Ulnar shape of extant primates: Functional signals and covariation with triquetrum shape.

OBJECTIVES: In this study, we investigated the shape differences of the distal ulna in a phylogenetic context among a broad range of primate taxa. Furthermore, we evaluated covariation between ulnar and triquetrum shape and a possible association between ulnar shape and locomotor behavior. MATERIALS AND METHODS: We applied 3D geometric morphometrics on a large dataset comprising the distal ulna of 124 anthropoid primate specimens belonging to 12 different genera. For each species, a mean shape was calculated using 11 Procrustes-aligned surface landmarks on the distal ulna. These mean shapes are used in a bgPCA, pPCA, and PACA and 3D morphs were used to visualize more subtle differences between taxa. A p2B-PLS analysis was performed to test the covariance between distal ulnar and triquetrum shape. RESULTS: The results show that more closely related species exhibit a similar distal ulnar shape. Overall, extant hominid ulnae show a shape shift compared to those of extant monkeys and hylobatids. This includes a shortening of the ulnar styloid process and dorspalmarly widening of the ulnar head, shape characteristics that are independent of phylogeny. Within the hominids, Pongo pygmaeus seem to possess the most plesiomorphic distal ulnar shape, while Gorilla and Homo sapiens display the most derived distal ulna. Cercopithecoids, hylobatids, and P. pygmaeus are characterized by a relatively deep ECU groove, which is a shape trait dependent of phylogeny. Although there was no significant covariation between distal ulnar shape and triquetrum shape, the shape differences of the distal ulna between the different primate taxa reveal a possible link with locomotor behavior. CONCLUSIONS: The comparative analyses of this study reveal different shape trends in a phylogenetic context. Highly arboreal primates, such as hylobatids and Ateles fusciceps, show a distal ulnar morphology that appears to be adapted to tensile and torsional forces. In primates that use their wrist under more compressive conditions, such as quadrupedal cercopithecoids and great apes, the distal ulnar morphology seems to reflect increased compressive forces. In modern humans, the distal ulnar shape can be associated to enhanced manipulative skills and power grips. There was no significant covariation between distal ulnar shape and triquetrum shape, probably due to the variation in the amount of contact between the triquetrum and ulna. In combination with future research on wrist mobility in diverse primate taxa, the results of this study will allow us to establish form-function relationships of the primate wrist and contribute towards an evidence-based interpretation of fossil remains.

Carpal kinematics and morphological correlates of wrist ulnar deviation mobility in nonhuman anthropoid primates.

OBJECTIVES: Primates employ wrist ulnar deviation during a variety of locomotor and manipulative behaviors. Extant hominoids share a derived condition in which the ulnar styloid process has limited articulation or is completely separated from the proximal carpals, which is often hypothesized to increase ulnar deviation range of motion. Acute angulation of the hamate's triquetral facet is also hypothesized to facilitate ulnar deviation mobility and mechanics. In this study, we test these longstanding ideas. METHODS: Three-dimensional (3D) carpal kinematics were examined using a cadaveric sample of Pan troglodytes, Pongo sp., and five monkey species. Ulnar styloid projection and orientation of the hamate's triquetral facet were quantified using 3D models. RESULTS: Although carpal rotation patterns in Pan and Pongo were uniquely similar in some respects, P. troglodytes exhibited overall kinematic similarity with large terrestrial cercopithecoids (Papio and Mandrillus). Pongo, Macaca, and Ateles had high wrist ulnar deviation ranges of motion, but Pongo did this via a unique mechanism. In Pongo, the triquetrum functions as a distal carpal rather than part of the proximal row. Ulnar styloid projection and wrist ulnar deviation range of motion were not correlated but ulnar deviation range of motion and the triquetrohamate facet orientation were correlated. CONCLUSIONS: Increased ulnar deviation mobility is not the function of ulnar styloid withdrawal in hominoids. Instead, this feature probably reduces stress on the ulnar side wrist or is a byproduct of adaptations that increase supination. Orientation of the hamate's triquetral facet offers some potential to reconstruct ulnar deviation mobility in extinct primates.

[Support algorithm for lateral elbow pain syndrome in adults]. / Douleurs latérales du coude chez l'adulte : algorithme de prise en charge.

