Shape analysis of the carpal joint in healthy and septic arthritis in newborn calves.

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.

Arthrographic description of the canine carpal joint cavities and its recesses.

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.

Dynamic assessment of scapholunate ligament status by real-time magnetic resonance imaging: an exploratory clinical study.

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. MATERIAL AND 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. CONCLUSION: 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.

Trabecular bone structure of the proximal capitate in extant hominids and fossil hominins with implications for midcarpal joint loading and the dart-thrower's motion.

OBJECTIVES: 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). MATERIALS AND METHODS: 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). RESULTS: 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. CONCLUSION: 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.

[Technique Optimization of Interposition Arthroplasty During Proximal Row Carpectomy with Regard to the Vascularity of the Capsule in Carpal Joint: Cadaverous Study]. / Optimalizace techniky interpozicní artroplastiky pri proximální karpektomii s ohledem na vaskularizaci dorzální kapsuly karpu: kadaverózní studie.

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.

Longitudinal evaluation of fentanyl concentrations in equine plasma and synovial fluid following application of transdermal fentanyl patches over one carpal joint.

OBJECTIVE: To determine if transdermally delivered fentanyl can achieve greater concentrations of fentanyl in synovial fluid when applied over a synovial structure. STUDY DESIGN: Randomized, experimental study. ANIMALS: 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). CONCLUSION: 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. CLINICAL SIGNIFICANCE: 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.

Joint capsule innervation does not explain the difference in symptoms between scaphotrapezial and trapeziometacarpal osteoarthritis.

OBJECTIVES: 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. MATERIALS AND 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). CONCLUSION: 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.

Scapholunate Instability: Diagnosis and Management - Anatomy, Kinematics, and Clinical Assessment - Part I.

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.

Midcarpal Instability.

Midcarpal instability (MCI) of the wrist represents multiple distinct clinical entities that all have in common abnormal force transmission across the midcarpal joint. This can be asymptomatic but can also result in painful wrist motion, a characteristic catch-up clunk, and symptoms of instability. The carpus is stabilized by numerous extrinsic and intrinsic ligaments. Dynamic joint reactive forces between the proximal and distal carpal rows help create reciprocal motion, which results in smooth, physiologic wrist mechanics. Diagnosis of MCI requires a thorough history, physical examination, and adequate imaging. MCI can be managed nonsurgically with activity modification, physical therapy, specialized orthotics, medications, and corticosteroid injections. A variety of surgical treatment options exists to treat symptomatic MCI. These include arthroscopic thermal capsulorrhaphy, ligament repair or reconstruction, radial osteotomies, and limited radiocarpal or intercarpal fusions. Capsulorrhaphy or ligament repair is favored for mild to moderate cases; osteotomies can be used for the correction of bony deformities contributing to instability, whereas partial wrist arthrodesis is indicated for severe or recurrent instability and fixed deformities.

[Research progress in etiology and clinical diagnosis and treatment of scaphotrapeziotrapezoid osteoarthritis].

Objective: To summarize the research progress of scaphotrapeziotrapezoid osteoarthritis (STT OA) and its etiology and clinical treatment. Methods: The domestic and foreign literature on STT OA in recent years was reviewed and the research progress was summarized. Results: STT OA is a common OA, which is highly prevalent in postmenopausal women and diagnosed by wrist X-ray films. The current treatment methods include conservative treatment and surgery. Among them, the conservative treatment can relieve clinical symptoms, but the long-term effectiveness is not ideal. In surgical treatment, scaphoid arthrodesis can effectively relieve wrist pain, but it sacrifices part of the range of motion and grip strength of the wrist, and there is a risk of fusion failure. Distal scaphoid resection and trapezium resection have the advantages of short operation time, simple operation, less damage to the joint capsule and ligament, and shorter postoperative external fixation time, but they lead to changes in carpal bone alignment and dorsal intercalated segmental instability. Arthroplasty can provide pain relief while restoring grip strength and preserving wrist motion, but there is a risk of dislocation of the prosthesis. Conclusion: At present, there is no gold standard for the STT OA treatment. The short-term effectiveness of arthroplasty and arthroscopic distal scaphoid resection are satisfactory, but the long-term effectiveness needs further study.

