Volumetric Analysis of Carpal Bones by Sex with 3D Slicer Software Program / Análisis Volumétrico de los Huesos del Carpo por Sexo con el Programa de Software 3D Slicer

SUMMARY: In this study, we aim to share the volumes of the carpal bone and the ratio of these volumes to the total volume of wrist bones from Computed Tomography (CT) images obtained from individuals of different ages and sex using 3D Slicer. Right wrist CT images of 0.625 mm slice thickness of 42 healthy individuals (21 female, 21 male) of both sexes were included in our study. Volume calculations were made by loading the images into 3D Slicer, an open-source software package. In this study, mean capitate volume was the largest in both sexes (male 3479.9±679.2; female 2207.1±272.1 mm3), while pisiform had the smallest mean volume (male 810.0±141.2; female 566.6±97.7 mm3). This order was ordered from largest to smallest as hamate, scaphoid, trapezium, lunate, triquetrum, trapezoid, and pisiform. According to this study, carpal bone volumes were larger in males than in females (p0.05). In this study, it was seen that carpal bone volume differed according to sex. However, it was observed that the bone volumes of both sexes took up the same amount in the total bone volume. This information will be very useful in sex determination, 3D anatomical material creation, implant applications and reconstructive surgery.

Nuestro objetivo fue determinar los volúmenes de los huesos del carpo y la relación entre estos volúmenes y el volumen total de estos huesos a partir de imágenes de TC obtenidas de individuos de diferentes edades y sexos utilizando 3D Slicer. En el estudio se incluyeron imágenes de TC del carpo de la mano derecha de los participantes en el estudio, con un grosor de corte de 0,625 mm, en 42 individuos sanos (21 mujeres, 21 hombres) de ambos sexos. Los cálculos de volumen se realizaron cargando las imágenes en 3D Slicer, un paquete de software de código abierto. El volumen medio del hueso capitado fue el mayor en ambos sexos (hombre 3479,9 ± 679,2; mujer 2207,1 ± 272,1 mm3), mientras que el hueso pisiforme tuvo el volumen medio más pequeño (hombre 810,0 ± 141,2; mujer 566,6 ± 97,7 mm3). De mayor a menor el volumen de los otros huesos fue: hamato, escafoides, trapecio, lunato, piramidal, trapezoide y pisiforme. Según este estudio, los volúmenes óseos del carpo eran mayores en hombres que en mujeres (p0,05). En este estudio se observó que el volumen de los huesos del carpo difería según el sexo. Sin embargo, se observó que los volúmenes óseos de ambos sexos ocuparon la misma cantidad del volumen óseo total. Esta información será de gran utilidad en la determinación del sexo, creación de material anatómico 3D, aplicaciones de implantes y cirugía reconstructiva.

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.

Association between carpal height ratio and ulnar variance in normal wrist radiography.

INTRODUCTION: 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. METHODOLOGY: 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). CONCLUSION: Age correlated significantly with a decline in carpal height ratio. Additionally, ulnar variance had a week positive yet significant correlation with carpal height ratio. LEVEL OF EVIDENCE: Cross-sectional study, Level III.

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.

Artificial intelligence for automated detection and measurements of carpal instability signs on conventional radiographs.

