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We also need to know about hypersensitivities
to metal, problems with a jeans botton or a
positive epicutan test.
We recommended the clinical investigations
should specifically target asymptomatic or
symptomatic local swellings after total knee
replacement and patients should be questioned
on problems with general hypersensitivity
reactions (skin rash), cardiomyopathy, and
neurological changes including sensory
changes, renal function impairment and thyroid
dysfunction.
When the blood does show signs of infection
we perform a punction of the joint.
In trouble we always perform an arthroscopy
(fig. 2) to do the microbiological investigation
with 5 samples for microbiologie and 5 samples
(3 close to the knee components and 2 in the
upperrecesus)forthehistologicalclassifications
which we sent to Prof. Krenn to Trier.
Krenn
et al
(2013) said that by means of
histopathology different pathogenetic synovial-
like interface membrane (SLIM) patterns that
lead to reduction of implant durability could be
discerned, such as periprosthetic particles,
bacterial infections and arthrofibrosis.
Subsequently,SLIMtypeshavebeendetermined
in a revised consensus classification including
particle-induced type (
type I
) so-called non-
septic loosening, infection type (
type II
) so-
called septic loosening, combination type (
type
III
) of bacterial and particle-induced types,
indifferent type with mechanical and functional
disorders (
type IV
), osseous pathologies
(
type V
), arthrofibrotic type (
type VI
,
endoprosthesis-associated arthrofibrosis) and
allergic/immunological/toxic reactions to
prosthesis material (
type VII
). Particles are
characterized histopathologically according to
the Krenn particle algorithm. In cases of severe
lymphocyte/macrophage infiltration, necrosis,
abrasion particle detection and granuloma
formation, a toxic or allergic reaction to implant
material should be considered.
Although hypersensitivity, allergy or metal ion
overloading is a rare complication you always
have to remember and before a revision a good
diagnosis is important. We have seen patients
with several revision operations where the
problem was not seen.
Fig. 2