Morphological characteristics of the Lisfranc ligament.

BACKGROUND: This study aimed to clarify the morphological characteristics of the Lisfranc ligament and the cuneiform 1-metatarsal 2&3 plantar ligament (CMPL). METHODS: Forty legs from 20 cadavers were examined. Classification proceeded according to the number of fiber bundles in the Lisfranc ligament and the CMPL. Morphological features measured were fiber bundle length, width, thickness, and angle. RESULTS: In Type I-a, the Lisfranc ligament and the CMPL were a single fiber bundle; in Type I-b, the Lisfranc ligament was a single fiber bundle, and the CMPL was two fiber bundles; in Type II-a, the Lisfranc ligament was a two fiber bundle, and the CMPL was a single fiber bundle; in Type II-b, the Lisfranc ligament and the CMPL were two fiber bundles; in Type III-a, the Lisfranc ligament was three fiber bundles, and the CMPL was a single fiber bundle; in Type III-b, the Lisfranc ligament was three fiber bundles, and the CMPL was two fiber bundles; in Type IV, the Lisfranc ligament and the CMPL could not be separated. Type I-a was seen in 37.5%, Type I-b in 10%, Type II-a in 30%, Type II-b in 7.5%, Type III-a in 7.5%, Type III-b in 2.5%, and Type IV in 5%. The Lisfranc ligament was significantly larger than the CMPL in total fiber bundle width, total fiber bundle thickness, and total fiber bundle angle. CONCLUSION: The Lisfranc ligament had up to 3 fiber bundles and the CMPL had one or two fiber bundles; classifications were four types and two subgroups.

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.

Estimación del sexo con metacarpos y metatarsos para población mexicana / Estimation of gender from metacarpals and metatarsals in a Mexican population

INTRODUCCIÓN: El objetivo de este estudio fue la obtención de funciones discriminantes para estimación del sexo a partir de mediciones directas en metacarpos y metatarsos para contribuir en la identificación de individuos desconocidos. MATERIAL Y MÉTODOS: Se analizaron métricamente los metacarpos y metatarsos de 112 esqueletos adultos contemporáneos (49 femeninos y 63 masculinos) de la Colección-UNAM del Laboratorio de Antropología Física, Facultad de Medicina, UNAM. Empleando un vernier digital se tomaron 5 medidas (longitud máxima y 4 anchuras) en cada uno de los huesos del metacarpo y del metatarso. RESULTADOS: Se desarrollaron 14 funciones discriminantes para los metacarpos, con porcentajes del 79,5% a 85,3% de asignación sexual correcta, siendo el segundo metacarpo el hueso más dimórfico de la muestra. Para el caso de los metatarsos se obtuvieron 5 funciones que van del 77,8% al 83,2% de certidumbre, siendo el primer metatarso el hueso más dimórfico. De manera general, las anchuras en ambas epífisis fueron las medidas más dimórficas. CONCLUSIONES: Las funciones discriminantes de metacarpos y metatarsos obtenidas presentan, de manera general, porcentajes por encima del 80%, lo cual concuerda con lo reportado para otras poblaciones; por lo tanto, pueden ser utilizadas en contextos forenses para la identificación humana, en restos completos o fragmentados, en el caso de no contar con otro elemento óseo, como la pelvis

INTRODUCTION: The aim of this study was to obtain discriminant functions for estimating gender from direct measurements of the metacarpal and metatarsal bones for identification of unknown individuals. MATERIAL AND METHODS: An analysis was performed on metacarpal and metatarsals bones of 112 adult contemporary skeletons (49 females and 63 males). The sample belongs to the Autonomous University of Mexico (UNAM) Collection from the Physical Anthropology Laboratory, UNAM Faculty of Medicine. Five measurements were taken (maximum length and four widths) of each metacarpal and metatarsal bones employing a digital calliper. RESULTS: Fourteen discriminant functions were developed for metacarpals with percentages from 79.5% to 85.3% of correct gender classification. The second metacarpal was the most dimorphic of the sample. For metatarsals, five discriminant functions were obtained, ranging from 77.8% to 83.2% of certainty. In this case the first metatarsal was the most dimorphic. In general terms, the widths of both epiphyses were the most dimorphic measurements. CONCLUSIONS: The discriminant functions of metacarpal and metatarsal bones obtained are generally above 80%, which is similar to reports from other populations. Therefore, it can be used in forensic contexts for human identification with complete or fragmented remains, in the cases where no other bone element is available, such as the pelvis

Distribution and development of the external sense organ pattern on the appendages of postembryonic and adult stages of the spider Parasteatoda tepidariorum.

