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.

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.

Anatomical features of some bones of the forelimbs of lions (Panthera leo) / Características anatómicas de algunos huesos de los miembros torácicos de leones (Panthera leo)

SUMMARY: We studied the bones of forelimb of four adult lions (Panthera leo) of both sexes to record the gross anatomical and morphometrical features of the scapula, humerus, radius and ulna. We observed some unique anatomical features that will be helpful for radiographic interpretation and forensic investigations. The lateral surface of scapula was unequally divided into supraspinous (fossa supraspinata) and infraspinous fossa (fossa infraspinata) by a well developed spine (spina scapulae). The acromion process was subdivided into suprahamate process (processus suprahamatus)and hamate process (processus hamatus); the later one was over hanged the glenoid cavity (cavitas glenoidalis), but the supraglenoid tubercle (tuberculum supraglenoidalis) was absent. The shaft (diaphysis) of humerus was compressed craniocaudally in proximal part, rounded to oval in middle part and compressed mediolaterally in distal part. A long, narrow supracondyloid foramen was found at distal limb just above the medial epicondyle (epicondylus medialis) which didn't connect the radial fossa (fossa radialis) with the olecranon fossa (fossa olecrani). The radius and ulna were twin bones where radius was articulated craniolateral to the ulna proximally and craniomedial to the ulna distally. However, the ulna was the longest bone in the forelimb of lion. The olecranon tuberosity of this bone had three prominences - two were cranially, whereas the caudal one was the largest and rounded. Distally projected styloid processes (processus styloideus) were found in the distal limb of both radius and ulna.

RESUMEN: Estudiamos los huesos de las miembros torácicos de cuatro leones adultos (Panthera leo) de ambos sexos para registrar las características anatómicas y morfométricas macroscópicas de la escápula, el húmero, el radio y la ulna. Se observaron algunas características anatómicas únicas que serán útiles para la interpretación radiográfica y las investigaciones forenses. La superficie lateral de la escápula se dividió de manera desigual en fosa supraespinosa y fosa infraspinosa por una columna bien desarrollada (espina de la escápula). El proceso del acromion se subdividió en proceso suprahamato (processus suprahamatus) y proceso hamato (processus hamatus); el tubérculo supraglenoideo (tuberculum supraglenoidalis) estaba ausente. La diáfisis (diafisis) del húmero estaba comprimida craneocaudalmente en la parte proximal, redondeada a ovalada en la parte media y comprimida mediolateralmente en la parte distal. Se encontró un foramen supracondileo largo y estrecho en la extremidad distal, por encima del epicóndilo medial (epicondylus medilaris) que no conectaba la fosa radial (fosa radial) con la fosa olecraneana (fossa olecrani). El radio y la ulna eran huesos idénticos en los que el radio se articulaba craneolateral a la ulna proximalmente, y craneomedial a la ulna distalmente. Sin embargo, la ulna era el hueso más largo del miembro torácico del león. La tuberosidad del olécranon de este hueso tenía tres prominencias: dos eran craneales, mientras que la caudal era la más grande y redondeada. Se encontraron procesos estiloides proyectados distalmente (processus styloideus) en la extremidades distales del radio y la ulna.

Prediction of the Size of the Fragment in Comminuted Coronoid Fracture Using the Contralateral Side: An Analysis of Similarity of Bilateral Ulnar Coronoid Morphology.

