The Origin and Meaning of "Intercalated Segment"

Imaging Diagnosis and Management of Carpal Trauma and Instability-An Illustrated Guide

Understanding the subtle signs of carpal instability and other unique injury patterns in the wrist is a critical skill for radiologists. Proper patient management and outcomes are directly dependent on the accurate interpretation of wrist imaging studies. This review will provide a detailed overview of typical imaging features of carpal trauma and instability, management, and complications, using multimodality imaging and original medical illustrations. A detailed overview of the osseous, ligamentous, arterial anatomy of the wrist, arcs of Gilula, and zones of vulnerability will be provided. Carpal fractures, dislocations, special radiographic views, and imaging pearls will be discussed. Instability patterns and the myriad of associate abbreviations (CID, CIND, CIC, CIA, VISI, DISI, SLD, LTD, MCI, SLAC, SNAC) will be clarified. Expected outcomes, potential complications, and management will be reviewed.

Forearm muscle activity estimation based on anatomical structure of muscles

Estimation of muscle activity using surface electromyography (sEMG) is an important non-invasive method that can lead to a deeper understanding of motor-control strategies in humans. Measurement using multiple active electrodes is necessary to estimate not only surface muscle activity but also deep muscle activity in dynamic motion. In this paper, we propose a method for estimating muscle activity of dynamic motions based on anatomical knowledge of muscle structures. To estimate muscle activity, a large number of signal sources are set in the muscle model, and connections between the signal sources are defined a priori based on the anatomical structure of the muscles. The signal source activities are first estimated by minimizing the Kullback-Leibler divergence with a continuity cost. Then, the muscle activity is computed from the signal source activity. In the experiments, five healthy participants performed five types of motion and the forearm sEMG was measured with 20-channel active electrodes. The estimation results for these motions were visualized in four dimensions as the three-dimensional position of the muscle over time. The results showed that the estimation was accurate, with a reproduction rate of 95% for the measured sEMG and continuity of the muscle activity. In addition, the results suggest the advantage of the proposed method over the conventional approaches in terms of estimating the muscle activity for both dynamic and abnormal motions.

Perilunate Injuries: Current Aspects of Management

Perilunate dislocations (PLD) and perilunate fracture dislocations (PLFD) are high-energy injuries which can result in long-term complications and significant disability. Early identification of these injuries, followed by prompt, appropriate management is key to optimising patient outcomes. Knowledge of the carpal anatomy is essential in order to understand the varied patterns of injury and plan appropriate definitive management. Emergent reduction and close monitoring of the median nerve, followed by prompt stabilisation or repair of the injured structures remain the mainstay of treatment. In this review, we present a summary of the current evidence regarding the identification and management of these complex injuries.

Imaging evaluation of traumatic carpal instability

PURPOSE

To review the epidemiology, pertinent wrist anatomy, classification system, and emergent imaging evaluation of carpal instability with a focus on radiographic assessment of instability.

METHODS

A review of current literature on carpal instability was performed with summary presentation of carpal instability epidemiology, carpal anatomy, imaging evaluation, and classification with imaging evaluation focused on diagnosis in the emergency setting.

RESULTS

Carpal instability is a common pathology in falls on outstretched hand and is likely underdiagnosed due to instability being occult or demonstrating subtle malalignment on static imaging of the wrist. While there is a complex network of intrinsic and extrinsic ligaments contributing to carpal instability, a detailed knowledge of these ligaments is not necessary for radiologists to make an accurate diagnosis in the emergency setting, as identification and classification of carpal instability is based on identification of carpal malalignment patterns on radiography as opposed to identification of specific ligament injuries on advanced imaging. The Mayo classification is the most widely used classification system, which divides carpal instability into four categories: dissociative, non-dissociative, complex, and adaptive. Understanding this classification system allows radiologists to successfully classify almost all carpal instability injuries they will encounter, even in the setting of unusual or rare instability patterns.

CONCLUSION

In working with the treating clinician, it is essential that the emergency radiologist is comfortable with identifying and classifying carpal instability. This will ensure prompt treatment of seemingly benign injuries and those that require intervention, surgical or otherwise, improving the likelihood of a good outcome.

Treatment of Acute Carpal Bone Fractures

Carpal bone fractures are common hand fractures that can be complicated by concomitant damage to surrounding structures, chronic comorbidities, or delays in diagnosis. This article provides an overview of wrist anatomy, an expedited review of the athlete's presenting condition, and a systematic approach to the evaluation of the wrist. Recommended treatment plans are based on a review of the literature and an evidence-based approach to imaging studies. It is imperative that sports medicine providers be aware of current literature for carpal bone fractures and collaborate with other medical subspecialties and the athlete to provide recommendations for a safe return to play.

Rehabilitation for scapholunate injury: Application of scientific and clinical evidence to practice

In this article, the development of a rehabilitation approach is describe using scapholunate injury as a model. We demonstrate how scientific and clinical evidence is applied to a treatment paradigm and modified based on emerging evidence. Role of the scapholunate interosseous ligament within the pathomechanics of the carpus, along with the progression of pathology, and specific rehabilitation algorithms tailored to the stage of injury. We review the recent and current evidence on the kinematics of wrist motion during functional activity, role of the muscles in providing dynamic stability of the carpus, and basic science of proprioception. Key relevant findings in each of these inter-related areas are highlighted to demonstrate how together they form the basis for current wrist rehabilitation. Finally, we make recommendations for future research to further test the efficacy of these approaches in improving functional outcomes.