Talus bone: normal anatomy, anatomical variations and clinical correlations

3D Geometric Morphometric Analysis of Calcaneal Morphology in Domestic Caprinae: Sheep (Ovis aries) and Goat (Capra hircus)

The calcaneus plays a critical role in balance, locomotion, and muscle attachment, making it a key structure for biomechanical adaptations. This study examined interspecies differences between sheep and goats, as well as intraspecies variations among different sheep breeds, in calcaneus morphology. A total of 128 right calcanei were analyzed using 3D geometric morphometric methods to allow detailed assessments of calcaneus shape and size. Among sheep, the Hamdani sheep displayed the largest calcaneus among the breeds, distinguishing them significantly from the others. In contrast, goats had a bilaterally narrower calcaneal body, while sheep featured a more pronounced distal portion that articulates with the talus and a deeper articular surface. Additionally, the sustentaculum tali were more developed in sheep. The bilaterally compressed calcaneal body in goats likely reflects their agility and ability to navigate steep, rocky terrains. In contrast, sheep's broader and more robust calcaneus may support their grazing lifestyle on flatter terrains, emphasizing their stability and weight-bearing capacity. These findings highlight the functional significance of calcaneal morphology in the locomotor strategies and physical capabilities of goats and sheep, providing valuable insights for comparative anatomy and veterinary science.

Beyond the imaging evaluation of fractures of the lateral process of the talus: Let's not forget concomitant injuries

Fractures of the lateral process of the talus (FLPT) are uncommon fractures that represent a clinical challenge. Traditional radiological classification systems rely predominantly on radiographic findings. However, due to the high rate of FLPT misdiagnosis and the limited accuracy in evaluating concomitant talar injuries through plain radiographs, novel imaging classification systems have been developed that aim to enhance the diagnosis of concomitant talar injuries, thereby optimizing patient management and reducing the incidence of long-term complications.

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.

Three-dimensional Mapping Analysis of Talus Fractures and Demonstration of Different Surgical Approaches for Talus Fractures

OBJECTIVE

The talus is an important component in the ankle, and its treatment after injury is crucial. However, complications and adverse events due to incomplete traditional classifications may still occur, and these classifications fail to analyze the patterns and distribution of fractures from a three-dimensional perspective. Therefore, in this study, we aimed to analyze the location and distribution of fracture lines in different types of talus fractures using three-dimensional (3D) and heat mapping techniques. Additionally, we aimed to determine the surface area of the talus that can be utilized for different approaches of internal fixation, aiding in the planning of surgical procedures.

METHODS

We retrospectively analyzed data from CT scans from 126 patients diagnosed with talus fractures at our two hospitals. We extracted the CT data of a healthy adult and created a standard talus model. We performed 3D reconstruction using patients' CT images and superimposed the fracture model onto the standard model for drawing fracture lines. Subsequently, we converted the fracture lines into a heat map for visualization. Additionally, we measured 20 specimens to determine the boundary for various ligaments attached to the talus. We determined the surface area of the talus available for different surgical approaches by integrating the boundary data with previously reported data on area of exposure.

RESULTS

Without considering the displacement distance of the fracture, fracture types were classified as follows, by combining Hawkins and Sneppen classifications: talar neck, 41.3%; posterior talar tubercle, 22.2%; body for the talus and comminuted, 17.5%; lateral talar tubercle, 11.9%; and talar head, 7.1%. We established fracture line and heat maps using this classification. Additionally, we demonstrated the available area for anteromedial, anterolateral, posteromedial, posterolateral, and medial malleolus osteotomy and Chaput osteotomy approaches.

CONCLUSION

Fracture line and heat map analyses can aid surgeons in planning a single or combined surgical approach for the reduction and internal fixation of talus fractures. Demonstrating the different surgical approaches can help surgeons choose the most effective technique for individual cases.

