Morphologic evaluation of vascular foramina in dry calcaneus.

PURPOSE: The purpose of this study is to provide reference data regarding the morphology of vascular foramina (VF) of calcaneus among the Turkish population. METHODS: This study was performed using 49 dry calcanei (26 right, 23 left). The number as well as the location of VF in relation of each surface of calcaneus were evaluated. The total length (TL), the distance between the most posterior point of calcaneus and the largest foramina on the medial (LMS), lateral (LLS), superior (LSS) and inferior (LIS) surfaces were measured and foraminal indexes of the largest foramina on the medial (FI1), lateral (FI2), superior (FI3) and inferior (FI4) surfaces were calculated. RESULTS: The mean values of the TL, LMS, LLS, LSS, LIS were measured to be 74.83 ± 6.00 mm, 41.34 ± 4.78 mm, 31.18 ± 7.63 mm, 49.61 ± 13.40 mm, 39.25 ± 13.56 mm, respectively. The mean values of the FI1, FI2, FI3 and FI4 were calculated to be 55.40 ± 6.21%, 41.73 ± 10.06%, 66.01 ± 16.82%, 52.16 ± 16.80%, respectively. The maximum numbers of VF were detected most commonly on the lateral (28.29%) and medial (26.45%) surfaces, and least commonly on the anterior (0.98%) and posterior (8.29%) surfaces. CONCLUSIONS: VF were observed to be most commonly located on the lateral and medial surfaces, and least commonly on the anterior and posterior surfaces. Having adequate knowledge of the morphologic and morphometric properties of the VF is important in regarding the surgical approaches to the calcaneus towards the aim of reducing the vascular damage, especially in lateral approaches for orthopedists and of using differential sign from cystic lesions for radiologists.

An atlas of anatomical variants of the human calcaneus.

The usefulness of anatomical variation is determined by the knowledge of why nonmetric traits appear. Clear descriptions of the traits are a necessary task, due to the risk of confusing anatomical variants and evidence of trauma. Numerous interpretations of the appearance of calcaneal anatomical variants add to the need of an anatomical atlas of calcaneal nonmetric traits. We have analyzed a total of 886 calcanei; 559 belong to different modern and pre-Hispanic samples, and 327 bones were studied from a reference collection from Athens. In this study, we present the anatomical variations that exist on the calcaneus bone, some of which have rarely been mentioned in previous research. The standardization of methods proposed may be useful to experts working in human anatomy, physical anthropology as well as comparative morphology, due to usefulness of this information during surgery, and bioanthropology to observe and study the lifestyle of past populations.

Influence of Talar and Calcaneal Morphology on Subtalar Kinematics During Walking.

BACKGROUND: Cadaver biomechanical testing suggests that the morphology of articulating bones contributes to the stability of the joints and determines their kinematics; however, there are no studies examining the correlation between bone morphology and kinematics of the subtalar joint. The purpose of this study was to investigate the influence of talar and calcaneal morphology on subtalar kinematics during walking in healthy individuals. METHODS: Forty ankles (20 healthy subjects, 10 women/10 men) were included. Participants walked at a self-selected pace while synchronized biplane radiographs of the hindfoot were acquired at 100 images per second during stance. Motion of the talus and calcaneus was tracked using a validated volumetric model-based tracking process, and subtalar kinematics were calculated. Talar and calcaneal morphology were evaluated using statistical shape modeling. Pearson correlation coefficients were used to assess the relationship between subtalar kinematics and the morphology features of the talus and calcaneus. RESULTS: This study found that a shallower posterior facet of the talus was correlated with the subtalar joint being in more dorsiflexion, more inversion, and more internal rotation, and higher curvature in the posterior facet was correlated with more inversion and eversion range of motion during stance. In the calcaneus, a gentler slope of the middle facet was correlated with greater subtalar inversion. CONCLUSION: The morphology of the posterior facet of the talus was found to a primary factor driving multiplanar subtalar joint kinematics during the stance phase of gait. CLINICAL RELEVANCE: This new knowledge relating form and function in the hindfoot may assist in identifying individuals susceptible to subtalar instability and in improving implant design to achieve desired kinematics after surgery.

Effect of sequential burr passes on osteotomy magnitude and calcaneal morphology in minimally invasive Zadek osteotomy.

