Bones of the Upper Limb PDF

.. ' l By Dr. Hoda Mahmoud Elaasar Dr. AL-Moatasem Bellah Al-Sherif Dr. Sherif Gala/ Professors of Anatomy & Embryology Faculty of Medicine-Cairo University Dr....

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' l By Dr. Hoda Mahmoud Elaasar Dr. AL-Moatasem Bellah Al-Sherif Dr. Sherif Gala/ Professors of Anatomy & Embryology Faculty of Medicine-Cairo University Dr. Ayman Abou El-Enein Professor of Anatomy & Embryology Faculty of Medicine-Cairo University Revised By Dr. Mohamed Bakry Professor of Anatomy & Embrology Shereen Abdelfattah Tarek Abdelgalil Assistant Professor of Anatomy Assistant Professor of Anatomy and Embryology and Embryology Department of Anatomy & Embryology Faculty of Medicine Cairo University Staff Members: Ehab Abdel-Aziz Hassan Heidar Helana Labib Hafiz Waly Soheir EI-Sharouny Saber Shena Mohamed Bakry Emad Naguib Wafik Halim Nabila Yousef Abdei-Halim Ibrahim Labib Mohamed Emad Sherif Galal Mamdouh Mahmoud Fayza Abdei-Raouf Abdei-Wakeel Essawy Safwat Wadie AI-Moatasem Bellah AI-Sherif Maha Ashmawy Amina Borhamy Hoda Alaasar Tarek Abdei-Salam Mohamed Wahdan Medhat Morsi Sherif Zaki Naglaa Ali Ayman Abou EI-Enein Abeer Oueida Inas Ahmed Hanan Nabeh Mogeda Mahdy Magdy Fouad Walaa Mohamed Sayed Shereen Abdelfattah Tarek Abdelgalil Ahmed Galal Ahmed AI-Zainy Doaa Mahmoud Hosam Yehya Sherif Fahmy Tamer Shawky Rasha Abd El Khalek Bahaa Khaled Waleed Abd El Galil Eid Nassar Ahmed Hamed  Contents Page Chapter 1 : Bones of the Upper Limb Shoulder girdle 1 Clavicle 2 Scapula 4 Humerus 8 Radius 14 Ulna 18 Bones of the hand 21 Muscles and ligaments attached to the bones of upper limb 25 Chapter 2: Pectoral Region Cutaneous nerves of the pectoral region 31 The mammary gland 32 The pectoral fascia 38 Muscles of the pectoral region 40 Chapter 3: Muscles of the Back Muscles connecting upper limb with vertebral column 43 Muscles of the Superficial Layer 44 Muscles of the deep Layer 48 Chapter 4 : Shoulder Region Muscles of the Shoulder Region 51 Muscles Connecting the Upper Limb with the Thoracic Wall 58 Chapter 5 : Axilla Axilla 63 Brachial Plexus 67 Axillary Artery 72 Axillary Vein 78 Chapter 6 : Arm Deep fascia of the arm 83 Muscles of the arm 83 Nerves of the Arm: 88 - Musculocutaneous nerve: 88 - Radial nerve 90 - Brachial Artery 94 Chapter 7 : Forearm Deep fascia of the forearm 101 Cubital fossa 102 Muscles of the front of the forearm 104 Muscles of the back of the forearm 110 Deep Group (Deep Extensors) 116 Anatomical snuff-box 120 Nerves in the Forearm: 122 - Ulnar nerve 122 - Median nerve 126 - Superficial radial nerve 130 - Posterior interosseous nerve 132 Flexor Retinaculum 133 Extensor Retinaculum 136 Arteries of the forearm radial artery: 138 - Radial artery 138 - Ulnar artery 141 Chapter 8 : Hand Skin of the hand 145 Deep fascia of the palm 145 Palmar aponeurosis 146 Facial spaces of the hand 148 Superficial distal pulp space of the finger 151 Muscles of the hand 151 Fibrous flexor sheathes 160 Synovial sheathes 162 Nerves in the Hand 164 Arteries of the Hand 167 Chapter 9 : Veins of the Upper Limb Superficial veins 174 Deep veins 176 Lymph drainage of the upper limb 179 Chapter 10 : Nerve Supply of Upper Limb & Nerve Injuries Cutaneous Nerve Supply of Upper Limb 182 Segmental Nerve Supply of Upper Limb 186 Nerve Injuries 187 Brachial Plexus Injuries 187 Axillary Nerve Injuries 189 Long Thoracic Nerve Injury 189 Ulnar Nerve Injury 189 Median Nerve Injury 191 Radial Nerve Injury 193 Chapter 11: Joints of the Upper Limb Acromio-clavicular joint 196 Sterno-clavicular joint 198 Shoulder joint 201 Elbow joint 206 Superior radio-ulnar joint 210 Inferior radio-ulnar joint 210 Pronation and supination 212 Interosseous membrane 214 Wrist joint 216 Mid.:.carpal joints 219 Carpo-metacarpal joint 219 Metacarpo-phalangeal joints 222 Interphalangeal joints 222  Bones of Upper Limb CHAPTER1 I LOs: By the end of the lectures, the student should be able to: Recognize the name of each bone of the upper limb. Determine the site and side of each bone. Put the bones in their anatomical position. Describe the important features of each bone. Determine the growing end of each long bone. Locate the site of attachment of the related muscles and ligaments. Describe the carrying angle and its importance Interpret some clinical problems resulted from fracture of the bones on anatomical basis of their relation to important structures. BONES OF UPPER LIMB The bones of upper limb include: 1- Bones of the shoulder (pectoral) girdle (clavicle and scapula). 