Femoral head wear and metallosis caused by damaged titanium porous coating after primary metal-on-polyethylene total hip arthroplasty: a case report

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.

Review of Wear Model Optimization for Ceramic and Metal Total Hip Arthroplasty with Medical Physics Applications

“…The method for dual and multiobjective optimization for ceramic THA and dual metal was previously published [1][2][3][4]29]. Algorithms implemented are based on classical Archard's model [1,2,15,16,20,28], but with vector-matrix and units' modifications [Casesnoves Algorithm, 2020-1]. A variant from this model with evoluted algorithms was developed in previous contributions [26].…”

“…The second comprises two strands: applications for THA improvements, and applications to avoid/ minimize THA complications, Table 10. Literature for pre-surgery and post-surgery THA pathology is profuse [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Laboratory applications are tribotesting predictions for wear rates, no matter what type of apparatus/experimental-system is used.…”

“…For example, post-operation increase of THA wear causes a post-operation biomechanical problem and viceversa [1][2][3][4]. Other factor, for instance, could be a post-operation deformation (cause) by osteoporosis, that could result (effect) in wear increase or THA malfunction [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17]. Therefore, there are two main surgicalpathology concepts: cause and effect.…”

“…It shows causality and multi-effect links for improvements and complications prevention. Literature and clinical case reviews are profuse in this matter [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17].…”

Mathematical Standard-Parameters Dual Optimization for Metal Hip Arthroplasty Wear Modelling with Medical Physics Applications

“…Metal prostheses/materials are subject, in general, to erosion and corrosion physical of chemical phenomena, and tribocorrosion happens on human plasma medium, when corrosion, due to plasma free radicals, becomes synergic with erosion. Other types of complications are caused by debris particles of the eccentric wear in the acetabular cup or the cup dislocation [10] when bone hardness is weak and screws cannot hold sufficiently. The in vitro experiment of THA devices to obtain tentative/precise erosive data is an important stage in the manufacturing process.…”