OBJECTIVES: To develop and validate an artificial intelligence (AI) system for measuring and detecting signs of carpal instability on conventional radiographs. MATERIALS AND METHODS: Two case-control datasets of hand and wrist radiographs were retrospectively acquired at three hospitals (hospitals A, B, and C). Dataset 1 (2178 radiographs from 1993 patients, hospitals A and B, 2018-2019) was used for developing an AI system for measuring scapholunate (SL) joint distances, SL and capitolunate (CL) angles, and carpal arc interruptions. Dataset 2 (481 radiographs from 217 patients, hospital C, 2017-2021) was used for testing, and with a subsample (174 radiographs from 87 patients), an observer study was conducted to compare its performance to five clinicians. Evaluation metrics included mean absolute error (MAE), sensitivity, and specificity. RESULTS: Dataset 2 included 258 SL distances, 189 SL angles, 191 CL angles, and 217 carpal arc labels obtained from 217 patients (mean age, 51 years ± 23 [standard deviation]; 133 women). The MAE in measuring SL distances, SL angles, and CL angles was respectively 0.65 mm (95%CI: 0.59, 0.72), 7.9 degrees (95%CI: 7.0, 8.9), and 5.9 degrees (95%CI: 5.2, 6.6). The sensitivity and specificity for detecting arc interruptions were 83% (95%CI: 74, 91) and 64% (95%CI: 56, 71). The measurements were largely comparable to those of the clinicians, while arc interruption detections were more accurate than those of most clinicians. CONCLUSION: This study demonstrates that a newly developed automated AI system accurately measures and detects signs of carpal instability on conventional radiographs. CLINICAL RELEVANCE STATEMENT: This system has the potential to improve detections of carpal arc interruptions and could be a promising tool for supporting clinicians in detecting carpal instability.

Validation of radiographic assessment of radiocarpal (mal)alignment in a normal population.

We measured radiocarpal alignment in 150 standard lateral radiographs of normal wrists. In 84% of the cases, the lines of the long axis of the capitate and radius did not cross within the carpus.

Comparison of proximal row carpectomy with RCPI® versus proximal row carpectomy with Eaton's capsular interposition in the management of advanced wrist osteoarthritis.

INTRODUCTION: Proximal row carpectomy (PRC) is one of the recommended techniques for managing wrist osteoarthritis, it implies the integrity of the lunate fossa of the radius and the proximal pole of the capitate. If PRC is not possible, it is suggested to consider combining it with a capsule interposition (such as Eaton's flap) or opting for intra- or radiocarpal arthrodesis. Another alternative is to combine capitate resurfacing with a pyrocarbon implant (RCPi®). The aims of this study was to assessed the results between proximal PRC+Eaton and those associated PRC+RCPi® for advanced wrist osteoarthritis. HYPOTHESIS: We hypothesized that there would be no differences in clinical or functional outcome between proximal row carpectomy associated with RCPI® and those associated with Eaton capsular flap. MATERIAL AND METHODS: It is a monocentric, retrospective, multi-operator study involving 83 wrists with osteoarthritis, included between January 2000 and December 2020 with a minimum follow-up period of 12 months. Thirty-nine patients underwent PRC+Eaton and 44 patients underwent RCPI® resurfacing. Data such as pain, flexion, extension and strength as well as functional scores (PRWE, Mayo and quick DASH) were collected from the patient files at the last check-up. RESULTS: Results were comparable between the two groups in terms pain (VAS), mobility (flexion and extension), strength (GRASP) and functional scores (PRWE, Mayo and quick DASH). Carpal height was better preserved in the PRC+RCPI® group, with a Youm and McMurtry index evaluated at 0.3 in the PRC+Eaton group compared to 0.4 in the PRC+RCPI® group (p-value<0.001). Radiocarpal arthrodesis was required in 16% of the PRC+Eaton group and 6.8% of the PRC+RCPI® group, with a statistically significant difference (p-value=0.023). DISCUSSION: This study reports clinical and functional results that suggest RCPI® is an interesting alternative and can be associated with proximal row carpectomy in advanced wrist osteoarthritis. LEVEL OF EVIDENCE: IV; retrospective study.

Comparison of computer-aided and manual measurements in the evaluation of carpal alignment.

The purpose of this study was to compare computer-aided analysis and different methods of manual measurements in the evaluation of carpal alignment. The radioscaphoid, radiolunate, radiocapitate and radiometacarpal angles were measured on cone-beam computed tomography (CT) scans of 30 healthy wrists by automated software (Disior Ltd.) and by hand surgeons using lateral radiographs reconstructed from the CT data. Hand surgeons were either given (n = 6) or not given (n = 7) prior instructions on how to perform the measurements. Inter- and intra-observer reliability of manual measurements ranged from good to excellent (intra-class correlation coefficients [ICC] 0.77-0.99), being highest in specialists with standardized methods and in reconstructed radiographs with bone overlap digitally removed. Computer-aided software provided excellent intra-observer reliability (ICC 0.94-1.00) consistently and values that were highly comparable (mean difference range 1°-7°) with the manual measurements made in optimal settings. Computer-aided software provides an accurate and repeatable method to measure carpal alignment in CT scans, minimizing observational errors.

