Magnetic resonance imaging of the dromedary camel carpus.

BACKGROUND: The dromedary camel (Camelus dromedarius) carpal joint presents multiple joints and constitutes several bones and soft tissues. Radiography and/or ultrasonography of the carpus are challenging due to structural superimposition. High-field magnetic resonance imaging (MRI) technique precludes superimposed tissues and offers high soft tissue contrast in multiple sequences and planes. Hence, understanding the normal MRI anatomy is crucial during clinical investigations. Magnetic resonance imaging is highly sensitive for investigation of soft tissues and articular cartilage; therefore, it is extensively used for outlining joint anatomy and evaluation of a wide range of musculoskeletal conditions. MRI images of a specific anatomical region acquired by using multiple sequences in various planes are necessary for a complete MRI examination. Given the dearth of information on the MRI features of the dromedary camel carpus, the current study demonstrates the MRI appearance of the clinically significant structures in the camel carpus in various sequences and planes using a high-field 1.5 Tesla superconducting magnet. For this purpose, twelve cadaveric forelimbs, obtained from 6 clinically sound lameness free adult dromedary camels, were examined. RESULTS: The cortex and medulla of the radius, carpal bones and metacarpus were evaluated. Articular cartilage of the carpal joints was depicted and showed intermediate intensity. Carpal tendons expressed lower signal intensity in all pulse sequences. The collateral and inter-carpal ligaments showed mixed signal intensity. CONCLUSIONS: The obtained data outlines the validation of MRI for investigation of the camel carpus and could set as a reference for interpretation in clinical patients.

Distal forelimb radiographic bone morphology in Thoroughbred foals during the first 10 months post-partum. Part 1: Carpus.

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. METHOD: 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. CONCLUSION: 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.

Pure traumatic unstable radiocarpal dislocation over pre-existing ulnar impingement syndrome, extensively arched carpus and medially rotated scaphoid: An exceptional and complex case report.

Introduction and importance: Radiocarpal dislocation is a rare and severe injury that demands urgent diagnosis and treatment. In this case report, we present the unique scenario of a 32-year-old male who suffered a traumatic pure unstable radiocarpal dislocation. This dislocation was associated with ulnar impingement syndrome, an extensively arched carpus, and a medially rotated scaphoid. The complexity of this injury underscores the importance of timely intervention and comprehensive management. Case presentation: The patient had a pre-existing short ulnar head with radial-sided deformity, radioulnar convergence, negative ulnar variance, erosive scalloping of the distal radius, subchondral sclerosis of the ulnar head, scapholunate diastasis, and distal radioulnar joint (DRUJ) diastasis. Following a high-velocity motor vehicle accident, the initial treatment involved closed reduction and radio-metacarpal external fixation. Additionally, surgical intervention was required for an open dislocation of the metatarsophalangeal (MTP) joint of the left hallux. Clinical discussion: The subsequent management of this complex case included the Sauvé-Kapandji procedure, ulnolunate and ulnotriquetral ligamentoplasty using the palmaris longus tendon, and scapholunate fusion. The patient reported no prior wrist instability or injury upon awakening, but mild mechanical wrist pain persisted after exertion. Follow-up assessments revealed residual pain during prono-supination, along with slightly limited radial inclination. This exceptional case highlights the biomechanical challenges and the need for a multidisciplinary approach in treating such injuries. Conclusion: To the best of our knowledge, this is the first documented instance of a traumatic pure unstable radiocarpal dislocation associated with ulnar impingement syndrome, an extensively arched carpus, and a medially rotated scaphoid. Despite the complexity, proper bone healing and favorable functional outcomes were achieved through meticulous surgical management. This case underscores the importance of individualized treatment strategies for rare and challenging wrist injuries.

Increasing Use of Total Wrist Arthroplasty-An Australian National Joint Registry Report.