Spiders are equipped with a large number of innervated cuticular specializations, which respond to various sensory stimuli. The physiological function of mechanosensory organs has been analysed in great detail in some model spider species (e.g. Cupiennius salei); however, much less is known about the distribution and function of chemosensory organs. Furthermore, our knowledge on how the sense organ pattern develops on the spider appendages is limited. Here we analyse the development of the pattern and distribution of six different external mechano- and chemosensory organs in all postembryonic stages and in adult male and female spiders of the species Parasteatoda tepidariorum. We show that except for small mechanosensory setae, external sense organs appear in fixed positions on the pedipalps and first walking legs, arranged in longitudinal rows along the proximal-distal axis or in invariable positions relative to morphological landmarks (joints, distal tarsal tip). A comparison to other Entelegynae spiders shows that these features are conserved. We hope that this study lays the foundation for future molecular analysis to address the question how this conserved pattern is generated.

A new African Titanosaurian Sauropod Dinosaur from the middle Cretaceous Galula Formation (Mtuka Member), Rukwa Rift Basin, Southwestern Tanzania.

The African terrestrial fossil record has been limited in its contribution to our understanding of both regional and global Cretaceous paleobiogeography, an interval of significant geologic and macroevolutionary change. A common component in Cretaceous African faunas, titanosaurian sauropods diversified into one of the most specious groups of dinosaurs worldwide. Here we describe the new titanosaurian Mnyamawamtuka moyowamkia gen. et sp. nov. from the Mtuka Member of the Galula Formation in southwest Tanzania. The new specimen preserves teeth, elements from all regions of the postcranial axial skeleton, parts of both appendicular girdles, and portions of both limbs including a complete metatarsus. Unique traits of M. moyowamkia include the lack of an interpostzygapophyseal lamina in posterior dorsal vertebrae, pronounced posterolateral expansion of middle caudal centra, and an unusually small sternal plate. Phylogenetic analyses consistently place M. moyowamkia as either a close relative to lithostrotian titanosaurians (e.g., parsimony, uncalibrated Bayesian analyses) or as a lithostrotian and sister taxon to Malawisaurus dixeyi from the nearby Aptian? Dinosaur Beds of Malawi (e.g., tip-dating Bayesian analyses). M. moyowamkia shares a few features with M. dixeyi, including semi-spatulate teeth and a median lamina between the neural canal and interpostzygapophyseal lamina in anterior dorsal vertebrae. Both comparative morphology and phylogenetic analyses support Mnyamawamtuka as a distinct and distant relative to Rukwatitan bisepultus and Shingopana songwensis from the younger Namba Member of the Galula Formation with these results largely congruent with newly constrained ages for the Mtuka Member (Aptian-Cenomanian) and Namba Member (Campanian). Coupled with recent discoveries from the Dahkla Oasis, Egypt (e.g., Mansourasaurus shahinae) and other parts of continental Afro-Arabia, the Tanzania titanosaurians refine perspectives on the development of African terrestrial faunas throughout the Cretaceous-a critical step in understanding non-marine paleobiogeographic patterns of Africa that have remained elusive until the past few years.

Gross osteology and radiology of the pelvic limb of the adult small East African goat.

The aim of this study was to provide the detailed normal gross osteology and radiographic anatomy of the pelvic limb in adult small East African goats as a reference for clinical use, biomedical research and teaching. Radiography of the pelvic limb was performed in five adult small East African goats. Bone specimens of four skeletally mature small East African goats were used for gross osteological study. The ilial wing was wide. The ischiatic tuberosity was prominent and well developed. The acetabulum was rounded. The minor trochanter was located caudomedially, and the femoral trochlea was deep and narrow. The lateral and medial condyles of the femur were approximately of the same size. The tibial tuberosity was prominent, and the cochlea grooves were deep with a pronounced intermediate ridge. The trochlea of the talus was deep. The patella presented a prominent tuberosity on the cranial surface. The metatarsal sesamoid bone was seen in all animals. The observed gross osteology and radiographic anatomy of the pelvic limb of small East African goats was consistent with the presence of strong extensor muscles of the hip, stifle and tarsus for propulsion during terrestrial walking and trotting.