The effect of ulnar variance on the pisotriquetral joint.

BACKGROUND: Pisotriquetral joint (PTJ) disorders are an important cause of ulnar-sided wrist pain but are often underrecognized. Ulnar variance (UV) has been associated with several wrist pathologies. PURPOSE: To determine the effect of UV on PTJ in patients with trauma. MATERIAL AND METHODS: A total of 143 patients (77 men, 66 women; mean age=41.64 ± 18.07 years) were included. Patients with fractures, severe and high-energy trauma, arthritic conditions, avascular necrosis, congenital deformity, bone and soft-tissue tumors, suboptimal image quality, and incorrect joint position were excluded. UV and the amount of PTJ subluxation were evaluated using coronal and sagittal computed tomography images. RESULTS: PTJ subluxation was divided into five grades. A statistically significant difference was found between the presence of PTJ subluxation and sex (P = 0.045). PTJ subluxation was more common in men (46.8%) than in women (30.3%). There was no significant difference between the presence of PTJ subluxation and age (P = 0.758). The patients were also divided into three groups as positive, neutral, and negative UV. A statistically significant relationship was found between the UV and presence of PTJ subluxation (P = 0.01). PTJ subluxation was significantly less in the neutral (none=51.1%, present=48.9%; P < 0.05) and negative (none=77.8%, present=22.2%; P < 0.05) groups. CONCLUSION: PTJ subluxation was found to be less among the groups with neutral and negative UV in our study population. PTJ subluxation is more common in men while there is no relationship with age. UV and gender may be risk factors for PTJ subluxation by affecting force dynamics at the wrist joint.

Application of a Joint Coordinate System Kinematic Model to the Canine Thoracic Limb.

OBJECTIVE: The aim of this study was to apply a three-dimensional kinematic model to the canine thoracic limb using a joint coordinate system. ANIMALS: Six clinically normal adult mixed-breed dogs. PROCEDURES: Dogs had 19 retroreflective markers affixed to the skin of the right forelimb. Twelve infrared cameras were arranged in a circle around the testing space, recording the locations of the markers as dogs walked and trotted through the testing space. Five trials were used of both walks and trots at velocities 0.9 to 1.2 m/s and 1.7 to 2.1 m/s respectively. Raw marker location data were used to generate a joint coordinate system, and a six degrees of freedom model of the canine forelimb was created. Three-dimensional kinematic angles were collected for the shoulder, elbow and carpal joints. RESULTS: Sagittal, transverse and frontal plane kinematics joint angles were generated by use of a joint coordinate system. Range of motion was calculated for each joint in all three planes. CONCLUSION AND CLINICAL RELEVANCE: This minimally invasive joint coordinate system model can be used in both clinical and research settings to determine changes in range of motion of the shoulder, elbow or carpus in the canine forelimb in three dimensions.

A fluid-structure interaction investigation of intra-articular pressure and ligament in wrist joint.

Understanding the stresses on the scapholunate interosseous ligament (SLIL) and its interaction with synovial fluid pressure could be vital to improve wrist treatment for various wrist conditions such as arthritis, sprains and tendonitis. This study investigated the interaction between the intra-articular pressure, specifically the synovial fluid pressure change and the SLIL stresses in a computational model during wrist radioulnar deviation (RUD). Magnetic resonance imaging (MRI) scans were used to acquire the anatomical model of the carpal bones and ligament, while the kinematics of scaphoid and lunate were obtained through dynamic computerized tomography (CT) scans. A two-way fluid-structure interaction (FSI) was used to model the dynamics between the scaphoid and lunate, the SLIL, and the synovial fluid. The synovial fluid pressure change was found to be small (-4.86 to 3.23 Pa) and close to that simulated in a previous work without the SLIL (-1.68 to 2.64 Pa). Furthermore, peaks of maximum fluid pressure were found to trail the peaks of ligament stress. Therefore, it is suggested that the influence of synovial fluid pressure on the ligament in the SLIL model is negligible and simulations of the scapholunate joint could forego fluid-structure interactions. Future studies can instead explore other structures in the carpus that can possibly contribute to the ligament stresses. Clinically, treatments can be targeted at these areas to help prevent or slow the progression of ligament injuries into serious consequences like the degenerative joint disease.

