In children, a fall onto the tip of the elbow frequently results in a distal humerus fracture. In these, the olecranon of the ulna is driven upward, resulting in a fracture across the distal humerus, above both epicondyles supracondylar fracture , or a fracture between the epicondyles, thus separating one or both of the epicondyles from the body of the humerus intercondylar fracture. With these injuries, the immediate concern is possible compression of the artery to the forearm due to swelling of the surrounding tissues.
If compression occurs, the resulting ischemia lack of oxygen due to reduced blood flow can quickly produce irreparable damage to the forearm muscles. This involves a complete transverse fracture across the distal radius that drives the separated distal fragment of the radius posteriorly and superiorly. This is the most frequent forearm fracture and is a common injury in persons over the age of 50, particularly in older women with osteoporosis.
It also commonly occurs following a high-speed fall onto the hand during activities such as snowboarding or skating. The most commonly fractured carpal bone is the scaphoid, often resulting from a fall onto the hand.
Deep pain at the lateral wrist may yield an initial diagnosis of a wrist sprain, but a radiograph taken several weeks after the injury, after tissue swelling has subsided, will reveal the fracture. Due to the poor blood supply to the scaphoid bone, healing will be slow and there is the danger of bone necrosis and subsequent degenerative joint disease of the wrist.
Watch this video to learn about a Colles fracture, a break of the distal radius, usually caused by falling onto an outstretched hand. When would surgery be required and how would the fracture be repaired in this case? Each upper limb is divided into three regions and contains a total of 30 bones.
The arm is the region located between the shoulder and elbow joints. This area contains the humerus. The proximal humerus consists of the head, which articulates with the scapula at the glenohumeral joint, the greater and lesser tubercles separated by the intertubercular bicipital groove, and the anatomical and surgical necks. The humeral shaft has the roughened area of the deltoid tuberosity on its lateral side. The distal humerus is flattened, forming a lateral supracondylar ridge that terminates at the small lateral epicondyle.
The medial side of the distal humerus has the large, medial epicondyle. The articulating surfaces of the distal humerus consist of the trochlea medially and the capitulum laterally. Depressions on the humerus that accommodate the forearm bones during bending flexing and straightening extending of the elbow include the coronoid fossa, the radial fossa, and the olecranon fossa.
The forearm is the region of the upper limb located between the elbow and wrist joints. This region contains two bones, the ulna medially and the radius on the lateral thumb side. The elbow joint is formed by the articulation between the trochlea of the humerus and the trochlear notch of the ulna, plus the articulation between the capitulum of the humerus and the head of the radius.
The proximal radioulnar joint is the articulation between the head of the radius and the radial notch of the ulna. The proximal ulna also has the olecranon process, forming an expanded posterior region, and the coronoid process and ulnar tuberosity on its anterior aspect. On the proximal radius, the narrowed region below the head is the neck; distal to this is the radial tuberosity.
The shaft portions of both the ulna and radius have an interosseous border, whereas the distal ends of each bone have a pointed styloid process. The distal radioulnar joint is found between the head of the ulna and the ulnar notch of the radius. The distal end of the radius articulates with the proximal carpal bones, but the ulna does not. The base of the hand is formed by eight carpal bones. The carpal bones are united into two rows of bones. The proximal row contains from lateral to medial the scaphoid, lunate, triquetrum, and pisiform bones.
Specifically, the scaphoid, lunate, and triquetrum bones contribute to the formation of the radiocarpal joint. The distal row of carpal bones contains from medial to lateral the hamate, capitate, trapezoid, and trapezium bones. The proximal and distal carpal rows articulate with each other at the midcarpal joint. The carpal bones, together with the flexor retinaculum, also form the carpal tunnel of the wrist.
The five metacarpal bones form the palm of the hand. The metacarpal bones are numbered 1—5, starting with the thumb side.
The first metacarpal bone is freely mobile, but the other bones are united as a group. The digits are also numbered 1—5, with the thumb being number 1. The fingers and thumb contain a total of 14 phalanges phalanx bones. The thumb contains a proximal and a distal phalanx, whereas the remaining digits each contain proximal, middle, and distal phalanges. A fracture through the joint surface of the distal radius may make the articulating surface of the radius rough or jagged.
This can then cause painful movements involving this joint and the early development of arthritis. Surgery can return the joint surface to its original smoothness, thus allowing for the return of normal function. The hand has a proximal transverse arch, a distal transverse arch, and a longitudinal arch.
The bones of the foot include the tarsus, metatarsus, and phalanges. Foot Bones. The bones of the foot consist of the tarsal bones of the ankle, the phalanges that form the toes, and the metatarsals that give the foot its arch. Ankle Bones. The ankle, or tarsus, consists of seven tarsal bones: the calcaneus, talus, cuboid, navicular, and three cuneiforms.
Foot Arches. The arches of the foot are formed by the interlocking bones and ligaments of the foot. They serve as shock-asborbing structures that support body weight and distribute stress evenly during walking. Download Appendicular Skeleton Lab Manual. See more from our free eBook library. Human Anatomy Atlas offers thousands of models to help understand and communicate how the human body looks and works. X-rays of the hand , hip , knee , and ankle.
Stony Brook University School of Medicine. The forearm consists of two bones, the ulna and radius. And the hand consists of 27 bones, which are grouped into the phalanges, metacarpals, and carpals. The major processes and markings of the humerus, ulna , and radius bones are shown in Figures , , and , respectively.
