Original scientific paper
https://doi.org/10.3325/cmj.2018.59.253
Femoral head wear and metallosis caused by damaged titanium porous coating after primary metal-on-polyethylene total hip arthroplasty: a case report
Domagoj Delimar
; Department of Orthopedic Surgery, University of Zagreb School of Medicine, Zagreb, Croatia
Ivan Bohaček
; Department of Orthopedic Surgery, University Hospital Center Zagreb, University of Zagreb School of Medicine, Zagreb, Croatia
Damjan Dimnjaković
; Department of Orthopedic Surgery, University Hospital Center Zagreb, University of Zagreb School of Medicine, Zagreb, Croatia
Dalibor Viderščak
; Department of Materials, Faculty of Mechanical Engineering andNaval Architecture, University of Zagreb, Zagreb, Croatia
Zdravko Schauperl
; Department of Materials, Faculty of Mechanical Engineering andNaval Architecture, University of Zagreb, Zagreb, Croatia
Abstract
Excessive metal femoral head wear has been described
only as revision surgery complication after primary ceramic-
on-ceramic total hip arthroplasty (THA). Here, we
present the first case of metal femoral head wear after primary
metal-on-polyethylene THA. A 56-year-old woman
was referred to our outpatient clinic 17 years after primary
right-sided THA, experiencing pain and decreased right
hip range of motion. Radiographic examination revealed
acetabular cup dislocation, eccentric femoral head wear,
damaged titanium porous coating of femoral stem, metallosis,
and pseudotumor formation. Endoprosthetic components
were extracted, but further reconstruction was
impossible due to presence of large acetabular bone defect.
Macro- and micro-structure of extracted components
were analyzed. Acetabular liner surface was damaged, with
scratches, indentations, and embedded metal debris particles
present on the entire inner surface. Analysis of metal
debris by energy-dispersive spectroscopy showed that it
consisted of titanium and stainless-steel particles. Femoral
head was gravely worn and elliptically shaped, with abrasive
wear visible under scanning electron microscope. No
signs of trunnionosis at head/neck junction were observed.
Microstructure of femoral head material was homogeneous
austenitic, with microhardness of 145 HV 0.2, which is
lower than previously described titanium hardness. In conclusion,
detached titanium porous coating of femoral stem
can cause stainless-steel femoral head wear in primary
metal-on-polyethylene THA. As soon as such detachment
becomes evident, revision surgery should be considered
to prevent devastating complications.
Keywords
Hrčak ID:
239191
URI
Publication date:
16.10.2018.
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