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.

Joint effusion is diagnostically important. The canine carpal joint effusion, which is sometimes difficult to detect clinically, has received less attention in diagnostic ultrasound (US) studies. The aim of the present study was to provide a description of the morphological appearance of the canine carpal joint cavities and recesses using US, radiography, helical computed tomography (CT) and three-dimensional volume rendering technique (3D-VRT) images and to prove the applicability of musculoskeletal US for the detection of artificial carpal joint effusion in dogs. The understanding of the characteristics of these structures in normal patients is essential in the diagnosis. Twenty-eight clinically and radiologically unremarkable canine carpal cadavers of different breeds were examined, representative images were selected and anatomical structures were labelled. The canine carpal joint cavities and in particular its recesses had a complex appearance with a basic structure found in all dogs: Antebrachiocarpal joint: dorsoproximal antebrachiocarpal recess, dorsodistal antebrachiocarpal recess, medial antebrachiocarpal recess, lateral antebrachiocarpal recess and five palmar antebrachiocarpal recesses. Middle carpal joint: two dorsal middle carpal recesses, medial common middle carpal and carpometacarpal recess, lateral common middle carpal and carpometacarpal recess, four palmar middle carpal recesses. The carpometacarpal joint had dorsal and palmar funnel-shaped and irregular, finely tubular extensions, the most prominent ran dorsal to metacarpal III, the maximum distal end represented the proximal metacarpal diaphysis. All recesses presented ultrasonographically as a generalized anechogenic to hypoechoic filled continuation of the articular capsule with an indistinct peripheral hypoechogenic to isoechogenic fine capsule, the synovial-connective tissue interface was difficult to identify. The novel results of this study provide the first morphological description of the ultrasonographic, radiographic and computed tomographic arthrographic appearance of the canine carpal joint cavities and recesses with different injection volumes. The canine carpal joint cavities and in particular its recesses had a complex appearance with a basic structure found in all dogs. The applicability of musculoskeletal US to visualize an artificial carpal effusion has been demonstrated. The results of this study, and in particular US, give the practitioner an advantage in visualizing joint effusion and assist in the decision to perform arthrocentesis.

PURPOSE OF THE STUDY The study aimed to propose an optimal based fl ap creation with the view to ensure long-term survival of the interposition arthroplasty. MATERIAL AND METHODS A total of 28 dorsal wrist capsules were collected from 16 cadavers (with age range at death 18 to 80 years, with no visible wrist pathology). Altogether 112 histological specimens were obtained from these 28 samples. Post-hoc Dunn\'s tests were used to analyse the percentage of vascularisation of individual sides of the dorsal capsule (circumference and area) at the 0.05 level of signifi cance. Spearmann\'s correlation analysis was used to assess the effect of age on vascularization of the dorsal wrist capsule. In cadavers in whom both capsules were collected, the limbs were compared. For the sake of comparison, the Wilcoxon matched pairs test was used. RESULTS Regarding statistical signifi cance, the largest share of the total circumference and area of the measured vessels of the dorsal capsule is constituted by the distal side (35.2% of the circumference and 30.9% of the area). The blood supply of the dorsal capsule received on the ulnar side is the lowest (12.9% of the circumference and 17.6% of the area). There was no signifi cant effect of age on vascularization of the dorsal wrist capsule confi rmed. Also, the comparison of vascularization of both limbs from a single cadaver did not yield any statistically signifi cant results. DISCUSSION Proximal row carpectomy is a long-established surgical technique used to manage the degenerative changes in the wrist. Our results showed the best vascularization on the distal and radial sides of the dorsal wrist capsule. In this light, the distally-based fl ap or the fl ap described by Berger, which respects the clinically important ligaments, appear to be the least invasive and help maintain the future stability of the wrist. CONCLUSIONS In clinical practice, we advise that a radially-based fl ap according to Berger is created and the distal side of the dorsal capsule, the most vascularized portion based on our results, is preserved as much as possible. The fl ap created in this manner also preserves the important carpal ligaments and appears to the authors of this study to be the most benefi cial, also with respect to the presence of the largest arteries, contrary to the distal side. Another option is to use a distally-based fl ap for interposition arthroplasty. Key words: interposition arthroplasty, proximal row carpectomy, vascularization, degenerative changes, wrist.

BACKGROUND: This study focuses on the relationship between forearm muscles, carpal ligaments, and their impact on scapholunate joint stability across varying forearm rotations. This is crucial for optimizing pre and postoperative rehabilitation strategies for scapholunate joint dysfunction.
OBJECTIVE: Our study aims to understand the kinetic influence of forearm muscles on scapholunate joint instability. We emphasize the significance of forearm rotation to enhance treatment efficacy.
METHODS: We conducted an experimental study to understand how forearm muscles contribute to the stability of the scapholunate joint during different degrees of forearm rotation and we focused on the joint effect of muscle groups rather than individual muscles for treatment protocols.
RESULTS: Our findings shed light on the conservative treatment of dynamic scapholunate instability and the postoperative rehabilitation of scapholunate ligament repair. We found that the effect of forearm muscles significantly contributes to preserve stability in the scapholunate joint across various forearm rotational positions. These insights have practical implications for hand therapists, offering innovative strategies to enhance clinical practice.
CONCLUSIONS: This research underscores the importance of considering forearm rotation when developing rehabilitation protocols for scapholunate joint instability and provides a valuable perspective in line with current rehabilitation principles.