2- Bone of the arm: The humerus. 3- Bones of the forearm: Radius (laterally) and ulna (medially). 4- Bones of the hand: Carpal and metacarpal bones and phalanges. SHOULDER{PECTORAL)GIRDLE It is formed of right and ternoclavicular joint left halves (Fig. 1). Each half is formed by the clavicle (in front) and cular scapula (on the back), articulating with each Scapula other at the acromio- clavicular joint. In front, the two halves of the shoulder girdle are Humerus connected to the sternum at the sterno- clavicular joints. Fig.1: Shoulder girdle (Anterior view)  Bones of Upper Limb I. CLAVICLE - Site: it is the anterior bone of the shoulder girdle. It is subcutaneous - Type: it is a long bone. Unlike other long bones, the clavicle differs in the following: 1. Its has no medullary cavity. 2. It is formed by membranous ossification; t it is the first long bone to ossify in the embryo. 3. It is the only long bone placed horizontally. - General Features (Figs. 2, 3): It has a shaft and two ends (medial and lateral) A. Ends: 1. Lateral (acromial) end: it is flattened and presents a small oval articular facet to articulate with the medial side of acromion at the acromio-clavicular joint. 2. Medial (sternal) end: it is enlarged (prismatic) and articulate with t he sternum at sternoclavicular joint. B. Shaft: It is 5-shaped with the lateral one third Convex backwards to meet the scapula and medial two thirds convex forwards to give passage for large vessels and nerves between neck and axilla. 1. The lateral1/3 of the shaft has the following features: It is falttened from above downward. Its anterior border has deltoid tubercle. Its Lower surface shows: a. Conoid tubercle: is lying close to the posterior border at junction of lateral third with medial two thirds of clavicle. b. Trapezoid ridge: Extends forwards and laterally from the conoid tubercle towards the acromial end. 2. The medial 2/3 of the shaft has the following features: It is cylindrical in cross section. Its lower surface has the following features: a. A rough impression near the sternal end that gives attachment to the costo-clavicular ligament. b. A longitudinal groove in the middle third of the bone for insertion of the subclavius muscle. c. A nutrient foramen, directed laterally  BonesofUpperLilnb Upper surface Lateral1/3 Medial2/3 Medial (Sternal) "--End '! Deltoid tubercle Anterior border Fig. 2: Clav.i cle (Superior Surface) Deltoid tubercle Groove for Subclavius Muscle Oval surface acromion Surface articulating with 1st costal cartilage LATERAL MEDIAL (Acromial) (Sternal) END END Quadrilateral surface articulating with manubrium sterni Impression for costo-clavicular ligament Conoid tubercle Fig. 3: CLAVICLE (INFERIOR SURFACE)  Bones of Upper Limb II. SCAPULA - Site: it is the posterior bone of the shoulder girdle. From 2nd to the i h ribs. - Type: flat bone. - General Features (Figs. 4, 5) : it is a large flattened triangular bone having: A. Two surfaces. B. Three borders. C. Three angles. D. Three processes. A. Surfaces 1. Anterior Surface (ventral or costal surface): It is directed forwards and medially, because of the oblique plane of the scapula. It is slightly concave and forms the subscapular fossa.. 2. Posterior Surface (dorsal Surface): Directed backwards and laterally. Slightly convex. Divided by a triangular horizontal shelf-like projection, termed the spine of scapula, into: a. A smaller upper area supraspinous fossa. b. A larger lower area infraspinous fossa. B. Borders 1. Lateral Border: It is thick oblique border. At its upper end, it shows a rough triangular area called 2. Medial Border It is thin and the longest border and nearly vertical. 5 em. from the spinous processes of the vertebrae At the root of the spine of scapula, it forms an obtuse angle. 