Radiographic Anatomy of the Extremities PDF

AN OVERVIEW OF ANATOMY OF REGIONAL EXTREMITIES (UPPER AND LOWER LIMBS)  SECTION ONE UPPER EXTREMITY  INTRODUCTION The upper extremity or arm is a functional unit of the upper body. It consists of three sections, the upper arm, forearm, and hand. It extends from the shoulder...

AN OVERVIEW OF ANATOMY OF REGIONAL EXTREMITIES (UPPER AND LOWER LIMBS)  SECTION ONE UPPER EXTREMITY  INTRODUCTION The upper extremity or arm is a functional unit of the upper body. It consists of three sections, the upper arm, forearm, and hand. It extends from the shoulder joint to the fingers and contains 30 bones. It also consists of many nerves, blood vessels (arteries and veins), and muscles. The nerves of the arm are supplied by one of the two major nerve plexus of the human body, the brachial plexus. The upper limb is divided into three regions. These consist of the arm, located between the shoulder and elbow joints The forearm, which is between the elbow and wrist joints The hand, which is located distal to the wrist. Therefore, each upper limb comprises of 30 bones. The Humerus is the single bone of the upper arm. The ulna (medially) and the radius (laterally) are the paired bones of the forearm. The base of the hand contains eight bones, each called a carpal bone, The palm of the hand is formed by five bones, each called a metacarpal bone. The fingers and thumb contain a total of 14 bones, each of which is a phalanx bone of the hand.  BONES OF THE UPPER LIMBS Humerus The humerus is the single bone of the upper arm region. At its proximal end is the head of the humerus. This is the large, round, smooth region that faces medially. The head articulates with the glenoid cavity of the scapula to form the glenohumeral (shoulder) joint. The margin of the smooth area of the head is the anatomical neck of the humerus. Located on the lateral side of the proximal humerus is an expanded bony area called the greater tubercle. The smaller lesser tubercle of the humerus is found on the anterior aspect of the humerus. Both the greater and lesser tubercles serve as attachment sites for muscles that act across the shoulder joint. Ulna and Radius Radius The radius runs parallel to the ulna, on the The ulna is located on the medial side of the forearm, and the radius is on the lateral (thumb) side of the forearm. The head lateral side. These bones are attached to of the radius is a disc-shaped structure that each other by an interosseous membrane. forms the proximal end. The small depression on the surface of the head Ulna articulates with the capitulum of the The ulna is the medial bone of the humerus as part of the elbow joint, whereas forearm. It runs parallel to the radius, the smooth, outer margin of the head which is the lateral bone of the fshaped articulates with the radial notch of the ulna at trochlear notch. This region articulates the proximal radioulnar joint.orearm. The with the trochlea of the humerus as part proximal end of the ulna resembles a of the elbow joint. crescent wrench with its large, C- Bones of the Wrist and Hand The eight carpal bones form the base of the hand. These are arranged into proximal and distal rows of four bones each. The metacarpal bones form the palm of the hand. The thumb and fingers consist of the phalanx bones.  JOINTS OF THE UPPER LIMB ACROMIOCLAVICULAR JOINT The acromioclavicular joint is an articulation in the shoulder region between the clavicle and the acromion of the scapula. It is a plane type synovial joint. STERNOCLAVICULAR JOINT It is a saddle-type synovial joint which acts to link the upper limb with the trunk. The sternoclavicular joint is formed by an articulation between three structures: Sternal end of the clavicle Manubrium of the sternum First costal cartilage (cartilage associated with the first rib) The articular surfaces are covered with fibrocartilage (as opposed to hyaline cartilage, present in the majority of synovial joints). The joint is separated into two compartments by a fibrocartilaginous articular disc. SHOULDER JOINT The shoulder joint is formed by an articulation between the head of the humerus and the glenoid cavity (or fossa) of the scapula. This gives rise to the alternate name for the shoulder joint – the glenohumeral joint. Like most synovial joints, the articulating surfaces are covered with hyaline cartilage. The head of the humerus is much larger than the glenoid fossa, giving the joint a wide