OBJECTIVE: To evaluate the morphological similarity of bilateral coronoid process. METHODS: A total of 128 sets of computed tomography images of bilateral coronoid process from patients between January 2015 and December 2016 were acquired for three-dimensional reconstruction to generate a coronoid process model. The patients were aged between 31.4 ± 9.3 years. The upper 40% of the coronoid process was trimmed as targeted fragment for morphological analysis. The height, length, width as well as the radius of the medial and lateral facet of the targeted fragment were compared in terms of laterality, age, and gender. To evaluate the similarity of the articular surface of the coronoid process, a local coordinate was created and coordinate transformation algorithm was developed to realign the bilateral coronoid process for the following matching. Then Delaunay triangulation was introduced for calculation of the area of the articular surface. After matching of articular surface of the upper 40% of bilateral coronoid process, the overlapping area of the articular surface was quantified to assess the similarity in morphology and compared in regard to age and gender. RESULTS: In this study, the height of the target fragment was 12.40 ± 2.74 mm, which was 12.62 ± 2.06 mm for male patients and 12.13 ± 3.76 mm for female patients (t = 0.94, P = 0.35). The height of the target fragment was 12.79 ± 1.76 mm for patients >40 years and 13.23 ± 3.16 mm for patients <40 years (t = 1.11, P = 0.27). The height of the target fragment of left and right coronoid process was 12.26 ± 3.40 mm and 12.74 ± 2.79 mm (t = 1.15, P = 0.25). The length of the target fragment was 23.81 ± 2.67 mm, which was 23.86 ± 2.11 mm for male patients and 23.76 ± 2.85 mm for female patients (t = 0.23, P = 0.82). The length of the target fragment was 22.92 ± 1.96 mm for patients >40 years and 23.23 ± 2.14 mm for patients <40 years (t = 0.76, P = 0.45). The length of the target fragment of left and right coronoid process was 22.52 ± 2.89 mm and 21.66 ± 3.01 mm, respectively (t = 1.00, P = 0.32). The width of the target fragment was 23.12 ± 1.92 mm on average, which was 23.06 ± 1.54 mm for male patients and 23.19 ± 2.82 mm for female patients (t = 0.33, P = 0.74). The width of the target fragment was 24.82 ± 2.23 mm for patients >40 years and 23.46 ± 3.38 mm for patients <40 years (t = 1.56, P = 0.12). The width of target fragment of left and right coronoid process was 24.42 ± 2.22 mm and 24.47 ± 2.69 mm, respectively (t = 1.31, P = 0.19). The radius of medial facet was 6.44 ± 1.01 mm, which was 6.41 ± 1.39 mm for male patients and 6.47 ± 0.95 mm for female patients (t = 0.28, P = 0.78). The radius of medial facet was 6.82 ± 1.28 mm for patients >40 years and 6.46 ± 0.94 mm for patients <40 years (t = 1.31, P = 0.19). The radius of medial facet of left and right coronoid process was 6.43 ± 1.24 mm and 6.64 ± 1.34 mm (t = 1.60, P = 0.11). The radius of lateral facet was 11.84 ± 3.71 mm, which was 11.61 ± 4.24 mm for male patients and 12.11 ± 3.09 mm for female patients (t = 0.74, P = 0.46). The radius of medial facet was 11.82 ± 3.28 mm for patients >40 years and 12.46 ± 3.94 mm for patients <40 years (t = 1.02, P = 0.31). The radius of lateral facet of left and right coronoid process was 11.97 ± 5.31 mm and 10.29 ± 3.29 mm, respectively (t = 1.70, P = 0.09). The covering percentage of the articular surface of the upper 40% of bilateral coronoid process was 87% ± 12% with the covering percentage as 85.3% ± 14.2% for male patients and 90.0% ± 11.2% for female patients (t = 0.75, P = 0.41). The covering percentage was 88.2% ± 11.7% for patients >40 years and it was 87.4% ± 13.2% for patients <40 years (t = 0.98, P = 0.33). CONCLUSIONS: The present study suggested that bilateral coronoid process shares high similarity in terms of 3D structure and articular surface morphology, which suggested that the osseous architecture of the coronoid process with comminuted fracture could be predicted by the morphological information of the contralateral side.

Three-dimensional modelling of computed tomography images of limb bones in gazelles (Gazella subgutturosa).

The objective of the present study was to model in 3D the detailed morphometric features of the thoracic and pelvic limb bones of the gazelle (Gazella subgutturosa), whose natural habitat is only in the Sanliurfa province, by using multidetector computerized tomography (MDCT) images. Materials from 14 (7 male and 7 female) dead gazelles were collected from the Harran University Veterinary Medicine Faculty clinics during or after treatment. MDCT images of the gazelles were taken and saved as DICOM (Digital Imaging and Communications in Medicine) files. MIMICS 20.1 software was used to generate a 3D reconstruction of the data, and morphological and morphometrical evaluation was performed. In respect of morphological features, the combined metacarpus (Mc) III and metacarpus Mc IV were the main weight-bearing metacarpal bone, while Mc II and Mc V were rudimentary. On the femur, the lateral condyle was bigger than the medial condyle at the caudodistal end and the medial wing of the trochlea femoris was larger than the lateral. As with the thoracic limb, the combined metatarsus (Mt) III and metatarsus Mt IV were the main weight-bearing metacarpal bone and they displayed a synostosis structure. There was no secondary metatarsus in the gazelles' pelvic limb. Based on digital measurements, the tibia was the longest bone of the gazelles' skeletal system, and there was a statistically significant sexual dimorphism throughout the skeleton at the levels of p < .05, p < .01 and p < .001. As a result, the present study's findings are useful as reference data for further studies on anatomy, surgery and archaezoology, while also being useful for classifying species and for forensic sciences.