BACKGROUND: Recent research interest has grown in exploring the role of muscles, isometric contraction, proprioception, and neuromuscular control in addressing dynamic scapholunate and lunotriquetral joint instability, marking a shift in the understanding of wrist stability.
OBJECTIVE: To present a comprehensive review of the carpal ligaments anatomy and wrist biomechanics, with a particular focus on the role of proprioception in dynamic carpal stability and their role in managing scapholunate (SL) and lunotriquetral (LTq) dynamic instabilities.
METHODS: We conducted a systematic search of the literature and review of the most relevant papers published and indexed in pubmed, related to wrist biomechanics, proprioception and its contribution to carpal dynamic stability.
METHODS: The study involved a comprehensive review of neuromuscular mechanisms in dynamic stabilization of the carpus, based on cadaver studies. The 3D position of the scaphoid, triquetrum, and capitate was monitored before and after tendon loading.
RESULTS: The extensor carpi ulnaris (ECU) and the flexor carpi radialis (FCR) are identified as the primary pronators of the midcarpal joint. The ECU\'s pronation effect can potentially strain the scapholunate ligament, while the supinator muscles, the abductor pollicis longus (APL), the extensor carpi radialis longus (ECRL), and the flexor carpi ulnaris (FCU), have a protective role, particularly in cases of scapholunate ligament dysfunctions. The FCR, despite being a pronator of the distal row, has a beneficial effect as it provokes supination of the scaphoid.
CONCLUSIONS: Comprehending carpal dysfunctions and instabilities hinges on understanding carpal anatomy and normal biomechanics. Proprioception, encompassing joint position sensation and neuromuscular control, is pivotal for stability. Biomechanical research informs tailored muscle strengthening for specific carpal issues. Supinator muscles should be strengthened for SL injuries, and ECU-focused strengthening and proprioceptive training are key for dynamic LTq instabilities. Ongoing research should delve into the intricate relationship between carpal ligaments, muscles, and proprioception to enhance wrist stability.

OBJECTIVE: Clinical-standard MRI is the imaging modality of choice for the wrist, yet limited to static evaluation, thereby potentially missing dynamic instability patterns. We aimed to investigate the clinical benefit of (dynamic) real-time MRI, complemented by automatic analysis, in patients with complete or partial scapholunate ligament (SLL) tears.
METHODS: Both wrists of ten patients with unilateral SLL tears (six partial, four complete tears) as diagnosed by clinical-standard MRI were imaged during continuous active radioulnar motion using a 1.5-T MRI scanner in combination with a custom-made motion device. Following automatic segmentation of the wrist, the scapholunate and lunotriquetral joint widths were analyzed across the entire range of motion (ROM). Mixed-effects model analysis of variance (ANOVA) followed by Tukey\'s posthoc test and two-way ANOVA were used for statistical analysis.
RESULTS: With the increasing extent of SLL tear, the scapholunate joint widths in injured wrists were significantly larger over the entire ROM compared to those of the contralateral healthy wrists (p<0.001). Differences between partial and complete tears were most pronounced at 5°-15° ulnar abduction (p<0.001). Motion patterns and trajectories were altered. Complete SLL deficiency resulted in complex alterations of the lunotriquetral joint widths.
CONCLUSIONS: Real-time MRI may improve the functional diagnosis of SLL insufficiency and aid therapeutic decision-making by revealing dynamic forms of dissociative instability within the proximal carpus. Static MRI best differentiates SLL-injured wrists at 5°-15° of ulnar abduction.

OBJECTIVE: Peritrapezial osteoarthritis (OA) includes scaphotrapezial and trapeziometacarpal OA. In clinical practice, scaphotrapezial OA seems better tolerated than trapeziometacarpal OA, with fewer complaints and better tolerance. The difference in pain could be linked to a difference in joint capsule innervation, perhaps with fewer nerve fibers in the scaphotrapezial than the trapeziometacarpal joint.
METHODS: We performed a histologic evaluation of these two joints to compare their respective innervation in 17 cadaveric specimens with peritrapezial OA. Radiographic scoring confirmed the presence of peritrapezial OA. Mean Kellgren-Lawrence score was 2.2 ± 1.1 in the trapeziometacarpal joint and 1.5 ± 0.7 in the scaphotrapezial joint (p = 0.08).
RESULTS: There was no difference between scaphotrapezial and trapeziometacarpal joints in number of neurofilaments: 5.2 ± 3.9 and 4.4 ± 4.5, respectively (p = 0.20). A significant difference was found in S100 staining (myelinated structures), with a higher rate in the scaphotrapezial joint: 11.8 ± 7.5 vs 6.6 ± 5.2 (p = 0.005).
CONCLUSIONS: The present study suggests that lower tolerance of trapeziometacarpal OA is not due to a difference in joint capsule innervation. On the contrary, we found a higher rate of myelinated tissues in the scaphotrapezial joint. These results suggested other pain pathways to explain clinical observations.

