Reliable landmarks for precise topographical analyses of pathological structural changes of the ovine tibial plateau in 2-D and 3-D subspaces

Abstract

Selecting identical topographical locations to analyse pathological structural changes of the osteochondral unit in translational models remains difficult. The specific aim of the study was to provide objectively defined reference points on the ovine tibial plateau based on 2-D sections of micro-CT images useful for reproducible sample harvesting and as standardized landmarks for landmark-based 3-D image registration. We propose 5 reference points, 11 reference lines and 12 subregions that are detectable macroscopically and on 2-D micro-CT sections. Their value was confirmed applying landmark-based rigid and affine 3-D registration methods. Intra- and interobserver comparison showed high reliabilities, and constant positions (standard errors < 1%). Spatial patterns of the thicknesses of the articular cartilage and subchondral bone plate were revealed by measurements in 96 individual points of the tibial plateau. As a case study, pathological phenomena 6 months following OA induction in vivo such as osteophytes and areas of OA development were mapped to the individual subregions. These new reference points and subregions are directly identifiable on tibial plateau specimens or macroscopic images, enabling a precise topographical location of pathological structural changes of the osteochondral unit in both 2-D and 3-D subspaces in a region-appropriate fashion relevant for translational investigations.

Supercapsular percutaneously-assisted total hip (SuperPath) versus mini-incision posterolateral total hip arthroplasty for hip osteoarthritis: a prospective randomized controlled trial

“…It has been associated with heavy physical occupational activities (3,4). If left untreated, hip OA typically leads to chronic pain, decreased quality of life, and various disabilities, and will often require total hip arthroplasty (THA) (5)(6)(7)(8). As the global population ages, THA has become a high-volume surgical intervention for patients with end-stage hip OA (9,10).…”

Axial alignment is a critical regulator of knee osteoarthritis

“…Ovine tibial plateaus ( n = 48 total, including n = 24 controls, n = 8 neutral OA, n = 8 varus OA, and n = 8 valgus OA) were scanned in a micro-CT scanner (SkyScan 1176, Bruker micro-CT; 90-kV tube voltage; 278-μA current; 18-μm isotropic resolution; combined 0.5-mm aluminum/copper filter; 0.4° intervals; 270-ms exposure time, three averaging frames) and reconstructed with NRecon (v.1.7.0.4, Bruker micro-CT). After identical rotation of the datasets, coronal images were saved (DataViewer software v.1.5.2.4, Bruker micro-CT) ( 3 , 52 ).…”

“…Subchondral bone plate and cartilage thickness were measured manually in three-thirds (outer, middle, and inner) of each subregion. For 3D reconstruction of the micro-CT, image sets, and modeling of Tb.Th, CTVox v.3.2.0 (Bruker micro-CT) was used ( 52 ). To generate a 3D model of the porosity of the subchondral bone plate, CTVol v.2.3.2.0 (Bruker micro-CT) was used ( 3 ).…”

The future of basic science in orthopaedics and traumatology: Cassandra or Prometheus?

“…This dilemma was already reflected by the classical remark of Henry Mankin, the renowned orthopaedic clinician scientist, who stated that the “cartilage does not yield its secrets easily, inducing cartilage to heal is not simple, … and progression to OA is sometimes so slow that we delude ourselves into thinking we are doing better than we are” [ 10 ]. Novel approaches for OA are being pursued to overcome this challenge, among which detailed investigation of topographical changes [ 11 ], OA pain [ 7 , 8 ] and possibly contributing environmental factors [ 12 ], while also advancing gene-based [ 13 ] and other targeted approaches [ 14 ] as future therapies.…”

“…Indentation-type (IT) AFM is particularly useful to determine elastic properties of the chondrocyte pericellular matrix and cartilage ECM and the most sensitive method for detecting minute changes in cartilage biomechanics [ 105 – 108 ]. µCT application for topographical analysis of pathological structural changes of the osteochondral unit in translational animal models is state of the art [ 11 ]. To observe microstructural changes, i.e.…”