Improved visualization of the bone-implant interface and osseointegration in ex vivo acetabular cup implants using photon-counting detector CT

• Published in: European radiology experimental Vol. 7; no. 1; p. 19
• Main Authors: Woisetschläger, Mischa, Booij, Ronald, Tesselaar, Erik, Oei, Edwin H. G., Schilcher, Jörg
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01-05-2023; Springer Nature B.V; SpringerOpen
• Subjects: Arthroplasty; Bone-Implant Interface - diagnostic imaging; Diagnostic Radiology; Imaging; Interfaces; Internal Medicine; Interventional Radiology; Joint prosthesis; Medicine; Medicine & Public Health; Neuroradiology; Original; Original Article; Osseointegration; Osteoarthritis (hip); Phantoms, Imaging; Photons; Radiology; Sensors; Tomography; Tomography (x-ray computed); Tomography, X-Ray Computed - methods; Transplants & implants; Ultrasound; Visualization; Osseointegration; Osteoarthritis (hip); Arthroplasty; Joint prosthesis; Tomography (x-ray computed)
• ISSN: 2509-9280; 2509-9280
• DOI: 10.1186/s41747-023-00335-y

Background
Successful osseointegration of joint replacement implants is required for long-term implant survival. Accurate assessment of osseointegration could enable clinical discrimination of failed implants from other sources of pain avoiding unnecessary surgeries. Photon-counting detector computed tomography (PCD-CT) provides improvements in image resolution compared to conventional energy-integrating detector CT (EID-CT), possibly allowing better visualization of bone-implant-interfaces and osseointegration. The aim of this study was to assess the quality of visualization of bone-implant-interfaces and osseointegration in acetabular cup implants, using PCD-CT compared with EID-CT.
Methods
Two acetabular implants (one cemented, one uncemented) retrieved during revision surgery were scanned using PCD-CT and EID-CT at equal radiation dose. Images were reconstructed using different reconstruction kernels and iterative strengths. Delineation of the bone-implant and bone-cement-interface as an indicator of osseointegration was scored subjectively for image quality by four radiologists on a Likert scale and assessed quantitatively.
Results
Delineation of bone-implant and bone-cement-interfaces was better with PCD-CT compared with EID-CT (
p
 ≤ 0.030). The highest ratings were given for PCD-CT at sharper kernels for the cemented cup (PCD-CT, median 5, interquartile range 4.25–5.00
versus
EID-CT, 3, 2.00–3.75,
p
 < 0.001) and the uncemented cup (5, 4.00–5.00
versus
2, 2–2, respectively,
p
 < 0.001). The bone-implant-interface was 35–42% sharper and the bone-cement-interface was 28–43% sharper with PCD-CT compared with EID-CT, depending on the reconstruction kernel.
Conclusions
PCD-CT might enable a more accurate assessment of osseointegration of orthopedic joint replacement implants.
Key points
• The bone-implant interface
ex vivo
showed superior visualization using photon-counting detector computed tomography (PCD-CT) compared to energy-integrating detector computed tomography.
• Harder reconstruction kernels in PCD-CT provide sharper images with lower noise levels.
• These improvements in imaging might make it possible to visualize osseointegration
in vivo
.