Three-dimensional CT examination of the forefoot and hindfoot of the hippopotamus and tapir during a semiaquatic walking.

Semiaquatic walking has resulted in the evolution of functional and morphological changes in various hoofed mammals, such as hippopotamus and Brazilian tapir. The biomechanics of skilful walking in wetlands or at the bottom of a waterbody involve the medio-lateral opening and closing of the feet to effectively support and stabilize the body on soft ground and to reduce the water resistance during recovery stroke, respectively. We demonstrate that the opening and closing of the feet in hippopotamus and Brazilian tapir are mediated by the adduction and abduction of the most medial and lateral phalanges from the CT examination. The axial toes, metacarpals and metatarsals do not contribute to changes in the width and shape of the feet, unlike the medial and lateral toes. We suggest that this semiaquatic walking motion is derived from the original terrestrial mode of locomotion, in contrast to the highly functional swimming motion using webs or fins in morphologically modified feet and tail. From the present data we demonstrate that semiaquatic locomotion evolved due to the acquisition of adductor-abductor mobility in the phalanges of the most medial and lateral digits, as shown in hippopotamus and Brazilian tapir.

Distances from the deep plantar arch to the lesser metatarsals at risk during osteotomy: a fresh cadaveric study.

BACKGROUND: The deep plantar arch is formed by anastomosis of the lateral and deep plantar arteries. Osteotomy of the lesser metatarsals is often used to treat metatarsalgia and forefoot deformity. Although it is known that some blood vessels supplying the lesser metatarsals are prone to damage during osteotomy, there is little information on the distances between the deep plantar arch and the three lesser metatarsals. The aims of this study were to identify the distances between the deep plantar arch and the lesser metatarsals and to determine how osteotomy could damage the arch. METHODS: Enhanced computed tomography scans of 20 fresh cadaveric feet (male, n = 10; female, n = 10; mean age 78.6 years at the time of death) were assessed. The specimens were injected with barium via the external iliac artery, and the distance from the deep plantar arch to each lesser metatarsal was measured on axial and sagittal images. RESULTS: The shortest distances from the deep plantar arch to the second, third, and fourth metatarsals in the axial plane were 0.5, 2.2, and 2.8 mm, respectively. The shortest distances from the distal epiphysis to a line passing through the deep plantar arch perpendicular to the longitudinal axis of the lesser metatarsal in the sagittal plane were 47.0, 45.7, and 46.4 mm, respectively, and those from the tarsometatarsal joint were 23.0, 21.0, and 18.6 mm. The deep plantar arch ran at the level of the middle third, within the proximal portion of this third in 11/20 (55.0%), 7/20 (35.0%), and 5/16 (31.2%) specimens, respectively, and at the level of the proximal third in 9/20 (45.0%), 13/20 (65.0%), and 11/16 (68.8%). CONCLUSIONS: Overpenetration into the medial and plantar aspect of the second metatarsal or the proximal and plantar aspect of the fourth metatarsal during shaft or proximal osteotomy could easily damage the deep plantar arch. Shaft or proximal osteotomy approximately 45-47 mm proximal to the distal epiphysis or 18-23 mm distal to the tarsometatarsal joint on the plantar aspect could interrupt blood flow in the deep plantar arch.

Hindlimb bone maturation during postnatal life in the Greater Rhea (Rhea americana, Aves, Palaeognathae): Implications for palaeobiological and zooarchaeological interpretations.

The objective of this study was to study the morphological pattern of bone maturation of the hindlimb bones of Rhea americana and find out how it can affect bone morphology after a taphonomic process. Juvenile specimens (n = 10) ranging from one month old to eight months old were studied. For comparison, bones from adults and juveniles from museum specimens (n = 4 and n = 6, respectively) were studied. In fresh bones, ossification centres were identified in the proximal and distal epiphyses of the tibiotarsi and in the proximal epiphysis of the tarsometatarsi, whereas the distal region of the femora and tarsometatarsi showed abundance of cartilage. The development and extension of the ossification centres of the tibiotarsi were different. In the proximal epiphysis, the centre presented less development with respect to the distal epiphysis. In the dry tibiotarsi, the proximal centre was absent and the distal one was well preserved. Both the fresh and dry juvenile tarsometatarsi presented unfused metatarsals and bulkier and wider aspect than the adult ones. The dry femora presented a noticeable excavation between condyles, whereas the dry tarsometatarsi showed the absence of the proximal epiphysis. The femora, tibiotarsi and tarsometatarsi possessed different traits of immaturity, which differentially affect the morphology of the preserved bones during a taphonomic process.

