E2265. Wrist Instability: A Radiology Story Beyond Terry Thomas
Wrist instability is a frequently encountered entity in clinical practice. Knowledge of the complex anatomy of the wrist is essential for the radiologist to understand the various pathologies resulting in biomechanical instability. Failure to diagnose and treat wrist instability in a timely fashion may cause carpal collapse and a significant morbidity. This presentation aims to provide the radiologist with practical knowledge to assist in the diagnosis of these conditions through an image rich case-based presentation demonstrating the spectrum of pathology, causes, and complications associated with wrist instability. This educational exhibit will focus on detailed anatomy with the help of illustrations and clinical radiographs, CT and MRI.
Educational Goals / Teaching Points
Radiographs are the usual initial imaging exam in the setting of wrist instability as the preferred screening exam for wrist trauma or chronic pain. Once wrist instability is observed or suspected, follow-up CT and MRI exams are performed to assess for fractures and degree of ligamentous injury. While late stage disease is often evident, early and less-advanced disease can present as a diagnostic challenge. With relatively complex radiographic manifestations, diagnosis of wrist fractures and dislocations require a high level of suspicion and a thorough knowledge to proceed with more expensive and advanced imaging like CT and MRI. This presentation aims to provide a review of both the subtle and obvious findings of carpal instability on radiographs, along with correlation of those findings with CT and MRI. This multimodality correlation will provide the audience with a better understanding of complex disease states.
Key Anatomic/Physiologic Issues and Imaging Findings/Techniques
The wrist has a complex anatomy composed of multiple small bones and joints. These joints are supported and stabilized by countless extrinsic and intrinsic ligaments. Instability of the wrist can be the result of traumatic or non-traumatic disease. Wrist instability results in modification of the osseous, ligamentous, muscular, and articular structures and may lead to chronic pain and degeneration. One of the common causes of carpal instability is scapholunate dissociation caused by scapholunate ligament disruption. The exhibit is inclusive of entities such as non-united scaphoid fracture and avascular necrosis of the lunate which intrinsically destabilize the wrist, resulting in instability. Lunate, peri lunate or mid-carpal pattern of dislocation are amongst other common causes of instability. Persistent disarticulation results in progressive osteoarthritis manifested as scapholunate or scaphoid non-union advanced collapse. Treatment options like four corner fusion and proximal carpectomy, used in treatment of advanced disease, will also be discussed as they may pose diagnostic challenge for non-musculoskeletal radiologists.
Knowledge of the radiological findings of carpal instability is essential, since timely management could prevent end stage disease. Radiographs are essential in screening early cases, followed by advanced imaging, like CT and MR, to precisely delineate the underlying pathology.