Calcaneum – Axial
A Stewart Whitley, Charles Sloane, Gail Jefferson, Ken Holmes, Craig Anderson in Clark's Pocket Handbook for Radiographers, 2016
Fig. 2.6a Positioning for axial calcaneum projection. The patient sits or lies supine on the X-ray table with both limbs extended. The affected leg is rotated medially until both malleoli are equidistant from the receptor. The ankle is dorsiflexed. The position is maintained using a bandage strapped around the forefoot and held in position by the patient. The receptor is positioned with its lower edge just distal to the plantar aspect of the heel.
Calcaneus deformity
Benjamin Joseph, Selvadurai Nayagam, Randall Loder, Ian Torode in Paediatric Orthopaedics, 2016
Congenital calcaneus deformity is usually part of calcaneovalgus, either seen as an isolated deformity or in association with congenital posteromedial bowing of the tibia. While congenital calcaneovalgus deformity usually resolves spontaneously during the first few weeks of life, all forms of paralytic calcaneus deformity tend to progress quite relentlessly throughout childhood. When there is a calcaneus deformity the normal pattern of the stance phase of gait is altered; the normal rockers are lost and the push-off is ineffective because the moment arm of gastrocsoleus is considerably reduced. Calcaneus deformity has a profound effect on the stability of the knee. In a child with a calcaneus deformity the knee can remain straight during the critical part of the stance phase when stability of the knee is essential, provided the quadriceps is functioning normally and the hamstrings are not spastic. In young children with paralytic calcaneus deformity, tenodesis of the Achilles tendon to the fibula can arrest progression of the deformity.
A to Z Entries
Clare E. Milner in Functional Anatomy for Sport and Exercise, 2019
The ankle and foot form a complex region containing many joints, which provide flexibility and enable the foot to adapt to its environment. Athletes with chronic ankle instability often protect their ankle with rigid ankle braces that limit the amount of supination. The bones of the foot and ankle are at risk of stress fracture, particularly in runners and military recruits. Key bones are the leg bones – the tibia and fibula – which form the proximal part of the ankle joint, and the foot bones – the talus and the calcaneus. The ankle and foot form a complex structure containing many bones and joints, which provide flexibility and enable the foot to adapt to its environment. The forearm is a unique structure because the two bones within it, the ulna and radius, are able to move from their normal side-by-side position to a crossed position.
Biomechanical comparison of conventional and optimised locking plates for the fixation of intraarticular calcaneal fractures: a finite element analysis
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2017
Hanbin Ouyang, Yuping Deng, Pusheng Xie, Yang Yang, Bingyun Jiang, Canjun Zeng, Wenhua Huang
Intraarticular calcaneal fractures can result in poor prognosis. Although operative fixation can improve the functional outcomes in most cases, surgical complications such as loss of reduction and wound healing problems may increase the risk of reoperation. Hence, this study aimed to design calcaneal locking plate with a lower profile and better biomechanical performance and to compare the redesigned plate with the traditional calcaneal plate via the finite element method. A Sanders’ type II-C intraarticular calcaneal fracture was simulated. Two fixation models utilising the branch-like calcaneal locking plate and the full plate were constructed. Topology optimisation was conducted to generate a new calcaneal plate design. A biomechanical comparison among the three groups of plates was performed using the finite element method. For the fracture simulated in this study, the optimised plate was superior to the traditional plate in terms of fixation stability and safety but was reduced in volume by approximately 12.34%. In addition, more rational stress distributions were observed in the redesigned plate, underscoring the superiority of this new design in terms of fatigue strength. These results demonstrate that the topology optimisation can be used to design a new implant with a minimised profile and no loss of fixation stability.
Biomechanical comparison of conventional and anatomical calcaneal plates for the treatment of intraarticular calcaneal fractures – a finite element study
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2016
Bin Yu, Wen-Chuan Chen, Pei-Yuan Lee, Kang-Ping Lin, Kun-Jhih Lin, Cheng-Lun Tsai, Hung-Wen Wei
Initial stability is essential for open reduction internal fixation of intraarticular calcaneal fractures. Geometrical feature of a calcaneal plate is influential to its endurance under physiological load. It is unclear if conventional and pre-contoured anatomical calcaneal plates may exhibit differently in biomechanical perspective. A Sanders’ Type II-B intraarticular calcaneal fracture model was reconstructed to evaluate the effectiveness of calcaneal plates using finite element methods. Incremental vertical joint loads up to 450 N were exerted on the subtalar joint to evaluate the stability and safety of the calcaneal plates and bony structure. Results revealed that the anatomical calcaneal plate model had greater average structural stiffness (585.7 N/mm) and lower von Mises stress on the plate (774.5 MPa) compared to those observed in the conventional calcaneal plate model (stiffness: 430.9 N/mm; stress on plate: 867.1 MPa). Although both maximal compressive and maximal tensile stress and strain were lower in the anatomical calcaneal plate group, greater loads on fixation screws were found (average 172.7 MPa compared to 82.18 MPa in the conventional calcaneal plate). It was noted that high magnitude stress concentrations would occur where the bone plate bridges the fracture line on the lateral side of the calcaneus bone. Sufficient fixation strength at the posterolateral calcaneus bone is important for maintaining subtalar joint load after reduction and fixation of a Sanders’ Type II-B calcaneal fracture. In addition, geometrical design of a calcaneal plate should worth considering for the mechanical safety in practical usage.
Influence of badminton practice on calcaneal bone stiffness and plantar pressure
Published in The Physician and Sportsmedicine, 2020
Alfredo Bravo-Sánchez, Javier Abián-Vicén, Fernando Jiménez, Pablo Abián
Objectives: The aim of this study was to analyze the plantar pressures and bone stiffness of the calcaneus in badminton players compare to healthy participants, as well as to detect possible asymmetries and chronic adaptations derived from the prolonged practice of badminton. Methods: Twenty-two badminton players (35.2 ± 13.6 years, 169.4 ± 8.2 cm, 67.6 ± 13.7 kg) and 30 healthy controls (32.2 ± 12.8 years, 170.7 ± 9.5 cm, 66.25 ± 14.84 kg) volunteered to participate in this investigation. A Footwork® Pro pressure platform was used to study plantar pressures and an Achilles® bone scanner was used to record the bone stiffness of the calcaneus. The variables analyzed were plantar surface, percentage of force per area (forefoot and hindfoot), distance between the center of pressure and the projection of the center of mass in standing, and calcaneal bone stiffness. Results: The values of bone stiffness of the calcaneus were higher in badminton players than control group in the dominant lower limb (Badminton = 114.32 ± 18.97 U.A. vs. Control = 102.07 ± 16.36 U.A.; p = 0.019) and non-dominant lower limb (Badminton = 115.12 ± 21.95 U.A. vs Control = 101.37 ± 15.72 U.A.; p = 0.014). Badminton players showed asymmetric values in mean pressure (dominant = 35.41 ± 6.05 Kpa vs. non-dominant = 39.21 ± 6.54 Kpa; p = 0.011) and distance among center of pressure of each foot and center of mass (dominant = 11.28 ± 1.65 cm vs. non-dominant = 10.48 ± 1.63 cm; p = 0.025). Conclusions: The calcaneal stiffness of the badminton players was higher than control group, which places badminton in the category of osteogenic sports. The badminton players showed an asymmetric pattern during the static balance, which may be an indicative of asymmetries derived from the continued practice of badminton.