range of movement at the cost of instability. To reduce the disproportion in surfaces, the glenoid by a fibrocartilage rim – called the glenoid labrum. ELBOW JOINT The elbow is the joint connecting the upper arm to the forearm. It is classed as a hinge-type synovial joint. The elbow joint consists of two separate articulations: Trochlear notch of the ulna and the trochlea of the humerus Head of the radius and the capitulum of the humerus Note: The proximal radioulnar joint is found within same joint capsule of the elbow, but most resources consider it as a separate articulation. RADIOULNAR JOINT The radioulnar joints are two locations in which the radius and ulna articulate in the forearm: Proximal radioulnar joint – located near the elbow. It is articulation between the head of the radius and the radial notch of the ulna Distal radioulnar joint – located near the wrist. It is an articulation between the ulnar notch of the radius and the ulnar head. Both of these joints are classified as pivot joints, responsible for pronation and supination of the forearm.  WRIST JOINT The wrist joint (also known as the radiocarpal joint) is an articulation between the radius and the carpal bones of the hand. It is condyloid-type of synovial joint which marks the area of transition between the forearm and the hand. The wrist joint is formed by an articulation between: Distal end of the radius and the articular disk. Proximal row of the carpal bones (except the pisiform). Together, the carpal bones form a convex surface, which fits into the concave shape of the radius and articular disk. The ulna is prevented from articulating with the carpal bones by the presence of a fibrocartilaginous ligament, the articular disk. Instead, the ulna articulates with the radius just proximal to the wrist – at the distal radioulnar joint. METACARPOPHALANGEAL JOINT The metacarpophalangeal joint is an articulation between the metacarpal head and the base of the proximal phalanx. There are five joints located in each hand – one for each digit. PROXIMAL INTERPHALANGEAL JOINT The proximal interphalangeal joint (PIPJ) refers to the articulation between the proximal and middle phalanx in the hand. It is present in all digits except the thumb. It is a synovial hinge joint which permits flexion and extension in center of the fingers, contributing to fine motor con DISTAL INTERPHALANGEAL JOINT The distal interphalangeal joints are saddle joints, formed by the distal trochlea of the medial phalanges and the articulating fossae of the distal phalanxes. RADIOGRAPHIC VIEW OF THE UPPER LIMB Radiographic Anatomy (x-ray anatomy) is anatomy discipline which involves the study of anatomy through the use of radiographic films. The x-ray film represents two-dimensional image of a three-dimensional object due to the summary projection of different anatomical structures onto a planar surface. Upper limb radiography is the radiological investigation of the shoulder girdle, humerus, ulna, radius, carpals and metacarpals of the hand. It is often utilised in the context of trauma to rule out fractures and dislocations. Upper extremity X-rays may be of the fingers, hands, wrists, elbows, forearms, upper arms or shoulders. These X-rays can help to find injuries (fractures and sports injuries), joint swelling (arthritis), weakened bones (osteoporosis) or other abnormalities that may be causing pain.  APPLIED ANATOMY OLECRANON FRACTURE: It is a break in the bony tip of the elbow. FRACTURE OF THE RADIUS AND ULNA: It is the most common fracture of the upper A fall onto an outstretched hand is the most common mechanism of injury for fractures of the radius and ulna HUMERAL SHAFT FRACTURE: It occurs at the diaphysis of the humerus. BOXER’S FRACTURE: This is the break in the neck of the 5th metacarpal bone in the hand. SCAPHOID AND CAPITATE FRACTURE:Also known as Scapho-capitate or Fenton syndrome is a rare carpal injury resulting from high energy traumas. There is a combined fracture of the scaphoid and capitate bones.  