Lateral elbow pain syndrome in adults is a frequent complaint leading to consultation in primary care medicine. The lateral side of the elbow joint represents a complex anatomy with close proximity of bony structures (humerus, radius, and ulna), ligaments (lateral ligament complex), tendons (origin of the extensors of the wrist and fingers), and nerves (branches of the radial nerve) making diagnostic and therapeutic management demanding. This article aims to provide a basis for reflection to better define treatment options for pathologies frequently encountered in clinical practice.

Les douleurs de la face latérale du coude chez l'adulte sont un motif fréquent de consultation en médecine de premier recours. La face latérale de cette articulation représente une anatomie complexe avec une proximité des structures osseuses (humérus, radius et ulna), ligamentaires (complexe ligamentaire latéral), tendineuses (origine des extenseurs du poignet et des doigts) et nerveuses (branches du nerf radial) rendant l'orientation diagnostique et la prise en charge thérapeutique exigeantes. Cet article propose une base de réflexion pour mieux définir les options de prises en charge des pathologies fréquemment retrouvées en pratique clinique.

Morphological characteristics of coronoid process and revisiting definition of coronoid hyperplasia.

The aim of this study was to assess the morphological characteristics of the coronoid process (CP) and define coronoid hyperplasia (CH) using cadaveric mandibles of a Caucasian population. A sample of 151 adult dry cadaveric mandibles (302 CPs) was acquired. Three distances were measured, which included the width, height, and length of CP. The surface area measurements involved area A: above the width distance line; area B: between incisura mandibulae-Alveolar ridge line and width distance line; area C: between distance lines of width and height. Finally, angulations of the CP and gonial angles were identified. Both length and surface area A + B acted as hyperplastic indicators. Based on the selection criteria, a sample of 197 CPs was included. The hooked shape (59%) was most commonly observed. No significant difference existed between left and right sides (p > 0.05). The mean values of length and surface area A + B were 2.2 ± 0.3 cm and 3.3 ± 0.8 cm2, and any values above 2.7 cm (n = 5 CPs- 2.5%) and 5.0 cm2 (n = 9 CPs- 4.6%) were described as hyperplastic, respectively. The presented data could act as quantitative reference for differentiating between normal and hyperplastic conditions.

Morphometrics of the coronoid process and the radial notch of the ulna: implications for fracture assessment.

PURPOSE: A comprehensive analysis of the morphology of fractures of the coronoid process (CP) can aid diagnosis and guide treatment. The involvement of the radial notch of the ulna (RN)-e.g., in anterolateral facet fractures and transverse fractures of the CP-may influence the biomechanical conditions of the proximal radioulnar joint. However, the morphometric relation between the CP and the RN and the extent to what the proximal radioulnar joint can be affected in these types of fractures is unknown. METHODS: A total of 113 embalmed, cadaveric ulnae were dissected. All soft tissue was removed. Strictly lateral, high-resolution photographs were taken and digitally analyzed. The height of the CP and its relation to the RN was measured. Sex differences and correlations between measured parameters were calculated. RESULTS: Mean height of the CP was 16 mm (range: 12-23 mm; SD: 2). Mean height of the RN was 16 mm (11-25 mm; 2.2). The 50% mark of the CP corresponded to 18% (0-56%; 11.2) of the height of the RN. No significant differences were found between male and female specimens. CONCLUSION: The RN of the ulna extends only to a small part to the CP. Transverse or anterolateral fractures of less than 50% of the coronoid process may involve only a small portion of the proximal radioulnar joint.

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.

Proximal ulna morphology in various pediatric population age groups: proximal ulna dorsal angulation (PUDA) and olecranon tip-to-apex (TTA) distance.

