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.

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.

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.

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).

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.

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.

Bone age assessment: Large-scale comparison of Greulich-Pyle method and Tanner-Whitehouse 3 method for Taiwanese children.

BACKGROUND: The Greulich-Pyle (GP) and Tanner-Whitehouse 3 (TW3) methods are two common methods for assessing bone age (BA). The applicability of these methods for populations other than those in the United States and Europe has been questioned. Thus, this study tested the applicability of these methods for Taiwanese children. METHODS: In total, 1476 radiographs (654 boys, 822 girls) were analyzed. A subset of 200 radiographs was evaluated to determine intrarater and interrater reliability and the time required to yield a BA assessment. BA was determined by two reviewers using the GP method and two of the TW3 methods (the Radial-Ulnar-Short bones [RUS] method and the carpals method [Carpal]). The GP and TW3 methods were directly compared using statistical techniques. A subgroup analysis by age was performed to compare BA and chronological age using a paired t test for each age group. RESULTS: The average times required to yield an assessment using the GP and TW3-RUS methods were 0.79 ± 0.14 and 3.01 ± 0.84 min (p < 0.001), respectively. Both the intrarater and interrater correlation coefficients were higher for the GP method (0.993, 0.992) than the TW3-RUS (0.985, 0.984) and TW3-Carpal (0.981, 0.973) methods. The correlation coefficient for the GP and TW3-RUS methods was highest in the pubertal stage (0.898 for boys and 0.909 for girls). The mean absolute deviations for the GP and TW3-RUS methods in the pubertal stage were 0.468 years (boys) and 0.496 years (girls). Both the GP and TW3-Carpal methods underestimated BA for boys in the prepubertal stage. Both the GP and TW3-RUS methods overestimated BA for girls in the pubertal and postpubertal stages. CONCLUSION: The GP and TW3-RUS methods exhibit strong agreement in the pubertal and postpubertal stages for both sexes. With appropriate adjustments based on Taiwanese data, both methods are applicable to our children.

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.

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.

Pre-operative imaging for surgical decision-making and the frequency of wrist arthrodesis and carpectomy procedures: a scoping review.

OBJECTIVES: Our objectives were to (1) analyze the imaging modalities utilized pre-operatively that influence surgical decision-making for wrist arthrodesis and carpectomy procedures and (2) determine the type and frequency of these procedures for the treatment of wrist arthritis. MATERIALS AND METHODS: This review was performed according to the guidelines of PRISMA Extension for Scoping Reviews. Using PubMed, Embase, and Scopus, peer-reviewed literature from 2011 to 2022 was searched for use of imaging in pre-operative decision-making for wrist arthrodesis and carpectomy surgical procedures. Data were compiled to determine the type(s) of imaging modalities used pre-operatively and types of surgical techniques reported in the literature. RESULTS: Of 307 articles identified, 35 articles satisfied eligibility criteria, with a total of 1377 patients (68% men; age mean, 50.9 years [range, 10-81]) and 1428 wrist surgical interventions. Radiography was reported for pre-operative planning in all articles for all patients. Pre-operative cross-sectional imaging was reported in 2 articles (5.7%), but no articles reported detailed data on how CT or MRI influenced pre-operative wrist arthrodesis and carpectomy procedure decision-making. A dozen different types of surgical techniques were reported. The four most common procedures were four-corner arthrodesis with scaphoid excision (846, 59%), proximal row carpectomy (239, 17%), total wrist arthrodesis (130, 9%), and scaphocapitate arthrodesis (53, 4%). CONCLUSION: Radiography is always used in pre-operative decision-making, but the literature lacks data on the influence of CT and MRI for selecting among a dozen different types of wrist arthrodesis and carpectomy procedures.

A Case for Acute Proximal Row Carpectomy for Perilunate Injuries.

Background: Perilunate injuries are complex injuries typically arising from high-energy injuries to the wrist. Standard treatment involves open reduction and internal fixation with ligamentous reconstruction; however, outcomes are fraught with complications including pain, stiffness, and arthrosis. Several case reports have demonstrated the role of proximal row carpectomy as a salvage procedure for complex carpal trauma in the setting of significant cartilage injury or bone loss. The authors believe that proximal row carpectomy may be an appropriate acute treatment in certain patient populations, with functional results similar to those obtained with ligamentous reconstruction. Methods: A retrospective review of two cases with perilunate dislocations managed with primary proximal row carpectomy are presented. Results: At greater than 1-year follow-up, both patients had stable radiocarpal alignment. Quick-DASH scores were 22.7 and 27.3. Conclusion: Primary proximal row carpectomy is a treatment option in the acute setting for perilunate injuries in elderly, lower-demand patients. Functional results are similar to those obtained with ligamentous reconstruction, with a shorter recovery period. Level of Evidence: IV.

