BACKGROUND: The risk of carpal injury in racehorses may be related to the morphology, yet whether carpal morphologies are set from birth or change through growth remains unclear.
OBJECTIVE: To quantify carpal bone changes through growth.
METHODS: Twenty privately owned Thoroughbred foals born between January 2022 and May 2023 were radiographed bimonthly from birth to 10 months of age. Imprint training was used to take radiographs safely without chemical restraints. Fifteen individual and 11 relative angular carpal parameters were measured using ImageJ on dorsopalmar radiographs of the carpus at zero degrees of vertical and horizontal rotation. Associations with age (growth), sex and the differences between left and right limbs were analysed separately using a linear mixed effects model.
RESULTS: Six individual carpal parameters changed with age (radial carpal joint [RCJ], Prx.dor. radial carpal [Cr], Prx.Cu, Dis.dor. third carpal [C3], Dis.pal.C3 and Dis.pal. intermediate carpal), and one was influenced by side, that is higher in the left carpus (Dis.pal.Cr). Seven relative parameters changed with age, and one relative parameter was influenced by side, that is higher in the left (Ra.met-RCJ). The proximo-dorsal bone surface angle of Cr and disto-dorsal bone surface angle of C3 became flatter over time, which may be associated with the re-direction of the load towards the sagittal carpal plane. Sex did not influence any of the carpal parameters, nor did the combined effect of age, side of the limb and sex.
CONCLUSIONS: Specific individual and relative angular carpal parameters changed significantly over time and some differed between the left and right limb, whereas other parameters did not change. The steeper carpal bone angles achieved proximally with the parameters that did change may improve stability by redirecting the load more medially through the carpus and the proximal and distal bones.

Background: Factors such as age and joint structure affect normal wrist motion. The midcarpal joint participates in flexion/extension, radial-ulnar/deviation (RUD), and since lunate/wrist type-2 is likely more stable than a lunate/wrist type-1, we suggest that midcarpal joint structure will affect wrist motion. Our purpose was to compare wrist motion in Caucasian and Japanese populations and to associate motion with midcarpal joint morphology. We hypothesised that radiographic structure would correlate with wrist motion. Methods: A total of 164 patients with normal wrist radiographs were included. Clinical measurements included wrist extension, flexion and RUD. Radiographic measurements included the radiocarpal joint: ulnar variance, radial height, radial inclination, volar inclination and carpal joint measurements: lunate type, capitate circumference and each of its joints contact measured and calculated as a proportion of capitate circumference. Results: The groups differed in wrist motion and in multiple radiographic measurements. When the two populations were analysed together, there were no significant associations between midcarpal joint type and wrist motion. The radiocarpal joint: ulnar variance was correlated with extension and radial deviation. Radial height was directly related to flexion, and both radial height and radial inclination were directly correlated with ulnar deviation. The intracarpal measurements: The main measurement affecting motion was the contact between the capitate and the scaphoid (as a proportion of capitate circumference) with lesser correlations of the contact of the capitate with the trapezoid and hamate. The most significant measurement associated with a lunate type-2 was scaphoid contact with the capitate p = 0.01. Logistic regression demonstrated that the measurements most associated with wrist motion were scaphoid contact with the capitate/capitate circumference and hamate contact with the capitate/capitate. Conclusions: This study supports discrepancies in wrist motion amongst different racial cohorts, and a relationship between bone/joint structure in the wrist and wrist motion. This can help treat wrist pathology. Level of Evidence: Level III (Diagnostic).

Trait functionality can act as a constraint on morphological development. Traits that become vestigialized can exhibit unstable developmental patterns such as fluctuating asymmetry (FA) and variation in populations. We use clearing and staining along with morphometric analyzes to compare FA and allometry of limbs in Western lesser sirens (Siren nettingi) to Ouachita dusky salamanders (Desmognathus brimleyorum). Our results describe new carpal phenotypes and carpal asymmetry in our sample of S. nettingi. However, we found no significant evidence of limb length asymmetry in S. nettingi. The degree of relative limb asymmetry correlates inversely with body size in both of our samples. This work provides strong evidence of increased mesopodal variation within a population of S. nettingi. Our work provides a basis for further study of a broader range of morphological traits across salamanders.

