MRI spectrum of injuries to the thumb metacarpophalangeal joint ulnar collateral ligament with a proposed expanded classification of injuries in American football players.

Injuries to the ulnar collateral ligament of the thumb metacarpophalangeal joint are of both historic and modern interest for athletes and non-athletes alike. The thumb metacarpophalangeal joint requires stability in both flexion and extension utilizing a combination of static and dynamic stabilizers. This article reviews the magnetic resonance imaging categorization of thumb ulnar collateral ligament injuries and proposes two additional injury patterns seen in high-level and professional athletes who play American football. In addition to the direct magnetic resonance imaging findings in collateral ligament tears, secondary findings of rotation and subluxation can be seen at the thumb metacarpophalangeal joint due to the altered physiologic forces on the joint. Internal brace augmentation via suture tape of a traditional ulnar collateral ligament repair is a novel surgical technique that provides protection during initial healing and the ensuing remodeling phase following repair or reconstruction, resulting in a faster return to play.

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.

Posterior Root Meniscal Tears: Preoperative, Intraoperative, and Postoperative Imaging for Transtibial Pullout Repair.

The menisci play an important biomechanical role in axial load distribution of the knees by means of hoop strength, which is contingent on intact circumferentially oriented collagen fibers and meniscal root attachments. Disruption of the meniscal root attachments leads to altered biomechanics, resulting in progressive cartilage loss, osteoarthritis, and subchondral edema, with the potential for development of a subchondral insufficiency fracture. Identification of meniscal root tears at magnetic resonance (MR) imaging is crucial because new arthroscopic surgical techniques (transtibial pullout repair) have been developed to repair meniscal root tears and preserve the tibiofemoral cartilage of the knee. An MR imaging classification of posterior medial meniscal root ligament lesions has been recently described that is dedicated to the posterior root of the medial meniscus. An arthroscopic classification of meniscal root tears has been described that can be applied to the anterior and posterior roots of both the medial meniscus and the lateral meniscus. This arthroscopic classification includes type 1, partial stable root tears; type 2, complete radial root tears; type 3, vertical longitudinal bucket-handle tears; type 4, complex oblique tears; and type 5, bone avulsion fractures of the root attachments. Knowledge of these classifications and the potential contraindications to meniscal root repair can aid the radiologist in the preoperative reporting of meniscal root tear types and the evaluation of the tibiofemoral cartilage. As more patients undergo arthroscopic repair of meniscal root tears, familiarity with the surgical technique and the postoperative radiographic and MR imaging appearance is important to adequately report the imaging findings. ©RSNA, 2016.