Plantar Pressure Measurements and Geometric Analysis of Patients With and Without Morton's Neuroma.

BACKGROUND: The purpose of this research was to see if there were any differences in peak pressure, contact time, pressure-time integrals, and geometric variables such as forefoot width, foot length, coefficient of spreading, and arch index between subjects with Morton's neuroma (MN) and control subjects. METHODS: Dynamic peak plantar pressure, contact time, pressure-time integral, and geometric data were extracted using the EMED-X platform in 52 subjects with MN and 31 control subjects. Differences in peak pressure, contact time, pressure-time integral, and geometric data between participants with and those without MN were determined using independent-samples t tests. There were no significant differences in age, weight, height, and body mass index between patients with MN and control subjects. RESULTS: There were no significant differences in the peak pressures of all masked areas and pressure-time integrals under metatarsal 2 to 4 heads between patients with MN and control subjects. In addition, no significant differences were observed between patients with MN and control subjects in geometric measurements of forefoot length, width, coefficient of spreading, foot progression angle, and arch index. CONCLUSION: No relationship was found in this study between peak pressure, contact time, and pressure-time integral under the metatarsal heads, forefoot width, foot length, coefficient of spreading, and foot progression angle in a symptomatic MN group compared with a control group. The need to perform osteotomies to treat MN not associated with other lesser metatarsal phalangeal joint pathologies is questionable. LEVEL OF EVIDENCE: Level III, Case-Control Study.

Fibrillar architecture at three different sites of the bovine superficial digital flexor tendon.

Superficial digital flexor tendon (SDFT) of the bovine hindlimb originates from the caudolateral aspect of the distal femur and finally inserts onto the plantar aspect of the middle phalanges. In the present study, morphology and morphometry of the bovine SDFT at the muscle-tendon junction (MTJ), middle metatarsus (mM) and tendon-bone interface (TBI) were investigated. Cross-sectional morphology at the three regions of SDFT were oval, semioval and ring-formed, respectively. Significant difference in cross-sectional area was found only between MTJ-mM and mM-TBI (P<0.05). Functional compression and friction from the adjacent structures could be the most potential interactions affecting such appearances. Morphometric data of tenocyte number, water content, and glycosaminoglycan (GAG) length and angle were found increasing in the proximodistal direction, except the fibril diameter and collagen fibril index (CFI). Statistical analyzes could reveal significant differences in average number of tenocytes (P<0.0001), CFI (between MTJ-mM and MTJ-TBI, P<0.05), water content (between MTJ-TBI, P<0.05), length of GAG chains (between MTJ-TBI, P<0.05), and angle of GAG chains (P<0.0001), respectively. The fibrillar characteristics at the three different areas, including fibril diameter distribution and interfibrillar distance, existed in conforming to the tensional axes in situ. In addition, length and angle of GAG chains were relevant to moving directions of the collagen fibrils.

MAGNETIC RESONANCE IMAGING, GROSS POSTMORTEM, AND HISTOLOGICAL FINDINGS FOR SOFT TISSUES OF THE PLANTAR ASPECT OF THE TARSUS AND PROXIMAL METATARSAL REGION IN NON-LAME HORSES.

Injuries of the plantar soft tissues of the tarsus and proximal metatarsus can be a source of lameness in horses, however published information is lacking on high field MRI characteristics of these tissues. Objectives of the current anatomic study were to (1) describe high-field MRI features of the plantar tarsal and proximal metatarsal soft tissues; and (2) compare MRI findings with gross and histological appearances of selected structures for a sample of cadaver limbs from non-lame horses. Single hindlimbs for 42 horses, and right and left hindlimbs for eight horses were scanned using high-field MRI. The MRI findings were described for the 50 single limbs; and the MRI, gross postmortem and histological findings were compared for the eight pairs of hindlimbs. The superficial digital flexor tendon had uniform low signal intensity, surrounded by the flexor retinaculum of intermediate to high signal intensity on all sequences. The lateral digital flexor tendon had slightly higher signal intensity, enclosed on the plantaromedial aspects by the low signal intensity metatarsocalcaneal ligament. The accessory ligament of the deep digital flexor tendon varied in size and signal intensity. The proximal and distal plantar ligaments, accessory ligament of the suspensory ligament, and calcaneoquartal ligament had low signal intensity. The long plantar ligament comprised a number of related parts, separated by lines of high signal intensity corresponding with fibrous septae seen in gross anatomical specimens. The plantar aspect of the ligament had uniform low signal intensity in all sequences, but the dorsal half was more heterogeneous with multifocal spots or lines of higher signal intensity.