PURPOSE: This study aimed to evaluate the impact of each burr pass on degree of correction, gap size and calcaneal morphology in MIS Zadek osteotomy. METHODS: MIS Zadek osteotomy was performed on ten cadaveric specimens using a 3.1 mm Shannon burr. After each burr pass, the osteotomy gap was manually closed, and the subsequent burr passes were carried out with the foot held in dorsiflexion, which was repeated five times. Lateral X-rays were taken before and after each burr pass. Two independent reviewers measured the dorsal calcaneal length after each burr passage, as well as changes in several calcaneal parameters including X/Y ratio, Fowler Philip angle, and Böhler angle. RESULTS: The average decrease in dorsal calcaneal cortical length with each burr pass was as follows: 2.6 ± 0.9 mm at the 1st pass, 2.4 ± 1 mm at the 2nd pass, 2 ± 1 mm at the 3rd pass, 1.6 ± 1 mm at the 4th pass, and 1.4 ± 0.7 mm at the 5th pass. The Fowler Philip and Böhler angles consistently decreased while the X/Y ratio consistently increased following each consecutive burr pass. Interobserver reliability analysis demonstrated good agreement for all parameters. CONCLUSION: The results revealed the trends of length and anatomical changes in the calcaneus with each burr pass. On average, a dorsal wedge resection of 10 mm was achieved after 5 burr passes. This data can aid surgeons in determining the optimal number of burr passes required for a particular amount of resection, ensuring the attainment of the desired patient-specific surgical outcome.

Sustentaculum tali in Chinese population: anatomy and clinical significance.

BACKGROUND: Previous studies lacked adequate quantitative data on sustentaculum tali (ST), especially in Chinese population. The aims of this study are to explore the quantitative morphology of ST in dried bone specimens, and to discuss its implications related to ST screw fixation, talar articular facet variation, as well as subtalar coalitions. METHODS: A total of 965 dried intact calcanei from Chinese adult donors were evaluated. All linear parameters were measured by two observers with a digital sliding vernier caliper. RESULTS: Most parts of ST body can accommodate a commonly-used 4-mm-diameter screw, but the minimum height of anterior ST is only 4.02 mm. The shapes of the STs are slightly affected by left-right, subtalar facet, but the subtalar coalition may potentially increase the sizes of STs. The incidence of tarsal coalition is 14.09%. Among the osseous connection, there are 58.8% of type A articular surface and 76.5% of middle and posterior talar facet (MTF and PTF) involvement. ROC curve shows that subtalar coalition will be detected when ST length is greater than 16.815 mm. CONCLUSIONS: Theoretically, all the STs can accommodate 4 mm diameter screw, but a 3.5 mm diameter screw is recommended to be placed in the middle or posterior of the small ST for safety. The shapes of the STs are greatly influenced by the subtalar coalition, while they are less affected by left-right, subtalar facet. The osseous connection is common in type A articular surface and always involved in the MTF and PTF. The cut-off value of the length of STs was confirmed as 16.815 mm for predicting subtalar coalition.

Anatomic Description of the Calcaneocuboid Joint: Implications for Staple Fixation.

Understanding the anatomy of the calcaneocuboid (CCJ) remains essential when selecting staple fixation to optimize osseous purchase during rearfoot procedures. This anatomic study quantitatively describes the CCJ in relation to staple fixation sites. The calcaneus and cuboid from 10 cadavers were dissected. Widths at 5 mm and 10 mm increments away from the joint were measured in dorsal, midline, and plantar thirds of each bone. The widths between each position's 5 mm and 10 mm increments were compared using the Student's t test. The widths among the positions at both distances were compared using an ANOVA then post hoc testing. Statistical significance was set at p ≤ 0.05. The middle (23 ± 3 mm) and plantar third (18 ± 3 mm) of the calcaneus at the 10 mm interval was greater than the 5 mm interval (p = .04). At 5 mm distal to the CCJ, the dorsal third of the cuboid maintained a statistically significant greater width than the plantar third (p = .02). The 5 mm (p = .001) and 10 mm (p = .005) dorsal calcaneus widths as well as the 5 mm (p = .003) and 10 mm (p = .007) middle calcaneus widths were significantly greater than the plantar widths. This investigation supports the use of 20 mm staple 10 mm away from the CCJ in dorsal and midline orientations. Care should be taken when placing a plantar staple within 10 mm proximal to the CCJ as the legs may extend beyond the medial cortex compared to dorsal and midline placements.

A comparison of effectiveness of sex estimation from the calcaneus and talus in a Thai population / Comparación de la efectividad de la estimación del sexo a partir del calcáneo y el talus en una población tailandesa

SUMMARY: Sex estimation is an important aspect of skeletal identification. In addition, previous studies have found that the sex estimation of each race is different. Thus, it is necessary to develop discriminant function equations for the estimation of sex for the Thai population. This study aims to investigate the relationship between width, length and height of the calcaneus and talus with regards to sex and compare the effectiveness of sex estimation between the calcaneus alone, the talus alone, and between both the calcaneus and talus. A total of 200 individuals (100 males and 100 females) were used in this study; ages ranged from 19 to 94 years. Thirteen variables of calcaneus and ten variables of talus were measured. The authors created discriminant function equations for the estimation of sex and tested the efficiency of the equations obtained by using a test group of 40 individuals (20 males and 20 females). By analyzing the mean values of the variables in the calcaneus and the talus, it was shown that males were significantly different from females (p0.05). A stepwise method was used to create 6 equations for sex estimation. The equations were categorized from between the calcaneus alone, the talus alone, and between both the calcaneus and the talus, providing a sex estimation accuracy of between 88.5 and 93.0 %. Using the test group, it was shown that discriminant function equations from the calcaneus alone, the talus alone, and the calcaneus and the talus together, can estimate sex at a high level of accuracy. Sex estimation accuracy was greater than 85 % in all equations. Therefore, the discriminant function equations from the calcaneus alone, the talus alone, and between both the calcaneus and the talus, from this study can be applied to the Thai population.