Skeletal age assessed by TW2 using 20-bone, carpal and RUS score systems: Intra-observer and inter-observer agreement among male pubertal soccer players.

The purpose of this study was to determine intra- and inter-observer agreement for the three skeletal ages derived from the TW2 method among male pubertal soccer players. The sample included 142 participants aged 11.0-15.3 years. Films of the left hand-wrist were evaluated twice by each of two observers. Twenty bones were rated and three scoring systems used to determine SA adopting the TW2 version: 20-bone, CARPAL and RUS. Overall agreement rates were 95.1% and 93.8% for, respectively, Observer A and Observer B. Although, agreement rates between observers differed for 13 bones (5 carpals, metacarpal-I, metacarpal-III, metacarpal-V, proximal phalanges-I, III and V, distal phalanx-III), intra-class correlationa were as follows: 0.990 (20-bone), 0.969 (CARPAL), and 0.988 (RUS). For the three SA protocols, BIAS was negligible: 0.02 years (20-bone), 0.04 years (CARPAL), and 0.03 years (RUS). Observer-associated error was not significant for 20-bone SA (TEM = 0.25 years, %CV = 1.86) neither RUS SA (TEM = 0.31 years, %CV = 2.22). Although the mean difference for CARPAL SAs between observers (observer A: 12.48±1.18 years; observer B: 12.29±1.24 years; t = 4.662, p<0.01), the inter-observer disagreement had little impact (TEM: 0.34 years: %CV: 2.78). The concordance between bone-specific developmental stages seemed was somewhat more problematic for the carpals than for the long bones. Finally, when error due to the observer is not greater than one stage and the replicated assignments had equal probability for being lower or higher compared to initial assignments, the effect on SAs was trivial or small.

Reliability of radio-ulnar and carpal alignment measurements in the wrist between radiographs and 3D imaging.

OBJECTIVE: Conventional radiography is the first modality to investigate the radio-ulno-carpal joint in the event of trauma or instability. This study sought to determine the reliability of cone beam computer tomography (CBCT) and scout of view in evaluating carpal alignment compared with conventional radiographs in order to assess the influence of wrist kinematics on usual measurements. MATERIALS AND METHODS: We prospectively recruited 305 patients who successively underwent plain radiography and CBCT. 51 patients with prior acute unilateral wrist trauma were eligible for entry into the study (mean age of 39 years). Three blinded readers performed the measurements separately. The axial method and bony axial lines defined previously in the literature were applied, with three categories of measurements performed, consisting of distal radio-ulnar, radiocarpal, and radio/carpometacarpal measurements. Intraclass correlation coefficients (ICCs) for paired t-test were calculated to assess inter- and intra-observer agreements. RESULTS: Inter-observer agreement was very high (>0.94) for all modalities. Intra-observer reliability between scout view and CBCT was almost perfect for all measurements. Intra-observer reliability between radiograph and scout view/CBCT was perfect for distal radio-ulnar measurements, substantial for radio-carpal, and moderate for radio/carpometacarpal measurements. CONCLUSION: In the absence of a strict position control between two imaging acquisitions, only distal radio-ulnar measurements were shown perfectly reliable when using these two imaging methods, which is suggestive of a minor relevance of ulnar/radial deviation. Excepting for some angles, the radio-carpal and radio-carpometacarpal measurements were shown to differ according to wrist position, being thus more sensitive to flexion/extension of the wrist.

Anatomical study of all carpal and adjoining bones of the wrist using 3D CT reconstruction -Finding the ultimate biomechanical theory.

BACKGROUND: The complex interplay of single wrist bones acting in combination with their ligamentous connections is still not fully understood. In this regard various theories exist, divisible in columnar and ring/row theories. The object of this study was to examine the mobility of the individual carpal bones as well as the ulna and metacarpals relative to each other in wrists of cadaveric hands using CT scans. METHODS: The regular wrist mobility of a total of 21 cadaveric hands was examined by CT imaging in neutral position, radial/ulnar abduction as well as wrist flexion and extension. The data were evaluated as 3D models by using a standardized global coordinate system and object coordinate systems. Rotation and translation of each carpal bone as well as radius/ulna and all metacarpal bones were evaluated. RESULTS: The principal motion took place in the carpus between the radius and the proximal carpal row followed by the midcarpal joint and the carpometacarpal joints and not mainly between the individual bones of a row. The scaphoid moves out of its row aggregate mainly during flexion and adapts to the motion of the distal carpal row. The trapezium and first metacarpal bones play a specific role detached from the remaining bones. CONCLUSIONS: With this study, a better understanding of the motion of the individual bones of the carpus, the metacarpals and the radius/ulna is shown. The study supports the row theory, where most motion takes place between the individual rows and not between the carpal bones, leaving the scaphoid and the first ray in a special role between the rows.