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Advances in fractures in the neck of the femur in adults
Published in K. Mohan Iyer, Hip Joint in Adults: Advances and Developments, 2018
Osteonecrosis: The incidence of AVN is 10%-45%, and recent studies fail to demonstrate association between time to fracture reduction and subsequent AVN. There is an increased risk with an increase in the initial displacement of the fracture. AVN can still develop in nondisplaced injuries and nonanatomical reduction. Major symptoms are not always present when AVN develops, and management of AVN is THA.Nonunion: The incidence of nonunion is 5%-30%. Increased incidence is seen in displaced fractures and in older patients (>60 years). Nonanatomic varus malreduction most closely correlates to nonunion.Nonunion can be managed by valgus intertrochanteric osteotomy, which is indicated in younger patients as long as the neck is not severely collapsed and the head is viable. It turns a vertical fracture line into a horizontal fracture line and decreases shear forces across the fracture line and increases compressive force.It can also be managed by free vascularised/nonvascularised fibula graft, as described earlier.
The Lower Extremities
Published in Melanie Franklyn, Peter Vee Sin Lee, Military Injury Biomechanics, 2017
The leg is supported by two bones: tibia and fibula. The tibia, the second longest bone of the body, resides in the medial portion of the leg while the fibula resides in the lateral portion of the leg and posterolateral of the tibia. The tibia is longer, larger in diameter and stronger than the fibula. The tibia is the primary weight-bearing bone of the leg and accounts for 85% to 90% of weight transfer depending on the position of the foot and ankle (Moore et al. 2011). The tibia articulates with the medial and lateral femoral condyles superiorly, with talus inferiorly and laterally, and with the fibula at its proximal and distal ends (Moore et al. 2011). The distal portion of the tibia and fibula diverges into medial malleolus of the tibia and lateral malleolus of the fibula (Figure 15.2).
Designing for Foot and Ankle Anatomy
Published in Karen L. LaBat, Karen S. Ryan, Human Body, 2019
The tarsal bones form the rear of the foot and can be subdivided into proximal bones and distal bones. The proximal bones include the calcaneus and the talus. The calcaneus is the largest tarsal bone. You can feel its solid structure at the back and bottom of your foot. The calcaneal (Achilles) tendon attaches to the calcaneus and extends to the strong muscles on the posterior of the leg. The talus, as the uppermost foot bone, interfaces with the bones of the leg above it, the tibia and the fibula, to form the ankle (talocrural joint). Find the joint by locating the intersection of the leg and the foot. Refer to the illustration of the lower limb in Chapter 5 if needed. Run your hands down the inside and outside length of your leg from about mid-calf until you feel two protrusions. On the medial side of your leg you will feel the medial malleolus which is the distal end of the tibia. Along the outside feel the lateral malleolus which is the most distal portion of the fibula. The medial malleolus is slightly higher. Because these protrusions of the ankle do not lie on the same transverse plane (parallel to the ground), the total circumference for footwear, like high-top, pull-on boots, should be designed to comfortably encircle both malleoli. The tibia transmits the weight of the body to the talus. The fibula, with the ankle ligaments, acts as a strut to stabilize the talus beneath the tibia. The talus is unusual, as no muscles attach to it (Hamill & Knutzen, 2003). The talus rests on the calcaneus below, forming the subtalarjoint. The ankle structure, while amazingly sturdy, is very flexible and also susceptible to sprains as described later in this chapter.
Effect of individual ankle taping components on the restriction of ankle external inversion moment
Published in Sports Biomechanics, 2023
Nahoko Sato, Hiroyuki Nunome, Mio Hattori, Yasuo Ikegami
During a lateral ankle sprain, ligaments between the fibula and the hindfoot, such as the anterior talofibular ligament, can be damaged (Hertel, 2002). Ankle taping that restricts only the hindfoot with respect to the fibula appears to be an efficient method of protecting these ligaments. However, as Pope et al. (1987) reported, this kind of taping does not provide direct protection, as the strength of the tape is substantially lower than that of the anterior talofibular ligament. This implies that ankle taping cannot protect ligaments directly but somehow providing indirect aid for limiting the production of ankle inversion moment. Our findings suggest that clinicians should apply a combination of the stirrup and figure eight components, rather than applying the stirrup components alone, which can reduce the hindfoot’s plantar flexion, to prevent ligament injury during a lateral ankle sprain.
Biomechanical analysis of mandibular defect reconstruction based on a new base-fixation system
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2022
Haipo Cui, Liping Gao, Jing Han, Jiannan Liu
The mandible is located below the face and is the only movable bone of the skull. It is mainly involved in important functions such as chewing, swallowing, occlusion, language, and expression. Partial resection of the mandible becomes clinically necessary due to tumor, trauma, cancer, and other factors. In order to maintain the important functions of the mandible after surgery, it needs to be reconstructed. The ideal state of mandibular reconstruction includes the following three requirements: (i) the appearance of the face should be close to normal after restoration; (ii) dentition and occlusal relationships should be normal; (iii) mastication and the language function should be normal or nearly normal (Ciocca et al. 2012; Azuma et al. 2014; Rubio-Palau et al. 2016). At present, fibula free flap grafting is the most common method for repairing mandibular defects. Hidalgo first used the fibula to repair mandibular defects during surgery in 1989 (Hidalgo 1989). The fibula has gradually become the most common donor area for the repair of large-scale defects of the mandibular bone in clinics due to the following characteristics: the sufficient amount of bone tissue that is resident in the fibula, the dual blood supply of the periosteum and the bone flap, the ability to withstand greater masticatory force, the simple preparation of a bone flap, the easier three-dimensional shaping of a bone flap, and its suitability for the implementation of dental implants (Grohmann et al. 2015).
An update of interbody cages for spine fusion surgeries: from shape design to materials
Published in Expert Review of Medical Devices, 2022
Guangshen Li, Lei Yang, Gang Wu, Zhanyang Qian, Haijun Li
In addition to obtaining autogenous bone from other parts such as ilium and fibula, it can also be obtained in the form of in situ bone defect repair. The absorbable interbody fusion cage is designed to achieve the effect of constantly filling the vacancy during the absorption of the cage. The absorbable interbody fusion cage plays a major load-bearing role at the initial stage of implantation, and a certain pore is needed to accommodate the bone growth, and the absorption of the cage affects its mechanical properties only after the bone growth has sufficient mechanical properties.