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Clinical Anatomy of Upper Limb. Dr. Zeenat Zaidi. Clavicle. It is the most commonly fractured bone in the body. The fracture occurs due to falling on the shoulder or the outstretched hand. It is most commonly fractured at the junction of the middle and outer thirds (weakest point).
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Clinical Anatomy of Upper Limb Dr. Zeenat Zaidi
Clavicle • It is the most commonly fractured bone in the body. • The fracture occurs due to falling on the shoulder or the outstretched hand. • It is most commonly fractured at the junction of the middle and outer thirds (weakest point). • The lateral fragment: • Depressed by the weight of the arm • Pulled medially and forwards by the adductors of arm (especially pectoralis major). • The medial fragment : • Pulled upward by the sternomastoid. • Involvement of supraclavicular nerves can be the cause of persistent pain over the side of the neck.
Humerus • Fractures of the proximal end: • Humeral head fracture: • may occur in anterior or posterior dislocations of shoulder • Greater tuberosityfracture: • It is due to direct trauma, dislocation of the shoulder joint or due to violent contraction of supraspinatus muscle. • The bone fragment will have the attachments of the rotator cuff muscles • Severe tearing of the rotator cuff with the dislocation can result in the greater tubercle remaining displaced posteriorly even after the joint is reduced. • Lesser tuberosityfracture • Surgical neck fractures: may result in injury to axillary nerve
Humerus • Fractures of the shaft: • Are common • The displacement of the fragments depends on the relation of the site of fracture to the insertion of the deltoid. muscle • If the fracture line is proximaltothe deltoid insertion: • The proximal fragment is adducted by the pectoralis major, latissimusdorsi and teres major. • The distal fragment is pulled proximally by deltoid, biceps & triceps. • If the fracture line is distaltothe deltoid insertion: • The proximal fragment is abducted by deltoid. • The distal fragment is pulled proximally by the biceps & triceps. • The radial nerve can be injured.
Humerus • Fractures of the lower end: • Supracondylarfracture: • Common in children • May injure median nerve and brachial artery • Medial epicondylefracture: • May injure the ulnar nerve
Radius • Fracture of the distal end (Colle’s fracture): • It is due to a fall on the outstretched hand in patients over (50) years. • The distal fragment of the radius is pulled posteriorly and superiorly • The distal articular surface is directed posteriorly. • The posterior displacement produces a posterior bump. • The deformity is referred to as, ‘dinner-fork deformity’ because the forearm and wrist resemble the shape of a dinner fork. • Smith’s fractureis a reversed Cole’s as the distal segment is displaced anteriorly
Fracture of the Scaphoid Bone • Common in young adults • Fracture line passes through the narrowest part of the bone • The blood supply to scaphoid may come from its distal end and the only way the proximal pole can receive any blood supply and nutrients is through the rest of the bone. Thus a fracture of the scaphoid in the proximal pole or waist, deprives the proximal fragment of its arterial supply, and this fragment undergoes avascular necrosis. • If the fragments will not unite properly, there will be permanent pain and weakness at the wrist • Deep tenderness in the anatomical snuff box after a fall on an outstretched hand in a young adult is an indication of fracture of scaphoid bone
Sternoclavicular Joint • Occasionally dislocated because of strong ligaments around • Anterior dislocation: medial end of clavicle pulled forward and upward • Posterior dislocation: medial end of clavicle pulled backward, which may press trachea, esophagus & great vessels in the root of the neck Anterior dislocation
Acromioclavicular Joint • The stability of the acromioclavicular joint depends on the strong coracoclavicular ligament • The joint may get injured by a severe blow such as a hard fall on the shoulder. • The acromian thrusts beneath the lateral end of the clavicle tearing the coracoclavicular ligament. This condition is called shoulder separation, asthe shoulder separates (falls away) from the clavicle because of the weight of the upper limb. • The displaced lateral end of clavicle is easily palpable
Shoulder Joint • It is the most commonly dislocated large joint. • Dislocations happen when a force overcomes the strength of the rotator cuff muscles and the ligaments of the shoulder. • Nearly all dislocations are anterior inferior dislocations, meaning that the humerus slips out of the front of the glenoid. • Only three percent of dislocations are posterior dislocations, or out the back.
Anteriorinferiordislocation Sudden violence applied to the humerus when the joint is fully abducted. The humeral head moves downward onto the inferior weak part of the capsule which tears. The humeral head comes to lie inferior to the glenoid fossa The acromion acts as a fulcrum and the head of the humerus is pulled upward and forwards by the strong flexors and adductors. Posterior displacement It is due to direct violence to the front of the joint. The shoulder loses its rounded appearance as the greater tuberosity is no more bulging laterally. The axillary nerve can be damaged.