The Foot's Arch and the Energetics of Human Locomotion.

The energy-sparing spring theory of the foot's arch has become central to interpretations of the foot's mechanical function and evolution. Using a novel insole technique that restricted compression of the foot's longitudinal arch, this study provides the first direct evidence that arch compression/recoil during locomotion contributes to lowering energy cost. Restricting arch compression near maximally (~80%) during moderate-speed (2.7 ms(-1)) level running increased metabolic cost by + 6.0% (p < 0.001, d = 0.67; unaffected by foot strike technique). A simple model shows that the metabolic energy saved by the arch is largely explained by the passive-elastic work it supplies that would otherwise be done by active muscle. Both experimental and model data confirm that it is the end-range of arch compression that dictates the energy-saving role of the arch. Restricting arch compression had no effect on the cost of walking or incline running (3°), commensurate with the smaller role of passive-elastic mechanics in these gaits. These findings substantiate the elastic energy-saving role of the longitudinal arch during running, and suggest that arch supports used in some footwear and orthotics may increase the cost of running.

The Distally Based Dorsal Metatarsal Artery Perforator Flap: Vascular Study and Clinical Implications.

Background Intrinsic flaps based on the dorsal metacarpal arteries are useful for coverage of dorsal hand, finger, and thumb defects. The purpose of this study was to explore the anatomy of the dorsal metatarsal arteries (DMtAs) in the foot to help define their clinical utility. We observed the size and numbers of distal perforators from the DMtAs and quantified the vascular perfusion pattern of the DMtA perforator across the skin. Methods Ten fresh cadaver feet were injected with latex and dissected to assess the size and number of distal perforators from the DMtAs. Five DMtA perforator flaps were injected with methylene blue to visualize and quantify the vascular territory of the skin flap to understand the clinical possibilities. In addition, a clinical case is described and shown. Results Ten fresh cadaver feet were dissected. The first DMtA was absent in two specimens and the second, third, or fourth DMtA was absent in one specimen each. The available DMtAs had between two and five cutaneous perforators supplying the skin (average, 3.7 perforators per DMtA). The largest perforators to the skin were always seen in the distal half of the DMtA and ranged from 0.4 to 0.8 mm (average, 0.5 mm). Methylene blue injections showed an average flap surface of 21.6 × 47.6 mm. Conclusion This cadaveric study demonstrates the usefulness of the DMtA perforator flap. The flap is a valuable addition to the arsenal of flaps to cover the dorsum of the toe, webspace, or defects exposing tendons on the distal dorsum of the foot.

Dynamic 3D scanning as a markerless method to calculate multi-segment foot kinematics during stance phase: methodology and first application.

Multi-segmental foot kinematics have been analyzed by means of optical marker-sets or by means of inertial sensors, but never by markerless dynamic 3D scanning (D3DScanning). The use of D3DScans implies a radically different approach for the construction of the multi-segment foot model: the foot anatomy is identified via the surface shape instead of distinct landmark points. We propose a 4-segment foot model consisting of the shank (Sha), calcaneus (Cal), metatarsus (Met) and hallux (Hal). These segments are manually selected on a static scan. To track the segments in the dynamic scan, the segments of the static scan are matched on each frame of the dynamic scan using the iterative closest point (ICP) fitting algorithm. Joint rotations are calculated between Sha-Cal, Cal-Met, and Met-Hal. Due to the lower quality scans at heel strike and toe off, the first and last 10% of the stance phase is excluded. The application of the method to 5 healthy subjects, 6 trials each, shows a good repeatability (intra-subject standard deviations between 1° and 2.5°) for Sha-Cal and Cal-Met joints, and inferior results for the Met-Hal joint (>3°). The repeatability seems to be subject-dependent. For the validation, a qualitative comparison with joint kinematics from a corresponding established marker-based multi-segment foot model is made. This shows very consistent patterns of rotation. The ease of subject preparation and also the effective and easy to interpret visual output, make the present technique very attractive for functional analysis of the foot, enhancing usability in clinical practice.

