Joints
Nonneoplastic disease
Implant related changes

Author: Vijay Shankar, M.D. (see Authors page)

Revised: 11 August 2017, last major update January 2013

Copyright: (c) 2002-2017, PathologyOutlines.com, Inc.

PubMed Search: Joints implant related changes

Cite this page: Shankar, V. Implant related changes. PathologyOutlines.com website. http://pathologyoutlines.com/topic/jointsimplantchanges.html. Accessed September 20th, 2017.
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

Images hosted on PathOut server:

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

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Metallosis surrounding implant and cervical neck

Gross images

Images hosted on PathOut server:

Case of the Week #300

Microscopic (histologic) images

Images hosted on PathOut servers:

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

Gout: sodium urate crystals under polarized light