Elbow Joint • Dislocations are common and most are posterior. Are more common in children, due to a fall on outstretched hand. The distal end of humerus is pushed anteriorly through weak part of the capsule • Pulled Elbow: occurs in children, when the child is lifted by the upper limb. The radial head is pulled out of the annular ligament
Rotator Cuff Tendinitis • Results due to excessive overhead activity of the upper limb. • It is a common cause of pain in the shoulder region • Normally during abduction of the shoulder joint, friction between the supraspinatus tendon and the acromion is minimized by the subacromial bursa. • Degenerative changes in the bursa are followed by degenerative changes in the tendon of supraspinatus that may extend to the tendons of the other rotator cuff • There is a spastic pain in the middle range of abduction.
Rupture of the Supraspinatus Tendon • In advanced cases of tendinitis, the necrotic supraspinatus tendon may become calcified and rupture • The patient is unable to initiate abduction of the arm
Tennis Elbow • Caused by partial tear or degeneration of the origin of superficial extensor muscles attached to the lateral epicondyle • It results due to excessive use of these muscles as in tennis, violinists and housewives. • Results in pain and tenderness over the lateral epicondyle that radiates to the lateral side of the forearm
Golfer’s Elbow (Medial Epicondylitis) • Caused by partial tear or degeneration of the origin of superficial flexor muscles attached to the medial epicondyle • It results due to excessive use of these muscles as in playing golf • Results in pain and tenderness over the medial epicondyle that radiates to the medial side of the forearm
Biceps Brachii& Osteoarthritis of the Shoulder Joint • Advanced osteoarthritic changes in the shoulder joint can cause erosion of the tendon of the long head of biceps by osteophytic changes. • The tendon may be reptured.
Volkmann’s Ischaemic Contracture • It is the contractures of the muscles of the forearm that follows fractures of the distal end of the humerus or fractures of the radius and ulna. • Spasm of a localized segment of the brachial artery reduces the blood flow to the flexors and extensor muscles so that they under go ischemic necrosis. • The flexor muscles are mostly affected • The muscles are replaced by fibrous tissue, which contract and result in the deformity
3 types of deformity exists: The long flexors of the carpals and fingers are more contracted than extensors. The wrist joint is flexed and the fingers are extended. The long extensorsof the fingers are greatly contracting The wrist and metacarpo-phalngeal joints are extended. The interphalngeal joints are flexed. Both the flexor and extensor are contracted: The wrist joint and the interphalangeal joints are flexed. The metacarpo-phalangeal joints are extended.
Dupuytren’sContracture • It is a localized thickening and contracture of the palmaraponeurosis. • It commonly starts near the root of the ring finger pulling it to the palm and flexing it at the metacarpo-phalngealjoint. Later the little finger is involved. • In long standing cases prolonged pulling of the fibrous sheaths of these two fingers would flex their proximal interphalangeal joints • Their distal interphalangealjoints are not involved and they actually become extended • Dupuytren's disease is familial, and may be associated with cigarette smoking, vascular disease, epilepsy, and diabetes.
Compartment syndromes of the forearm • The deep facial sheath, the interosseous membrane & the fibrous intermuscular septae divide the forearm into compartments, that contain muscles, vessels and nerves • There is very little room within each compartment, and any edema will cause secondary vascular compression. • The veins are affected first and later the arteries
Tenosynovitis & Infection of the Fascial Spaces of Palm • May get infected and distended with pus, after penetrating wounds of the palm
Pulp-Space Infection (Felon) • This is the commonest hand infection. Pus more often gathers in the finger tips than anywhere else in the hand. • It is more common in the thumb and index fingers. • Bacteria enter the space through needles or nails. • Accumulation of inflammatory exudate within the small compartments of the pulp would rapidly increase its pressure. There is little room for swelling, so that infection causes a throbbing pain early. • If infection is not decompressed, it can extend into the terminal phalanx.
Pus from the pulp can track: through to the skin outside through the periosteum, causing osteomyelitis of the distal phalanx. Since the blood supply of the diaphysis of the phalanx passes through the pulp space (in children), the infection would result in necrosis of the diaphysis. Its epiphysis is supplied by a separate artery, so this usually survives the infection. The synovial sheaths of the affected fingers can be involved because of their close relationships to the proximal part of the pulp space.
Venipuncture • The superficial veins of the upper limb are used for venipuncture, transfusion and cardiac cathetrization. • When a patient is in shock, the superficial veins are not always visible. It is very important to know their course and the relations to important landmarks. • The cephalic vein: • At the wrist, it passes posterior to the styloid process of the radius. • In the cubital fossait is separated from the brachial artery by the bicipital aponeurosis which protects the artery from irritating drugs. • In the deltopectoral groove, it communicates with the external jugular vein by a small vein that passes in front of the clavicle. Fracture of the clavicle can tear this communicating vein and causes a large hematoma.