Midcarpal Instability: A Historical and Etymological Review.

Although midcarpal instability was first described almost 45 years ago, this uncommon condition is still poorly understood by most clinicians today. Adding to the confusion, it is known by 2 different names: midcarpal instability and carpal instability nondissociative. In this article, we describe the history of the recognition of instability of the midcarpal joint, including its pathomechanics, classification, and treatment. We hope that a more complete understanding of the etymology and kinematics of the disorder will facilitate its future recognition and assist in appropriate treatment decision making.

Joint-sparing arthroscopic management of avascular necrosis of the capitate.

Avascular necrosis of the proximal pole of the capitate is an exceedingly rare pathology with few therapeutic solutions. The largest published series concerned a cohort of 6 cases over 10 years. The present case concerns our experience with avascular necrosis of the capitate in a 20-year-old woman. Due to her age and high functional demand, we opted for a minimally invasive solution using arthroscopy. We performed an X-shaped palmaris longus tendon interposition arthroplasty at the midcarpal joint between the capitate and the lunate. We here report 2 years' follow-up.

Novel arthrocentesis approaches to the carpal joint of the Dromedary Camel (Camelus dromedarius).

The knowledge gap regarding the topography and anatomy of the dromedary's carpal joint must be bridged to improve diagnostic and treatment procedures such as ultrasonography, arthrocentesis, and arthroscopy. Thirty-five distal forelimbs were harvested from 21 dromedaries and studied through gross dissection, casting, ultrasonography, and computerized tomography. Representative three-dimensional models of the joint cavities, recesses, and pouches were obtained using various casting agents. The safety and feasibility of different arthrocentesis approaches were evaluated. This study provides a detailed description of dorsally located joint recesses and palmarly located joint pouches. The dorsomedial and dorsolateral approach is recommended for arthroscopy and arthrocentesis of the radiocarpal and intercarpal joint when the carpus is flexed. However, caution must be exercised during these approaches to prevent needle injury to the articulating cartilage. Caution is necessary to prevent the formation of inadvertent communication between the dorsally located tendon sheaths and joint cavities. Arthrocentesis via the lateral approach to the lateropalmar pouch is the most favourable approach for the radiocarpal joint. A subtendinous synovial bursa was found between the lateropalmar pouch of the radiocarpal joint and the extensor carpi ulnaris muscle. The subtendinous synovial bursa must be considered during the lateral arthrocentesis approach. The palmar approach is not recommended for arthrocentesis due to the high risk of injury to nerves, veins, and arteries located palmarly.

A detailed macroscopic scoring system for experimental post-traumatic Osteoarthritis in the equine middle carpal joint.

OBJECTIVE: Osteoarthritis (OA) is a significant health issue in humans as well as horses. Experimental models of equine carpal OA have been used to investigate OA pathogenesis and potential therapeutic candidates. A 5-scale scoring system (OARSI) for macroscopic pathological cartilage changes already exists, but there is a need for a scoring system with better differentiation of severity. The aim of this study was therefore to develop and validate such a scoring system. RESULTS: New scoring system were developed for cartilage erosions (Copenhagen Equine Total Cartilage Score, CEqTCS) along with synovial membrane pathology and osteochondral fragment healing (Copenhagen Equine Carpal Osteoarthritis Score, CEqCOAS). For the CEqTCS there was excellent intraclass agreement (ICC = 0.993; CI 0.985-0.996; p = 1.08e-31) and consistency (ICC = 0.992; CI 0.985-0.996; p = 4.61e-31), as well as excellent interclass agreement (ICC = 0.974; CI 0.948-0.987, p = 2e-22) and consistency (ICC = 0.973; CI 0.946-0.987; p = 2.77e-22), while the OARSI system had moderate (κ = 0.47) and weak (κ = 0.28) inter- and intra-class agreement, respectively. The OARSI score and the CEqTCS correlated excellently, but every OARSI grade encompassed a wide range of CEqTCS grades. The new score for assessment of equine OA provides means to a better differentiation of OA changes than the existing OARSI system.