Surgical importance of radiographically aided morphometry of the proximal ulna / Importancia quirúrgica de la morfometría de la ulna proximal con examen radiográfico

This study was conducted to define the proximal ulnar morphometry with respect to dorsal and intramedullary implant design. Eighty two dry Anatolian ulnae were evaluated by both the traditional and digital morphometric analysis methods. Also the medullary cavities and cortical bone thicknesses were measured from radiographic images. The mean value of ulnar length (UL) was 25.06 cm; distance between the most prominent anterior point of the superior surface of the olecranon (MAPO) and the most posterior point of the olecranon (MPPO), distance between the MPPO and maximum anterior angulation (MAA), distance between the MPPO and the maximum varus angulation (MVA) were; 1.67 cm, 5.36 cm and 7.56 cm, respectively. The average antero-posterior diameters at midolecranon plane (MOP), MAA plane (MAAP) and MVA plane (MVAP) were; 1.78 cm, 1.68 cm and 1.41 cm; transverse diameters of same planes were; 1.96 cm, 1.65 cm and 1.51 cm, respectively. The mean olecranon angle (OA), MAA and MVA were: 113.35°, 9.12° and 13.82°; also the mean circumferences at same planes were 6.48 cm, 6.37 cm and 5.16 cm, respectively. The mean antero-posterior medullary diameter at MAAP and mean transverse medullary diameter at MVAP were; 6.83 mm and 7.22 mm, respectively. Mean anterior and posterior cortical bone thicknesses at MAAP were: 3.61 mm and 4.25 mm; the mean medial and lateral cortical bone thicknesses at MVAP were: 4.06 mm and 4.13 mm, respectively. Dorsal angulation and medullary angulation of the proximal ulna presents different architecture. Unique morphological architecture of the proximal ulna should be taken into consideration in means of surgical operations and examination of radiographic images. It can be inferred that standardized bony landmarks may helpful during the process of designing and manufacturing precurved dorsal plates and as well as variable proximal ulnar implants.

Este estudio se realizó para definir la morfometría ulnar proximal con respecto al diseño de implante dorsal e intramedular. Ochenta y dos ulnas de Anatolia secas fueron evaluadas por los métodos de análisis morfométrico tradicional y digital. También se midieron las cavidades medulares y el grosor del hueso cortical a partir de imágenes radiográficas. El valor medio de la longitud ulnar (LU) fue de 25,06 cm; distancia entre el punto anterior más prominente de la superficie superior del olécranon (SSO) y el punto más posterior (PPO), la distancia entre el PPO y la angulación anterior máxima (AAM), la distancia entre el PPO y la angulación máxima en varo (AMV) fueron; 1,67 cm, 5,36 cm y 7,56 cm, respectivamente. Los diámetros anteroposteriores medios en el plano medio del olécranon (PMO), el plano AAM (AAP) y el plano AMV fueron; 1,78 cm, 1,68 cm y 1,41 cm; los diámetros transversales de los mismos planos eran; 1,96 cm, 1,65 cm y 1.51 cm, respectivamente. El ángulo medio del olécranon (AMO), AAM y MVA fueron: 113,35 °, 9,12 ° y 13,82 °; También las circunferencias medias en los mismos planos fueron 6,48 cm, 6,37 cm y 5,16 cm, respectivamente. El diámetro medular anteroposterior medio en AMV y el diámetro medular transversal medio en AMV fueron; 6,83 mm y 7,22 mm, respectivamente. Los grosores óseos corticales anteriores y posteriores medios en AMV fueron: 3,61 mm y 4,25 mm; Los espesores medios de los huesos corticales medial y lateral en AMV fueron: 4,06 mm y 4,13 mm, respectivamente. La angulación dorsal y la angulación medular de la ulna proximal presentan una arquitectura diferente. La arquitectura morfológica única de la ulna proximal debe tenerse en cuenta en las operaciones quirúrgicas con el examen de imágenes radiográficas. Se puede inferir que los puntos de referencia óseos estandarizados pueden ser útiles durante el proceso de diseño y fabricación de placas dorsales precurvadas y también de implantes ulnares proximales variables.