PURPOSE: To measure proximal ulna dorsal angulation (PUDA) and olecranon tip-to-apex distance (TTA) in pediatric population to aid surgeons with data for proximal ulna fractures fixation. METHODS: Retrospective review of the hospital radiographic database. All elbow radiographs were identified and after implementing exclusion criteria, included were 95 patients aged 0-10; 53 patients aged 11-14; and 53 patients aged 15-18. PUDA was defined as the angle between lines placed on the "flat spot" of the olecranon and the dorsal edge of the ulnar shaft and TTA as the distance between the tip of the olecranon to the apex of angulation. Two evaluators performed measurements independently. RESULTS: In age group 0-10, mean PUDA was 7.53°, range 3.8-13.7, 95% CI 7.16-7.91, while mean TTA was 22.04 mm, range 8.8-50.5, 95% CI 19.92-24.17. In age group 11-14, mean PUDA was 4.99°, range 2.5-9.3, 95% CI (4.61-5.37), while mean TTA was 37.41 mm, range 16.5-66.6, 95% CI (34.91-39.90). In age group 15-18, mean PUDA was 5.18°, range 2.9-8.1, 95% CI (4.75-5.61), while mean TTA was 43.79 mm, range 24.5-79.4, 95% CI (41.38-46.19). PUDA was negatively correlated with age (r = - 0.56, p < 0.001), while TTA was positively correlated with age (r = 0.77, p < 0.001). Reliability levels of 0.81-1 or 0.61-0.80 were achieved for most of intra- and inter-rater reliabilities besides two levels of 0.41-60 and one of 0.21-0.40. CONCLUSION: The main study finding is that in most cases mean age-group values may serve as a template for proximal ulna fixation. There are some cases in which X-ray of contralateral elbow may provide surgeon with a better template. LEVEL OF EVIDENCE: II.

Knuckle-walking in Sahelanthropus? Locomotor inferences from the ulnae of fossil hominins and other hominoids.

Because the ulna supports and transmits forces during movement, its morphology can signal aspects of functional adaptation. To test whether, like extant apes, some hominins habitually recruit the forelimb in locomotion, we separate the ulna shaft and ulna proximal complex for independent shape analyses via elliptical Fourier methods to identify functional signals. We examine the relative influence of locomotion, taxonomy, and body mass on ulna contours in Homo sapiens (n = 22), five species of extant apes (n = 33), two Miocene apes (Hispanopithecus and Danuvius), and 17 fossil hominin specimens including Sahelanthropus, Ardipithecus, Australopithecus, Paranthropus, and early Homo. Ulna proximal complex contours correlate with body mass but not locomotor patterns, while ulna shafts significantly correlate with locomotion. African apes' ulna shafts are more robust and curved than Asian apes and are unlike other terrestrial mammals (including other primates), curving ventrally rather than dorsally. Because this distinctive curvature is absent in orangutans and hylobatids, it is likely a function of powerful flexors engaged in wrist and hand stabilization during knuckle-walking, and not an adaptation to climbing or suspensory behavior. The OH 36 (purported Paranthropus boisei) and TM 266 (assigned to Sahelanthropus tchadensis) fossils differ from other hominins by falling within the knuckle-walking morphospace, and thus appear to show forelimb morphology consistent with terrestrial locomotion. Discriminant function analysis classifies both OH 36 and TM 266 with Pan and Gorilla with high posterior probability. Along with its associated femur, the TM 266 ulna shaft contours and its deep, keeled trochlear notch comprise a suite of traits signaling African ape-like quadrupedalism. While implications for the phylogenetic position and hominin status of S. tchadensis remain equivocal, this study supports the growing body of evidence indicating that S. tchadensis was not an obligate biped, but instead represents a late Miocene hominid with knuckle-walking adaptations.

Anatomy of the distal radioulnar ligament in cats.

OBJECTIVES: The aim of this study was to describe the anatomy of the distal radioulnar ligament in the cat, using gross and histological sections from cadaveric feline carpi. METHODS: Eight feline cadaveric distal radioulnar joints were included in the study, including six that were paraffin- and two that were polymethyl methacrylate-embedded. Each of the sections of the distal radioulnar joint and ligament were viewed macroscopically and microscopically using a dissection microscope and a standard light microscope with polarising capacity. RESULTS: On gross examination, the distal radioulnar ligament could be seen as a triangular-shaped structure extending between the dorsal surface of the distal radius and ulna. The centre of the ligament had a greater density of tightly packed collagen fibres, while fibrocartilage was identified at the site of both the radial and ulnar entheses. Articular cartilage was noted to extend to the most proximal part of the bulbous portion of the distal ulna and corresponding axial aspect of the distal radius. CONCLUSIONS AND RELEVANCE: In the cat, there appears to be a less extensive interosseous component of the distal radioulnar ligament compared with the dog and cheetah. Instead, the ligament follows the articular surfaces of the distal radius and ulna. These anatomical differences may account for increased rotation of the feline antebrachium and have clinical implications, particularly with regard to the management of antebrachiocarpal joint injuries.