3. Superior Border It is thin, sharp and the shortest border. Near its lateral end, it shows a small supra-scapular notch and coracoid process  Bones of Upper Limb A small oval facet on medial border of acromion articulating with clavicle Coracoid process Upper border Supraglenoid tubercle Glenoid cavity (lateral angle) , Ridges for origin of subscapularis muscle Inferior angle Fig. 4: Scapula Anterior (ventral) surface  Bones of Upper Limb. C. Angles 1. Inferior angle It is an acute angle and lies over the 7th rib 2. Superior angle It is nearly a right angle and lies over the 2 nd rib. 3. Lateral angle It is broadened and may be regarded as the head of scapula and is connected to the flat body by a slightly constricted neck. On its free surface, it carries the glenoid cavity for articulation with the head of the humerus (the socket of the shoulder joint). The glenoid cavity has the following features: a. It is pear-shaped (narrow above and wider below) with prominent margins. It is shallow concave forming a poor socket for the head of the humerus. b. It is completely smooth and is covered by a layer of hyaline articular cartilage. c. It is directed laterally and slightly forwards and upwards. Above the glenoid cavity, there is a small supra-glenoid tubercle and below it there is infra-glenoid tubercle D. Processes 1. Spine of Scapula It is a horizontal shelf-like process projecting backwards from the upper part of dorsal surface. It is triangular in shape having: 1. Two surfaces; upper and lower 2. Two free borders, Posterior and lateral: - The posterior free border: is called crest of the spine and is felt subcutaneously, it has the following features: a. It has upper and lower margins (lips) and an intermediate surface (in- between) which shows a rough prominence near its medial end (root of spine). b. At its lateral end, the crest bends and turns upwards and forwards to form the acromion process. - The lateral free border bound a notch called spina-glenoid notch lying between it and the glenoid cavity through which the supra-spinous and infra-spinous fossae communicate. I Bones of Upper Limb. '7... :"" _ Coracoid process Medial border Rough impression for conoid ligament Acromion process Upper border Acromial ~~=.......-~Spine-glenoid +-angel notch ~Glenoid cavity (lateral angle) spine Flat strip for muscle attachment Fig. 5: Scapula Posterior (dorsal) surface  Bones of Upper Limb 2. Acromion Process: It is a rectangular process which projects upwards and forwards as a continuation of the lateral end of the crest of the spine. Its medial border carries a small oval facet to articulate with lateral end of the clavicle at the acromio-clavicular joint. Its lateral border is continuous with the spine at the acromial angle. 3. Coracoid Process: It arises from the superior border of scapula just lateral to supra-scapular notch and bends forwards and slightly laterally. The process has: a tip upper , lower surfaces and medial and lateral borders. BONE OF THE ARM HUMERUS - Site: it is the bone of the arm. - Type: long bone. - General Features (Figs. 6, 7): it consists of expanded upper and lower ends and a shaft. A. Upper End: 1. Head (the ball of the shoulder joint): It is less than half of a large sphere. It is directed upwards, backwards and medially to articulate with the glenoid cavity. Its articular surface is about four times the area of the glenoid cavity. 2. Anatomical Neck: It is a faint constriction immediately adjoining the margin of the head. N.B. The upper end of the humerus joins the shaft at the surgical neck 3. Lesser Tuberosity {Tubercle): It projects forwards immediately below the anatomical neck. It continues downwards as the medial lip of bicipital groove.  Bones of Upper Limb Head of humerus Middle and Greater tuberosity lower impressions on the back of greater Lesser tuberosity tuberosity Lateralli] (for muscle attachments) Floor Bicipital.. groove Med1a11IP Obliuque ridge for origin of late:::.ra-:1--1--M head of triceps Impression for insertion of -+ coraco-brachialis Coronoid fossa Lateral Lateral epicondyle epicondyle Trochlea Trochlea Fig. 6: Humerus Fig. 7: Humerus Posterior view Anterior view  Bones of Upper Limb 4. Greater Tuberosity (Tubercle): It occupies the lateral part of the upper end of the humerus. Its anterior margin continues downwards as the lateral lip of bicipital groove. Its upper and posterior aspect shows three flattened impressions for muscular attachment. N.B.: The two tuberosities are separated from each other on the anterior aspect by a groove called the intertubercular or bicipital groove. The bicipital groove extends downwards into the front of the upper part of the shaft where it has lateral and medial lips with a floor in between. B. Lower End: It is expanded transversely and presents articular and non-articular portions. 