OBJECTIVE: To determine if transdermally delivered fentanyl can achieve greater concentrations of fentanyl in synovial fluid when applied over a synovial structure.
METHODS: Randomized, experimental study.
METHODS: Six healthy adult horses.
METHODS: Each horse had two 100 μg/h fentanyl matrix patches applied on the dorsal aspect of one, randomly assigned, carpometacarpal joint (CMCJ) for 48 h. Whole blood and bilateral synovial samples from the intercarpal joint were obtained at 0, 2, 6, 12, 24, 36 and 48 h. Fentanyl concentrations were measured with liquid chromatography-mass spectrometry.
RESULTS: All subjects achieved detectable concentrations of fentanyl in both plasma and synovial fluid. Time to peak synovial and plasma concentration was 12 h. At 6 h, the synovial concentration in the untreated carpus (0.104 ng/mL ± 0.106) was lower than plasma fentanyl concentrations 0.31 ± 0.27 (p = .036). At 12 h, both treated (0.55 ng/mL ± 0.3) and untreated (0.53 ng/mL ± 0.28) synovial fluid fentanyl concentrations were lower than plasma (0.87 ng/mL ± 0.48) concentrations (p < .001 and p = .001, respectively). Synovial concentrations of fentanyl did not differ between treated and untreated joints (p > 0.608 for all time points).
CONCLUSIONS: Application of fentanyl matrix patches directly over the CMCJ did not result in increased fentanyl concentrations in the synovial fluid of the treated intercarpal joint in normal horses.
CONCLUSIONS: There is likely no analgesic advantage to placing fentanyl patches directly over the affected joint, as it did not result in increased synovial concentrations at the tested site.

This research examines whether the distribution of trabecular bone in the proximal capitates of extant hominids, as well as several fossil hominin taxa, is associated with the oblique path of the midcarpal joint known as the dart-thrower\'s motion (DTM).
We analyzed proximal capitates from extant (Pongo n = 12; Gorilla n = 11; Pan n = 10; fossil and recent Homo sapiens n = 29) and extinct (Australopithecus sediba n = 2; Homo naledi n = 1; Homo floresiensis n = 2; Neandertals n = 3) hominids using a new canonical holistic morphometric analysis, which quantifies and visualizes the distribution of trabecular bone using relative bone volume as a fraction of total volume (rBV/TV).
Homo sapiens and Neandertals had a continuous band of high rBV/TV that extended across the scaphoid, lunate, and hamate subarticular regions, but other fossil hominins and extant great apes did not. A. sediba expressed a distinct combination of human-like and Pan-like rBV/TV distribution. Both H. floresiensis and H. naledi had high rBV/TV on the ulnar-side of the capitate but low rBV/TV on the radial-side.
The proximal capitates of H. sapiens and Neandertals share a distinctive distribution of trabecular bone that suggests that these two species of Homo regularly load(ed) their midcarpal joints along the full extent of the oblique path of the DTM. The observed pattern in A. sediba suggests that human-like stress at the capito-scaphoid articular surface was combined with Pan-like wrist postures, whereas the patterns in H. floresiensis and H. naledi suggest their midcarpal joints were loaded differently from that of H. sapiens and Neandertals.

Injuries to the scapholunate joint are the most frequent cause of carpal instability. The sequelae of these injuries account for considerable morbidity, and if left untreated, may lead to scapholunate advanced collapse and progressive deterioration of the carpus. Rupture of the scapholunate interosseous ligament and its critical stabilizers causes dyssynchronous motion between the scaphoid and lunate. Additional ligament injury or attenuation leads to rotary subluxation of the scaphoid and increased scapholunate gap. Intervention for scapholunate instability is aimed at halting the degenerative process by restoring ligament integrity and normalizing carpal kinematics. In the first section of this review, we discuss the anatomy, kinematics, and biomechanical properties of the scapholunate ligament as well as its critical ligament stabilizers. We provide a foundation for understanding the spectrum of scapholunate ligament instability and incorporate meaningful new anatomical insights that influence treatment considerations. The purpose is to provide an update regarding the anatomy of the scapholunate ligament complex, importance of the critical ligament stabilizers of the proximal carpal row, introduction of safe technique to surgically expose the scaphoid and lunate, as well as pathoanatomy as it pertains to the treatment of scapholunate dissociation. In the second section of this review, we propose a novel ligament-based treatment algorithm based on the stage of injury, degree and nature of ligament damage, and presence of arthritic changes.