Association of ulnar variance with three-dimensional carpal alignment and demographics in asymptomatic volunteers.

BACKGROUND: Several carpal pathologies are considered to be related to ulnar variance. Recently, computer-aided computed tomography (CT) analysis software was introduced to quantify three-dimensional (3D) carpal alignment with high accuracy and reliability. PURPOSE: To determine the association of ulnar variance with 3D carpal alignment and demographics. MATERIAL AND METHODS: A wrist of 121 asymptomatic volunteers (69 men, 52 women; mean age = 38 ± 10.4 years) was imaged in the neutral wrist position with cone-beam CT. Computer-aided CT analysis software (Bonelogic), based on segmentation and numerical modelling, was used to define ulnar variance and standardized 3D axes for all carpal bones. The association of ulnar variance with 3D carpal alignment, age of the volunteer, and side and dominance of the imaged wrist was assessed. RESULTS: The mean ulnar variance was -1.6 ± 1.5 mm (range = -5.3 to 2.4 mm). The mean ulnar variance was -1.9 mm and -1.1 mm in men and women (P = 0.007), respectively. Of the imaged 121 wrists, 18 (15%) had positive and 103 (85%) negative ulnar variance. There was no association between ulnar variance and any of the radio- or intercarpal angle values in either the sagittal or coronal plane (ρ = -0.16…0.17, r = -0.13….0.12). The ulnar variance showed no association with side (P = 0.51) or dominance (P = 0.27) of the imaged wrist. CONCLUSION: 3D carpal alignment is not affected by ulnar variance. The association of ulnar variance with sex may in part explain the difference in reported prevalence of some carpal pathologies, such as ulnar impaction syndrome and Kienböck's disease.

The accuracy of Cameriere methods in Turkish children: chronological age estimation using developing teeth and carpals and epiphyses of the ulna and radius.

The aim of the present study was to develop a specific formula by measuring the developing teeth, carpal bones, and epiphyses of the ulna and radius to determine the chronological age in Turkish children. The left developing permanent mandibular teeth were evaluated, and the number of teeth with closed apex was recorded. The distance between the inner sides of open apex/apices was measured by using the ImageJ program and divided by the tooth length. The sum of the normalized open apices was also calculated. The carpal area (Ca), covering the epiphyses of ulna and radius and the carpal bones, was measured on the X-rays of left hand. The areas of each carpal bone and epiphyses of the ulna and radius were measured, and these measurements were added together to obtain the bone area (Bo). The Bo/Ca ratio between the total area of carpal bones and the carpal area was calculated to normalize the measurements. The accuracy of the equations formulated by Cameriere was evaluated, and a new regression equation was developed accordingly. The new formula showed no statistically significant difference between the chronological and the estimated age for females, males, and total sample. The new formula, which hit the age with 72.80% accuracy, was more successful in predicting chronological age than other adjusted regression equations. The new regression model, created for the Turkish children by using both developing teeth and hand-wrist bones, was considerably successful in estimating the chronological age.

Sex Determination by the Machine Learning Algorithms Through Using Morphometric Measurements of the Carpal, Metacarpal, and Phalangeal Bones / Determinación del Sexo Mediante Algoritmos de Aprendizaje Automático Mediante el Uso de Mediciones Morfométricas de los Huesos del Carpo, el Metacarpo y las Falanges