1. Articular portion: (the condyle; conjoined capitulum and trochea). It is divided by a faint groove into capitulum (laterally) and trochlea (medially) to articulate with radius and ulna forming the elbow joint. a. Capitulum It is a smooth, rounded convex projection (less than half of a sphere). It articulates with the upper surface of the head of radius. b. Trochlea It is a smooth pulley-shaped surface, slightly constricted near its middle. It articulates with the trochlear notch of the ulna. 2. Non-articular portion: includes the medial and lateral epicondyles and the olecranon, coronoid and radial fossae. a. Medial epicondyle: (Funny bone) It is a large blunt projection, more prominent than the lateral epicondyle. It can be easily felt subcutaneously. On its posterior surface there is shallow groove for ulnar nerve b. Lateral epicondyle: It is a less marked projection.  Bones of Upper Limb c. Olecranon fossa: It is a deep hollow on the posterior surface above the trochlea. It receives the tip of the olecranon process of ulna when the elbow is fully extended. d. Coronoid fossa: It is a smaller hollow on the anterior surface above the trochlea. It receives the tip of the coronoid process of ulna when the elbow is fully flexed. e. Radial fossa: It is a very shallow depression lying on the anterior surface above the capitulum (lateral to the coronoid fossa). It receives the margin of head of radius in full flexion of the elbow. C. The Shaft It is nearly cylindrical in its upper half and triangular in section in its lower half. It presents 3 surfaces and 3 borders. 1. Three Borders: a. Anterior border (from below upwards): It is smooth and rounded in the lower half of the shaft. In the middle part, it forms the anterior limb of deltoid tuberosity. In the upper part, it becomes continuous with the lateral lip of bicipital groove. b. Medial border: It is clear in the lower half of the shaft. Its lower part becomes sharp and is called medial supra-condylar ridge. It terminates below at the medial epicondyle. At the middle of the shaft, it presents a rough area , c. Lateral border:. Its lower part becomes sharp and is called lateral supra-condylar ridge. It terminates below at the lateral epicondyle.  Bones of Upper Limb 2. Three Surfaces: a. Antero-medial surface: It is smooth A little below its middle, it shows a nutrient foramen which is directed downwards. b. Anterolateral surface: At its middle, it is marked by a V-shaped rough area which is called deltoid tuberosity (deltoid insertion). c. Posterior surface: Its upper third is crossed by a faint ridge for origin of the lateral head of the triceps muscle. Its middle third is crossed by a wide, shallow groove (radial or spiral groove) which passes downwards and laterally, then turns forwards to reach the antero-lateral surface where it fades away. The Carrying Angle The medial margin of the trochlea projects downwards more than the lateral margin producing an angle between the long axis of the humerus and the long axis of the supinated forearm when the elbow is fully extended (Fig. 8). This angle is about 15 degrees and is more marked in females. Clinical importance: It allows the forearm to swing clear from the pelvis especially in the female who has a wider pelvis. This angle disappears when the forearm is pronated or the elbow is flexed. Bones of Upper Limb  Bones of Upper Limb BONES OF THE FOREARM I. RADIUS - Site: it is the lateral bone of the forearm. - Type: it is a long bone. - General Features (Figs. 9, 10, 11, 12): it has a shaft, upper and lower expanded ends but the lower end is much expanded than the upper end. A.UpperEnd 1. Head It is disc shaped. It has two smooth articular surfaces: 1. Upper circular concave articular surface which articulates with the capitulum of the humerus to form part of the elbow joint. 2. Its circumference, which is smooth and broader medially, articulates with radial notch of ulna to form superior radio-ulnar joint 2. Neck: is the constricted part below the head 3. Radial Tuberosity: projects antero-medially below the neck. Its anterior part is smooth while its posterior part is rough. B. Lower End: It is a flattened expanded end having five surfaces: 1. Anterior suriace: smooth and slightly concave. 2. Posterior suriace: is rough and convex: Near its middle, it shows dorsal tubercle {of Lister) which forms the medial boundary of a narrow deep oblique groove. On its lateral part, (lateral to the deep groove) it shows a wide shallow groove which is divided into two parts by a faint vertical ridge. On its medial part, it shows a wide shallow groove. 