Osteology of the Lower Limb 2022 PDF

UNIVERISITY OF MEDICAL SCIENCES, ONDO STATE, DEPARTMENT OF ANATOMY. ANA 210 LECTURE: OSTEOLOGY OF THE LOWER LIMB BY: OLUWATUNASE GIDEON  OUTLINE Introduction to Gross Anatomy of the Lower limbs Arrangement of lower limb bones Gross Anat...

UNIVERISITY OF MEDICAL SCIENCES, ONDO STATE, DEPARTMENT OF ANATOMY. ANA 210 LECTURE: OSTEOLOGY OF THE LOWER LIMB BY: OLUWATUNASE GIDEON  OUTLINE Introduction to Gross Anatomy of the Lower limbs Arrangement of lower limb bones Gross Anatomy of the Femur Gross Anatomy of the patella Gross Anatomy of tibia and fibula Gross Anatomy of the bones of the foot Associated clinical correlate 2  OBJECTIVES At the end of this lecture, the students should understand: Introduction to Gross Anatomy of the Lower limbs Arrangement of lower limb bones Gross Anatomy of the Femur Gross Anatomy of the patella Gross Anatomy of tibia and fibula Gross Anatomy of the bones of the foot Associated clinical correlate 3  INTRODUCTION The skeleton of the lower limb (inferior appendicular skeleton) may be divided into two functional components: the pelvic girdle (usually discussed with the pelvic region) the bones of the free lower limb The pelvic girdle attaches the free lower limb to the axial skeleton 4  ARRANGEMENT OF LOWER LIMB BONES Body weight is transferred from the vertebral column through the sacro-iliac joints to the pelvic girdle and from the pelvic girdle through the hip joints to the femurs To support the erect bipedal posture better, the femurs are oblique (directed inferomedially) within the thighs so that when standing, the knees are adjacent and placed directly inferior to the trunk, returning the center of gravity to the vertical lines of the supporting legs and feet. 5 6  FEMUR The femur is the longest and heaviest bone in the body. It transmits body weight from the hip bone to the tibia when a person is standing. Its length is approximately a quarter of the person’s height. The femur consists of a shaft (body) and two ends, superior or proximal and inferior or distal 7 8 9  PATELLA is a large sesamoid bone that is formed in the tendon of the quadriceps femoris muscle after birth This triangular bone, located anterior to the midcondylar region of the femur, articulates with the patellar surface of the femur The subcutaneous anterior surface of the patella is convex. The thick base (superior border) slopes infero-anteriorly and the lateral and medial borders converge inferiorly to form the pointed apex. The posterior articular surface is smooth, covered with a thick layer of articular 10 11  TIBIA AND FIBULA The tibia and fibula are the bones of the leg The tibia articulates with the condyles of the femur superiorly and the talus inferiorly and in so doing transmits the body’s weight. The fibula mainly functions as an attachment for muscles, but it is also important for the stability of the ankle joint. The shafts of the tibia and fibula are 12 13 14  TIBIA is located on the anteromedial side of the leg, nearly parallel to the fibula. It is the second largest bone in the body. It flares outward at both ends to provide an increased area for articulation and weight transfer Unlike that of the femur, the shaft of the tibia is truly vertical within the leg. 15  FIBULA lies posterolateral to the tibia and is firmly attached to it by the tibiofibular syndesmosis, which includes the interosseous membrane The fibula has no function in weight bearing. It serves mainly for muscle attachment, providing distal attachment (insertion) for one muscle and proximal attachment (origin) for eight muscles. The fibers of the tibiofibular syndesmosis are arranged to resist the resulting net downward pull on the fibula. 16  BONES OF THE FOOT The bones of the foot include the tarsus metatarsus and phalanges There are 7 tarsal bones, 5 metatarsal bones, and 14 phalanges 17 18  TARSUS Consists of seven bones : talus, calcaneus, cuboid, navicular, and three cuneiforms. Only one bone, the talus, articulates with the leg bones. 19 20  METATARSUS Consists of five metatarsals that are numbered from the medial side of the foot In the articulated skeleton of the foot, the tarsometatarsal joints form an oblique tarsometatarsal line joining the midpoints of the medial and shorter lateral borders of the foot. Thus, the metatarsals and phalanges are located in the anterior half (forefoot) and the tarsals are in the posterior half (hindfoot) 21  PHALANGES The 14 phalanges of the lower limb are as follows: the 1st digit (great toe) has 2 phalanges (proximal and distal); the other four digits have 3 phalanges each: proximal, middle, and distal. Each phalanx has a base (proximally), a shaft, and a head (distally). The phalanges of the 1st digit are short, broad, and strong. The middle and distal phalanges of the 5th digit may be fused in elderly people. 22  CLINICAL CORRELATE Injuries to the lower limb Injuries to the hip bone Coxa vara and coxa valga Dislocation of the femoral head Femoral fracture Tibial fracture Fibular fracture Bone grafting Calcaneal fracture 23