DOS Kongressen 2014 ·
199
Radiologic and histologic appearance of metal-
bone interphase in failed tibial component in total
knee arthroplasty. A retrieval study.
Tue Smith Jørgensen, Thomas Lind, Henrik Schrøder, Eva Balslev
Ortopædkirurgisk afdeling, Herlev hospital; ortopædkirurgisk afdeling,
Gentofte Hospital; patolgisk afdeling, Herlev hospital
Background:
Little information is available considering lack of ingrowth of bone
into the porous coated knee prosthesis. Ususally described as fibrous tissue in
the bone-metal interphase. Our five retrieval cases showed macro- and micro-
scopic signs of hyaline cartilage in the tibia bone-metal interphase.
Purpose / Aim of Study:
We want to describe the histological findings in the
tibia bone-metal interphase, and correlate this to the radiologic and scintigraph-
ic findings in connection with suspected aseptic loosening especially on the tibia
side.
Materials and Methods:
The five patients all underwent primary knee surgery
during the period 2004- 2006 with uncemented knee prosthesis of porous
coated type (PFC). Four with osteoarthritis and one with rheumatoid arthritis.
They were chosen for secondary operation because of pain and suspected loose
tibia component. At revision the resected bone slice was send for pathological
examination. Pre- and post op. x-rays are measured to evaluate the amount of
primarily resected bone. Pubmed Keywords: uncemented, TKA, failure, cement-
less, press fit condylar tibia component, tantalum knee, bone ingrowth. Bone
metal interphase
Findings / Results:
In all the samples, which surface turned against the pros-
thesis we found hyaline cartilage-like tissue. No articles were found, regarding
hyaline cartilage in the bone metal interphase, during our Pubmed search. Only
histological confirmed fibrous tissue were described. We discuss some consid-
erations regarding level of resection, possible diagnostic features and the radio-
logical appearance.
Conclusions:
One of the possible modes of failure of uncemented knee pros-
thesis could be the interference of cartilage formating cells, occluding the in-
terphase, before the osseointegration can take place. In some of the specimens,
small areas of ingrowth around the tibial peg, was observed.
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