The bones of the hands are divided into three groups. The carpals articulate with the ulna and radius bones of the forearm and are named after the carpus, or wrist. There are 8 carpal bones and each has its own name. In Figure they are numbered so that 1-trapezium, 2-trapezoid, 3-capitate, 4-hamate, 5-pisiform, 6-triquetrum, 7-lunate, 8- scaphoid.
Figure The left humerus and its various processes and markings. The left ulna in brown and its major markings and processes. In addition, four major nerves for shoulder and upper limb muscles are closely associated with different regions of the humerus, and thus, humeral fractures may also damage these nerves.
This involves a complete transverse fracture across the distal radius that drives the separated distal fragment of the radius posteriorly and superiorly. This is the most frequent forearm fracture and is a common injury in persons over the age of 50, particularly in older women with osteoporosis.
It also commonly occurs following a high-speed fall onto the hand during activities such as snowboarding or skating. The most commonly fractured carpal bone is the scaphoid, often resulting from a fall onto the hand.
Deep pain at the lateral wrist may yield an initial diagnosis of a wrist sprain, but a radiograph taken several weeks after the injury, after tissue swelling has subsided, will reveal the fracture. Due to the poor blood supply to the scaphoid bone, healing will be slow and there is the danger of bone necrosis and subsequent degenerative joint disease of the wrist. Watch this video to learn about a Colles fracture, a break of the distal radius, usually caused by falling onto an outstretched hand.
When would surgery be required and how would the fracture be repaired in this case? Each upper limb is divided into three regions and contains a total of 30 bones. The upper arm is the region located between the shoulder and elbow joints.
This area contains the humerus. The proximal humerus consists of the head, which articulates with the scapula at the glenohumeral joint, the greater and lesser tubercles separated by the intertubercular bicipital groove, and the anatomical and surgical necks. The humeral shaft has the roughened area of the deltoid tuberosity on its lateral side. The distal humerus is flattened, forming a lateral supracondylar ridge that terminates at the small lateral epicondyle.
The medial side of the distal humerus has the large, medial epicondyle. The articulating surfaces of the distal humerus consist of the trochlea medially and the capitulum laterally. Depressions on the humerus that accommodate the forearm bones during bending flexing and straightening extending of the elbow include the coronoid fossa, the radial fossa, and the olecranon fossa. The forearm is the region of the upper limb located between the elbow and wrist joints. This region contains two bones, the ulna medially and the radius on the lateral thumb side.
The elbow joint is formed by the articulation between the trochlea of the humerus and the trochlear notch of the ulna, plus the articulation between the capitulum of the humerus and the head of the radius. The proximal radioulnar joint is the articulation between the head of the radius and the radial notch of the ulna.
The proximal ulna also has the olecranon process, forming an expanded posterior region, and the coronoid process and ulnar tuberosity on its anterior aspect. On the proximal radius, the narrowed region below the head is the neck; distal to this is the radial tuberosity.
The shaft portions of both the ulna and radius have an interosseous border, whereas the distal ends of each bone have a pointed styloid process. The distal radioulnar joint is found between the head of the ulna and the ulnar notch of the radius. The distal end of the radius articulates with the proximal carpal bones, but the ulna does not. The base of the hand is formed by eight carpal bones. The carpal bones are united into two rows of bones.
The proximal row contains from lateral to medial the scaphoid, lunate, triquetrum, and pisiform bones. The scaphoid, lunate, and triquetrum bones contribute to the formation of the radiocarpal joint. The anterior hamate has a prominent bony hook. The proximal and distal carpal rows articulate with each other at the midcarpal joint. The carpal bones, together with the flexor retinaculum, also form the carpal tunnel of the wrist.
The five metacarpal bones form the palm of the hand. The metacarpal bones are numbered 1—5, starting with the thumb side. The first metacarpal bone is freely mobile, but the other bones are united as a group.
The digits are also numbered 1—5, with the thumb being number 1. The fingers and thumb contain a total of 14 phalanges phalanx bones. The thumb contains a proximal and a distal phalanx, whereas the remaining digits each contain proximal, middle, and distal phalanges.
A fracture through the joint surface of the distal radius may make the articulating surface of the radius rough or jagged.
This can then cause painful movements involving this joint and the early development of arthritis. Surgery can return the joint surface to its original smoothness, thus allowing for the return of normal function. The hand has a proximal transverse arch, a distal transverse arch, and a longitudinal arch. These allow the hand to conform to objects being held.
These arches maximize the amount of surface contact between the hand and object, which enhances stability and increases sensory input. In this case, metal plates and screws can be used to stabilize the fractured bone. Which region of the humerus articulates with the radius as part of the elbow joint?
Your friend runs out of gas and you have to help push his car. Discuss the sequence of bones and joints that convey the forces passing from your hand, through your upper limb and your pectoral girdle, and to your axial skeleton. As you push against the car, forces will pass from the metacarpal bones of your hand into the carpal bones at the base of your hand.
Forces will then pass through the midcarpal and radiocarpal joints into the radius and ulna bones of the forearm. These will pass the force through the elbow joint into the humerus of the arm, and then through the glenohumeral joint into the scapula. The force will travel through the acromioclavicular joint into the clavicle, and then through the sternoclavicular joint into the sternum, which is part of the axial skeleton.
Name the bones in the wrist and hand, and describe or sketch out their locations and articulations.
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