3. Lateral suriace: projects downwards to form the styloid process. 4. Medial suriace: shows ulnar notch which articulates with the head of ulna to form inferior radio-ulnar joint. 5. Inferior (carpal) suriace: is concave articular surface, which shares in the wrist joint and is divided by a slight constriction into: A. A medial quadrilateral area articulates with the lunate bone. B. A lateral triangular area articulates With the SCaphoid bone, I Bones of Upper Limb *UPPER END Superior RIU joint Upper circular ] concave surface Head of Radius Coronoid process-+ Circumference Radial notch--+---~ Smooth anterio~ of ulna part Radial Rough posterior tuberosity part Anterior border P-~r--Anterior oblique line Lateral surface *SHAFT....,.._Pronator tuberosity....... Anterior border Lateral (interosseous) border _ __,_~..,..,..+--Anterior surface -~...,_- Medial (interosseous) border L--t_lnferior Rl U joint Head Ulnar notch of radius Styloid process ULNA RADIUS *LOWER END Fig. 9: Ulna & radius (Anterior view)  Bones of Upper Limb c. Shaft: It increases gradually in thickness as followed downwards. It is gently curved being convex laterally. It is triangular in section having three borders and three surfaces: a. Borders: 1. Interosseous {medial) border: It begins below the radial tuberosity and its middle part is prominent. 2. Anterior border: Above, it begins from radial tuberosity and runs obliquely downwards and laterally; this part is called anterior oblique line. 3. Posterior border: Above, it begins from the posterior part of radial tuberosity and runs obliquely downwards and laterally (similar to the anterior oblique line) and is called posterior oblique line b. Surfaces: 1. Anterior surface It is slightly concave. It presents a nutrient foramen, which is directed upwards. 2. Posterior surface: It is generally flat and featureless. 3. Lateral surface: It is convex presents a rough impression (pronator tuberosity) at it middle for insertion of the pronator teres muscle. Ulna Radius Ulnar notch Groove for.ovt..,nuu- recurrent Posterior ul1:tar ,.ec;·urrent Flexor CatPI D'l'lavicle & acromio- clavicular joint Subacromial bursa Synovial membrane Glenoid labrum Deltoid muscle Glenoid cavity of scapula Fig.179: Coronal section in the shoulder joint I Capsula. fold with axllla v ecess of synovial m. Supraspinatus tendon Coracoid process Coraco-humeral liaament Acromion Biceps tendon (long head) Subacromial bursa Superior gleno-humeral Infraspinatus tendon ligament Glenoid cavity Subscapularis tendon Communication with bursa of subscapularis I Middle gleno-humeral Teres minor tendon ligament Svnovial membrane (cut) Inferior gleno-humeral ligament Fig. 180: Shoulder joint (Opened)  Joints of Upper Limb F. Lateral rotation: 1. Infra-spinatus. 2. Posterior fibers of deltoid. 3. Teres minor. G. Circumduction: it is a combinatton oft~~ above-mentioned movements. ! Mechanism of abduction of the shoulder Supraspinatus initiates abduction from 0-15 or 18 degrees. The middle (acromial) fibers of deltoid then continue abduction to 90 or 100 degrees. After this range, the head cannot move any further because greater tuberosity impinges on coraco-acromial ligament. Raising the arm above the head from 90-180 degrees, the scapula rotates ~ over the chest wall so that the glenoid cavity becomes directed upwards, i.e., it is a movement of the shoulder girdle. This is done by upper and lower fibers of trapezius with lowerS digitations serratus anterior muscles. N.B. During abduction of the arm, there are simultinaneous movements of the shoulder IJoint and shoulder girdle, so that eveJY 10° of abduction at the shoulder joint there is an addition of 5 due to an abward rotation of the scapula; this is continuous until the range of 90° of abduction when the whole movement takes place by upward rotation of the scapula. Elbow Joint - Type: synovial, uniaxial (hinge) joint. - Bony parts (articular surfaces) (Fig. 181): Proximally: the condyle of humerus (trochlea and capitulum). Distally: trochlear notch of ulna and head of radius, where trochlea articulates with trochlear notch of ulna and capitulum articulates with upper circular surface of the head of radius. - Capsule (Figs. 182, 183): it is attached to the lower end of humerus and the upper end of ulna and radius as follows: Above and in front: it is attached to the humerus just above the coronoid and radial fossae and extends to the root of the medial and lateral epicondyles.  