Background and Purpose There is limited literature reporting the long-term results and outcomes of total wrist arthroplasty (TWA). The aim of this study was to describe the incidence, usage, and survival of wrist arthroplasty using data from the Australian Orthopaedic Association National Joint Replacement Registry (AOANJRR). Methods Data included all primary TWA procedures from 2006 to 2021. The primary outcome assessed was revision surgery. Utilization of TWA, etiology leading to TWA, patient demographics, and surgical factors were also assessed. Results There were 439 primary TWA procedures performed across the 16-year reporting period. Four prostheses (Motec, Universal 2, Freedom, and ReMotion) have been used, with a recent increased usage toward the Motec, which accounted for 97.4% of prostheses implanted in 2021. There has also been an increase in the number of surgeons performing TWA over time. The most common underlying etiology was osteoarthritis (72.7%), followed by rheumatoid arthritis (15.9%). Implantation for inflammatory arthropathy remained relatively constant across time; however, TWA has been utilized with increasing frequency for the treatment of osteoarthritis and other indications more recently. The cumulative percent revision at 10 years was 18.3%. Loosening accounted for 25.6% of all revisions, followed by osteolysis (12.8%), pain (12.8%), and instability (7.7%). Attempted conversion to an arthrodesis occurred in 10.3% of all revisions. Conclusion There has been an increase in both the volume of TWA performed and the number of surgeons undertaking this procedure in Australia over the past 16 years. The Motec system has become the prosthesis of choice. Medium-term revision rates are inferior when compared with Australian data for hip, knee, and shoulder arthroplasty.

Needle Arthroscopy Versus Conventional Arthroscopy in the Evaluation of Carpal Pathology: A Comparative Study.

BACKGROUND: The needle scope is a less invasive intervention to evaluate carpal pathology. We hypothesize that there is no difference in the evaluation and diagnostic capability of the needle scope versus the conventional wrist arthroscope. METHODS: Twenty patients indicated for wrist arthroscopy were prospectively enrolled. Prior to insertion of the 2.7-mm arthroscope, the needle scope evaluated for synovitis; cartilage damage (location and modified Outerbridge classification); integrity of the volar, scapholunate (SL), and lunotriquetral ligaments; and the triangular fibrocartilage complex (TFCC). Following needle scope evaluation, the surgeon completed a survey regarding the visualization and diagnosis. The 2.7-mm arthroscope was then inserted, and the surgeon completed the second portion of the survey. Statistical analysis was then completed to determine statistical significance. RESULTS: Twelve patients were female (60%), and the mean age was 39.8 years (±11.8 years). Eleven patients underwent arthroscopy for TFCC pathology, 4 patients for SL tearing, and 5 patients for extensive synovitis. There was no difference between the needle scope and wrist arthroscopy diagnosis. There was no difference between radiocarpal and midcarpal visualization. Surgeon-rated ease of use and diagnostic confidence were the same between two groups. The needle scope was better able to visualize the scapho-trapezium-trapezoid and carpometacarpal joints; however, the image was of marginally decreased quality. CONCLUSION: In this study, there was no difference between radiocarpal or midcarpal visualization and surgeon-rated ease of use, while diagnostic confidence was the same between two groups. LEVEL OF EVIDENCE: II (prospective cohort study)-Diagnostic.

Exploring Age-Related Variations in Carpal Bone Volume: Implications for Clinical Practice and Anatomical Understanding.

BACKGROUND: Clinically recognizing the changes in carpal bone volumes and understanding their implications in predicting osteoarthritis (OA) is crucial in clinical practice This study aimed to explore age-related differences in carpal bone volumes across genders, leveraging computed tomography (CT) wrist scans to create 3D surface models of these bones. METHODS: Carpal bone volumes were calculated using the 3D Slicer software from CT scans obtained from Frankston Hospital and additional datasets from Brown and Auckland Universities. The data were statistically processed using Stata V13. Double-sided P-values < .05 were considered statistically significant. The study was conducted in accordance with the ethical standards laid out in the Declaration of Helsinki. RESULTS: A total of 181 patients were analyzed, and 48% of whom were female. A statistically significant positive Spearman correlation (rho = 0.37-0.611, P <.05) was observed between increasing age and the volume of all surveyed carpal bones (scaphoid, lunate, triquetrum, pisiform, hamate, capitate, and trapezium) across genders. Intrauser and interuser reliabilities for 3D Slicer-generated volumes of trapezium and pisiform bones were statistically significant, with Interclass Correlation Coefficient (ICC) values of 0.86 and 0.95, respectively. CONCLUSION: Trapezial volumes increase with age, potentially due to the presence of OA and consequent osteophyte formation. This pattern is more prevalent among older individuals and women. However, the positive correlation between carpal bone volume and age was consistent across all carpal bones and both genders, regardless of OA presence. These findings suggest that carpal bone volume may naturally increase with age, independent of OA-related changes. LEVEL OF EVIDENCE: III, cohort study.

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.

Scaphoid proximal pole ejection in perilunate injury: a case report and pathophysiological hypothesis.

