Stress distribution pattern in the distal radioulnar joint before and after ulnar shortening osteotomy in patients with ulnar impaction syndrome

Qualitative assessment of cartilage degeneration and morphology of the sigmoid notch using T1rho and T2 mapping: a cross-sectional study

BackgroundThe morphology of radial sigmoid notch varies widely among individuals. It remains unclear whether variations in sigmoid notch morphology influence cartilage degeneration in this region. T1rho and T2 mapping, which are useful magnetic resonance imaging (MRI) methods to assess early cartilage degeneration, may help us evaluate the relationship between the morphology and cartilage degeneration of sigmoid notch.PurposeTo investigate the relationship between cartilage degeneration of radial sigmoid notch and its morphology.Material and MethodsWe investigated the dominant wrists of 40 healthy volunteers (mean age = 34.1 years) using 3-T MRI. We measured the inclination, depth, and width of the sigmoid notch on an axial multi-echo gradient-echo, and the ulnar head diameter on coronal T2-weighted images. T1rho and T2 values of the volar, central, and dorsal cartilages of the sigmoid notch were measured on coronal T1rho and T2 mapping. We evaluated the relationships of T1rho or T2 values of the three regions with age and morphological measurements using Pearson's correlation analysis and multiple linear regression analysis.ResultsThe T2 value of the dorsal sigmoid notch positively correlated with age and width of the sigmoid notch. Multiple linear regression analysis showed that older age and wider sigmoid notch significantly increased the dorsal T2 value.ConclusionA wider sigmoid notch and aging may induce cartilage degeneration in the dorsal sigmoid notch. This association can help future studies about distal radioulnar joint diseases.

The Transverse Sigmoid Notch Morphology Unravelled

Background: Several studies have described pathology in relation to transverse sigmoid notch morphology, using the Tolat transverse sigmoid notch classification. It is believed that the entire shape of a sigmoid notch can be described using Tolat sigmoid types. We hypothesised that the determination of the sigmoid notch shape (SNS) depends on the level of the transverse CT plane on the axial axis of the distal radius. The aim of this study was to determine and compare the transverse SNS on different axial CT levels in the same wrist. Methods: The transverse SNS of 53 participants were independently qualitatively classified by two researchers in accordance with the four morphologies described by Tolat et al. The SNS was determined at two levels on the axial axis of the distal radius; at the level of the most prominent part of Lister tubercle, determined on the sagittal plane and at the level of the 'smallest distance between the ulnar head and sigmoid notch' (SDUS). Results: Forty-seven percent of the wrists demonstrated different SNS types according to Tolat classification, depending on the axial level of the CT scan. Interobserver agreement on the transverse sigmoid shape was 87% at Lister tubercle and 85% at SDUS, which can both be interpreted as 'excellent'. Conclusions: Despite an excellent interobserver agreement, 47% of the study population had different transverse sigmoid notch types within the same wrist. We, therefore, conclude that Tolat transverse sigmoid classification may not be useful for the description of potential pathology in relation to the sigmoid notch morphology.

Computed tomography Osteoabsorptiometry: Review of bone density, mechanical strength of material and clinical application

Computed Tomography (CT) imaging is an effective non-invasive examination. It is widely used in the diagnosis of fractures, arthritis, tumor, and some anatomical characteristics of patients. The density value (Hounsfield unit, HU) of a material in computed tomography can be the same for materials with varying elemental compositions. This value depends on the mass density of the material and the degree of X-ray attenuation. Computed Tomography Osteoabsorptiometry (CTOAM) imaging technology is developed on the basis of CT imaging technology. By applying pseudo-color image processing to the articular surface, it is used to analyze the distribution of bone mineralization under the articular cartilage, evaluate the position of prosthesis implantation, track the progression of osteoarthritis, and determine the joint injury prognosis. Furthermore, this technique was combined with indentation testing to discuss the relationship between the high bone density area of the articular surface, the mechanical strength of the bone, and the anchorage stability of the implant, in addition to the study of the relationship between mechanical strength and bone density. This narrative study discusses the pre- and postoperative evaluation of medical device implantation position, orthopedic surgery, and the clinical treatment of bone injury and degeneration. It also discusses the research status of CTOAM technology in image post-processing engineering and the relationship between bone material and mechanical strength.