La estimación del sexo es un aspecto importante de la identificación esquelética. Estudios previos han encontrado que la estimación del sexo de cada raza es diferente. Por lo tanto, es necesario desarrollar ecuaciones de funciones discriminantes para la estimación del sexo de la población tailandesa. Este estudio tuvo como objetivo investigar la relación entre el ancho, el largo y la altura de los huesos calcáneo y talus con respecto al sexo y comparar la efectividad de la estimación del sexo entre el calcáneo solo, el talus solo y entre el calcáneo y el talus. Se utilizaron un total de 200 huesos de individuos adultos (100 hombres y 100 mujeres), cuyas edades oscilaron entre 19 y 94 años. Se midieron trece variables del calcáneo y diez variables del talus. Los autores crearon ecuaciones de funciones discriminantes para la estimación del sexo y probaron la eficiencia de ellas usando un grupo de prueba de huesos de 40 individuos (20 hombres y 20 mujeres). Al analizar los valores medios de las variables en el calcáneo y el talus, se demostró que los huesos de los hombres eran significativamente diferentes al de las mujeres (p0.05). Se utilizó un método paso a paso para crear 6 ecuaciones para la estimación del sexo. Las ecuaciones se clasificaron entre el calcáneo solo, el talus solo y entre el calcáneo y el talus, lo que proporcionó una precisión de estimación del sexo de entre 88,5 y 93,0 %. Usando el grupo de prueba, se demostró que las ecuaciones de funciones discriminantes del calcáneo solo, el talus solo y el calcáneo y el talus juntos pueden estimar el sexo con un alto nivel de precisión. La precisión de la estimación del sexo fue superior al 85 % en todas las ecuaciones. Por lo tanto, las ecuaciones de la función discriminante del calcáneo solo, el talus solo y entre el calcáneo y el talus de este estudio se pueden aplicar a la población tailandesa.

Investigation of the relationship between foot deformities and radiographic measurements of the talus and calcaneus / Investigación de la relación entre las deformidades del pie y las mediciones radiográficas del talo y del calcáneo

SUMMARY: The weight of the body is transmitted to the foot through the subtalar joint and talus. Considering the important location of the talus and calcaneus, the morphological structures of these bones may affect the biomechanics of the subtalar joint. At the same time, the morphological structure of these bones is important in some common foot deformities. We aimed to investigate whether the various measurements of the talus and calcaneus are associated with different foot deformities in this study. In this study, radiography images of 158 (72 male and 86 female) patients within the mean age of 44 years were retrospectively examined. Eleven different measurements of the talus and calcaneus were obtained from the lateral and antero-posterior radiographs of the patients. A total of 158 patient's routine clinic radiographs were retrospectively assessed, which have calcaneal spur (n=63), hallux valgus (n=32) and control group (n=63). We determined that the body height of the calcaneus, maximum width of the head of the talus, minimum anterior width of the calcaneus were significantly different between calcaneal spur group and control group. Maximum length fibular malleolar facet of the talus was significantly different between age groups. And we determined that the calcaneal index was significantly different between hallux valgus group and control groups. Also all measurements were significantly different between males and females. As a result, some measurements that significantly determine the morphology of the talus and calcaneus were found to be significant between deformity groups and control groups. We think that our study will contribute to the literature as it is the first study in which the measurements obtained from the radiographic images of the talus and calcaneus are associated with foot deformities.

El peso del cuerpo se transmite al pie a través de la articulación subtalar y el talo. Teniendo en cuenta la importante ubicación del talo y el calcáneo, las estructuras morfológicas de estos huesos pueden afectar la biomecánica de la articulación subtalar. Al mismo tiempo, la estructura morfológica de estos huesos es importante en algunas deformidades comunes del pie. Nuestro objetivo fue investigar si las diversas medidas del talo y el calcáneo están asociadas con diferentes deformidades del pie en este estudio. Se examinaron retrospectivamente imágenes radiográficas de 158 pacientes (72 hombres y 86 mujeres) con una edad promedio de 44 años. Se obtuvieron once medidas diferentes del talo y el calcáneo a partir de las radiografías lateral y anteroposterior de los pacientes. Se evaluaron retrospectivamente un total de 158 radiografías clínicas de rutina de los pacientes, los cuales tenían espolón de calcáneo (n=63), hallux valgus (n=32) y grupo control (n=63). Determinamos que la altura del cuerpo del calcáneo, el ancho máximo de la cabeza del talo, el ancho anterior mínimo del calcáneo fueron significativamente diferentes entre el grupo con espolón calcáneo y el grupo control. La longitud máxima de la faceta maleolar fíbular del talo era significativamente diferente entre los grupos de edad. También determinamos que el índice calcáneo fue significativamente diferente entre el grupo de hallux valgus y los grupos controles. Además, todas las medidas fueron significativamente diferentes entre hombres y mujeres. Como resultado, algunas medidas que determinan la morfología del talo y el calcáneo resultaron significativas entre los grupos de deformidad y los grupos controles. Estimamos que nuestro estudio contribuirá a la literatura debido a que es el primer reporte en el que las medidas obtenidas de las imágenes radiográficas del talo y el calcáneo se asocian con deformidades del pie.

