Imaging of Cartilage and Chondral Defects: An Overview

Abstract

A healthy articular cartilage is paramount to joint function. Cartilage defects, whether acute or chronic, are a significant source of morbidity. This review summarizes various imaging modalities used for cartilage assessment. While radiographs are insensitive, they are still widely used to indirectly assess cartilage. Ultrasound has shown promise in the detection of cartilage defects, but its efficacy is limited in many joints due to inadequate visualization. CT arthrography has the potential to assess internal derangements of joints along with cartilage, especially in patients with contraindications to MRI. MRI remains the favored imaging modality to assess cartilage. The conventional imaging techniques are able to assess cartilage abnormalities when cartilage is already damaged. The newer imaging techniques are thus targeted at detecting biochemical and structural changes in cartilage before an actual visible irreversible loss. These include, but are not limited to, T2 and T2* mapping, dGEMRI, T1 imaging, gagCEST imaging, sodium MRI and integrated PET with MRI. A brief discussion of the advances in the surgical management of cartilage defects and post-operative imaging assessment is also included.

MRI Features That Contribute to Decision-Making for Treatment of Capitellar OCD Lesions: An Expert Consensus Using the Delphi Method

“…While not universally agreed upon, most orthopaedic surgeons utilized non–fat saturated sequences for geographic qualities and fluid-sensitive sequences for chondral and subchondral evaluation. 8 , 22 Some experts felt that additional sequences were beneficial as part of their review and endorsed the use of gradient echo, often referred to as GRE. However, many experts did not routinely review these sequences or have them available for their MRI assessment.…”

A New Approach to Postoperative Rehabilitation following Mosaicplasty and Bone Marrow Aspiration Concentrate (BMAC) Augmentation

“…According to Nischal et al, MRI stands out as the most dependable tool for evaluating chondral lesions. Additionally, MRI plays a vital role in monitoring progress following the surgical management of cartilage defects and in assessing post-surgical outcomes [ 41 ]. The modified Outerbridge classification is used to assess the cartilage defects of traumatic etiology based on MRI in a clinical scenario, based on the arthroscopic assessment of the knee.…”

Management of Articular Cartilage Defects in the Knee: An Evidence-Based Algorithm

“…There are several intraoperative classification systems to grade severity of chondral defects, including the Outerbridge arthroscopic system and the International Cartilage Repair Society (ICRS) classification system 18,19 . The Outerbridge system is graded on a scale of 0 to 4, with 0 representing normal articular cartilage and 4 representing full-thickness chondral defects, exposed subchondral bone, and reactive bone changes 19 (Table I). The ICRS classification system also grades osteochondral defects intraoperatively on a zero to 4 scale, with zero indicating intact cartilage and 4 indicating a full-thickness cartilage defect, including the subchondral bone plate 20 (Table II).…”

“…Lesions are typically defined by defect size and severity, with common size cutoffs cited in the literature (small, <2 cm 2 ; medium, 2 cm 2 to 5 cm 2 ; and large, >5 cm 2 ) 17 . There are several intraoperative classification systems to grade severity of chondral defects, including the Outerbridge arthroscopic system and the International Cartilage Repair Society (ICRS) classification system 18,19 . The Outerbridge system is graded on a scale of 0 to 4, with 0 representing normal articular cartilage and 4 representing full-thickness chondral defects, exposed subchondral bone, and reactive bone changes 19 (Table I).…”