BACKGROUND: The wrist joint is a complex anatomical structure, and various radiographic parameters are utilized to assess its normal alignment and orientation. Among these parameters are carpal height ratio (CHR) and ulnar variance (UV). Previous literature has indicated that factors such as age and gender may influence these parameters; However, there is a lack of studies investigating these differences specifically in the Middle East or Jordan. Additionally, no prior research has explored the relationship between UV and CHR. Therefore, the objective of this study is to investigate these critical radiological parameters and their associations.
METHODS: A cross-sectional study design was employed, wherein a total of 385 normal wrist X-rays were reviewed, and CHR and UV were measured. Intra-observer and inter-observer reliability assessments were conducted to ensure the consistency and accuracy of measurements. Additionally, the association between UV and CHR was measured and plotted for further analysis.
RESULTS: In our study, the mean CHR was 0.5 (range: 0.4 to 1.5), and the mean UV was - 0.3 mm (range: -5.8 mm to 4.1 mm). We found a significant negative correlation between CHR and age (p < 0.05). No significant gender differences were observed in UV and CHR. Additionally, a weak positive correlation was found between UV and CHR (Pearson correlation coefficient = 0.13, p = 0.01; adjusted R2 = 0.014, p = 0.02).
CONCLUSIONS: Age correlated significantly with a decline in carpal height ratio. Additionally, ulnar variance had a week positive yet significant correlation with carpal height ratio.
METHODS: Cross-sectional study, Level III.

UNASSIGNED: Pigmented Villonodular Synovitis (PVNS) is a rare disease of osteoskeletal tissue. Cytodiagnosis of PVNS on fine needle aspiration (FNA) smears is therefore rarely reported. The PVNS usually affects the larger joints. The involvement of the smaller joints and bones are uncommon.
UNASSIGNED: The reported case is one such rarity wherein the diagnosis of PVNS was carried out on the FNAC. The case showed the involvement of all carpal bones except for the pisiform. The 2 nd- 5 th metacarpal bases were also found to be involved in the disease process. The presence of sheets of synoviocytes with brown altered hue to the cytoplasm along with multinucleate giant cells and pigmented macrophages were characteristically present in the smears of FNA. The diagnosis was confirmed on the tissue biopsy. The present case is reported for its unusual multiosteotic involvement of wrist joint bones and the metacarpal bones simultaneously with radiological evidence. The cytomorphology of the lesion in the present case were noteworthy as a learning experience in reporting of PVNS of wrist joint on FNA smears.

The complexity of wrist anatomy and mechanics makes it challenging to develop standardized measurements and establish a normative reference database of wrist biomechanics despite being studied extensively. Moreover, heterogeneity factors in both demographic characteristics (e.g. gender) and physiological properties (e.g. ligament laxity) could lead to differences in biomechanical behaviour even within healthy groups. We investigated the kinematic behaviour of the carpal bones by creating a virtual web-like network between the bones using electromagnetic (EM) sensors. Our objective was to quantify the changes in the carpal bones\' biomechanical relative motions and orientations during active wrist motion in the form of orb-web architecture. Models from five cadaveric specimens at different wrist positions: (1) Neutral to 30° Extension, (2) Neutral to 50° Flexion, (3) Neutral to 10° Radial Deviation, (4) Neutral to 20° Ulnar Deviation, and (5) Dart-Throw Motion - Extension (30° Extension/10° RD) to Dart-Throw Motion Flexion (50° Flexion/20° UD), in both neutral and pronated forearm have been analyzed. Quantification analyses were done by measuring the changes in the network thread length, as well as determining the correlation between the threads at different wrist positions. We observed similarities in the kinematic web-network patterns across all specimens, and the interactions between the network threads were aligned to the carpal bones\' kinematic behaviour. Furthermore, analyzing the relative changes in the wrist web network has the potential to address the heterogeneity challenges and further facilitate the development of a 3D wrist biomechanics quantitative tool.

Septic arthritis is common in newborn calves due to poor birth and housing hygiene. This study investigated the pathological deformities caused by arthritis in the carpal bones of calves using geometric morphometry. The changes in the carpal joint bones of newborn calves with septic arthritis were examined through shape analysis. The study included 20 healthy Simmental calves and 30 Simmental calves with septic arthritis. Dorso-palmar x-ray images of the carpal joint were taken, and geometric morphometry was performed on these images using 25 landmarks. The first principal components (PC1) represented 26.92% of the total variation, while PC2 represented 13.84%. One of the most significant shape changes with increasing PC1 occurred in the os carpi intermedium. The study found that it was statistically possible to discriminate between radiometric carpal joint images of Simmental calves in the control and arthritis groups using geometric morphometry. In newborn calves with septic arthritis, the trochlea radi was located more proximally. There was an enlargement of the os carpi intermedium and a tendency towards the os carpi ulnare in female calves with septic arthritis. These results indicate significant bone deformation due to septic arthritis. Geometric morphometric methods can be clinically useful, as demonstrated in this study. Researchers can statistically explore these shape analyses, opening new avenues for research in this field. This method not only enhances our understanding of morphological changes but also provides a framework for clinical investigations and discoveries in related areas.

