and then extending vertically into the deeper zones (fibrillation). Proliferation of chondrocytes, forming clusters around fissures, and increased proteoglycan synthesis are thought to represent unsuccessful attempts at healing. Progressive loss of articular cartilage occurs by abrasion, with eventual exposure of the underlying bone. The bone becomes greatly thickened and the surface polished (eburnation – Figure 13.32). Cystic spaces containing loose fibrous tissue appear in the subchondral bone. Bone remodelling alters the shape of the joint surface. This is particularly obvious in osteoarthritis of the femoral head in which the superior weight-bearing surface is flattened. At the margin of the articular cartilage, outgrowths of cartilage develop and undergo ossification to become osteophytes. These may cause deformity and limitation of movement. Palpable osteophytes of the distal and proximal interphalangeal joints are known as Heberden's and Bouchard's nodes respectively.
SBA Answers and Explanations
Published in Vivian A. Elwell, Jonathan M. Fishman, Rajat Chowdhury, SBAs for the MRCS Part A, 2018
Vivian A. Elwell, Jonathan M. Fishman, Rajat Chowdhury
The patient has osteoarthritis (OA). In degenerative joint disease, patients present with joint pain, tenderness, and stiffness due to the process of progressive deterioration of articular cartilage and formation of new bone (osteophytes) at the joint surface. While OA can affect any joint in the body, the disorder commonly affects the hands, hips, knees, neck, and lumbar spine. In the hands, OA typically targets the proximal interphalangeal joints, distal interphalangeal joints, and the first carpometacarpal joints. X-ray shows that the affected joint spaces are narrowed with reactive subchondral sclerosis (eburnation). Bony erosions are centrally located (in contrast to the marginal erosions in rheumatoid arthritis). Other classic radiographic findings include osteophytes and subchondral cysts. Heberden’s nodes at the DIP joints and Bouchard’s nodes at the PIP joints of the hands are areas of osteophyte formation. Moreover, periarticular soft tissue swelling, intra-articular loose bodies, and osseous fusion can also be seen.
Biocultural Perspectives on Health and Disease
Published in Debra L. Martin, Anna J. Osterholtz, Bodies and Lives in Ancient America, 2015
Debra L. Martin, Anna J. Osterholtz
DJD is generally defined by changes in the articular surface areas of joint systems. Following the exposure of subchondral bone, the articular surface regions become pitted, with marginal lipping and erosion; eventually eburnation takes place. Eburnation is the formation of a very hard callus on bone surfaces that are rubbing together without being cushioned by lubricating fluids. DJD is not an inflammatory disease but develops with age and the breakdown of the cartilage and lubricating system. The condition is slowly progressive but is not found to occur in all older adults in the same form. Thus, the condition probably is the accumulation of years of alterations of the articular cartilage and breakdown of the joint and occurs with extreme variability across individuals. Lifestyle and activity play an important role in either buffering an individual from arthritis or enhancing the chance that the condition will appear. For instance, a professional athlete may begin to exhibit DJD at a far younger age than an individual who does not engage in consistent rigorous exercise and activity. The weight-bearing joints such as the lower back, hip, and knees and those exposed to chronic trauma such as the shoulder and elbow are most frequently affected (Jurmain 1991). The pattern, distribution, severity, and onset by age class and sex in adults can be used to interpret the role of cultural activity, as well in the overall understanding of quality of life for individuals within the community.
Relationships between osteoarthritic changes (osteophytes, porosity, eburnation) based on historical skeletal material
Published in Annals of Human Biology, 2020
Anna Myszka, Janusz Piontek, Jacek Tomczyk, Aleksandra Lisowska-Gaczorek, Marta Zalewska
The present study, and other results, do not allow us to draw any final conclusions about inter-relationships between the three types of OA. However, they show that the process of osteoarthritic change formation should not be treated as a continuation sensu stricto, from osteophytes, through porosity, to eburnation, as suggested by Kellgren and Lawrence (1957). The context of their occurrence suggests a rather more independent aetiology, and, indeed, the aetiology of OA changes does not seem to overlap. Osteophytes have been linked to ageing (Ozdemir et al. 2006), genes (Spector and MacGregor 2004), traumatic injuries, musculoskeletal system diseases (Lane et al. 1993), bone mineral density, obesity (Wong et al. 2016), mechanical loading (Felson 2003) and diet (Muraki et al. 2014; Shea et al. 2015). Porosity, a non-contact phenomenon, is connected with a defect in local bone or cartilage nutrition (Woods 1995). Eburnation occurs at the point of maximum mechanical loading and is thought to be a result of the mechanical process of abrasion due to bone-to-bone contact and biomechanical stress (Ortner and Putschar 1985; Felson and Neogi 2004).