A cadaveric study of radial and ulnar bowing in the sagittal and coronal planes.

BACKGROUND: This study provides a comprehensive, full-length assessment of radial and ulnar bowing in anteroposterior (AP) and sagittal planes. METHODS: Radial and ulnar AP and lateral bowing were assessed using orthogonal digital photographs of 211 randomly selected cadaveric bilateral forearms (422 radius, 422 ulna bones) from a well-preserved osteologic collection. RESULTS: In the radial AP plane, an apex-radial bow was present at a mean of 58% of bone length (slightly distal to midpoint), with a mean depth of 1.3 cm. In the radial lateral plane, an apex-dorsal bow occurred at a mean of 45% of bone length, with a mean depth of 0.8 cm. In the ulnar AP plane, apex-radial bow occurred at a mean of 32% of bone length with a mean depth of 1.0 cm. In the ulnar lateral plane, the majority of specimens (81%) had an apex-dorsal bow, whereas 19% had a reverse (apex-volar) bow. Lateral ulnar bow was located at a mean of 33% of bone length with a mean depth of 2.0 cm, with 36% of specimens possessing a lateral bow located at 35% or more distal along the ulna. Side-to-side differences for bow location and depth were less than 2% of bone length. CONCLUSIONS: Ulnar lateral bow was found to be more distal than in previously published works, which analyzed only the proximal ulna, and this study describes a reverse ulnar bow in 19% of specimens. This demonstrates lateral ulnar morphology to be more variable than previously defined with minimal side-to-side variability, which are important considerations for fracture fixation and elbow arthroplasty.

Percutaneous Plate Osteosynthesis of Ulnar Shaft Fractures: A Surgical Technique and Case Series.

Treatment of ulnar diaphyseal fractures can range broadly from nonoperative with immobilization to surgical intervention with a variety of implants or approaches. At a Level 1 trauma center, a series of ulnar shaft fractures have been treated using a percutaneous plating technique that is base beneath the extensor carpi ulnaris. This technique description illustrates relevant anatomy, important patient and injury characteristics, implant considerations, and potential outcomes and complications. The described treatment option provides an effective way of spanning comminuted fracture patterns without disrupting the surrounding biology while providing stable fixation. An associated patient series is included which enumerates associated injuries and describes limited follow-up. In the multiply injured trauma patient, such a fixation method also had potential benefits for their overall care and rehabilitation.

Anátomo-radiografia dos ossos longos do membro torácico do Tamandua tetradactyla / Anatomo-radiography of long-bones in thoracic limb of Tamandua tetradactyla

Objetivou-se descrever os acidentes anatômicos dos ossos longos do membro torácico de Tamandua tetradactyla por meio de análises macroscópicas e radiográficas. Foram utilizados 34 espécimes, que foram a óbito por atropelamento. A avaliação do úmero demonstrou as mesmas estruturas presentes nos animais domésticos, além de outras sem prévia descrição. Já no antebraço, rádio e ulna se apresentaram completamente separados, e apesar de, como o úmero, serem identificados alguns dos mesmos acidentes anatômicos descritos em outras espécies, também notamos particularidades. Todas as estruturas descritas na análise macroscópica foram identificadas à radiografia, quando realizada em pelo menos duas projeções ortogonais. As estruturas anátomo-radiográficas dos ossos longos do T. tetradactyla demonstraram grande variaçãoanatômica em comparação a outros mamíferos, o que torna a referida espécie muito singular. Assim o conhecimento de suas particularidades é fundamental para abordagens clínico-cirúrgicas mais seguras.

The objective was to describe the anatomical accidents of the long bones of the thoracic limb of Tamandua tetradactyla by means of macroscopic and radiographic analyzes. We used 34 specimens, which were death by running over. Evaluation of the humerus demonstrated the same structures present in domestic animals, besides others without previous description. In the forearm, radius and ulna were completely separated, and although, like the humerus, some of the same anatomical accidents described in other species were identified, we also noticed particularities. All the structures described in the macroscopic analysis were identified on radiography, when performed in at least two orthogonal projections. The anatomic-radiographic structures of the long bones of T. tetradactyla showed great anatomical variation compared to other mammals, which makes the species very unique. Thus knowledge of their particularities is fundamental for safer clinical-surgical approaches.