Joints of Upper Limb Humerus (Anterior view) LATERAL MEDIAL /Medial / epicondyle Capitulum-..., of humerus - - Trochlea of humerus Radial notch , '' ,_ ' ' ' Articular' circumference ' - Coronoid proces~ \ - - - Ulnar tuberosity Fig. 181: Articular surfaces of elbow joint Line of attachment of capsule of elbow joint uperior radio-ulnar joint r-:~. -1o.c..-..... __... ··-· ·"....,...,r --...,.~..... -...,r - ""'-·· r-:::J. 100. AlL.-.-1.-.- a...... -r...,_~""....,_._ -r - a...- joint (Anterior view) joint (Posterior view)  Joints of Upper Limb 2. Above and behind: it is attached to the lower end of the humerus, just above the olecranon fossa 3. Below: the capsule is attached to the margins of the olecranon and the annular ligament, which encircles the head of the radius. N.B. The elbow and the superior radioulnar joint have a common capsule. The capsule is thin in front and behind but it is thick on each side due to the presence of the strong collateral ligaments. - Ligaments (Figs. 184, 185): 1. Medial (ulnar) collateral ligament: fan-shaped and is attached above to the medial epicondyle and below to the medial margin of trochlear notch (medial margin of olecranon and coronoid processes). It prevents abduction of the elbow joint. 2. Lateral (radial) collateral ligament: is a strong triangular ligament. It is attached above, by its apex, to the lateral epicondyle and below, by it base, to the outer surface of annular ligament. It prevents adduction. - Intra-capsular structures: they include the articular surfaces as well as the coronoid, radial and olecranon fossae and the synovial membrane, which is continuous with that of superior radio-ulnar joint. The medial and lateral epicondyles are extra-capsular. -Arterial supply: from the anastomosing arteries around the elbow. - Nerve supply: from musculo-cutaneous, radial, ulnar and median nerves. - Movements: 1. Extension: triceps muscle assisted by anconeus 2. Flexion: mainly by Brachialis and biceps. It is assisted by brachia-radialis and superficial flexors of the forearm.  Joints of Upper Limb. - - - - - Capitulum Head of radius Radial collateral ligament Anular ligament of radius Fig. 184: Radial collateral ligament of elbow joint (Lateral view) Anular ligament of radius Oblique cord Interosseous membrane Medial epicondyle Anterior cordlikl band Of ulnar Posterior fanlike collateral band ligament "'-~~!Iii!-- Oblique band Tubercle on coronoid process Olecranon of ulna Fig. 185: Ulnar collateral ligament of elbow joint (Medial view)  Joints of Upper Limb RADIO-ULNAR JOINTS 1. Superior Radio-Ulnar Joint - Type: synovial, uniaxial (pivot) joint. - Bony parts (articular surfaces) (Figs. 184, 185): the circumference of the head of radius rotates against the radial notch of ulna. - Capsule: it is continuous above with the capsule of the elbow joint. Their joint spaces are continuous together. - Synovial membrane: The synovial membrane is a downward prolongation of the synovial membrane of the elbow joint. - Ligaments (Figs. 184, 185, 186) 1. Annular ligament: Is about 3/4 of a circle attached to the anterior & posterior borders of the radial notch of the ulna.Encircles the head of radius. It is slightly narrower below than above and this prevents the head of radius from being dislocated downwards. 2. Quadrate ligament: it is quadrangular band connecting the lower margin of the radial notch of the ulna to the medial aspect of the neck of radius. It lies just below the joint, thus closing its cavity from below. 2. Inferior radio-ulnar joint - Type: Synovial, uniaxial (pivot) joint. -Articular surfaces (Fig. 187): a. The head of ulna b. The ulnar notch of radius. c. The articular disc: It is a fibrocartilaginous triangular disc attached by its apex into a depression between the styloid process and the inferior surface of the ulnar head while the base is attached to lower edge of the ulnar notch of radius. Its upper surface is concave and articulates with the head of ulna. Its lower surface is also concave and it articulates with the lunate bone. It separates the cavity of inferior radio-ulnar joint from that of the wrist joint.  Joints of Upper Limb olecranon process of ulna lateral collateral ligament Fig. 186: Annular ligament (Anterior view} Head of radius Annular ligament Fig. 188: Quadrate ligament of Fig. 187: Superior radioulnar joint (Ant. View) superior rad iou lnar joint (Ant. View) Recessus sacciform synovial membrane triangular carti laginous ligament styloid process styloid process medial ligament lateral ligament...