Three-Dimensional Printing-Assisted Masquelet Technique in the Treatment of Calcaneal Defects.

OBJECTIVE: The aim of the present study was to summarize the clinical efficacy of three-dimensional (3D) printing technology combined with the Masquelet technique in the treatment of calcaneal defects. METHODS: From January 2018 to April 2019, 3D printing combined with induced masquelet technology was used to treat four patients with calcaneal defects, including two men and two women. The patients were aged 22-52 years old, with an average age of 36 years. There were two cases of traffic accident injuries, there was one case of a fall from height, and there was one case of crush injury. CT scans were used to reconstruct the bilateral calcaneus, mirror technology was used to construct the bone defect area, and Materialise 3-matic software was used to design the calcaneus shaper mold and 3D print the mold. During the operation, the mold was used to shape the bone cement and fill the bone defect. In the second stage, the bone cement was removed and autologous bone was implanted to repair the bone defect. All patients were followed up to observe the effect. RESULTS: All four patients were followed up for 14 months (range, 10-18 months). There were three cases of infectious bone defects: two cases of Escherichia coli and one case of Pseudomonas aeruginosa. The 3D printed mold was used to shape the bone cement. During the operation, it was found to have a high degree of matching with the defect area of calcaneus. There is no need to adjust it again, and the wound healed well after the first stage. In the second stage of surgery, it was found that the induced membrane formed was complete and of appropriate size; the bone cement was easily removed during the operation. The fracture healing time was 3-6 months, with an average of 4 months. At the last follow up, there was no pain and the patients walked with full weight bearing. The Maryland score was 94 points (range, 88-98 points); three cases were excellent and one case was good. The AOFAS score ranged from 86 to 98, with an average of 92.8 points; three cases were excellent and one case was good. CONCLUSION: Three-dimensional printing technology combined with induced membrane technology is an effective approach for treating calcaneal bone defects.

Morphological analysis of Gissane's angle utilising a statistical shape model of the calcaneus.

INTRODUCTION: Gissane's crucial angle (GA) facilitates to diagnose calcaneal fractures, and serves as an indicator of the quality of anatomical reduction after fixation. The study aimed to utilise statistical shape models (SSM) for analysing the complex 3D surface anatomy of the calcaneus represented by the simplified GA measurement on lateral radiographs. MATERIALS AND METHODS: SSMs were generated from CT scans of paired adult calcanei from 10 Japanese and 31 Thai specimens. GA measurements in 3D and 2D were obtained for the lateral, central and medial anatomy of the posterior facet and sinus tarsi. The correlation between calcaneal length and GA was analysed. Regression and principal component (PC) analyses were conducted for analysing morphological variability in calcaneal shape relating to GA. The bilateral symmetry of the obtained measurements was analysed. RESULTS: The mean GA (lateral) for the Japanese specimens was 105.1° ± 7.5 and 105.4° ± 8.5 for the Thai. The projected 2D angles of the central and medial measurements were larger (P < 0.00) than the 3D values. The medial projected 2D angles were larger (P ≤ 0.02) compared to the lateral. Despite the bilateral symmetry of GA and calcaneal length, their correlation displayed clear signs of asymmetry, which was confirmed by regression and PC analyses. CONCLUSIONS: Japanese and Thai specimens revealed lower GAs (both range and mean) compared to reported reference values of other ethnicities. As a reduced GA is generally indicative of a calcaneal fracture, our results are important to surgeons for their diagnostic assessment of Japanese and Thai patients. The results indicate that the GA measurement on a plain radiograph is a simplified representation of the lateral-to-central 3D calcaneal anatomy but significantly underestimates the angle measurement on the medial aspects of the respective surface areas.

A calcaneal tunnel for CFL reconstruction should be directed to the posterior inferior medial edge of the calcaneal tuberosity.