Correlation between broiler lameness and anatomical measurements of bone using radiographical projections with assessments of consistency across and within radiographs.

Lameness represents a major welfare and production issue in the poultry industry with a recent survey estimating 27% of birds lame and 3% unable to walk by 40 d of age. A variety of factors may induce lameness and are typically grouped into 2 broad classes on the basis of being infectious or skeletal in nature with the latter accounting for the majority of cases. The current work sought to build upon a large body of literature assessing the anatomical properties of bone in lame birds. Our specific objectives sought to identify relationships between relevant anatomical properties of the tibia and metatarsus using digital quantification from radiographs of legs and a measure of walking difficulty. Resulting output was statistically analyzed to assess 1) observer reliability for consistency in placing the leg during the radiograph procedure and quantification of the various measures within a radiograph, 2) the relationship between the various measurements of anatomical bone properties and sex, bird mass, and gait score, and 3) the relationship between each measurement and leg symmetry. Our anatomical bone measures were found to be reliable (intra-rater and test-retest reliabilities < 0.75) within radiograph for all measures and 8 of the 10 measures across radiographs. Several measures of bone properties in the tibia correlated to difficulty walking as measured by gait score (P < 0.05), indicating greater angulations with increasing lameness. Of the measures that manifested a gait score × bird mass interaction, heavier birds appeared to exhibit less angulation with increasing difficulty walking with lighter birds the opposite. These interactions suggest possibilities for influencing effects of activity or feed intake on bone mineralization with the bone angulation observed. Our efforts agree with that of others and indicate that angulation of the tibia may be related to lameness, though subsequent efforts involving comprehensive measures of bird activity, growth rates, and internal bone structure will be needed if the validity of the measures are to be accepted.

Magnetic resonance imaging of plantar soft tissue structures of the tarsus and proximal metatarsus in foals and adult horses.

OBJECTIVES: The object of this study was to describe previously defined soft tissue structures by using spin and gradient sequences in a 0.5 Tesla magnetic resonance system in order to improve the characterisation of tendon and ligaments at the plantar region of the equine tarsus and metatarsus while considering possible age-related variations. METHODS: Cadaveric hindlimbs from twenty-two Warmblood horses with an age range from one month to twenty-five years were examined in spin and gradient echoes. The proximal suspensory ligament from six limbs was dissected to assign the signal intensities histologically. For statistical analysis, horses were divided into two groups (≤3 years and >3 years) for evaluating signal intensity and homogeneity of the plantar tendons and ligaments. RESULTS: Focal increase of the signal intensity within the deep digital flexor tendon was significantly more present in horses older than three years. Signal alterations of the long plantar ligament were seen without a significant dependency to age. The accessory ligament of the deep digital flexor tendon could not be visualized on all images within the region of interest. The morphology of the proximal suspensory ligament was not affected by age-related changes. CLINICAL RELEVANCE: Spin and gradient echoes in MRI were suitable to identify and assess soft tissue structures at the plantar aspect of the equine tarsus and proximal metatarsus. Age-related appearance must be considered when interpreting magnetic resonance images.

Computed tomography and cross-sectional anatomy of the metatarsus and digits of the one-humped camel (Camelus dromedarius) and buffalo ( Bos bubalis).

The purpose of the present study was to provide a detailed computed tomography (CT) and cross-sectional anatomic reference of the normal metatarsus and digits for the camel and buffalo, as well as to compare between metatarsus and digits in these animals to outstand a basis for diagnosis of their diseases. Advantages, including depiction of detailed cross-sectional anatomy, improved contrast resolution and computer reformatting, make it a potentially valuable diagnostic technique. The hind limbs of 12 healthy adult camel and buffalo were used. Clinically relevant anatomic structures were identified and labelled at each level in the corresponding images (CT and anatomic slices). CT images were used to identify the bony and soft tissue structures of the metatarsus and digits. The knowledge of normal anatomy of the camel and buffalo metatarsus and digits would serve as initial reference to the evaluation of CT images in these species.