Shape variation in the limb long bones of modern elephants reveals adaptations to body mass and habitat.

During evolution, several vertebrate lineages have shown trends towards an increase in mass. Such a trend is associated with physiological and musculoskeletal changes necessary to carry and move an increasingly heavy body. Due to their prominent role in the support and movement of the body, limb long bones are highly affected by these shifts in body mass. Elephants are the heaviest living terrestrial mammals, displaying unique features allowing them to withstand their massive weight, such as the columnarity of their limbs, and as such are crucial to understand the evolution towards high body mass in land mammals. In this study, we investigate the shape variation of the six limb long bones among the modern elephants, Elephas maximus and Loxodonta africana, to understand the effect of body mass and habitat on the external anatomy of the bones. To do so, we use three-dimensional geometric morphometrics (GMMs) and qualitative comparisons to describe the shape variation, at both the intraspecific and interspecific levels. Our results reveal that the two species share similar negative ontogenetic allometric patterns (i.e. becoming stouter with increased length) in their humerus and femur, but not in the other bones: the proximal epiphyses of the stylopod bones develop considerably during growth, while the distal epiphyses, which are involved in load distribution in the elbow and knee joints, are already massive in juveniles. We attribute this pattern to a weight-bearing adaptation already present in young specimens. Among adults of the same species, bone robustness increases with body mass, so that heavier specimens display stouter bones allowing for a better mechanical load distribution. While this robustness variation is significant for the humerus only, all the other bones appear to follow the same pattern. This is particularly visible in the ulna and tibia, but less so in the femur, which suggests that the forelimb and hindlimb adapted differently to high body mass support. Robustness analyses, while significant for the humerus only, suggest more robust long bones in Asian elephants than in African savanna elephants. More specifically, GMMs and qualitative comparisons indicate that three bones are clearly distinct when comparing the two species: in E. maximus the humerus, the ulna and the tibia display enlarged areas of muscular insertions for muscles involved in joint and limb stabilization, as well as in limb rotation. These results suggest a higher limb compliance in Asian elephants, associated with a higher dexterity, which could be linked to their habitat and foraging habits.

Osteology and radiographic anatomy of the thoracic limb of the greater cane rat (Thryonomys swinderianus).

The greater cane rat (Thryonomys swinderianus) is mainly distributed in the humid and sub-humid regions of the sub-Saharan Africa. It is believed to be the second largest African rodent. The aim of this study was to describe the normal osteology and radiographic anatomy of the thoracic limb of the greater cane rat as a reference for teaching, clinical use, anatomical studies and biomedical research. Five intact dead greater cane rats were used for radiographic examination. Radiographic findings were correlated with bone specimens. The clavicle was seen in all animals. The scapula was wide with well-developed acromion and coracoid process. The major and minor tubercles did not extend higher than the head of the humerus. The deltoid tuberosity was very prominent. The medial epicondyle was larger than its lateral counterpart, and the supratrochlear foramen was present. The radial tuberosity was further distally located. The ulnar head was well-developed, and the olecranon tuber was square-shaped. The distal physes for the radius and ulna appeared transverse. The carpus had eight bones. The manus presented with five widely spread digits. The first digit was reduced in size and placed such that the dorsal and palmar surfaces face almost medial and lateral, respectively. Additionally, two rudimentary digits were seen. Variations exist in the normal osteology and radiographic anatomy of the thoracic limb in different species. Knowledge of the normal osteology and radiographic anatomy of the thoracic limb of individual species is important for species identification and diagnosis of musculoskeletal diseases involving the thoracic limb.

The lateral ulnar collateral ligament: Anatomical and structural study for clinical application in the diagnosis and treatment of elbow lateral ligament injuries.