PURPOSE: Anatomical reconstruction of the calcaneofibular ligament (CFL) is a common technique to treat chronic lateral ankle instability. A bone tunnel is used to fix the graft in the calcaneus. The purpose of this study is to provide some recommendations about tunnel entrance and tunnel direction based on anatomical landmarks. METHODS: The study consisted of two parts. The first part assessed the lateral tunnel entrance for location and safety. The second part addressed the tunnel direction and safety upon exiting the calcaneum on the medial side. In the first part, 29 specimens were used to locate the anatomical insertion of the CFL based on the intersection of two lines related to the fibular axis and specific landmarks on the lateral malleolus. In the second part, 22 specimens were dissected to determine the position of the neurovascular structures at risk during tunnel drilling. Therefore, a method based on four imaginary squares using external anatomical landmarks was developed. RESULTS: For the tunnel entrance on the lateral side, the mean distance to the centre of the CFL footprint was 2.8 ± 3.0 mm (0-10.4 mm). The mean distance between both observers was 4.2 ± 3.2 mm (0-10.3 mm). The mean distance to the sural nerve was 1.4 ± 2 mm (0-5.8 mm). The mean distance to the peroneal tendons was 7.3 ± 3.1 mm (1.2-12.4 mm). For the tunnel exit on the medial side, the two anterior squares always contained the neurovascular bundle. A safe zone without important neurovascular structures was found and corresponded to the two posterior squares. CONCLUSION: Lateral landmarks enabled to locate the CFL footprint. Precautions should be taken to protect the nearby sural nerve. A safe zone on the medial side could be determined to guide safe tunnel direction. A calcaneal tunnel should be directed to the posterior inferior medial edge of the calcaneal tuberosity.

Associations of Sex Steroids With Changes in Calcaneal Quantitative Ultrasound Measurements: A Longitudinal Study in Chinese Male Adolescents.

This 2-year longitudinal study aimed to detect the associations of sex steroids, sex hormone-binding globulin with bone parameters and the changes thereof in Chinese male adolescents. A total of 642 male students aged 12-16 years from a secondary school in Jiangmen, China, were included. Total testosterone (T), total oestradiol (E2), and sex hormone-binding globulin were measured by chemiluminescence immunoassay. The bioavailable T (BioT) and E2 (BioE2) were calculated. The speed of sound, broadband ultrasound attenuation, and stiffness index of the right heel were measured by Sahara Clinical Bone Sonometer at both baseline and 2-year follow-up. The confounding effects of age, height, weight, pubertal stage, physical activity, energy-adjusted dietary calcium intake, and dietary vitamin D intake were adjusted. The baseline value of each bone parameter was also adjusted in the longitudinal analysis. Results showed that total T and BioT were positively associated with bone parameters and changes in them (ß = 0.076-0.115, p < 0.05). A threshold effect of BioT on broadband ultrasound attenuation, stiffness index and their changes were also observed. Positive associations between BioT and bone mass gain were observed only in individuals with BioT levels <240.0 ng/dl (ß = 0.088-0.131, p < 0.05). Moreover, total E2 or BioE2 were found to be inversely associated with speed of sound and its change (ß = -0.109 to -0.077, p < 0.05). This study supported that in Chinese male adolescents, serum T was a positive predictor for bone formation with a threshold effect, and E2 could have influence on the changes in bone architecture during puberty. These findings may improve the understanding of the effects of sex steroids on the acceleration of bone formation in male adolescents and provide useful information for the prediction model establishment of peak bone mass.

The Influence of Radiograph Obliquity on Böhler's and Gissane's Angles in Calcanei.

In calcaneal fractures, Böhler's and Gissane's angles are considered important parameters to guide treatment strategy and provide prognostic information during follow-up visits. Therefore, lateral radiographs have to be accurate. The aim of this study was to evaluate the effect of craniocaudal and posteroanterior angular variations (i.e., simulate lower leg malposition) from the true lateral radiograph on Böhler's and Gissane's angles. In this radioanatomical study, 15 embalmed, skeletally mature, human anatomic lower limb specimens were used. Using predefined criteria, a true lateral radiograph (i.e., 0° angular variation) was obtained. Angular variations from this true lateral radiograph were made from -30° to +30° deviation in the craniocaudal and posteroanterior direction at 5° intervals. Böhler's and Gissane angles were independently assessed by 2 experienced trauma surgeons. Böhler's angle decreased with increasing caudal angular variations (maximum -4.3° deviation at -30°). With increasing of the posterior angular variations, Böhler's angle increased (maximum 5.0° deviation at +30°) from the true lateral radiograph, but all deviations were within the measurement error. The deviation of the angle of Gissane was most pronounced in the cranial direction, with the mean angle decreasing by -8.8° at +30° angular variation. Varying angular obliquity in the caudal and posteroanterior direction hardly affected Gissane's angle. Foot malpositioning during the making of a lateral radiograph has little influence on Böhler's and Gissane's angles. If used for clinical decision-making in initial treatment and during follow-up of calcaneal fractures, these parameters can reliably be obtained from any lateral radiograph.