BACKGROUND: Four-corner arthrodesis with scaphoid excision (FCA) and proximal row carpal resection (PRC) are frequently performed in wrists with post-traumatic Scaphoid Non- Union Advanced Collapse (SNAC)/Scapho-Lunate Advanced Collapse (SLAC) osteoarthritis. The aim of this study was to compare the clinical outcomes of these two procedures.
METHODS: This single-center, retrospective cohort study included all patients who had PRC or FCA between January 1st, 2009 and January 1st, 2019 and who were followed up. Follow-up included: mobility (radial deviation, ulnar deviation, flexion, extension), strength (grip test, pinch test), function (QuickDash, patient-rated wrist evaluation [PRWE]), subjective mobility, and global satisfaction scores.
RESULTS: Among 25 patients included, 11 had PRC and 14 had FCA with a mean follow-up of 69.5 months [12-132]. Radial deviation was 18° versus 14° (p = 0.7), ulnar deviation was 21° versus 22° (p = 0.15), flexion was 39° versus 30° (p = 0.32), extension was 32.5° versus 29.5° (p = 0.09), grip test compared to the controlateral side was 72% versus 62% (p = 0.53), Quick Dash score was 12.5 versus 17.6 (p = 0.84), PRWE was 18.7 versus 17.6 (p = 0.38), subjective mobility was 7.8 versus 7.5 (p = 0.23), and satisfaction score was 8.7 versus 9 (p = 0.76), respectively, in the FCA group and the PRC group. Re-operation rates were 14% patients in the FCA group and 0% in the PRC group.
CONCLUSIONS: This study found no significant difference between FCA and PRC on strength, mobility, and function in patients with post-traumatic SLAC or SNAC stage II wrist arthritis. Both FCA and PRC seem to be reliable surgical techniques with good outcomes with more revision in the FCA group.

OBJECTIVE: To describe the successful surgical management of a previously unreported Salter-Harris type I fracture of the accessory carpal bone in a dog.
METHODS: An 11-week-old intact female Golden Retriever-Poodle cross presented with a history of a marked left forelimb lameness following a suspected fall from a height.
UNASSIGNED: On physical examination, the patient demonstrated a severe left forelimb lameness and pain on palpation and range of motion of the left carpus. Orthogonal radiographs of the distal left forelimb demonstrated a type I Salter-Harris fracture of the accessory carpal bone with proximal displacement of the palmar fragment.
RESULTS: The patient underwent open reduction and internal fixation wherein the fracture was reduced and stabilized with two 1.1-mm Kirschner wires. Postoperatively, the patient was initially managed with a carpal flexion bandage for 2 weeks and then a soft padded bandage was maintained until 4 weeks postoperatively. The patient recovered well and was walking and weight-bearing comfortably following removal of the carpal flexion bandage. Repeat radiographs performed 4 and 8 weeks postoperatively demonstrated adequate fracture healing but showed mild proximocaudal implant displacement. Implant removal was not performed, as the patient was doing well at home and the implant migration appeared static and was not causing clinical morbidity.
CONCLUSIONS: To the authors\' knowledge, this was the only reported case of a Salter-Harris fracture of the accessory carpal bone in a dog and the only described case of successful surgical stabilization.

UNASSIGNED: Perilunate dislocations are rare high-energy injuries which may often have the potential to cause lifelong disability of the wrist if not addressed optimally. Hence, early recognition, diagnosis, and intervention are of paramount importance in the restoring function and prevention of morbidity. Lunate dislocations are the fourth and last stage of perilunate dislocations being extremely rare, with volar dislocations representing <3% of perilunate dislocations.
UNASSIGNED: A 24-year-old man suffered from an alleged history of fall from a bike on an outstretched hand following which he developed complaints of pain and swelling in the right wrist. On examination, the patient has relative sensory loss over the lateral half of the palm with no vascular deficit. An accurate range of motion could not be documented due to severe pain. Standard digital X-rays revealed lunate displaced and angulated volarly with a typical \"spilled teacup\" appearance along with radial and ulnar styloid fractures.
UNASSIGNED: The patient was initially given an attempt of closed reduction which was not successful and was followed with open reduction and internal fixation with both volar and dorsal approach with Kirschner wires. The patient\'s wrist was immobilized for 6 weeks with below elbow cast with the removal of k wires at 8 weeks after which wrist ROM exercises were started.
UNASSIGNED: The patient was followed up for 6 months and now has a functional range of motion of the wrist with no sensory deficit and is able to continue with his profession as a car mechanic.
UNASSIGNED: Mayfield progression Stage 4 perilunate dislocations are uncommon with a poor prognosis if not addressed timely. Hence, these injuries need to be identified early and optimally managed with surgical intervention for a favorable outcome.