The lateral ulnar collateral ligament (LUCL) is considered one of the main stabilizers of the elbow. However, its anatomical description is not well established. Imaging techniques do not always have agreed upon parameters for the study of this ligament. Therefore, herein, we studied the macro and microanatomy of the LUCL to establish its morphological and morphometric characteristics more precisely. Fifty-five fresh-frozen human elbows underwent dissection of the lateral collateral ligament. Morphological characteristics were studied in detail. Ultrasound (US) and magnetic resonance (MR) were done before dissection. Two specimens were selected for PGP 9.5 S immunohistochemistry. Ten additional elbows were analyzed by E12 sheet plastination. LUCL was identified in all specimens and clearly defined by E12 semi-thin sections. It fused with the common extensor tendon and the radial ligament. The total length of the LUCL was 48.50 mm at 90°, 46.76 mm at maximum flexion and 44.10 mm at complete extension. Three morphological insertion variants were identified. Both US and MR identified the LUCL in all cases. It was hypoechoic in the middle and distal third in 85%. The LUCL was hypointense on MR in 95%. Free nerve endings were present on histology. The LUCL is closely related to the anular ligament. It is stretched during flexion and supination. US and MR can reliably identify its fibers. Anatomical data are relevant to the surgeon who repairs the ligaments of the elbow. Also, to the radiologist and pain physician who interpret imaging and treat patients with pain syndromes of the elbow.

Morphometric feature description of the proximal ulna based on quantitative measurement: a key consideration for implant design.

PURPOSE: To perform quantitative measurements of the anatomic morphology of the proximal ulna and establish the morphologic references based on Chinese for the surgical protocol and implant design. METHODS: The computed tomography data of 156 upper extremities were involved in this study. The ulna model was reconstructed in Mimics. Ten distance and 6 angle parameters were measured by 4 independent investigators with a new quantitative measurement method. The intraclass correlation coefficient was used to evaluate the measuring reliability. Gender and side differences of measured parameters were evaluated. RESULTS: Measurements showed a mean coronoid height of 15 mm, which was 42% of ulnar height with gender-specific differences (mean 16 mm in men and 14 mm in women, P < 0.001). A mean unsupported anteromedial facet width of 8 mm was 61% of the coronoid anteromedial facet. A larger opening angle correlates to a larger olecranon-diaphysis angle (P < 0.001) and larger coronoid height (P = 0.001). A mean proximal ulna dorsal angulation of 4.7° is present in 80% of models at an average of 52 mm distal to olecranon tip. The average proximal ulna varus angulation was 16° at a mean of 74 mm distal to the olecranon tip. Morphological features between the left and right sides were highly consistent. The ICC was between 0.789 and 0.978 for inter-observer and between 0.696 and 0.997 for intra-observer reliability. CONCLUSIONS: The proximal ulna features variable morphology but minor side differences among individuals. Over half of the anteromedial facet was not supported by the proximal ulnar diaphysis, making the coronoid vulnerable to elbow trauma. Preconditioning or customized design of the ulnar plate in the clinical setting with the help of contralateral morphology may be a good choice.

Prediction of height using ulna length in African-Caribbean children.

Standing height is an essential anthropometric measurement in pediatrics. In children unable to stand upright, measurement of ulna to predict standing height is recommended, but height prediction equations based on the ulna have not been established in children of African ancestry. We hypothesized that such equations would result in lower predicted height compared to using equations derived from non-African children. We measured prospectively standing height and both ulna in 358 African-Caribbean children without bone deformity or muscle disease, referred to two pulmonary function test laboratories. Interobserver variability was low for standing height (n = 54) and ulna measurement (n = 51) (mean biases [95%CI]: -0.02 [-0.99; 0.95] and 0.05 [-0.91; 1.01] cm, respectively), as well as inter-ulna variability (n = 352; mean bias 0.03 95%CI [-0.66; 0.73] cm). We used the mean value of 247 bilateral ulna measurements to calculate prediction equations using a generalized linear model including age, sex, ulna length, and geographic origin group, the latter showing no influence on the model. In the validation population of 107 children, the median difference [inter-quartile range] between standing height and ulna-predicted height was -0.4 [-2.7; 1.0] cm. Of 260 reliable baseline spirometry, there was a strong concordance between bronchial obstruction diagnosis established using standing height or ulna-predicted height (kappa coefficient: 0.85 [0.77; 0.94]) with only 11 (4.3%) children misclassified. The ulna predicted height calculated from African-Caribbean prediction equations resulted in a smaller height than the height calculated using equations derived from non-African children.

The triangular fibrocartilage complex in the human wrist: A scoping review toward uniform and clinically relevant terminology.

