Spontaneous tibial insert dislodgement in unicompartmental knee prosthesis

Case contributed by Chris O'Donnell , 24 Oct 2016
Diagnosis certain
Changed by Yaïr Glick, 28 Sep 2019

Updates to Case Attributes

Title was changed:
Spontaneous unicompartment knee prosthesis tibial insert dislodgement in unicompartmental knee prosthesis
Presentation was changed:
Sudden severe left knee pain.Previous unicompartment (medial)medial unicompartmental knee prosthesis insertion.
Age changed from 70 to 70 years.
Body was changed:

Polyethylene spacers or inserts are inserted between the 2 components of a prosthesis for articulation, much like articular cartilage.They are attached to the tibial component in a knee prosthesis and are prone to wear over time and can lead to foreign body reaction (particle(particle disease or aggressive granulomatosis). Rarely they can dislodge. The polyethylenePolyethylene is radiolucent thus; thus, radio-opaque markers are inserted by the manufacturer so that theirthe position canof the spacer could be monitored.

  • -<p>Polyethylene spacers or inserts are inserted between the 2 components of a prosthesis for articulation much like articular cartilage. <br><br>They are attached to the tibial component in a knee prosthesis and are prone to wear over time and can lead to foreign body reaction (particle disease or aggressive granulomatosis). Rarely they can dislodge. <br><br>The polyethylene is radiolucent thus radio-opaque markers are inserted by the manufacturer so that their position can be monitored.</p>
  • +<p>Polyethylene spacers or inserts are inserted between the 2 components of a prosthesis for articulation, much like articular cartilage. They are attached to the tibial component in a knee prosthesis and are <a title="Polyethylene wear" href="/articles/polyethylene-wear">prone to wear</a> over time and can lead to foreign body reaction (<a title="Particle disease" href="/articles/aggressive-granulomatosis-post-hip-replacement">particle disease</a> or <a title="Aggressive granulomatosis post hip replacement" href="/articles/aggressive-granulomatosis-post-hip-replacement">aggressive granulomatosis</a>). Rarely they can dislodge. <br><br>Polyethylene is radiolucent; thus, radio-opaque markers are inserted by the manufacturer so that the position of the spacer could be monitored.</p>

Updates to Link Attributes

Title was removed:
Spontaneous unicompartment knee prosthesis tibial insert dislodgement
Type was removed.
Visible was set to .

Updates to Primarylink Attributes

Updates to Study Attributes

Findings was added:

In a previous X-ray exam, the markers were symmetrically positioned between the femoral and tibial components with an associated lucent gap - this is normal.

Modality was set to X-ray.
Images Changes:

Image X-ray (Frontal) ( update )

Perspective was set to Frontal.

Image X-ray (Lateral) ( update )

Perspective was set to Lateral.

Image 1 X-ray (Frontal) ( create )

Image 2 X-ray (Lateral) ( create )

Updates to Study Attributes

Findings was changed:

Two linear radio-opaque markers outline the polyethylene insert that normally sits on the tibial component of the unicompartmentunicompartmental (medial) knee prosthesis. In 2012 theThe markers are symmetrically positioned between the femoral and tibial components with an associated lucent gap - this is normal. On the later examination the markers are antero-medialanteromedial to the articulation with loss of the lucent articular gap, indicating insert dislodgement.

Images Changes:

Image X-ray (Lateral) ( update )

Description was removed:
current

Image X-ray (Frontal) ( update )

Description was removed:
current

Image X-ray (Frontal) ( update )

Description was removed:
2012

Image X-ray (Lateral) ( update )

Description was removed:
2012

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