Vascular foramina of talus: an anatomical study with reference to surgical dissection.

PURPOSE: To study the distribution and morphometry of vascular foramina of adult human talus in Indian population. METHODS: The study was carried out by using 56 adult human tali. The location, size, number and foraminal index of vascular foramina on head, neck and body of each bone were examined macroscopically. The difference in location of vascular foramina was further studied in relation to the pattern of calcaneal articular facets on talus. RESULTS: The vascular foramina were present on the superior neck, inferior neck and medial surface of talar body in all (100%) the bones. The Kruskal-Wallis test followed by series of Mann-Whitney test for post hoc analysis showed the number of vascular foramina was significantly greater on inferior surface of neck and medial surface of body. The number of vascular foramina ranged from 0 to 25. About 77.05% of foramina were ≥ 0.5 mm in size. The mean foraminal index of the closest foramina on inferior surface of neck and medial surface of body was 47.90% and 37.23%, respectively. The mean foraminal index of the farthest foramina on inferior surface of neck and medial surface of body was 75.08% and 71.35%, respectively. CONCLUSION: The present study has provided additional information on the vascular foramina of tali. This knowledge is important to the orthopedic, vascular and podiatric surgeons while performing the surgeries of hind foot. We opine that the lateral approach would be more beneficial in the surgical procedures to talus.

The lateral fibulotalocalcaneal ligament complex: an ankle stabilizing isometric structure.

PURPOSE: Ankle lateral collateral ligament complex has been the focus of multiple studies. However, there are no specific descriptions of how these ligaments are connected to each other as part of the same complex. The aim of this study was to describe in detail the components of the lateral collateral ligament complex-ATFL and CFL-and determine its anatomical relationships. METHODS: An anatomical study was performed in 32 fresh-frozen below-the-knee ankle specimens. A plane-per-plane anatomical dissection was performed. Overdissecting the area just distal to the inferior ATFL fascicle was avoided to not alter the original morphology of the ligaments and the connecting fibers between them. The characteristics of the ATFL and CFL, as well as any connecting fibers between them were recorded. Measures were obtained in plantar and dorsal flexion, and by two different observers. RESULTS: The ATFL was observed as a two-fascicle ligament in all the specimens. The superior ATFL fascicle was observed intra-articular in the ankle, in contrast to the inferior fascicle. The mean distance measured between superior ATFL fascicle insertions increases in plantar flexion (median 19.2 mm in plantar flexion, and 12.6 mm in dorsal flexion, p < 0.001), while the same measures observed in the inferior ATFL fascicle does not vary (median 10.6 mm in plantar flexion, and 10.6 mm in dorsal flexion, n.s.). The inferior ATFL fascicle was observed with a common fibular origin with the CFL. The CFL distance between insertions does not vary with ankle movement (median 20.1 mm in plantar flexion, and 19.9 mm in dorsal flexion, n.s.). The inferior ATFL fascicle and the CFL were connected by arciform fibers, that were observed as an intrinsic reinforcement of the subtalar joint capsule. CONCLUSION: The superior fascicle of the ATFL is a distinct anatomical structure, whereas the inferior ATFL fascicle and the CFL share some features being both isometric ligaments, having a common fibular insertion, and being connected by arciform fibers, and forming a functional and anatomical entity, that has been named the lateral fibulotalocalcaneal ligament (LFTCL) complex. The clinical relevance of this study is that the superior fascicle of the ATFL is anatomical and functionally a distinct structure from the inferior ATFL fascicle. The superior ATFL fascicle is an intra-articular ligament, that will most probably not be able to heal after a rupture, and a microinstability of the ankle is developed. However, when the LFTCL complex is injured, classical ankle instability resulted. In addition, because of the presence of LFTCL complex, excellent results are observed when an isolated repair of the ATFL is performed even when an injury of both the ATFL and CFL exists.

Independent Attachment of Lateral Ankle Ligaments: Anterior Talofibular and Calcaneofibular Ligaments - A Cadaveric Study.

Anatomic knowledge of lateral ligaments around the lateral malleolus is important for repair or reconstruction of ankle instability. The detailed structure of the connective fibers between the anterior talofibular ligament (ATFL) and the calcaneofibular ligament (CFL) is unknown. To clarify the anatomic structure of ATFL and CFL and the connective fiber between the 2 ligaments, the lateral ligament was dissected in 60 ankles of formalin-fixed cadavers, and the distance was measured between bony landmarks and fibular attachment of ATFL and CFL using a digital caliper. All ankles had connective fibers between ATFL and CFL. The structure of connective fibers consisted of a thin fiber above the surface layer of ATFL and CFL; it comprised thin fibrils of the surface layer covering the lower part of ATFL and the front part of CFL. Both ATFL and CFL were independent fibers, and both attachments of the fibula were isolated. Single bands of ATFL were noted in 14 of 60 (23.3%) ankles, double bands that divided the superior and inferior bands were observed in 42 of 60 (70.0%) ankles, and multiple bands were observed in 4 of 60 (6.7%) ankles. A cord-like and a flat and fanning type of CFL was noted in 22 (36.7%) and 38 (63.3%) of the 60 ankles, respectively. Distances between ATFL/CFL and articular and inferior tips of the fibula were 4.3 ± 1.1 mm/7.6 ± 1.6 mm and 14.3 ± 1.9 mm/7.4 ± 1.7 mm, respectively (mean ± standard deviation). The results of this study suggest that knowledge of more anatomic structures of ATFL, CFL, and connective fiber will be beneficial for surgeons in the repair or reconstruction of the lateral ligament of the ankle.