The aim of this scoping review was to assess the composition, terminology, and anatomy of the triangular fibrocartilage complex (TFCC) of the wrist and propose unambiguous terminology regarding the individual components. The review was conducted according to the methodological framework by Arksey and O'Malley (International Journal of Social Research Methodology, 2005, 8, 19-32). Electronic databases were searched from inception until September 1, 2021 for original anatomical studies, using MeSH terms and keywords on terminology and anatomy of TFCC components. Studies using gross dissections or macro- or microscopic histology were included. Animal studies, fetal studies and studies with unknown disease status, were excluded. A total of 24 studies were included. The articular disc, the radioulnar ligaments, the meniscus homologue and the extensor carpi ulnaris tendon (sub)sheath were unanimously classified as TFCC components. One study did not include the ulnolunate and ulnotriquetral ligaments and only one study did include the ligamentum subcruentum. The largest disagreement existed regarding the inclusion of the ulnar collateral ligament. Terminological ambiguity was seen in "triangular fibrocartilage," "triangular ligament," "igamentum subcruentum," and the "proximal and distal lamina." Anatomical ambiguity existed especially regarding the radioulnar ligaments, the ulnar attachments of the TFCC and the ulnar collateral ligament. Definitions of the individual TFCC components are redundant, ambiguous, and ill-defined and therefore subject to different interpretations. In order to preclude confusion, consensus regarding terminology is recommended. We proposed a concise definition of the healthy TFCC that can be used as a starting point for future studies and current clinical practice.

Morphological affinities of a fossil ulna (KNM-WS 65401) from Buluk, Kenya.

The morphological affinities of a primate proximal ulna (KNM-WS 65401) recovered from the late Early Miocene site Buluk, Kenya, are appraised. Nineteen three-dimensional landmarks on ulnae from 36 extant anthropoid species (n = 152 individuals) and KNM-WS 65401, as well as a subset of 14 landmarks on six ulnae belonging to other East African Miocene catarrhine taxa, were collected. To quantify ulnar shape, three-dimensional geometric morphometric techniques were used and linear dimensions commonly cited in the literature were derived from the landmark data. KNM-WS 65401 is situated between monkeys and hominoids in the principal components morphospace. KNM-WS 65401 shares features such as a short olecranon process, broad trochlear notch, and laterally oriented radial notch with extant hominoids, whereas features such as an anteriorly directed trochlear notch and flat, proximodistally elongated, and anteroposteriorly narrow radial notch are shared with extant monkeys. Principal component scores and linear metrics generally align KNM-WS 65401 with both suspensors and arboreal quadrupeds, but quadratic and linear discriminant analyses of principal component score data provide posterior probabilities of 80% and 83%, respectively, for assignment of KNM-WS 65401 to the suspensory group. Compared with fossil ulnae from other Miocene primates, KNM-WS 65401 is morphologically most distinct from KNM-LG 6, attributed to Dendropithecus macinnesi, and morphologically most similar to KNM-WK 16950R, attributed to Turkanapithecus kalakolensis. The KNM-WS 65401 individual likely possessed more enhanced capabilities for elbow joint extension, perhaps during suspensory behaviors, compared with other Miocene primates in the sample.

Sex estimation using ulna in a Thai population / Estimación del sexo utilizando la ulna en una población tailandesa

SUMMARY: Sex estimation from fragmentary bone remain is still challenge for forensic pathologist. Ulna has been reported useful for sex estimation by metric analysis. This study generated sex estimation function for fragment and complete of ulnar bone in a Thai population. The function was generated from 200 pairs of ulnar bone, and others 20 pair of ulnar bone were used for test the accuracy of the functions. Olecranon width was the best single variable for sex predicting of proximal part of ulna, which right olecranon width could be classified the sex 90.5 %. While distal end width of ulna was the variable for predicting the sex of distal part, which left distal end width could be classified the sex with 83.0 %. Stepwise discriminant function analysis was applied to proximal part. For proximal part of right ulna 4 measurements were selected (inferior-medial trochlear notch length, olecranon width, olecranon-coronoid process length, and maximum proximal ulnar width), while the left side, superior trochlear notch width, olecranon width, and maximum proximal ulnar width were chosen, and their functions could be predicted the sex with 91.0 % and 90.0 %, respectively. Our results indicated the ulnar bone had high ability for estimating the sex in a Thai population.