The Effect of Humeral and Ulnar Bone Tunnel Placement on Achieving Ulnar Collateral Ligament Graft Isometry: A Cadaveric Study.

PURPOSE: To assess simulated ulnar collateral ligament (UCL) graft length change, using surgically dissected anatomic landmarks, between multiple combinations of humeral and ulnar bone tunnels. METHODS: Three equidistant humeral and ulnar tunnels were created at each UCL footprint of 10 cadaveric elbows. Suture was passed between 9 possible tunnel combinations for each elbow and affixed to an isometry gauge. Each elbow was moved through an arc of 0, 30, 60, 90, and 120° for each tunnel combination. Changes in isometry gauge spring displacement (and, in effect, tension) were recorded. RESULTS: There was an overall significant effect (P < .0001) of tunnel placement at all degrees of flexion. Pairwise comparisons revealed increases in displacement between the central and posterior tunnel positions of the medial epicondyle, with significant differences (P = .0009) occurring when paired with both the central and posterior aspect of the sublime tubercle. Significant differences (P < .0001) were noted between the anterior and posterior humeral tunnel positions. CONCLUSIONS: Simulated UCL graft isometry is dependent upon optimal bone tunnel placement. No significant differences were noted between ulnar tunnel locations when paired with any given humeral tunnel. Conversely, deviation anterior or posterior from the centroid of the UCL footprint on the medial epicondyle significantly affected isometry at all degrees of flexion recorded with the greatest amount of displacement occurring with pairi4ng of posterior tunnels on both the humeral and ulnar footprints. CLINICAL RELEVANCE: This anatomic study highlights the importance of medial elbow bone tunnel placement and its effect on simulated UCL graft isometry.

Ulnolunate Distance and Lunate Height: Reliability Testing.

PURPOSE: Many methods for measuring ulnar variance have been described. The purpose of this study was to introduce the use of both lunate height and ulnolunate distance on the zero-rotation view as well as to assess the intra- and interobserver reliabilities of these measurements. The hypothesis was that the use of concave surfaces in the measurement of both lunate height and ulnolunate distance will yield a higher intra- and interobserver reliability than ulnar variance, which uses the convex surface of the distal radius. METHODS: Seven hand fellows reviewed 32 radiographs. Measurements of lunate height, ulnolunate distance, and ulnar variance, using the method of perpendiculars, were recorded to the nearest 0.5 mm. Intraclass correlation coefficient (ICC) was then calculated for each radiograph for intra- and interobserver reliability. RESULTS: The ICC measurements were similar for lunate height, ulnolunate distance, and ulnar variance. The inter- and intraobserver reliability was similar for all 3 measurements. CONCLUSIONS: Measurements of ulnar variance utilize the concave surface of the distal radius. The use of the convex surface of the lunate and pole of the ulna does not seem to improve the reliability of these measurements. Further studies are necessary to confirm the clinical utility of these measurements. CLINICAL RELEVANCE: The use of ulnolunate distance and lunate height as an adjunct to ulnar variance may assist in evaluation of distal radius fractures and ulnocarpal abutment, improve surgeon communication, and contribute to our overall knowledge of the wrist.

Quantifying the Center of Elbow Rotation: Implications for Medial Collateral Ligament Reconstruction.

BACKGROUND: Medial collateral ligament (MCL) reconstruction of the elbow mandates precise characterization of where the centerline of elbow rotation projects onto the medial epicondyle (ME). A muscle-splitting approach allows the flexor-pronator muscles to remain attached to the ME and facilitates visualization of the MCL remnant, the sublime tubercle, and the ulnohumeral joint line. Knowledge of where the centerline of rotation intersects the ME relative to the ulnohumeral joint line may assist the surgeon during placement of the proximal drill hole. METHODS: Models were created from the computed tomography scans of 29 normal elbows. The centerline of rotation, center of the trochlea, sublime tubercle, and ulnohumeral joint line were identified. Measurements were taken from the ulnohumeral joint line to the center of the trochlea and to the centerline of rotation in the sagittal view and along the course of the MCL. RESULTS: The centerline of rotation intersected the ME in a consistent location. With the elbow flexed 90°, the trochlea center and the centerline of rotation are essentially in line with each other. There are significant differences between the distances from the ulnohumeral joint line to the center of the trochlea and to the centerline of rotation in both the sagittal view and along the course of the MCL. CONCLUSIONS: The centerline of rotation is located 14.31 mm (1.70) from the ulnohumeral joint line in the sagittal view and 16.54 mm (2.09) from the ulnohumeral joint line along the course of the MCL.