Isolated ejection of the scaphoid proximal pole in perilunate injuries is rare, with only 4 reports in the literature, and does not correspond to the biomechanical situations in the Herzberg or Mayfield classifications. Bone ejection incurs a risk of avascular necrosis despite good osteosynthesis, notably because of precarious vascularization. We present a case of scaphoid proximal pole ejection and a theoretical hypothesis of the biomechanics of this injury. LEVEL OF EVIDENCE: 4.

Carpal fractures: epidemiology, classification and treatment of 6542 fractures from the Swedish Fracture Registry.

This study describes the age and sex distribution, trauma mechanism, treatment and influence of patient-reported outcomes of 6542 carpal fractures from the Swedish Fracture Registry (SFR). The most commonly fractured carpal bone was the scaphoid (60%), followed by the triquetrum (25%), hamate (5%) and trapezium (4%). The mean age at injury was 41 years, and 69% of patients were male. The age and sex distribution of carpal fractures differed substantially between the different carpal bones. Men were more likely to sustain a carpal fracture after high-energy trauma and were more likely to be treated surgically. Carpal fractures had a small negative effect on the Short Musculoskeletal Function Assessment Hand/Arm Index and EQ-5D scores 1 year after the injury.Level of evidence: IV.

Multifocal giant cell tumor of the carpus: Unusual presentation. Case report and review of the literature.

INTRODUCTION AND IMPORTANCE: Giant cell tumors (GCTs) of bone in the carpus are rare. Carpal GCTs are usually solitary lesions; multifocal involvement is exceptional. These lesions have a higher risk of local recurrence after intralesional curettage than those in other body areas. CASE PRESENTATION: We present a case of a 28-year-old male with a six-month history of a palpable mass in the dorsal aspect of the left wrist. Physical examination revealed a 2 cm, mildly tender mass. Magnetic resonance revealed a large intermediate signal lesion involving completely hamate bone and the distal portion of the triquetrum. Histological examination confirmed a giant cell tumor of the carpus. The patient underwent en-bloc resection of the hamate bone extending to the distal part of the pyramidal. The defect was reconstructed using polymethylmethacrylate cement (PMMA), and intercarpal arthrodesis with the capitate was achieved. Follow-up at 18 months revealed a good clinical evolution, wrist range of motion of 30° of extension, 30° of flexion, and 10° of ulnar and radial deviation without evidence of tumoral recurrence. CLINICAL DISCUSSION: The current literature suggests a high incidence of local recurrence in carpal GCT, so wide excision with carpal arthrodesis is recommended, especially in Campanacci III and multifocal involvement. CONCLUSION: Carpal GCT is exceptional, mainly affecting the hamate, capitate, and scaphoid. Most literature supports wide excision of carpal GCT owing to the high recurrence rate with intralesional procedures.

Morphology and ontogeny of carpus and tarsus in stereospondylomorph temnospondyls.

Skeletal development is well known in temnospondyls, the most diverse group of Paleozoic and Mesozoic amphibians. However, the elements of carpus and tarsus (i.e., the mesopodium) were always the last bones to ossify relative to the other limb bones and with regard to the rest of the skeleton, and are preserved only in rare cases. Thus, in contrast to the other parts of the limb skeleton, little is known about the ontogeny and sequence of ossification of the temnospondyl carpus and tarsus. We intended to close this gap by studying the ontogenies of a number of Permo/Carboniferous stereospondylomorphs, the only temnospondyls with preserved growth series in which the successive ossification of carpals and tarsals can be traced. Studying the degree of mesopodial ossification within the same species show that it is not necessarily correlated with body size. This indicates that individual age rather than size determined the degree of mesopodial ossification in stereospondylomorphs and that the largest individuals are not necessarily the oldest ones. In the stereospondylomorph tarsus, the distal tarsals show preaxial development in accordance with most early tetrapods and salamanders. However, the more proximal mesopodials exhibit postaxial dominance, i.e., the preaxial column (tibiale, centrale 1) consistently started to ossify after the central column (centralia 2-4, intermedium) and the postaxial column (fibulare). Likewise, we observed preaxial development of the distal carpals in the stereospondylomorph carpus, as in most early tetrapods for which a statement can be made. However, in contrast to the tarsus, the more proximal carpals were formed by preaxial development, i.e., the preaxial column (radiale, centrale 1) ossified after the central column (centralia 2-4, intermedium) and before the postaxial column (ulnare). This pattern is unique among known early tetrapods and occurs only in certain extant salamanders. Furthermore, ossification proceeded from distal to proximal in the central column of the stereospondylomorph carpus, whereas the ossification advanced from proximal to distal in the central column of the tarsus. Despite these differences, a general ossification pattern that started from proximolateral (intermedium or centrale 4) to mediodistal (distal tarsal and carpal 1) roughly in a diagonal line is common to all stereospondylomorph mesopodials investigated. This pattern might basically reflect the alignment of stress within the mesopodium during locomotion. Our observations might point to a greater variability in the development of the mesopodium in stereospondylomorphs and probably other early tetrapods than in most extant tetrapods, possibly mirroring a similar variation as seen in the early phases of skeletogenesis in salamander carpus and tarsus.

