Bone & joints



Topic Completed: 1 March 2013

Minor changes: 29 December 2020

Copyright: 2002-2021,, Inc.

PubMed Search: [Arthritis] joints "loattrfree full text"[sb]

Vijay Shankar, M.D.
Page views in 2020: 3,956
Page views in 2021 to date: 4,079
Cite this page: Shankar V. Arthritis-general. website. Accessed October 25th, 2021.
Definition / general
  • Joint pain, limitation of motion or instability, due to dysfunctional articulating surfaces, loss of integrity of muscles / tendons around joint or their innervation or mechanical properties of cartilaginous or bony extracellular matrix
  • When specimen is received, disease is usually advanced, making precise cause difficult to determine
  • If etiology is not known, examine synovial fluid before biopsy to detect TB or other granulomatous lesions
Gross description
  • Cartilage has irregular surface with pitting and loss of cartilage
  • Subchondral bone shows eburnation (polishing due to friction of bone against bone in joint), fractures
  • Bony spurs (osteophytes), loose bodies (detached cartilage or cartilage/bone within joint space with necrotic calcified centers, may become attached to synovial membrane, revascularize and convert to viable bone)
Gross images

Images hosted on other servers:


Microscopic (histologic) description
  • Findings are related to either injury or reparative change
  • Injury:
    • Death of chondrocytes (no visible nuclei) or necrotic chondrocytes, marked irregularity and thickening of tidemark (indicates disturbed calcification) or duplication of tidemark
    • Surface of cartilage may be intact
    • Diminution of basophilic staining due to proteoglycan depletion
    • Vertical and horizontal clefts within cartilage matrix extending from articular surface
    • If rapid injury, synovium often contains pieces of bone or cartilage and chronic inflammatory cells
    • Loose bodies may have concentric rings of calcification and may grow into enormous size
    • Endochondral ossification can occur in loose bodies
    • Subchondral bone has superficial bone necrosis, microfractures, replacement of bone by solid or cystic fibromyxomatous tissue
  • Repair:
    • Chondrocyte proliferation within damaged cartilage or from underlying bone and periphery of joint
    • Bone / joint proliferative cartilage is cellular fibrocartilage, more coarse and disorganized with polarized light
    • Usually marked osteoblastic activity, new bone formation, thickening of superficial trabeculae
    • Marked synovial cell hyperplasia with multilayering or papillary folds, often containing hemosiderin (evidence of bleeding)
    • Polarized microscopy demonstrates discontinuity between collagen network of repair cartilage and preexisting cartilage
Microscopic (histologic) images

Images hosted on other servers:

Sheep with cylindrical metal implant

Back to top
Image 01 Image 02