Sonoanatomy and Stepwise/Systematic Ultrasound Examination of the Extrinsic/Intrinsic Wrist Ligaments

Ultrasound has emerged as the most useful imaging tool for investigating wrist and hand disorders, with several published ultrasound protocols having demonstrated their practicality in scanning the wrist tendons and nerves. However, ligaments of the wrist are networked in a complex manner, deterring sonographers from examining them with an organized strategy. Furthermore, because of the non-parallel alignment between the radiocarpal, mid-carpal, and carpal–metacarpal joints, precise recognition of the carpal bones is challenging, although ultrasound is paramount for visualizing the wrist ligaments. In this regard, the current article for point of view aims to elaborate sonoanatomy of the carpal bones and to present a stepwise systematic approach for navigating the extrinsic and intrinsic wrist ligaments.

How to Report: Wrist MRI

Knowledge of the imaging anatomy of the wrist is essential for reporting magnetic resonance imaging (MRI). This familiarity should include the carpal bones, tendons (extensor and flexor compartments), triangular fibrocartilage complex (TFCC), intrinsic and extrinsic ligaments, and nerves, especially the median and ulnar nerves. Limitations of MRI in visualizing these structures, particularly the intrinsic ligaments and the TFCC, need to be considered. This article outlines the main features to comment on when reporting common conditions of the wrist on MRI, with some examples of terminology that can be used to describe these abnormalities.

Osteonecrosis of carpal bones in systemic sclerosis

Background. Systemic sclerosis (SSc) is a rare chronic disease, with unknown aetiology and complex pathogenesis. The hand is often implied in the main clinical findings, being affected primarily by the vascular component (Raynaud phenomenon, digital ulcers). One of the possible complications of the hand vasculopathy is osteonecrosis (ON) of the carpal bones. In these cases, the lunate is the most frequently affected, followed by the scaphoid. In the ON process, not only the vascular supply is important, but the nearby mechanical factors and anatomic variants of the wrist. Our objective was to reveal the most important aspects regarding the ON of the carpal bones in patients with SSc. Methods. A systematic literature review was performed through July 31, 2021 on Pubmed and Cochrane databases. The eligible articles were read in full text and were included in this paper, in the absence of exclusion criteria and after consensus between two reviewers. Results. Ten articles met the inclusion criteria, their main results being described in this review. In all studies, ON of the lunate and the scaphoid is associated with advanced SSc and severe Raynaud phenomenon. Conclusions. In conclusion, carpal ON is a rare complication of SSc, especially of the diffuse type. There is limited data on this condition, its prevalence being difficult to estimate due to the lack of symptoms.

Surgical Solution for Total Carpectomy due to Destructive Wrist Pan-Osteomyelitis Using a Free Femoral Condyle Osteocutaneous Flap for Wrist Arthrodesis

Osteomyelitis of the hand is rare, even more so in the carpal bones. Patients with rheumatoid arthritis (RA) have a higher infection rate overall, and up to a 14-fold increase in the incidence of septic arthritis of the hand. The destruction of immunologic barriers, such as cartilage and joint capsules, as well as the use of immunosuppressive medications will have an impact on the higher incidence of articular infections and osteomyelitis in these patients. Infection in these cases is often overlooked because of the similarity of presentation to an acute event of RA. When osteomyelitis is present, rapid and aggressive treatment should be given. Surgical debridement, lavage, and excision of necrotic bone is the best choice, followed by cemented antibiotic impregnated spacer to resolve the acute scenario. Vascularized bone grafts (VBG) can then be used for a definitive solution, as these have great biologic properties that increase the possibility of a good outcome. We hereby present a report of a wrist arthrodesis, using a free medial femoral condyle VBG for the treatment of destructive osteomyelitis of the carpal bones in a female patient with RA.