RESUMEN: La estimación del sexo a partir de restos óseos fragmentarios sigue siendo un desafío para el patólogo forense. Se ha informado de la utilidad de la ulna para la estimación del sexo mediante análisis métrico. En este estudio se analizó la estimación del sexo para un fragmento y de la ulna completa en una población tailandesa. La función se generó a partir de 200 pares de ulnas y se utilizaron otras 20 pares de ulnas estimando la precisión de las funciones. El ancho del olécranon fue la mejor variable individual para predecir el sexo en la parte proximal de la ulna (90, 5 %). Si bien el ancho del extremo distal de la ulna fue la variable para predecir el sexo, el ancho del extremo distal izquierdo podría clasificarse por sexo con un 83,0 % de certeza. Se aplicó un análisis de función discriminante escalonada a la parte proximal. Para la parte proximal de la ulna derecha se seleccionaron 4 medidas (longitud de la incisura troclear inferior-medial, ancho del olécranon, longitud del proceso olecraneano-proceso coronoides y ancho ulnar proximal máximo), mientras que en el lado izquierdo, fue determinado el ancho de la incisura superior troclear, ancho del olécranon y ancho ulnar proximal máximo. Se eligió el ancho, y se pudo predecir el sexo en el 91,0 % y 90,0 % de los casos, respectivamente. Nuestros resultados indicaron que la ulna tenía una alta capacidad para estimar el sexo en una población tailandesa.

Morphological symmetry of the radius and ulna-Can contralateral forearm bones utilize as a reliable template for the opposite side?

The most important precondition for correction of the affected forearm using data from the contralateral side is that the left and right bone features must be similar, in order to develop patient-specific instruments (PSIs) and/or utilize computer-assisted orthopedic surgery (CAOS). The forearm has complex anatomical structure, and most people use their dominant hand more than their less dominant hand, sometimes resulting in asymmetry of the upper limbs. The aim of this study is to investigate differences of the bilateral forearm bones through a quantitative comparison of whole bone parameters including length, volume, bowing, and twisting parameters, and regional shape differences of the forearm bones. In total, 132 bilateral 3D radii and ulnae 3D models were obtained from CT images, whole bone parameters and regional shape were analyzed. Statistically significant differences in whole bone parameters were not shown. Regionally, the radius shows asymmetry in the upper section of the central part to the upper section of the distal part. The ulna shows asymmetry in the lower section of the proximal part to the lower section of the central part. Utilizing contralateral side forearm bones to correct the affected side may be feasible despite regional differences in the forearm bones of around 0.5 mm.

The ulnar interosseous tuberosity exists: a radiological and descriptive cadaveric study.

PURPOSE: The anatomy of the ulna seems to have already been described exhaustively, particularly at its extremities, but very little in its middle third. We report the existence of an interosseous tuberosity on the interosseous border of the ulnar shaft that we have named the "tuberositas interossea ulnarii" (TIU). METHODS: First, we analyzed all side view X-rays of the forearm in neutral rotation, as well as forearm CT scans carried out during a 1-year period in our hospital. On these radiographic examinations, we evaluated the presence or absence of the TIU, its length, the thickness of the interosseous cortex at its level, above and below compared with anterior, posterior, and lateral bone cortices. In the second part of the study, we dissected cadaveric forearms to determine which ligaments and muscles were attached to it. RESULTS: A total of 91 standard forearm radiographs and 13 CT scans were analyzed. In all cases, the ulnar interosseous tuberosity was present. The mean tuberosity length was 107.5 mm (± 18.2), without any significant gender influence. It corresponded to a thickening (6.9 mm then 4.6 mm above and 3.9 mm below; p < 0.0001) of the ulnar interosseous cortex. Then, ten anatomic subjects (six females, four males) were dissected. We observed that this tuberosity served as an attachment for the central band of the interosseous membrane, for the deep flexor and extensor muscles for the long fingers, and for the abductor pollicis longus muscle's inner attachment. CONCLUSION: Tuberositas interossea ulnarii exists besides the tuberositas interossea radii, corresponds to thickening of the cortex and may play a role in the stability of the forearm and the function of the long fingers.