Cross-sectional Area Just Proximal to the Carpal Tunnel According to the Ulnar Variances: Positive Ulnar Variance and Carpal Tunnel Syndrome.

PURPOSE: We evaluated the relationship between the area around the distal radioulnar joint according to the ulnar variances and the cross-sectional area using magnetic resonance imaging (MRI) scans in this prospective study of patients with carpal tunnel syndrome (CTS). METHODS: From among a total of 243 patients who had been diagnosed with CTS between March 2012 and February 2017 at our hospital, 41 patients with positive ulnar variance were enrolled in group 1. As control groups, 39 healthy volunteers who underwent MRI evaluations were included in group 2 (neutral ulnar variance) and group 3 (negative variance). Basic demographic data, including age, sex, and body mass index, were recorded for all 3 groups. An area encompassing the contents of carpal tunnel (nerves/tendons) was designated as area "A," and the area just beneath the subcutaneous fat was designated as area "B" at the levels of the lunate (L) and pisiform (P) on axial MRI. Ratios of these areas ("A/B at L" and "A/B at P") were evaluated in terms of their correlations with ulnar variance. RESULTS: Mean age, sex, and body mass index were not statistically different among the groups, respectively. Within each group, there was no difference between "A/B at L" and "A/B at P," respectively. When comparing the 3 groups, "A/B at L" and "A/B at P" were all significantly decreased in group 1 than in other groups. Regardless of the group, ulnar length negatively correlated with both "A/B at L" and "A/B at P" ratios. CONCLUSIONS: We found a positive relationship between decreased cross-sectional area around the distal radioulnar joint and positive ulnar variance on radiologic investigation. These findings show the importance of variance in the positive ulna variance to the development of CTS.

Insertional anatomy of the anterior medial collateral ligament on the sublime tubercle of the elbow.

BACKGROUND: Acute injuries to the anterior medial collateral ligament (AMCL) can occur due to valgus trauma or during other dislocating events to the elbow. AMCL lesions are often associated with bony lesions, such as radial head fractures or fractures of the coronoid process. We analyzed the insertion of the AMCL on the sublime tubercle in relation to surrounding osseous structures. We aimed to increase the understanding of the involvement of the AMCL in bony lesions to the sublime tubercle. METHODS: We investigated 86 elbows from 43 embalmed human specimens. We measured the most ventral extensions of the AMCL at the sublime tubercle in relation to a clearly defined and reproducible landmark. We used as our landmark a horizontal line (baseline) originating on the lesser sigmoid notch in a right angle to the ulnar ridge. RESULTS: The mean distance of the coronoid process tip to the baseline was 4.0 mm (standard deviation [SD], 1.3 mm; range, 1.4-6.7 mm). The mean distance of the ventral extension of the AMCL to the horizontal line was 3.7 mm (SD, 2.6 mm; range: 9.4-2.2 mm). The mean horizontal distance between the ventral aspect of the AMCL and the coronoid tip was 13.7 mm (SD, 2.5 mm; range, 7.7-20.5 mm). CONCLUSIONS: We present a detailed description of the insertional anatomy of the AMCL at the sublime tubercle. These values could be helpful for classifications of coronoid fractures and to estimate the involvement of the AMCL in fractures of the sublime tubercle.

The lateral collateral ligament complex of the elbow: quantitative anatomic analysis of the lateral ulnar collateral, radial collateral, and annular ligaments.