SUMMARY: In the study, it was aimed to predict sex from hand measurements using machine learning algorithms (MLA). Measurements were made on MR images of 60 men and 60 women. Determined parameters; hand length (HL), palm length (PL), hand width (HW), wrist width (EBG), metacarpal I length (MIL), metacarpal I width (MIW), metacarpal II length (MIIL), metacarpal II width (MIIW), metacarpal III length (MIIL), metacarpal III width (MIIIW), metacarpal IV length (MIVL), metacarpal IV width (MIVW), metacarpal V length (MVL), metacarpal V width (MVW), phalanx I length (PILL), measured as phalanx II length (PIIL), phalanx III length (PIIL), phalanx IV length (PIVL), phalanx V length (PVL). In addition, the hand index (HI) was calculated. Logistic Regression (LR), Random Forest (RF), Linear Discriminant Analysis (LDA), K-nearest neighbour (KNN) and Naive Bayes (NB) were used as MLAs. In the study, the KNN algorithm's Accuracy, SEN, F1 and Specificity ratios were determined as 88 %. In this study using MLA, it is understood that the highest accuracy belongs to the KNN algorithm. Except for the hand's MIIW, MIIIW, MIVW, MVW, HI variables, other variables were statistically significant in terms of sex difference.

En el estudio, el objetivo era predecir el sexo a partir de mediciones manuales utilizando algoritmos de aprendizaje automático (MLA). Las mediciones se realizaron en imágenes de RM de 60 hombres y 60 mujeres. Parámetros determinados; longitud de la mano (HL), longitud de la palma (PL), ancho de la mano (HW), ancho de la muñeca (EBG), longitud del metacarpiano I (MIL), ancho del metacarpiano I (MIW), longitud del metacarpiano II (MIIL), ancho del metacarpiano II (MIIW), longitud del metacarpiano III (MIIL), ancho del metacarpiano III (MIIIW), longitud del metacarpiano IV (MIVL), ancho del metacarpiano IV (MIVW), longitud del metacarpiano V (MVL), ancho del metacarpiano V (MVW), longitud de la falange I (PILL), medido como longitud de la falange II (PIIL), longitud de la falange III (PIIL), longitud de la falange IV (PIVL), longitud de la falange V (PVL). Además, se calculó el índice de la mano (HI). Regresión logística (LR), Random Forest (RF), Análisis discriminante lineal (LDA), K-vecino más cercano (KNN) y Naive Bayes (NB) se utilizaron como MLA. En el estudio, las proporciones de precisión, SEN, F1 y especificidad del algoritmo KNN se determinaron en un 88 %. En este estudio que utiliza MLA, se entiende que la mayor precisión pertenece al algoritmo KNN. Excepto por las variables MIIW, MIIIW, MIVW, MVW, HI de la mano, otras variables fueron estadísticamente significativas en términos de diferencia de sexo.

Quantitative 3-D CT Demonstrates Distal Row Pronation and Translation and Radiolunate Arthritis in the SNAC Wrist.

BACKGROUND: In scaphoid nonunion advanced collapse (SNAC) wrist arthritis, we analyzed the 3-dimensional (3-D) deformity patterns of carpal alignment secondary to scaphoid nonunion and quantified subchondral arthritis by investigating alterations in bone density. METHODS: We constructed 3-D models of the carpal bones and radius from 51 patients with scaphoid nonunion (nonunion group) and 50 healthy controls (control group). We quantified the differences in 3-D geometric position of the distal carpal row relative to the distal radius in SNAC wrists versus controls. In addition, we assessed the bone density of anatomic regions of interest in the radiocarpal and capitolunate joints relative to the pisiform bone density to characterize degenerative changes in SNAC wrists. RESULTS: The distal carpal row pronated by a difference of 14° (7.2° versus -6.7°; p < 0.001), deviated ulnarly by a difference of 19° (7.7° versus -11.2°; p < 0.001), shifted dorsally by a difference of 17% of the dorsovolar width of the distal radius (21.0% versus 4.4%; p < 0.001), shifted radially by a difference of 8% of the radioulnar width of the distal radius (13.2% versus 5.3%; p < 0.001), and migrated proximally by a difference of 12% of the lunate height (96.3% versus 108.8%; p < 0.001) in the nonunion group compared with the control group. Additionally, it was found that bone density was greater at the capitolunate joint (capitate head: 140.4% versus 123.7%; p < 0.001; distal lunate: 159.9% versus 146.3%; p < 0.001), the radial styloid (157.0% versus 136.3%; p < 0.001), and the radiolunate joint (proximal lunate: 134.8% versus 122.7%; p < 0.001; lunate fossa: 158.6% versus 148.1%; p = 0.005) in the nonunion group compared with the control group. CONCLUSIONS: Scaphoid nonunion exhibited a unique deformity pattern and alteration in bone-density distributions. The distal carpal row not only shifted dorsally and migrated proximally but also pronated, deviated ulnarly, and shifted radially. Bone density was greater at the capitolunate joint, the radial styloid, and surprisingly, the radiolunate joint. Our findings give insight into the natural history and progression of arthritis of the SNAC wrist. Additionally, future studies may give insight into whether successful treatment of scaphoid nonunion arrests the progression of arthritis. LEVEL OF EVIDENCE: Prognostic Level III . See Instructions for Authors for a complete description of levels of evidence.