Stiffening in the carpus of Prosantorhinus germanicus (Perissodactyla, Rhinocerotidae) from Sandelzhausen (Germany)

Prosantorhinusgermanicus is a small, short-legged, teleoceratine rhino from the Miocene of Sandelzhausen (Bavaria, Germany). P.germanicus shows a high variation in some of its carpal bones. A unique modification of the articulation of Intermedium and Carpale 4 is described here. Special emphasis is given to additional articulation facets at the palmar processes of both bones. These additional contacts, working as stop facets, are unique among rhinos and restrict the flexion of the mid-carpal joint. Some individuals show these additional facets which prohibit the flexion within the wrist and therefore stiffen the carpus. Carpale 4 specimens without the additional facets show knob-like structures instead. These knobs are most likely precursory structures of those facets and the facets are fully developed in heavier males. A skeletal sexual dimorphism is not visible in the sample as all bones are in the same size range. The wrist stiffening in the mid-carpal joint supports a greater bodyweight and therefore could coincide with P.germanicus as a proposed dwarfed rhinoceros species. The stiffening can also be interpreted in favor of a semiaquatic mode of life. The stiffened carpus is more resistant against injuries while walking on muddy grounds in a wet environment.

Unilateral congenital lunate absence: A case report

Isolated congenital aplasia of carpal bones in the absence of an associated congenital syndrome is exceedingly rare. Since the first documented case report of congenital carpal bone absence in 1911, only 12 additional case reports have been published. Here we present a case report of an otherwise healthy 43-year-old male with unilateral congenital absence of the lunate, which has only been previously reported once in the literature.

Internal Mechanics of a Subject-Specific Wrist in the Sagittal Versus Dart-Throwing Motion Plane in Adult and Elder Models: Finite Element Analyses

Introduction: Most of the wrist motions occur in a diagonal plane of motion, termed the dart-throwing motion (DTM) plane; it is thought to be more stable compared with movement in the sagittal plane. However, the effect of the altered carpus motion during DTM on the stress distribution at the radiocarpal joint has yet to be explored. Aim: To calculate and compare the stresses between the radius and two carpal bones (the scaphoid and the lunate) in two wrist positions, extension and radial extension (position in DTM), and between an adult and an elder model. Methods: A healthy wrist of a 40-year-old female was scanned using Magnetic Resonance Imaging in two wrist positions (extension, radial extension). The scans were transformed into three-dimensional models and meshed. Finite element (FE) analyses in each position of the wrist were conducted for both adult and elder models, which were differentiated by the mechanical properties of the ligaments. The distal surfaces of the carpal bones articulating with the metacarpals were loaded by physically accurate tendon forces for each wrist position. Results: The von Mises, shear stresses and contact stresses were higher in the extension model compared with the radial-extension model and were higher for the radius-scaphoid interface in the adult model compared with the elder model. In the radius-scaphoid interface, the stress differences between the two wrist positions were smaller in the elder model (11.5% to 22.5%) compared with the adult model (33.6–41.5%). During radial extension, the contact area at the radius-lunate interface was increased, more so in the adult model (222.2%) compared with the elder model (127.9%), while the contact area at the radius-scaphoid was not affected by the position of the wrist in the adult model (100.9%) but decreased in the elder model (50.2%) during radial extension. Conclusion: The reduced stresses during radial extension might provide an explanation to our frequent use of this movement pattern, as the reduced stresses decrease the risk of overuse injury. Our results suggest that this conclusion is relevant to both adults and elder individuals.

Comprehension of Midcarpal Instability

The midcarpal instability is the state with instability between the proximal and distal carpal rows, without dissociation between carpal bones. It can be divided into the intrinsic one that is caused by ligament hyperlaxity, and extrinsic one that is caused secondarily by the malunion of distal radius. The pathophysiology of the intrinsic one is still unknown, and the treatment is also controversial. On the other hand, the extrinsic one can be treated by corrective osteotomy of the radial malunion. This review investigated the comprehension, definition, classification, symptoms, diagnosis, and treatment of the midcarpal instability.