Vascular Foramina of Dry Human Talus: A Morphological Study

Background The talus is the second largest tarsal bone and makes the osseous link between the leg and foot region. The branches of the dorsalis pedis, posterior tibial, and peroneal arteries enter vascular foramina (VF) on the various surfaces of the talus and provide intraosseous blood supply. Understanding the morphology and morphometry of VF might be helpful in reducing the risk of vascular injury associated with surgical interventions to the talus.  Aim and objectives The purpose of this study is to contribute reference data for the morphology of VF of talus in a sample from Türkiye. Materials and methods This study was performed on 62 dry talus samples from Türkiye. The number, location, size, and foraminal index of the VF were evaluated on each talus. The total and medial surface lengths, distances of the closest and furthest foramina on the inferior surface, and distances of the closest and furthest foramina on medial surface were measured. Results No VF was detected on articular surfaces and the head of the talus. The majority of VF (1754; 81.17%) were detected on the neck, and 708 (40.36%) were located on the inferior surface of the neck. On the body, VF was mostly detected on the medial surface (233; 57.25%). The mean foraminal indices of the closest and furthest foramina on the inferior surface were 38.85% and 77.89%, respectively. The mean foraminal index of the closest foramina on the medial surface was 33.52%, and the furthest foramina on the medial surface was 63.91%. The total number of VF on 62 tali was determined as 2161. The majority (1521; 70.38%) of the size of VF was ≥0.6 mm. The mean total length was 55.14±4.69 mm, and the medial surface length was 49.18±4.18 mm. Conclusion Knowing the morphologic and morphometric properties of the VF gains importance during surgical interventions to the talus to reduce vascular damage. According to our results, lateral approaches to the talus may be safer than other approaches. To our knowledge, there is no study about the morphology of VF of the talus in Türkiye samples. We believe that the results of this study will provide reference data for morphology and morphometry of VF of talus.

Effects of Peroneus Brevis versus Peroneus Longus Muscle Training on Muscle Function in Chronic Ankle Instability: A Randomized Controlled Trial

Chronic ankle instability (CAI) is a common injury that can occur in daily life or sporting events. Injuries to the anterior talofibular, posterior talofibular, and calcaneofibular ligaments are common, and the core of rehabilitation training involves strengthening the peroneus muscle. Many studies on rehabilitation training have focused on strengthening the peroneus brevis muscle, and few studies have focused on specific training to strengthen the peroneus longus muscle. Therefore, this study aims to investigate changes in the symptoms and functions of patients by applying training to strengthen the peroneus longus and peroneus brevis muscles. Home-based training and mobile monitoring were utilized for 12 weeks, divided into peroneus brevis training (PBT) and peroneus longus training (PLT), in 52 adult males with CAI. Participation was voluntary, with enrollment done through a bulletin board, and intervention training allocation was randomly assigned and conducted in a double-blind manner. This study was registered as a trial protocol (KCT 0008478). Foot and ankle outcome scores (FAOS), isokinetic ankle strength tests, and Y-balance tests were performed before and after the intervention. Both PLT and PBT significantly improved in FAOS, inversion, and eversion at angular velocities of 30°/s and 120°/s and in the anterior and posterolateral directions of the Y-balance test (p < 0.05). Interaction effects by time and group were not significant for the FAOS (p > 0.05). However, PLT improved eversion muscle strength and muscle power to a greater degree, compared with PBT, in the anterior and posterolateral directions of the Y-balance test (p < 0.05). In conclusion, both PLT and PBT were effective for CAI patients; in addition, PLT had greater potential for improving strength and balance.

[Therapy of degenerative changes in the ankle joint with US-guided linear hyaluronic acid injections. A review]

The article discusses the issue and our own experience of local therapy for osteoarthritis of the ankle joint with injections of linear hyaluronic acid under ultrasound navigation. Since the ankle joint is difficult in terms of surgical treatment in general and endoprosthetics in particular, a course of intra-articular injection of 1% Flexotron® Forte hyaluronate, especially in the early stages of dystrophic changes in cartilage, is a promising method for relieving pain, chondroprotection and preserving the biomechanics of the joint, and ultrasound navigation when performing manipulation, it ensures the most accurate introduction of the drug into the joint cavity.