[Arthroplasty of the hand and wrist]. / Endoprothetik an Hand und Handgelenk.

Arthrosis and autoimmune arthritis frequently lead to major impairment of hand function. Primary therapy consists of well- tried conservative treatments and joint preserving surgical options for special indications. In advanced stages silicon spacers remain the gold standard surgical option for replacement of proximal interphalangeal and metacarpophalgeal joints of the fingers. Alternatively, surface replacement prostheses can restore the biomechanical properties of these joints more porperly. In case of the carpometacarpal (CMC) joint of the thumb, arthroplasty is gaining popularity as modern implants show excellent mid-term outcome. Although current forth generation implants for wrist replacement are promising, total wrist arthroplasty is currently reserved for exceptional indications.

Carpal dislocations.

Carpal dislocations result from sequential disruption of the complex relationship between the bones and ligaments of the wrist. Injuries to the carpus occur via predictable mechanisms, an understanding of which is critical to identify and treat these frequently missed patterns of injury and to avoid the sequela of chronic instability. Lunate dislocations are by far the most common, but isolated dislocation of other carpal bones can also occur. Open reduction and internal fixation still remains the gold standard for treatment regardless of the debate around the specific approaches. These high-energy injuries are associated with significant long-term morbidity even when identified promptly and appropriately treated. This review will focus on the evaluation and management of common forms of carpal dislocations.

Radiographic Appearance of the Fore Digit and Carpal Joint in the Mule Foal from Birth to 3 Months of Age.

Few studies have established the normal radiographic anatomical development of the donkey foal and, to date, no data are available for mules. Our aim was thus to evaluate the radiographic development of the fore digit and carpal joint in the mule foal from 0 to 3 months of age. Ten forelimbs of five healthy full-term mule foals were included. Radiographs of the fore digit lateromedial and dorsopalmar and the carpus dorsopalmar were performed weekly for the first month of age, and bi-monthly during the following two months. Fore digit growth plate closure times, morphological, angular, and linear radiographic parameters, and also carpal cuboidal bone mineralization were evaluated. Growth plates were graded as open, closing, and closed. Carpal bone appearance was graded as mature, slightly immature, or immature. Growth plate closure times showed the following: middle phalangeal distal physis (DP) closed at birth, and proximal physis (PP) started to close at around two months; first phalanx DP closed at seven days, and PP started to close at three months; and third metacarpal bone DP started to close at two months. Carpal bones were immature at birth. Distal phalanx (PD) was triangular at birth, palmar processes had developed by one month, and proximal sesamoid bones were trapezoidal by three months. The hoof wall, PD dorsal wall, and palmar angles values changed in parallel, and hoof capsule thickness increased. No PD remodeling evidence within the hoof capsule or variations in the hoof axis with growth were found. We identified a baseline for the interpretation of forelimb radiological features in mule foals. The specific features found were intermediate between those found in horses and donkeys.

Immediate Proximal Row Carpectomy for Severe Perilunate Dislocation Injuries: A Minimum 5-Year Follow-Up.

Background: In patients with perilunate injuries (PLI) with multiple ligamentous and bony injuries involving the proximal carpal row, open reduction and internal fixation (ORIF) can be difficult and lead to poor functional outcomes. Proximal row carpectomy (PRC) is an alternative procedure that has been used for severely comminuted fractures. The aim of our study is to evaluate the long-term functional outcome (minimum 5 years) of patients that underwent an emergency PRC for PLI. Methods: We conducted a retrospective study of patients who underwent PRC at our centre between 2001 and 2016. Only patients with follow-up data of more than 5 years were included in the study. We evaluated range of motion, grip strength, Mayo Modified Wrist Score (MMWS) and Quick Disabilities of Arm, Shoulder and Hand (Quick-DASH). Radiographic analyses were performed to assess the presence of radiocarpal osteoarthritis and the space between the radius and capitate. Results: Thirteen patients were included, with an average follow-up of 78.07 months (6.5 years). The MMWS was 65 points (four excellent and good, four fair and five poor results) and the Quick-DASH score was 30 points. X-ray analysis reported only 15.3% of patients with radiocarpal arthrosis and an average radio-capitate joint space of 1.92 mm. Conclusions: The outcomes of PRC in the management of PLI are comparable to the results reported in literature for conventional ORIF. PRC is a simpler procedure that minimises the need for re-intervention. Level of Evidence: Level IV (Therapeutic).

