The etiology of calcaneal fracture is usually high energy trauma such as fall from a height or motor vehicle crash 1,2.
Intra articular fractures of calcaneus occurs following eccentric loading of the talus on the calcaneus.(fig 5.1) The severity, type and location of fracture are determined by the position of the foot, the direction and magnitude of applied force and quality of bone 49.
Eccentric axial loading of talus on calcaneus produces a primary shear line that is parallel to posterolateral edge of talus and passes through posterior calcaneal facet. This primary fracture line separates the calcaneum in to two parts viz posterolateral and anteromedial (fig 5.1). Each fragment consists of a portion of posterior facet. The amount of posterior
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belonging to each facet depends on how much medial or lateral split occurs which in turn depends upon the inversion or eversion position of foot50. If eccentric axial loading continues, a secondary fracture line develops from the primary fracture line. Secondary fracture line creates superolateral(thalamic fragment). When this line exists superiory it is DEPRESSION type and when exists posterior, it is TONGUE type21.(fig 5.2) With further axial loading, the talus drives the superolateral fragment into cancellous spongy bone of calcaneal body fragments and causes blow out fracture of lateral wall which impinges on fibulocalcaneal space, making prone to fibulocalcaneal impingement and peroneal tendon entrapment.51 Because of primary shear lines are present on medial side, the fractures on the medial side are well defined and uncommunited whereas in the lateral side, the fractures on the lateral are communitted and poorly defined because of axial impaction and lateral expansion. The body fragment is released from its attachment anteriorly, it loses its alignment and tilts into varus and is planteflexed by tendoachilles. Further secondary line extended anteriorly into the calcaneocuboid joint.52 The forces have major impact in the surrounding soft tissues. In medial side as there is shearing stretch injury and compression injury on plantar aspect. The lateral wall soft tissue is relatively spared. The blisters are more commonly seen in medial side, hemorrhage on planter aspect, the areas of maximum tissue disruption53. Bohlers angle gets reduced, talocalcaneal angle which indicates varus valgus alignment of heel decreases, the heel height decreases, width of calcaneum at the level of blow out increases and subtalar joint becomes incongruent.54 Fig 5.1.Mechanism of calcaneum fracture A: the midline of the tibia and calcaneum are shown parallel but laterally displaced with respect to each other B.
As the primary fracture line develops, the body of calcaneum displaces laterally and proximally which impacts the lateral portion of the posterior facet against the posterior lateral edge of talus leading to shearing off of the lateral wall and development of posterior secondary fracture line.
C. As the body of calcaneum progresses proximally and lateral, it causes the superolateral fragment to rotate medially and to impact into spongy calcaneous bone which sweeps out the sheared off lateral wall fragment and results in commounited fragments impinging into the peronal tendon space against fibula.
Source: Paley D, Hall H. Calcaneal fracture controversies Can we put Humpty Dumpty together again? Orthop Clin North Am. 1989 Oct;20(4):665-77
Fig 5.2. Multiple views showing primary and secondary fracture lines in calcaneum
fractures. Source: . Paley D, Hall H. Calcaneal fracture controversies Can we put Humpty Dumpty together again? Orthop Clin North Am. 1989 Oct;20(4):665-77
The tough compact bone is not needed in the middle therefore compressive and tearing forces cancel each other out mid-way through the bone.
The knee joint is formed by the articulation of the distal end of the femur and the proximal end of the tibia. The fibula is only involved to the extent that it serves as an attachment site for connective tissue. In this paper, the anatomy of the joint will be discussed.
In dorsiflexion the ATFL is loose, the CFL is taut, and the PTFL is maximally stretched. The reversed happens in plantarflexion. The CFL prevents adduction and acts virtually independently in neutral and in dorsiflexed positions. The maximum load to failure of the CFL is roughly 2-3.5 times greater than that for the ATFL. The ATFL can stretch the greatest amount before failure this allows internal rotation of the talus during plantarflexion, in contrast to the CFL and PTFL. The ATFL main role is to restrict internal rotation of the talus ...
Hemothorax. Retrieved from http://emedicine.medscape.com/article/2047916-overview#aw2aab6b2b4 Norvell, J. G. (2013, June 11). Tibia and Fibula Fracture Clinical Presentation. Retrieved from http://emedicine.medscape.com/article/826304-clinical Queensland Government.
Osteoporosis is a condition, which advances with age, resulting in fragile, weak bones due to a decrease in bone mass. Externally osteoporotic bone is shaped like normal bone, however it’s internal appearance differs. Internally the bone becomes porous due to a loss in essential minerals, including phosphate and calcium. The minerals are loss more quickly than they can be replaced and in turn cause the bones to become less dense and weak. The bones become prone to fracture, due to their weakness. Therefore the awareness of the disease tends to occur after a fracture has been sustained. The bones most commonly affected are the ribs, wrist, pelvis and the vertebrae.