BACKGROUND: Injury to the lateral ulnar collateral ligament (LUCL) complex of the elbow often results in posterolateral rotatory instability. Although surgical reconstruction of the LUCL is often required, gaps in our understanding of the LUCL complex remain. The purpose of this study was to provide a robust and accurate characterization of the lateral elbow ligamentous complex. METHODS: The LUCLs, radial collateral ligaments, and annular ligaments in 10 cadaveric elbows were 3-dimensionally digitized and reconstructed using computed tomography. Surface areas, origin and insertion footprint areas, distances between perceived footprint centers and geometric footprint centroids, distances to key landmarks, and ligament isometry were measured. RESULTS: The mean surface area of the LUCL was 229.3 mm2. The mean origin and insertion footprint areas were 26.0 mm2 and 22.9 mm2, respectively. The mean distance between the apparent centers and the geometric centroids of the footprints was 1 mm. The center of the LUCL origin was 10.7 mm distal to the lateral epicondyle and 8.2 mm from the capitellar articular margin. The center of the LUCL insertion was 3.3 mm distal to the apex of the supinator crest. The LUCL showed anisometric properties as elbow flexion increased (P < .001). CONCLUSIONS: The LUCL origin center was 10.7 mm from the lateral epicondyle, whereas the insertion center was 3.3 mm from the apex of the supinator crest. The visually estimated footprint centers were generally within 1 mm of the geometric centroid. These geometries and distances to key landmarks will be informative for surgeons seeking to perform anatomic ligament reconstruction procedures.

Computed Tomography Analysis of the Radial Notch of the Ulna.

PURPOSE: The anatomy of the radial head and capitellum has been extensively studied; however, the anatomy of the radial notch of the ulna (RNU) has received little attention. This imaging-based anatomic study characterizes the morphology of the RNU. METHODS: Ninety-eight cadaveric arms (57 male, 72 ± 14 y) were imaged with computed tomography, and 3-dimensional reconstructions of the proximal ulna were constructed. The anteroposterior and proximal-distal dimensions of the RNU as well as the radius of curvature at standardized levels were measured in 2-mm increments. The orientation of the RNU was also determined. RESULTS: The proximal-distal and anteroposterior dimensions of the RNU were 12 ± 2 mm (range, 7-16 mm) and 18 ± 3 mm (range, 12-24 mm), respectively. The average radius of curvature of the RNU was 15 ± 0 mm (range, 15-16 mm). The radius of curvature did not change significantly when comparing the proximal and distal aspect of the RNU. The RNU was rotated 33° ± 2° (range, 31° to 38°) externally relative to the transverse plane of the ulna. The average depth of the RNU at its deepest point was 2.2 ± 0.4 mm (range, 1.5-2.7 mm). The depth decreased from proximal to distal, being most shallow distally. The depth changed by an increase of the radius of curvature, as well as by rotation in the frontal plane. CONCLUSIONS: The RNU anatomy was variable, generally extending laterally from proximal to distal. This suggests that a radial head implant should taper from proximal to distal to optimize contact at the RNU. CLINICAL RELEVANCE: The present study investigates the detailed anatomy of the radial notch of the ulna using computed tomography scans. The data might help improve the design of prosthetic components.

Predicción de estatura e índice de masa corporal a partir de segmentos corporales: Utilización de las ecuaciones de Gauld en una muestra argentina / Prediction of height and body mass index based on body segments: Use of Gauld's equations in an Argentine sample

En niños que, por su condición, la estatura no se puede medir o no representa el crecimiento óseo real, puede recurrirse a su cálculo a partir de la medición de segmentos corporales. Objetivos. 1. Comparar el valor de la estatura observada (EO) y predicha (EP) a partir de segmentos corporales mediante las ecuaciones de Gauld et al. 2. Analizar la aplicabilidad en el cálculo e interpretación del índice de masa corporal (IMC). Materiales y métodos. Muestra de niños y adolescentes sin alteraciones músculo-esqueléticas. Se registró estatura, envergadura, longitud del cúbito, antebrazo, tibia, altura de la pierna, peso y desarrollo puberal. Se calculó el IMC. Se analizaron diferencias y concordancias entre EO y EP mediante Bland-Altman y coeficiente de correlación intraclase. Para el IMC, se calculó el error de predicción absoluto y la concordancia mediante coeficiente kappa. Resultados. Se incluyeron 220 niños y adolescentes entre 6,04 y 19,1 años. El coeficiente de correlación intraclase entre EP y EO fue > 0,9 en todas las ecuaciones. La EP sobreestimó en promedio la EO en menos de 2,0 cm, excepto al utilizar la medición del cúbito (2,6 cm en mujeres y 3,4 cm en varones). El promedio del error de predicción absoluto para IMC fue < 5 %, excepto para el cúbito y el coeficiente kappa fue > 0,7. Conclusiones. En nuestra muestra, las ecuaciones de Gauld et al. fueron adecuadas para predecir la estatura y calcular el IMC. La mayor diferencia entre EO y EP fue al utilizar la longitud del cúbito.