Surgical treatment for the uncommon bi-articular fracture of trapezium: A case report.

Trapezium fracture is a rare condition that goes undetected and exposes to long-term comorbidities: chronic pain and rhizartrosis. Our work aims to summarize the clinical presentation and improve leading to therapeutic guidelines which are not well established by reporting a case of ORIF with mini-screws for a displaced fracture of the body of the trapezium with a satisfactory outcome.

Comparison of radiography and CT for the evaluation of third carpal bone slab fractures in Thoroughbred racehorses.

Slab fractures of the third carpal bone (C3) are a common cause of lameness in Thoroughbred racehorses. Information on fracture morphology is commonly obtained from radiographs or CT. This retrospective, methods comparison aimed to explore the agreement between radiography and CT for imaging C3 slab fractures and discuss the contribution of the latter to clinical case management. Thoroughbred racehorses with a slab or incomplete slab fracture of C3 identified on radiographs that subsequently underwent CT examination were included. Fracture characteristics (location, plane, classification, displacement, comminution) and fracture length as a percentage of the proximodistal length of the bone, termed the proximodistal fracture percentage (PFP) were recorded independently from both modalities and then compared. Across all fractures (n = 82) radiographs and CT showed slight agreement on the presence of comminution (Cohen's Kappa (κ) 0.108, P 0.031) and moderate agreement on fracture displacement (K 0.683, P < 0.001). Computed tomography identified comminution in 49 (59.8%) and displacement in nine (11.0%) fractures that were not detected by radiographs. Half of the fractures were only seen on flexed dorsoproximal-dorsodistal oblique (DPr-DDiO) radiographs and therefore were of unknown length without additional CT imaging. Incomplete fractures that could be measured on radiographs (n = 12) had a median (IQR) PFP of 40% (30%-52%) on radiographs and 53% (38%-59%) on CT, a statistically significant difference (P = 0.026). Radiography and CT showed the poorest agreement when determining the presence of comminution. Additionally, radiography often underestimated the incidence of displacement, and fracture length, and resulted in more fractures being classified as incomplete when compared to CT.

Periarticular distal radius fractures and complex ligamentous injury: The role of arthroscopic evaluation.

Purpose: Distal radius fractures are associated with a high incidence of concomitant soft tissue injuries, including lesions of the triangular fibrocartilage complex and intercarpal ligaments. While advanced imaging has allowed for greater identification of such tears, discerning which lesions pose a functional consequence remains a challenge for the hand surgeon. A review and guideline for arthroscopic evaluation of suspected combined injuries is presented. Results: Arthroscopic evaluation of distal radius fractures provides several unique advantages in such instances. Articular reduction can be performed via direct visualization with improvement in step-off and gapping. Furthermore, ligamentous injuries and carpal alignment can be directly assessed and treated. Conclusions: Subtle features of combined ligamentous trauma may be overlooked in the presence of more obvious fracture patterns. Wrist arthroscopy allows not only for a gold-standard method of evaluating of these soft tissue injuries, but also a means of treatment.

Comparison of Radiography and Computed Tomography for Evaluation of Third Carpal Bone Fractures in Horses.

Radiographs underestimate the extent of bone injury in horses with third carpal bone (C3) fractures (Fx). We aimed to describe bone pathologies identified using computed tomography (CT) and compare the diagnostic value of digital radiography (DR) and CT in horses with C3 Fx. CT images of 15 racehorses with C3 Fx and 10 controls were reviewed (Part 1) then DR and CT images of 26 racehorses (24 Thoroughbred, 2 Standardbred) with C3 Fx (Part 2) were evaluated. Agreement on fracture geometry and concomitant bone lesions was tested between DR and CT using the kappa statistic (Part 2). For agreement analysis, 38 limbs were used (27 Fx carpi from 26 horses and 11 contralateral carpi). Intermodality agreement was good for recognition of displacement, fair for comminution, articular surface bone loss and osseous fragmentation, and poor-slight for recognition of whether the Fx was complete, additional fissures and lucencies. CT provides more detailed information than DR regarding bone pathology and fracture configuration in horses with C3 fracture. Correlation of CT findings with clinical information and outcome needs to be explored; however, the more accurate diagnosis possible with CT is likely valuable when deciding on the most appropriate management and for surgical planning.