SECTION TWO: LOWER EXTREMITY  INTRODUCTION The lower limb/ extremities of the body are specialized for the transmission of body weight and locomotion. Parts /region of the lower limb: For descriptive purposes the lower limb is made up of six regions namely: Gluteal region Thigh or femoral region Knee or knee region Leg or leg region Ankle or talocrural region Foot or foot region  BONES OF THE LOWER LIMB Each region of the lower limb contains 31 bones. Hip bone/innonimate bone of the gluteal region(1) Femur ,the bone of the thigh(1) Patella or knee cap(1) Tibia and Fibula ( the bones of the leg)(2) Tarsals bones(7) Metatarsals bones(5) Phalanges(14) HIP BONE The hip bone is a large irregular bone of the hip.It is formed by the fusion of 3 primary bones ,the illeum, Ischium and the pubis FEMUR Is the longest and strongest bone of the body. It is slanted to allow for balance of the body and it also absorb the weight of the body. PATELLA Is the largest sesamoid bone located within the tendon of the quadriceps femoris, which articulates with the femur but not with the tibia.  TIBIA AND FIBULA Tibia  Fibula Is the weight-bearing medial bone of the leg. Has little or no function in weight bearing but provides attachment for muscles. Has the tibial tuberosity into which the patellar ligament inserts. Has a head (apex) that provides attachment for the fi bular collateral Has medial and lateral condyles that articulate with the condyles of ligament of the knee joint. the femur. Has a projection called the lateral Has a projection called the medial malleolus. malleolus Tarsals bone It consists of 7 tarsals bone, they include: Talus Calcaneus Navicular bone Cuboid bone 3 Cuneiform bones Metatarsals bone These are miniature long bone. There are numbered from medial to lateral as first, second, third ,fourth and fifth. Hence we have 5 metatarsals bone. Phalanges Consists of 14 bones (two in the first digit and three in each of the others).  JOINTS OF THE LOWER LIMB HIP JOINT Is a multiaxial ball-and-socket synovial joint between the acetabulum of the hip bone and the head of the femur and allows abduction and adduction, flexion and extension, and rotation. KNEE JOINT Is the largest and most complicated joint. Although structurally it resembles a hinge joint, it is a condylar type of synovial joint between two condyles of the femur and tibia. In addition, it includes a saddle joint between the femur and the patella. TIBIOFIBULAR JOINT : A. Proximal Tibiofibular Joint: Is a plane-type synovial joint between the head of the fibula and the tibia that allows a little gliding movement. B. Distal Tibiofibular Joint: Is a fibrous joint between the tibia and the fibula. KNEE JOINT TIBIOFIBULAR JOINT ANKLE (TALOCRURAL) JOINT Is a hinge-type synovial joint between the tibia and fibula superiorly and the trochlea of the talus inferiorly, permitting dorsiflexion and plantarflexion. JOINTS OF THE FOOT  RADIOGRAPHIC VIEW OF THE LOWER LIMB Lower limb radiography is the radiological investigation of the pelvis, hip joint, femur, knee joint, tibia, fibula, ankle joint, tarsal bones of the foot and metatarsals. It is often utilised in the context of trauma to rule out fractures and dislocations.  APPLIED ANATOMY A hip dislocation is a condition in which the ball of the hip joint, called the femoral Head, comes out of the socket, called the acetabulum. This can be caused by a fall or a car Fracture neck of femur: It is very common in elderly particularly in women due to osteoporotic Changes in the neck. The Knee is one of the most common joints to be affected by osteoarthritis (OA), and it can lead to serious effects on one’s mobility, quality of life and livelihood. Pain, swelling and stiffness of knee. Cartilage damage and loss can make it difficult even to walk or climb stairs. Osteomyelitis of the upper end of tibia: The upper end of tibia is the commonest site of acute Osteomyelitis, but knee joint remain unaffected because the capsule of knee joint is attached Near to the margins of articular surface proximal to the epiphyseal line(this is a line that exists at the end of the bone. Fibular fracture: The fibula is commonly fractured, 2 to 5 cm proximal to the distal end of the Lateral malleolus. It is often associated with ‘fracture dislocation of the ankle joint. Fracture neck of talus: It sometimes occurs due to forceful dorsiflexion of foot. Calcaneal fracture: It occurs when a person falls on his heels from a considerable height. March fracture: It typically occurs in the shaft or neck of second and third metatarsals due to aggressive prolonged march past by the soldiers. Fracture of the tuberosity (styloid process) of the fifth metatarsal: It usually occurs due to Forced inversion of the forefoot, when the tendon of peroneus brevis pulls off the styloid Process leading to its avulsion. This fracture is also called Jones’ fracture after the name of an