When height cannot be measured or does not account for actual bone growth in children, due to their condition, it may be estimated using equations based on body segments. Objectives. 1. To compare observed height (OH) and predicted height (PH) based on body segments using the equations of Gauld et al. 2. To analyze its applicability in the estimation and interpretation of body mass index (BMI). Materials and methods. A sample of children and adolescents without musculoskeletal alterations. Height, arm span, length of the ulna, the forearm, the tibia and the leg, weight, and pubertal development were registered. BMI was estimated. Differences and agreements between OH and PH were analyzed using the Bland-Altman method and an intraclass correlation coefficient. For BMI, the absolute prediction error and agreement were estimated using a Kappa coefficient. Results. Two hundred and twenty children and adolescents aged 6.04-19.1 years were included. The intraclass correlation coefficient between PH and OH was > 0.9 in all equations. In average, PH overestimated OH by less than 2.0 cm, except when using the ulna length (2.6 cm among girls and 3.4 cm among boys). The average absolute prediction error for BMI was < 5 %, except for the ulna length, and the Kappa coefficient was > 0.7. Conclusions. In our sample, the equations of Gauld et al. were adequate to predict height and estimate BMI. The greatest difference between observed height and predicted height was observed when using the ulna length.

Computed Tomographic Trochlear Depth Measurement in Normal Dogs.

OBJECTIVES: The main purpose of this study was to describe the relationship between patellar maximal craniocaudal thickness and femoral trochlear groove depth in normal dogs and to valuate the intra-observer or inter-observer variability of maximal trochlear depth and maximal patellar craniocaudal thickness using computed tomography. METHODS: Trochlear groove depth and patellar maximal craniocaudal thickness of 40 limbs (20 dogs) were measured by three independent veterinarians using three-dimensional multiplanar reconstruction computed tomography images. The patellar maximal craniocaudal thickness/trochlear depth ratio was determined. RESULTS: The mean ratio of these stifles was 0.46 (range 0.24-0.70), meaning that the mean maximal depth of the trochlea was 46% of the mean maximal-patellar thickness. CLINICAL SIGNIFICANCE: A wide range of maximal-patellar-craniocaudal-thickness/maximal trochlear-depth ratio was found suggesting that breed studies should be performed to determine a breed-specific patellar-thickness/trochlear-depth ratio. To make decisions on when and where to perform a sulcoplasty during patellar luxation surgery, patella/trochlea thickness relationship should be measured for each breed with patellar tracking from stifle hyperflexion to stifle hyperextension.

The Sigmoid Notch View for Distal Radius Fractures.

PURPOSE: This study defines the sigmoid notch view of the distal radius. Specifically, we tested the null hypothesis that there is no relationship between the subchondral stripe of bone seen on a sigmoid notch view of the distal radius and the articular surface of the sigmoid notch. METHODS: We used 44 wrist specimens for anatomic and fluoroscopic analysis. We measured the articular depth of the sigmoid notch from its deepest point and classified the shape of the sigmoid notch. We then placed a radiopaque marker at the nadir of the articular surface and quantified the fluoroscopic depth of the sigmoid notch. A sigmoid notch view, which was a tangential fluoroscopic view of the volar and dorsal lips of the sigmoid notch, was obtained. The relationship of the articular surface to the stripe of subchondral bone seen on this view, called the sigmoid stripe, was determined. RESULTS: Anatomic analysis revealed sigmoid notch types with proportions similar to those in previous descriptions. The marker for the articular surface was superimposed or just ulnar to the sigmoid stripe in all specimens. In flat face and ski slope notches, this was coincident with the volar and dorsal lips of the sigmoid notch. In C- and S-type notches, there was a measurable distance from the articular surface marker to the edges of the bone of the volar and dorsal lips of the sigmoid. CONCLUSIONS: The articular surface marker at the nadir of the sigmoid notch is always coincident or ulnar to the sigmoid stripe in the sigmoid notch view. CLINICAL RELEVANCE: Surgeons can use the sigmoid notch view as a reliable method to (1) evaluate the integrity of the articular surface, (2) ensure hardware is not placed in the distal radioulnar joint, and (3) guide placement of volar locking plates in the coronal plane.