Ultrasound evaluation of mechanical injury of bovine knee articular cartilage under arthroscopic control

Abstract

A local cartilage injury can trigger development of posttraumatic osteoarthritis (OA). Surgical methods have been developed for repairing cartilage injuries. Objective and sensitive methods are needed for planning an optimal surgery as well as for monitoring the surgical outcome. In this laboratory study, the feasibility of an arthroscopic ultrasound technique for diagnosing cartilage injuries was investigated. In bovine knees (n = 7) articular cartilage in the central patella and femoral sulcus was mechanically degraded with a steel brush modified for use under arthroscopic control. Subsequently, mechanically degraded and intact adjacent tissue was imaged with a high frequency (40 MHz) intravascular ultrasound device operated under arthroscopic guidance. After opening the knee joint, mechanical indentation measurements were also conducted with an arthroscopic device at each predefined anatomical site. Finally, cylindrical osteochondral samples were extracted from the measurement sites and prepared for histological analysis. Quantitative parameters, i.e., reflection coefficient (R), integrated reflection coefficient (IRC), apparent integrated backscattering (AIB), and ultrasound roughness index (URI) were calculated from the ultrasound signals. The reproducibilities (sCV %) of the measurements of ultrasound parameters were variable (3.7% to 26.1%). Reflection and roughness parameters were significantly different between mechanically degraded and adjacent intact tissue (p < 0.05). Surface fibrillation of mechanically degraded tissue could be visualized in ultrasound images. Furthermore, R and IRC correlated significantly with the indentation stiffness. The present results are encouraging; however, further technical development of the arthroscopic ultrasound technique is needed for evaluation of the integrity of human articular cartilage in vivo.

In Vivo Evaluation of the Potential of High-Frequency Ultrasound for Arthroscopic Examination of the Shoulder Joint

“…In addition to acquisition of high-resolution ultrasound images, we determined qualitative and quantitative ultrasound parameters which correlated with the ICRS grading scores, as derived from conventional arthroscopy. Our results are consistent with earlier studies where this technique was tested in vitro, 11,21 in an animal joint ex vivo, 35 and in vivo in clinical arthroscopy of the human knee joint. 12 Arthroscopic ultrasound was found to be more effective in detecting early stage cartilage damage compared to the 1.5 T routine clinical magnetic resonance imaging.…”

Pre-clinical Characterization of Tissue Engineering Constructs for Bone and Cartilage Regeneration

“…63 Furthermore, mechanical tests to assess the shear, tensile and compressive properties of engineered cartilage have been typically destructive. Indentation testing is a type of compressive test that offers a potential technique for in situ , non-destructive mechanical analysis of cartilage, and has been used in conjunction with arthroscopy and imaging techniques such as computed tomography, ultrasound (US), magnetic resonance spectroscopy, and x-ray to quantify characteristics such as the dynamic mechanical modulus, 6, 18, 73 cartilage thickness, 6, 18, 73 stiffness, 6, 46, 84, 120 and degeneration. 6, 18 Although in many of these accounts indentation testing was performed on harvested tissue, which does not directly demonstrate in vivo diagnostic capabilities for clinical translation, work is continually being done to minimize the invasiveness of this procedure to improve mechanical analysis and understanding of cartilage repair and degeneration.…”

“…However, the combination of indentation testing, histology, and, particularly imaging, may play an important role in validating the diagnostic capacity of each tool separately. 120 …”

Dynamic impact force and association with structural damage to the knee joint: An ex-vivo study

“…With the advent of magnetic resonance imaging, classifications for traumatic osteochondral injuries have been proposed that were consequently refined (Deutsch and Mink, 1990;Mink and Deutsch, 1989;Bohndorf, 1996Bohndorf, , 1999. In addition, ultrasound-based work on impact injuries to cartilage and the subchondral bone has been presented (Virén et al, 2009(Virén et al, , 2011(Virén et al, , 2012.…”