Comparison of micro-CT post-processing methods for evaluating the trabecular bone volume fraction in a rat ACL-transection model.
Trabecular bone volume fraction assessments are likely sensitive to the analysis method and selection of the region of interest. Currently, there are several methods for selecting the region of interest to analyze trabecular bone in animal models of post-traumatic osteoarthritis. The objective of this study was to compare three published methods for determining the trabecular bone volume fraction of the medial tibial epiphyses in ACL transected and contralateral ACL intact knees. Micro-computed tomography images of both knees were obtained five weeks post-operatively and evaluated using three methods: (1) the Whole Compartment Method that captured the entire medial compartment, (2) the centrally located Single Core Method, and (3) the Triplet Core Method that averaged focal locations in the anterior, central, and posterior regions. The Whole Compartment Method detected significant bone loss in the ACL transected knee compared to the ACL intact knee (p<0.001), with a loss of 15.2±3.9%. The Single Core and the Triplet Core Methods detected losses of 7.5±10.5% (p=0.061) and 14.1±13.7%(p=0.01), respectively. Details regarding segmentation methods are important for facilitating comparisons between studies, and for selecting methods to document trabecular bone changes and treatment outcomes. Based on these findings, the Whole Compartment Method is recommended, as it was least variable and more sensitive for detecting differences in the bone volume fraction in the medial compartment.
Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA.
K E
KE
Chin
Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA.
N P
NP
Karamchedu
Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA.
T K
TK
Patel
Department of Medical Biostatistics, University of Vermont, Burlington, VT, USA.
G J
GJ
Badger
Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA.
M R
MR
Akelman
Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA.
D C
DC
Moore
Department of Orthopaedic Surgery, Boston Children׳s Hospital, Boston, MA, USA.
B L
BL
Proffen
Department of Orthopaedic Surgery, Boston Children׳s Hospital, Boston, MA, USA.
M M
MM
Murray
Department of Orthopaedics, Warren Alpert Medical School of Brown University/Rhode Island Hospital, Providence, RI, USA; School of Engineering, Brown University, Providence, RI, USA. Electronic address: Braden_Fleming@brown.edu.
B C
BC
Fleming
D000818:Animals; D016118:Anterior Cruciate Ligament / Q000000981:diagnostic imaging* / Q000601:surgery; D000071556:Cancellous Bone / Q000000981:diagnostic imaging* / Q000502:physiology; D006614:Hindlimb / Q000000981:diagnostic imaging; D007091:Image Processing, Computer-Assisted / Q000379:methods*; D011917:Rats, Inbred Lew; D013977:Tibia / Q000000981:diagnostic imaging* / Q000502:physiology; D055114:X-Ray Microtomography
Bone; Knee; Ligament; Micro-computed tomography; Osteoarthritis