When we are born, our bones start out as hyaline cartilage (hyalos- meaning glass). You can think of hyaline cartilage, in this case, as the “framework” for the future bones. This cartilage is formed by multiplying cells called chondrocytes. This rapid cell division, then, helps our framework grow. This growth occurs in the epiphyseal plates located near the ends of these growing bones. This is associated by two different names: interstitial and appositional. Interstitial growth is when those chondrocytes divide, and this increases the length of our soon-to-be bones. On the opposing side, we have appositional growth, which helps in adding thickness to our bones. (I’ll go into this more a little bit later.)
An ankle fracture is a break in one or more of the three bones that make up the ankle joint. The ankle joint is made up by the lower (distal) sections of your lower leg bones (tibia and fibula) along with a bone in your foot (talus). Depending on how bad the break is and if more than one ankle joint bone is broken, a cast or splint is used to protect and keep your injured bone from moving while it heals. Sometimes, surgery is required to help the fracture heal properly.
In order to understand how the menisci can be injured, you must understand the basic anatomy of the menisci and why they are important. The menisci are two oval (semilunar) fibrocartilages that deepen the articular facets of the tibia and cushion any stresses placed on the knee joint. They enhance the total stability of the knee, assist in the control of normal knee motion, and provide shock absorption against compression forces between the tibia and the femur (Booher, 2000). Articular cartilage covers the ends of the bones that make up the joint. The articular cartilage surface is a tough, very slick material that allows the surfaces to slide against one another without damage to either surface. This ability of the meniscus to spread out the force on the joint surfaces as we walk is important because it protects the articular cartilage from excessive forces occurring in any one area on the joint surface, leading to degeneration over time (Sutton, 1999).
Type IV of OI is much rarer, comprising only 5% of cases. The bones may appear normal at the time of the first...
The roof of the orbit is composed of two main structures called orbital plate of the frontal bone and part of lesser wing of the sphenoid bone. The floor of the orbit is composed of three main structures called maxillary bone, zygomatic bone, and palatine bone. The medial wall of the orbit is composed of orbital plate of the ethmoid bone, lacrimal bone, maxillary bone, and sphenoid bone. The lateral wall of the orbit is composed of orbital surface of the zygomatic bone and the greater wing of the sphenoid bone. Weakest bones are in the floor and medial wall of the orbit and if pressure is applied through the tissues or the sturdier bones usually causes blowout fractures. In addition, there are numerous 6 ocular muscles and other tissues that surround the orbit.
A shoulder that has been dislocated can cause serious pain. Often, a shoulder can be dislocated due to injury from sports or traumatic impact during an accident. In some older patients, a dislocated shoulder can occur for a number of reasons that don't involve trauma.
Now, a clear definition of what an ankle sprain is and the causes of ankle sprains will be given. An ankle sprain happens when a ligament is either stretched out too far or is completely torn. “The lateral stabilizing ligaments, which include the anterior talofibular, calcaneofibular and posterior talofibular ligaments, are most often damaged.” (Wolfe 2001) A twisted ankle
Blunt force trauma is defined as a traumatic event caused by the introduction of any blunt instrument forcefully, causing injury to the body or head. The Severity of injury is determined by various factors. It may be due to mechanical force such as compression, traction, torsion or shear. Impact of the injury and severity depends on object and movement of victim. Injuries occurred may be internal such as lacerations of internal tissues, organs, fractures of bones or may be external such as abrasion, avulsion, contusion and laceration (Pollak & Saukko, 2009). Severity also depends on anatomical site impacted for ex: Lacerations have irregular margin, hanging causes abrasions, contusions and hyoid bone fractures, Ocular hemorrhages in case of blunt trauma to eyes or Fracture of ribs when hit on chest by a blunt object (Ressel, Hetzel, & Ricci, 2016). Severity is also determined by the duration of time and amount of force applied. Nature of trauma is of importance in forensic medicine. It helps in
The fibula is a leg bone located on the lateral side of the tibia, with which it is connected above and below. It is the smaller of the two bones, and the slenderest of all the long bones, and plays a significant role in stabilizing the ankle and supporting the muscles of the lower leg. The fibula is the smaller, non-weight bearing, of the two bones in the lower leg, while the tibia is the larger, weight bearing bone. The fibula and tibia moves very little relative to each other and the joints that it forms contribute significantly to the function of the lower leg. The joint it forms permit the fibula to adjust its position relative to the tibia, increasing the range of motion of the ankle. Fibular fractures are not often a severe injury, because the bone is supports only about 17% of the body weight.
The Ankle Joint, otherwise known as the Talocrural Articulation, is a synovial hinge joint that connects the distal tibiofibular joint to the upper surface of the body of the talus. Owing its strength to the shape of the articulating bones as well as the ligaments and tendons attached to it, the ankle joint is relatively stable in the neutral position.