Joints
Nonneoplastic disease
Implant related changes


Topic Completed: 1 January 2013

Minor changes: 26 September 2019

Copyright: 2002-2019, PathologyOutlines.com, Inc.

PubMed Search: Joints implant related changes

Vijay Shankar, M.D.
Page views in 2019: 4,173
Page views in 2020 to date: 1,312
Cite this page: Shankar V. Implant related changes. PathologyOutlines.com website. http://www.pathologyoutlines.com/topic/jointsimplantchanges.html. Accessed May 24th, 2020.
Definition / general
  • Tissue around failed implants is often submitted for examination
  • Causes of joint failure are infection (usually staphylococci, also inflammatory cells) and mechanical (granulomatous reaction to debris in joint)
  • Debris: due to metallic component of joint (gray black irregular fragments, often within histiocytes, particularly with titanium implants), polyethylene component of joint (thread-like particles up to 20 microns within histiocytes, visible only under polarized light), methyl methacrylate "grout" (dissolution during routine process reveals irregular holes from 1 - 100 microns), silicone rubber (bosselated, faintly yellow, refractile but not birefringent); all are associated with histiocytes and giant cells
  • Implants can result in aggressive metallosis eroding bone and causing joint failure (Acta Orthop 2010;81:402)
  • Frozen section: assessment of infected joint based on 5+ neutrophils/HPF (excluding surface fibrin and inflammatory exudates) in 5+ separate fields is 43% sensitive and 97% specific for infection compared to culture (Mod Pathol 1998;11:427)
Radiology images

Case of the Week #300


Images hosted on other servers:

Polyethylene liner wear

Case reports
  • 61 year old woman with loosening of her total hip replacement (THR) prosthesis after a fall (Case of the Week #300)
Clinical images

Images hosted on other servers:

Metallosis surrounding implant and cervical neck

Gross images

Case of the Week #300
Microscopic (histologic) images

Case of the Week #300

Polarizing light showed
crystal-like structures
consistent with polyethylene
particles



Images hosted on other servers:

Prosthetic synovitis:
hyperplastic synovial
membrane adjacent
to prosthesis

Methylmethacralate
debris (linear webs)
surrounded by
giant cells

Polyethylene flakes (shiny linear material) surrounded by foreign body giant cell reaction (polarized microscopy)

Calcium pyrophosphate crystals under polarized light

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