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).

Correlation between delayed carpal tunnel syndrome and carpal malalignment after distal radial fracture.

BACKGROUND: Delayed carpal tunnel syndrome after Colles' fracture is a common complication particularly following conservative treatment. The aim of the study was to verify the correlation of different radiological parameters of carpal alignment and the development as well as the severity of DCTS in elderly female patients within 6 months of distal radial fracture (DRF). METHODS: This is a retrospective case-control study that included 60 female patients with DRF within 6 months treated conservatively (30 patients with signs and symptoms suggestive of DCTS and 30 asymptomatic patients as a control group). Electrophysiological evaluation was done for all the participants, as well as radiological assessment to measure parameters of carpal alignment mainly radiocapitate distance (RCD), volar prominence height (VPH) and volar tilt (VT). RESULTS: There was a statistical significant difference between both groups regarding the radiological parameters of carpal alignment (The mean values of RCD, VT and VPH were - 11.48 mm, - 20.68° angle, and 2.24 mm respectively in the symptomatic group). A strong correlation was found between decrease in the parameters of carpal alignment and the severity of DCTS. Logistic regression analysis showed that VT is strongly involved in the development of DCTS. The threshold value of the VT was - 20.2° angle (sensitivity 0.83; specificity 0.9; odds ratio 45; 95% CI 0.894-0.999; p < 0.001). CONCLUSIONS: Anatomical alteration of the carpal tunnel after DRF with dorsal displacement of the carpal bones contribute to the development of DCTS. Decreasing VT and VPH and RCD are the most significant independent predictors for the development of DCTS in conservatively managed DRF. Protocol ID: 0306060.

Lunotriquetral Coalition.

Lunotriquetral (LT) coalition is the most common carpal coalition. Four morphological types of LT coalition have been described. LT coalition is usually asymptomatic, but rarely a fibrocartilaginous type may cause ulnar wrist pain. We report a case of bilateral asymptomatic LT coalition that was seen incidentally on conventional radiography taken after a wrist injury. Conventional radiography is the first imaging technique to detect and classify this type of LT coalition. Magnetic resonance imaging is a useful tool to investigate possible associated pathology of the carpal joints, particularly if surgical treatment of a symptomatic patient is anticipated.

Three-dimensional carpal alignment: computer-aided CT analysis of carpal axes and normal ranges.

