Structural and mechanical characterisation of the peri-prosthetic tissue surrounding loosened hip prostheses. An explorative study.
Very little is known about the structure and properties of peri-prosthetic fibrous tissue that is found around loose orthopaedic implants. We describe a method for characterizing the structural organisation (histology, confocal microscopy) as well as the nano- and micro-scale mechanical behaviour (atomic force microscopy, nanoindentation) of peri-prosthetic fibrous tissue. The tissue was collected from 11 patients undergoing revision surgery due to aseptic loosening. Sirius Red and Movat histological staining procedures indicated that the tissue mainly consists of collagen fibres and ground substance. However, large inter- and intra-patient variations in the relative proportions of these tissue components were found, as well as in collagen fibre orientation and possibly also maturation. The nano-scale Young׳s moduli ranged from 0-950kPa, but showed large inter-patient variability. When the results per sample were presented in a probability density function, we could roughly discriminate one peak in the 0-100kPa range and/or one peak in the 100-500Pa range. These nano-scale moduli seem to respectively present the mechanical properties of glycosaminoglycan (GAG) and collagen molecules. The majority of the micro-scale Young׳s moduli ranged between 0.5 and 2.0kPa for all samples. This explorative study provides new insights in (the variations of) structural organisation and mechanical properties of peri-prosthetic tissue.
Department of Orthopaedics, Leiden University Medical Center, Leiden, The Netherlands; Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Delft, The Netherlands.
Astrid
A
Moerman
Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Delft, The Netherlands.
Amir A
AA
Zadpoor
Department of Orthopaedics, Leiden University Medical Center, Leiden, The Netherlands.
Angela
A
Oostlander
Department of Orthopaedics, Leiden University Medical Center, Leiden, The Netherlands.
Monique
M
Schoeman
Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Delft, The Netherlands; Department of Orthopaedics, University Medical Center Utrecht, Utrecht, The Netherlands.
Parisa
P
Rahnamay Moshtagh
Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Delft, The Netherlands; Department of Orthopaedics, University Medical Center Utrecht, Utrecht, The Netherlands.
Behdad
B
Pouran
Department of Orthopaedics, Leiden University Medical Center, Leiden, The Netherlands; Department of Biomechanical Engineering, Faculty of Mechanical, Maritime, and Materials Engineering, Delft University of Technology, Delft, The Netherlands. Electronic address: e.r.valstar@lumc.nl.
Edward
E
Valstar
D000368:Aged; D000369:Aged, 80 and over; D019644:Arthroplasty, Replacement, Hip; D003094:Collagen / Q000737:chemistry; D055119:Elastic Modulus; D005109:Extracellular Matrix / Q000737:chemistry; D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D018625:Microscopy, Atomic Force; D008875:Middle Aged; D011475:Prosthesis Failure
D003094:Collagen
Hip replacement; Histology; Peri-prosthetic tissue; Tissue biomechanics