Calcaneus: The largest of the TARSAL BONES which is situated at the lower and back part of the FOOT, forming the HEEL.Subtalar Joint: Formed by the articulation of the talus with the calcaneus.Talus: The second largest of the TARSAL BONES. It articulates with the TIBIA and FIBULA to form the ANKLE JOINT.Foot Deformities, Acquired: Distortion or disfigurement of the foot, or a part of the foot, acquired through disease or injury after birth.Achilles Tendon: A fibrous cord that connects the muscles in the back of the calf to the HEEL BONE.Tarsal Joints: The articulations between the various TARSAL BONES. This does not include the ANKLE JOINT which consists of the articulations between the TIBIA; FIBULA; and TALUS.Heel: The back (or posterior) of the FOOT in PRIMATES, found behind the ANKLE and distal to the TOES.Clubfoot: A deformed foot in which the foot is plantarflexed, inverted and adducted.Fractures, Bone: Breaks in bones.Tarsal Bones: The seven bones which form the tarsus - namely, CALCANEUS; TALUS; cuboid, navicular, and the internal, middle, and external cuneiforms.Foot: The distal extremity of the leg in vertebrates, consisting of the tarsus (ANKLE); METATARSUS; phalanges; and the soft tissues surrounding these bones.Bone Density: The amount of mineral per square centimeter of BONE. This is the definition used in clinical practice. Actual bone density would be expressed in grams per milliliter. It is most frequently measured by X-RAY ABSORPTIOMETRY or TOMOGRAPHY, X RAY COMPUTED. Bone density is an important predictor for OSTEOPOROSIS.Intra-Articular Fractures: Fractures of the articular surface of a bone.Osteoblastoma: A benign, painful, tumor of bone characterized by the formation of osteoid tissue, primitive bone and calcified tissue. It occurs frequently in the spine of young persons. (From Dorland, 27th ed; Stedman, 25th ed)Fractures, Closed: Fractures in which the break in bone is not accompanied by an external wound.Bone Cysts: Benign unilocular lytic areas in the proximal end of a long bone with well defined and narrow endosteal margins. The cysts contain fluid and the cyst walls may contain some giant cells. Bone cysts usually occur in males between the ages 3-15 years.Deer: The family Cervidae of 17 genera and 45 species occurring nearly throughout North America, South America, and Eurasia, on most associated continental islands, and in northern Africa. Wild populations of deer have been established through introduction by people in Cuba, New Guinea, Australia, New Zealand, and other places where the family does not naturally occur. They are slim, long-legged and best characterized by the presence of antlers. Their habitat is forests, swamps, brush country, deserts, and arctic tundra. They are usually good swimmers; some migrate seasonally. (Walker's Mammals of the World, 5th ed, p1362)Osteoporosis: Reduction of bone mass without alteration in the composition of bone, leading to fractures. Primary osteoporosis can be of two major types: postmenopausal osteoporosis (OSTEOPOROSIS, POSTMENOPAUSAL) and age-related or senile osteoporosis.Tendon Transfer: Surgical procedure by which a tendon is incised at its insertion and placed at an anatomical site distant from the original insertion. The tendon remains attached at the point of origin and takes over the function of a muscle inactivated by trauma or disease.Fracture Fixation, Internal: The use of internal devices (metal plates, nails, rods, etc.) to hold the position of a fracture in proper alignment.Absorptiometry, Photon: A noninvasive method for assessing BODY COMPOSITION. It is based on the differential absorption of X-RAYS (or GAMMA RAYS) by different tissues such as bone, fat and other soft tissues. The source of (X-ray or gamma-ray) photon beam is generated either from radioisotopes such as GADOLINIUM 153, IODINE 125, or Americanium 241 which emit GAMMA RAYS in the appropriate range; or from an X-ray tube which produces X-RAYS in the desired range. It is primarily used for quantitating BONE MINERAL CONTENT, especially for the diagnosis of OSTEOPOROSIS, and also in measuring BONE MINERALIZATION.Felidae: The cat family in the order CARNIVORA comprised of muscular, deep-chested terrestrial carnivores with a highly predatory lifestyle.Foot Injuries: General or unspecified injuries involving the foot.External Fixators: External devices which hold wires or pins that are placed through one or both cortices of bone in order to hold the position of a fracture in proper alignment. These devices allow easy access to wounds, adjustment during the course of healing, and more functional use of the limbs involved.Ankle Joint: The joint that is formed by the inferior articular and malleolar articular surfaces of the TIBIA; the malleolar articular surface of the FIBULA; and the medial malleolar, lateral malleolar, and superior surfaces of the TALUS.Radius: The outer shorter of the two bones of the FOREARM, lying parallel to the ULNA and partially revolving around it.