- pisiform trapezium triquetra! ~~........,.,.,.~ joint cavity trapezoid Fig. 189: Inferior radioulnar joint (coronal section}  Joints of Upper Limb - Capsule: it is slightly thickened anteriorly and posteriorly while above it is lax to allow for the wide movement of pronation. - Synovial membrane (Fig. 190): it lines the capsule and projects upwards as a small pouch called recessus sacciformis between the radius and ulna in front of the interosseous membrane. Pronation and Supination -Joints: they occur at the superior and inferior radio-ulnar joints (pivot joints). - Axis of movement (Fig. 191): it is a vertical axis which passes from the center of head of radius above to the rough impression of the head of ulna below (attachment of the apex of the articular disc). - Mechanism of movement: The head of radius simply rotates within the ring formed by the radial notch of ulna and the annular ligament (at the superior radio-ulnar joint). The shaft of radius swings while the shaft of ulna remains relatively fixed. At the inferior radio-ulnar joint: the lower end of the radius and the articular disc (below the head of ulna) rotate around the head of ulna; the radius carries the hand with it. The movement is in the form of a circle, the centre of which is at the attachment of the apex of the articular disc to the root of styloid process of ulna (i.e., the head of ulna acts as a fixed bone around which the lower end of the radius rotates). a. In Supination: The radius and ulna lie parallel to each other. The palm faces forwards. The thumb is directed laterally. The interosseous membrane is tense. b. In Pronation: The shaft of radius lies across the front of the shaft of ulna so that the lower end of radius lies now on the medial side of the ulna. The hand moves with the radius so that the palm now looks backwards. The thumb is now directed medially. The interosseous membrane becomes lax. The carrying angle at the elbow disappears - Muscles working on the radioulnar joints: A. Supinators: are the biceps (the main supinator of the flexed elbow) and the supinator, in addition to brachioradialis, which puts the forearm in the mid- prone position. B. Pronators: are the pronator teres and pronator quadratus, in addition to brachioradialis, which puts the forearm in the mid- prone position. N.B.: In general, supinators are more powerful than the pronators. Biceps is the most powerful supinator during flexion of elbow while supinator is the main supinator during extension of the elbow.  Joints of Upper Limb 213 " \ \ \ \ \ \ \ \ \ \ \ \ \ I \ I \ I \ I \ I \ I \ I \ I \ I ~ \ \ \ ~ Supination Pronation Fig. 190: Movements of radioulnar joints (Anterior view)  Joints of Upper Limb Interosseous Membrane In addition to superior and inferior radio-ulnar joints, the radius and ulna are also joined by a fibrous membrane called interosseous membrane. - Attachment (Fig. 191): Laterally: it is attached to the interosseous border of radius. Medially: it is attached to the interosseous border of ulna. Above: it ends at a free border 2.5 em below the radial tuberosity. Below: it blends with the capsule of inferior radio-ulnar joint. - Direction of fibers: the fibers of the interosseous membrane run obliquely downwards and medially from radius to ulna. - Functions: 1. Increases the area (both in front and at the back) for the origin of numerous muscles of the forearm. Muscles which take origin from its anterior surface: a. Flexor pollicis longus b. Flexor digitorum profundus Muscles which take origin form its posterior surface: a. Abductor pollicis longus b. Extensor pollicis longus c. Extensor pollicis brevis d. Extensor indicis 2. The radius receives forces from the hand. The interosseous membrane, due to the direction of its fibers, which, in turn, transmits forces upwards to the humerus. - Relations: The anterior interosseous nerve and vessels lie on its anterior surface. The anterior interosseous artery pierces it 5 em above its lower end. The posterior interosseous vessels pass backwards above its upper border. Pronator quadratus crosses in front of its lower part. Muscles attached to its anterior and posterior surfaces.  