Radiocarpal Fusion: Indications, Technique, and Modifications.

Degenerative disorders of the wrist may affect isolated joints and inhibit normal functions of the wrist secondary to pain and stiffness. These processes that affect only the radiocarpal joint may be secondary to posttraumatic osteoarthritis, primary osteoarthritis, or rheumatoid arthritis. Radiocarpal wrist arthrodesis may help preserve some of the native wrist kinematics while alleviating pain and improving the range of motion. However, the surgeon must ensure that the patient's pathologic process primarily affects the radiocarpal articulations while relatively sparing the midcarpal articulations. Depending on the location of the pathology, isolated radiolunate or radioscapholunate arthrodesis have been described to preserve some motion in the midcarpal joint. To maximize motion in the midcarpal joint after radiocarpal arthrodesis, techniques for distal scaphoid and triquetrum excision have been described. We report patient outcomes for various techniques and describe our preferred technique for radioscapholunate arthrodesis using distal scaphoid excision.

Bilateral Ulnar Deviation Supination Stress Test to Assess Dynamic Scapholunate Instability.

PURPOSE: We describe a new radiologic test to assess the integrity of the scapholunate ligament in dynamic scapholunate dysfunction. METHODS: A bilateral forearm-holding device was designed to perform a comparative radiographic assessment of the scapholunate joint gap during resisted isometric contraction of the extensor carpi ulnaris muscle with full supination of the forearm. The concept is based on the known scaphoid pronation effect of this muscle. Clinical data from 12 patients were collected retrospectively and used to analyze the patients' symptomatic and asymptomatic (contralateral) wrists with a newly developed test called the Bilateral Ulnar Deviation Supination (BUDS) test. A wrist arthroscopy was performed in all cases as a reference standard for the radiologic test. RESULTS: The test was positive in 7 patients, with a mean scapholunate joint gap of 4.8 mm. The mean differences in the scapholunate joint gaps between both wrists were 2.6 mm in BUDS-positive patients and 0.2 mm in BUDS-negative patients. A Geissler stage III or IV scapholunate ligament rupture was confirmed in all BUDS-positive patients; by contrast, BUDS-negative patients exhibited either no lesion or a Geissler stage I injury. CONCLUSIONS: The BUDS test is a new radiologic test based on proven biomechanical effects that is able to accurately assess dynamic scapholunate dysfunctions. The analysis carried out found a correlation between radiographic and arthroscopic findings. Further research is needed to confirm the validity and reliability of the test. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic III.

Validation of ultrasonography for measurement of cartilage thickness in the equine carpus.

Articular cartilage thinning is an important hallmark of osteoarthritis (OA), and ultrasonography (US) is a clinically accessible tool potentially suitable for repeated evaluation. The aim of the present prospective methods comparison study was to validate US as a tool for measuring cartilage thickness in the carpus of the horse. Eight Standardbred trotters underwent US examination with 9 and 15 MHz linear transducers. Six anatomical locations in the radiocarpal joint (RCJ) and middle carpal joint (MCJ) were examined. The same joints were assessed by ultrahigh field (9.4 Tesla) magnetic resonance imaging (MRI) and histology. Associations between measurements obtained by the different modalities were assessed by ANOVA, Deming regression, Pearson correlation and Bland-Altman plots. Histologically assessed total cartilage thickness (the noncalcified cartilage (NCC) plus the calcified cartilage zone (CCZ)) overestimated thickness compared to MRI (P < 0.01) and US (P < 0.01). US 15 MHz had substantial agreement with MRI and NCC histology, and repeatability was acceptable (coefficient of variation = 8.6-17.9%) when used for assessment of cartilage thickness in the RCJ. In contrast, 9 MHz US showed poorer agreement with MRI and NCC histology, as it overestimated the thickness of thin cartilage and underestimated the thickness of thicker cartilage in the RCJ and MCJ. Moreover, repeatability was suboptimal (coefficient of variation = 10.4-26.3%). A 15 MHz transducer US is recommended for detecting changes in RCJ cartilage thickness or monitoring development over time, and it has the potential for noninvasive assessment of cartilage health in horses.