Characteristics of anterior inferior calcaneal cortex.

BACKGROUND: Minimal invasive surgery of calcaneal fracture provided satisfactory outcomes. In tongue type calcaneal fracture, percutaneous screw usually purchases in anterior inferior calcaneal cortex. However, there was no detail about the cortex of anterior inferior calcaneus so the surface anatomy and cortical thickness of this area were studied. METHODS: 88 calcaneus from embalmed cadavers were enrolled. Anterior part of the inferior cortex was identified. Surface anatomy was examined. Length, anterior and posterior widths were measured. Anterior inferior calcaneal cortex was divided into anterior, middle and posterior segments. The cortical thickness at middle, medial most and lateral most of 3 segments were measured. RESULTS: Anterior inferior calcaneal cortex was a long trapezoidal shape with well-defined borders as a dense and thick cortical bone, convex relief from medial and lateral walls. Mean(SD) length was 33.40(3.46) millimeters (mm). Median(min,max) of anterior and posterior width were 10.50(8.21,19.26) mm and 14.00(10.05,20.42) mm, respectively. Mean(SD) of middle cortical thickness of anterior and middle segment were 3.12(0.76) and 3.72(0.74). Median(min,max) middle cortical thickness of posterior segment was 3.13(1.62,6.51) mm. Whereas, of the medial most were 1.31(0.78,3.11), 1.31(0.90,2.57) and 1.26(0.85,2.61) mm and of the lateral most were 1.17(0.67,2.64), 1.38(0.80,2.55) and 1.31(0.84,2.61) mm, respectively. Inter-intraobserver reliabilities of the measurements were >0.79. The statistical analysis showed the middle cortex is significantly the thickest (P<0.001) and posterior width is significant wider than the anterior (P<0.001). CONCLUSIONS: Anterior inferior calcaneal cortex has special characteristics in term of surface anatomy, width and thickness. For the percutaneous screw insertion from posterosuperior to anterior inferior calcaneus in tongue type calcaneal fracture, we recommend that screw should purchase in middle cortex due to maximal cortical thickness as well as its cortical width could accept 6.5 or 7.0mm screw without screw extrusion.

Three-Dimensional (3D) Computed Tomographic (CT) Assessment of the Sustentaculum Tail to Find Distinctive Characteristics: Implications for Surgery.

BACKGROUND With the complexity of calcaneal fracture (CF) increasing, its treatment has changed to include inserting the screw used to secure the facies articular posterior into the sustentaculum tail (ST). Some research progress has been made in this area, but there has been little in-depth research on the anatomical morphology of the sustentaculum tail, which is necessary for clinical surgery, and more information about Chinese anatomic characteristics and improved surgical techniques for CF are needed. MATERIAL AND METHODS This anatomical study, based on a three-dimensional (3D) computed tomographic (CT) reconstruction technique, included 287 dry calcaneus, consisting of 144 left and 143 right calcaneus. The images were reconstructed in 3D after CT scanning. Seven subjects were enrolled (L and R): (1) The vertical distance from inside the sustentaculum tail (IST) to inside the facies articularis talaris posterior; (2) The vertical distance from IST to the outside facies articularis talaris posterior; (3) The thickness of sulcus calcaneal nadir; (4) The distance from IST to processus medislis tuberis calcaneus; (5) The distance from IST to calcaneal posterosuperior tuber; (6) The angle of the prolate axial intersection between ST and calcaneus on the normal superior as ˂α; and (7) The angle of the prolate axial intersection between ST and calcaneus on the normal posterior as ˂ß. All measurement results were analyzed by SPSS 22.0. RESULTS Based on morphological classification, the average length of AB, AC, AE, and AF on left ST were 16.956±1.391 mm, 37.803±2.525 mm, 43.244±3.617 mm, and 51.113±4.455 mm, respectively. Among the others, Ë‚ß was 81.227±6.317 mm on the left and 74.581±9.008 mm on the right (P<0.05). CONCLUSIONS These results suggest better ways to treat the special characteristics and to reduce the risk of CF surgery.

