Quantitative bone marrow lesion, meniscus, and synovitis measurement: current status

Imaging plays a pivotal role in osteoarthritis research, particularly in epidemiological and clinical trials of knee osteoarthritis (KOA), with the ultimate goal being the development of an effective drug treatment for future prevention or cessation of disease. Imaging assessment methods can be semi-quantitative, quantitative, or a combination, with quantitative methods usually relying on software to assist. The software generally attempts image segmentation (outlining of relevant structures). New techniques using artificial intelligence (AI) or deep learning (DL) are currently a frequent topic of research. This review article provides an overview of the literature to date, focusing primarily on the current status of quantitative software-based assessment techniques of KOA using magnetic resonance (MR) imaging. We will concentrate on the imaging evaluation of three specific structural imaging biomarkers: bone marrow lesions (BMLs), meniscus, and synovitis consisting of effusion synovitis (ES) and Hoffa's synovitis (HS). A brief clinical and imaging background review of osteoarthritis evaluation, particularly relating to these three structural markers, is provided as well as a general summary of the software methods. A summary of the literature with respect to each KOA assessment method will be presented overall as well as with respect to each specific biomarker individually. Novel techniques, as well as future goals and directions using quantitative imaging assessment, will be discussed.

Preoperative and Postoperative Imaging of Scapholunate Ligament Primary Repair and Modified Brunelli Reconstruction

Injury of the scapholunate ligament (SLL) complex can lead to scapholunate dissociation, characterized by scapholunate interval widening and volar rotary subluxation of the scaphoid. Loss of the mechanical linkage between the scaphoid and lunate results in carpal instability and eventual scapholunate advanced collapse (SLAC) arthropathy. SLL complex injuries vary from acute and traumatic to chronic and degenerative. A staging system can be used to guide treatment options for these injuries on the basis of the reparability of the SLL dorsal band, carpal alignment and malalignment reducibility, and cartilage damage. Preoperative imaging with radiography and MRI is a component of injury staging and aids in planning surgical procedures. If the SLL dorsal band is reparable, then direct primary ligament repair with dorsal capsulodesis or dorsal intercarpal (DIC) ligament transfer can be performed. If the SLL dorsal band is irreparable with normal alignment or reducible malalignment, then reconstruction can be performed. In the setting of irreducible malalignment or SLAC arthropathy, a salvage procedure can be performed. Knowledge of SLL primary repair and various reconstruction techniques is important not only when evaluating postoperative images but also for accurate description of SLL injuries and aiding the surgeon in treatment planning. The authors present the normal anatomy of the SLL complex, a staging classification of SLL injury with radiographic and MRI findings, and common surgical procedures. Special attention is given to the operative techniques and postoperative imaging appearances of primary SLL repair with DIC ligament transfer and modified Brunelli reconstruction. ^©RSNA, 2021.