Assessment of carpal alignment traditionally uses carpal bone axes measured on lateral radiographs. In this study, three-dimensional axes were defined for carpal bones using segmentation and numerical modelling of CT data of 121 neutrally positioned, asymptomatic wrists. The geometric axis was used for radius, scaphoid and capitate, whereas the axis based on a line perpendicular to the articular surface was used for the other carpal bones. Normal values of radiocarpal angles in the radial coordinate and the reliability of the computer-aided analysis are reported. The mean sagittal radiocarpal angles (positive in palmar direction) were as follows: scaphoid 58° (SD 10°), lunate 0° (SD 11°), triquetrum 12° (SD 8°), trapezium 17° (SD 8°), trapezoid -10° (SD 7°), capitate -17° (SD 9°) and hamate 2° (SD 7°). The mean coronal radiocarpal angles (positive in ulnar direction) were -42° (SD 9°), -20° (SD 4°), -49° (SD 4°), -32° (SD 6°), -16° (SD 5°), 2° (SD 7°) and 8° (SD 6°), respectively. The intra-observer reliability of the measurements was excellent (mean intraclass correlations coefficient 0.98). This study provides guidelines on how to measure and quantify carpal alignment three-dimensionally, and a database for the normal values. Together, these may be useful when analysing various wrist pathologies and kinematics of the wrist.

Diagnostic performance of traditional radiographic indices in detection of carpal collapse in Kienböck's disease.

Correctly identifying carpal collapse is important for adequate treatment of Kienböck's disease. This study aimed to assess the accuracy of traditional radiographic indices in detecting carpal collapse to differentiate between Lichtman stages IIIa and IIIb. In 301 patients, carpal height ratio, revised carpal height ratio, Ståhl index and radioscaphoid angle were measured on plain radiographs by two blinded observers. As a reference standard, Lichtman stages were determined by an expert radiologist using CT and MR imaging. The interobserver agreement was excellent. In the differentiation between Lichtman stages IIIa and IIIb, measurements of indices showed moderate to good sensitivity (0.60-0.95) and low specificity (0.09-0.69) using normal cut-off values from the literature, while receiver operating curve analysis revealed poor area under the curve (58-66%). Traditional radiographic indices showed poor diagnostic performance in detecting carpal collapse in Kienböck's disease and did not reach sufficient accuracy in the differentiation between Lichtman stages IIIa and IIIb.Level of evidence: III.

Age estimation of puppies based on the radiographically assessed development of ossification centres in the carpal and metacarpal regions.

BACKGROUND: The need for proper age determination in puppies has increased enormously due to the growing illegal trade in puppies that are too young to be removed from the litter or too young to have been properly vaccinated against rabies. METHODS: Dorsopalmar and mediolateral radiographs of the (meta)carpal region, either taken from puppy cadavers or from the Faculty's patient database, were studied in a cross-sectional study of 252 puppies of various sizes, aged 6-212 days. The appearance and development of ossification centres as a function of age in five regions of interest in the (meta)carpal region were scored using a two- to six-step scoring system based on shape and delineation. RESULTS: A positive correlation with age was found for all investigated regions. Intra- and interrater agreement between two observers was excellent, except for the distal epiphyses of the metacarpal bones. Postnatal ossification started after the second week of life with the carpal bones, closely followed by the radial trochlea. All ossification centres were present in all puppies from 84 days, except for the sesamoid bone in the tendon of the long abductor muscle of the first digit. Timing of appearance differed significantly between different sized breeds. There were no significant differences between the sexes. LIMITATIONS: Age distribution was not balanced for all breed size classes. CONCLUSIONS: The radiographic timing of the appearance and development of ossification centres in the carpal region is a promising method for age estimation in puppies.

Epidemiology of carpal fractures: is it only about the scaphoid?

Because of their low incidence, studies about carpal fractures are rare. The aim of the present study was to analyze epidemiology and treatment of fractured carpal bones. We retrospectively analyzed data of 178 patients admitted to our emergency room with carpal fractures over 6 years. More males than woman were injured. In 91%, a CT scan was performed. The most commonly affected bone was the triquetrum followed by the scaphoid. Almost all triquetral fractures were treated conservatively as opposed to perilunate dislocations that were all operated on. Half of all patients with scaphoid fractures were operated. Young men had the highest risk to sustain a carpal fracture. The triquetrum and the scaphoid are most frequently affected. Usually a CT scan is needed. Treatment of scaphoid and perilunate luxation fractures is rather operative whereas the other fractures mostly allow conservative casting. Nevertheless, correct indication for treatment is important to avoid sequelae.