Types and morphometric study of calcaneal articular facets on human tali of Thai population / Tipos y estudio morfométrico de las facetas articulares calcáneas en talus humano de la población tailandesa

Patterns and variant morphometries of calcaneal articular facets on talus are concerned before performing of joint ankle surgery, including used as a sex determination. Types of talar facets have been documented in many populations except in Thai race. Therefore, this study attempted to classify the types of talus facets and to measure the facet lengths on dried tali of Thais. The 372 dried tali (204 males, 168 females) from Khon Kaen University Bone Collection were observed for variant types and measured for their facet lengths. The facets were classified into 6 types: type I, tree facet are separated (1.88 %); type II (A), the anterior and middle facets are partially connected with predominant ridge (34.68 %); type II (B), the anterior and middle facets are partially connected with slight ridge (32.53 %); type III, the anterior and middle facets are fully fused to form a single facet (2.96 %); type IV, the anterior and middle facets are partially separated by a ridge and partly by a groove (27.42 %); type V, all facets are continuous fused to form a single facet (0.54 %). In addition, the morphometric lengths of AP (anterior to posterior process) and ML1&2 (medial to lateral process) in male are significantly greater than those of female. The AP, ML, and ML2 of male are 56.71±0.16, 41.63±0.18, and 37.85±0.36 mm, while of female are 51.21±0.12, 37.74±0.16, and 33.85±0.28 mm, respectively. This incidence can be used as ankle surgery consideration and an anthropological marker for sex determination of unidentified talus.

Los patrones y las variantes morfométricas de las facetas articulares calcáneas en el talus deben considerarse antes de la realización de la cirugía del tobillo a nivel articular, incluido su uso para la determinación del sexo. Se han documentado los tipos de facetas en el talus en muchas poblaciones, excepto en la raza tailandesa. Por lo tanto, este estudio clasificó los tipos de facetas del talus y se midieron las longitudes de las facetas del talus, en muestras secas de indiviuos tailandeses. Se analizaron 372 talus secos (204 de hombres, 168 de mujeres) de la colección de huesos de la Universidad Khon Kaen, se observaron distintos tipos de variantes y se midieron las longitudes de las facetas. Las facetas se clasificaron en 6 tipos: tipo I, faceta de árbol separadas (1,88 %); tipo II (A), facetas anterior y media parcialmente conectadas con la cresta predominante (34,68 %); tipo II (B), facetas anterior y media están parcialmente conectadas con una ligera cresta (32,53 %); tipo III, facetas anterior y media están completamente fusionadas para formar una sola faceta (2,96 %); tipo IV, facetas anterior y media están parcialmente separadas por una cresta y en parte por una ranura (27,42 %); tipo V, todas las facetas se fusionan continuamente para formar una sola faceta (0,54 %). Además, las longitudes morfométricas del proceso anterior o posterior (AP) y del proceso medial a lateral (ML1 y ML2) en el varón son significativamente mayores que las de la mujer. El AP, ML1 y ML2 de los hombres son 56,71 ± 0,16, 41,63 ± 0,18 y 37,85 ± 0,36 mm, mientras que las mujeres son 51,21 ± 0,12, 37,74 ± 0,16 y 33,85 ± 0,28 mm, respectivamente. Esta incidencia se puede utilizar como una consideración en la cirugía de tobillo y un marcador antropológico para determinar el sexo del talus no identificado.

Anatomy of medial plantar superficial branch artery perforators: Facilitation of medial plantar superficial branch artery perforator (MPAP) flap harvesting and design for finger pulp reconstruction.

BACKGROUND: Medial plantar artery perforator (MPAP) flap was proposed as proper option for finger pulp reconstruction. To provide the previously unavailable vessel information required for this small flap design, this study aimed to gather all necessary anatomy of MPA, MPAP, and their territories of blood supply to apply in clinical MPAP flap reconstruction minimizing perforator injury. METHODS: Dissection of 30 Thai cadaveric feet for visualizing superficial branch of MPA and its perforators (MPAP) using acrylic dye cannulation were performed. Diameter, length, number of branches, course, distributing areas of these vessels, and also their areas of blood supply were recorded in relation to specified landmarks, eg, C-MTH line; medial calcaneal tuberosity to plantar side of the first metatarsal head and S point; emerging point of superficial branch of MPA from deep fasciae into subcutaneous layer. RESULTS: Average diameter of MPA at its origin and total length are 1.63 ± 0.3 and 52.8 ± 16.1 mm, respectively. It provides 1-3 perforators, with an average size and length of 0.36 ± 0.11 and 23.2 ± 5.47 mm, respectively. Its distribution is mostly in the posteromedial quadrant within 50 and 30 mm from the midpoint of C-MTH line and the S point, respectively. The estimated perforator flap area is 2.5 cm × 1.5 cm and 4.5 cm × 2.5 cm for single and double perforators, respectively. CONCLUSIONS: MPAP flap was proved as another ideal option for finger pulp reconstruction. Its limitation is small size of perforators but this can be overcome by using MPA for microsurgical anastomosis instead.