Clinical evaluation of fibularis tertius muscle prevalence / Evaluación clínica de la prevalencia del músculo fibular tercero

The fibularis tertius muscle (FTM) in man has been developed over time to acquire subsequent bipedal gait. The FTM functions as a crucial contributor in dorsiflexion and eversion, postulated over the years as a stabilizer of the talocrural joint, avoiding forced investment and protecting the anterior talofibular ligament. The literature describes that FTM is absent in 10 percent of cases, with no data on Chilean population. A study of surface anatomy in 168 young subjects, 60 percent female and 40 percent male students at the Universidad de Talca, Chile, with a mean age of 20.6 +/- 1.68 years, was conducted. The presence of FTM was identified following the implementation of a clinical assessment protocol that determines the presence of muscle on the basis of a progression called F1, F2, and F3. The FTM was present in 49.11 percent of cases. On the right side, 20 percent (n = 37) of the subjects presented the FTM in F2 and 30 percent (n = 50) in F3. On the left side, 1 percent (n = 2) showed the muscle in F1, 21 percent (n = 35) in F2, and 26 percent (n = 44) in F3. Our results contrast with the high prevalence of FTM in the literature and suggest studies of association with lesions of the talocrural region.

El músculo fibular tercero (MFT) es un músculo que en el hombre se ha desarrollado paulatinamente, al adquirir la posición bípeda y posteriormente la marcha. Dentro de las funciones del MFT destaca su contribución en la flexión dorsal y eversión, postulándose que actuaría como estabilizador de la articulación talocrural, al evitar la inversión forzada y proteger al ligamento talofibular anterior. La literatura describe que el MFT se encuentra ausente en un 10 por ciento de los casos, no existiendo datos de la población chilena. Se realizó un estudio de anatomía de superficie en 168 sujetos jóvenes, el 60 por ciento de sexo femenino y 40 por ciento de sexo masculino, estudiantes de la Universidad de Talca, Chile, con edad promedio de 20,6 +/- 1,68 años. La presencia del MFT se identificó tras la aplicación de un protocolo de evaluación clínica que determina la presencia del músculo en base a una progresión denominada F1, F2, F3. El MFT estuvo presente en el 49,11 por ciento de los casos. En el lado derecho el 20 por ciento (n=37) de los sujetos presenta el MFT en F2 y un 30 por ciento (n=50) en F3. En el lado izquierdo un 1 por ciento (n=2) exhibe el músculo en F1, 21 por ciento (n=35) en F2 y un 26 por ciento(n=44) en F3. Nuestros resultados contrastan con la alta prevalencia del MFT descrita en la literatura y se sugiere la realización de estudios de asociación con las lesiones de la región talocrural.

Implications for the anatomy of the flexor hallucis brevis insertion.

BACKGROUND: Excessive hallux proximal phalangeal base removal during first MTP resection arthroplasty, implant arthroplasty, or amputation can compromise the flexor hallucis brevis (FHB) insertion leading to first MTP joint plantarflexion weakness, cock-up toe deformity, and altered forefoot loading. MATERIAL AND METHODS: The insertional anatomy of the FHB tendon was measured in 30 fresh frozen cadaver specimens. The FHB was then cyclically loaded and bone sequentially removed from the proximal phalangeal base until specimen failure occurred. RESULTS: The mean length of the lateral and medial FHB insertions measured 9.0 +/- 0.6 mm and 8.0 +/- 0.5 mm, respectively (p < 0.0001). The mean width of the lateral and medial FHB insertions measured 7.1 +/- 1.0 mm and 8.8 +/- 1.4 mm, respectively (p < 0.0001). FHB insertion length as a percentage of total proximal phalangeal length was 26% +/- 3% medially and 30% +/- 3% laterally. Twenty-two specimens failed at the FHB insertion site after an average of 7.8 +/- 1.0 mm or 24% +/- 3% of the total length of the proximal phalanx had been resected from the base. CONCLUSION: Six millimeters of bone or 20% of the proximal phalangeal length could be safely removed from the hallux proximal phalangeal base without compromising the integrity of the FHB insertion to a physiologic load. Retaining 10 mm of the hallux proximal phalangeal base during amputation would preserve the medial FHB insertion and sacrifice none to less than 0.4 mm of the lateral insertion in our specimens. CLINICAL RELEVANCE: This study demonstrates how much hallux proximal phalangeal base can be resected during first MTP arthroplasty or needs to be retained during amputation to preserve FHB function.