Joints of Upper Limb Biceps tendon --Oblique cord Interosseous membrane Ulna Fig. 191: lnteroseous membrane (Anterior view)  Joints of Upper Limb Wrist Joint - Type: synovial, biaxial (ellipsoid) joint. - Bony parts (articular surfaces) (Fig. 192): A. Proximal articular surface: has an ellipsoid outline with a transverse diameter of about 5 em. and an antero-posterior diameter of about 2 em. It is slightly concave in both directions. It is formed by: The inferior surface of lower end of radius, which is divided into a lateral triangular part to articulate with the scaphoid and a medial quadrilateral part to articulate with the lunate. The articular disc of inferior radio-ulnar joint, which lies below the head of ulna (separating it from the triquetra! bone). B. Distal articular surface: is formed of three carpal bones; from lateral to medial they are scaphoid, lunate and triquetra! bones. Scaphoid and lunate lie below the radius. Triquetra! lies below the articular disc below the head of ulna. These three bones form together an oval surface, which is convex in all directions. N.B. The ulna does not come in direct contact with the carpal bones and does not share in the formation of the wrist joint because of the presence of the articular disc of cartilage below the head of ulna. Therefore/ the wrist joint is called radio-carpal joint - Capsule: The capsule is attached to the margins of the articular surfaces. - Ligaments (Figs. 193, 194): Radial collateral ligament: extends from the tip of styloid process of radius to lateral side of scaphoid and trapezium. Ulnar collateral ligament: extends from end of styloid process of ulna to medial side of triquetra! and pisiform bones. Palmar radiocarpal ligament: extends obliquely and medially from anterior margion of lower end of radius and its styloid process to anterior surface of scaphoid, lunate and truquetral bones. Palmar ulnocarpal ligament: extends from the base of styloid process of ulna and anterior margin of the articular disc to the anterior surface of lunate and triquetra! bones Dorsal radiocarpal ligament: extends downwards and medially from the posterior surface of lower end of radius to dorsal surface of scaphoid, lunate and triquetra! bones, it is weaker than the palmar one.  Joints of Upper Limb Pisiform Lunate Flexor carpi radialis Scaphoid Triquetrum Synovial membrane Styloid process of Styloid process of ulna radius Articular disc Inferior surface of radius Ligamentous anterior border of articular disc Fig. 192: Wrist joint (Opened) showing articular surfaces (Anterior view) Oorsal view Ulnocapitate- +-''#- and ulnolunate ligaments Fig. 193: Ligaments of wrist joint Fig. 194: Ligaments of wrist joint (Anterior view) (Posterior view)  Joints of Upper Limb - Arterial supply: from the arteries forming the anterior and posterior carpal arterial arches. - Nerve supply: by anterior and posterior interosseous nerves. -Movements: A. Flexion: 1. Flexor carpi radialis 2. Flexor carpi ulnaris 3. Palmaris longus 4. Flexor digitorum superficialis and profundus. 5. Flexor pollicis longus B. Extension: 1. Extensor carpi radialis longus 2. Extensor carpi radialis brevis 3. Extensor carpi ulnaris 4. Extensor digitorum, extensor indicis, extensor digiti minimi. C. Adduction: 1. Flexor carpi ulnaris 2. Extensor carpi ulnaris D. Abduction: 1. Extensor carpi radialis longus 2. Extensor carpi radialis brevis 3. Flexor carpi radialis 4. Abductor pollicis longus 5. Extensor pollicis brevis - Relations: Anteriorly: the flexor retinaculum and the structures passing both deep and superficial to it. Posteriorly: the extensor retinaculum and the structures passing deep to it. Postero-laterally: the anatomical snuff-box.  Joints of Upper Limb Mid-Carpal Joint -Type and Variety (Fig. 195): synovial; modified ellipsoid joint. - Bony parts {articular surfaces): it is the joint between: The proximal row of carpal bones, as one unit. The distal row of carpal bones, as the second unit. - Capsule: it has a common capsule and a common joint cavity. - Ligaments: the carpal bones are held together by strong interosseous ligaments. - Movements: its movements are complimentary to those of wrist joint but much more limited. It allows limited flexion, extension, abduction and adduction (the same muscles as the wrist are concerned). Carpo-Metacarpal Joints 1. All the metacarpal bones, except that of the thumb, join the carpus in such a way that their palmar surfaces look forwards. The metacarpal bone of the thumb joins the trapezium in such a way that the thumb is rotated about 90 degrees so that its palmar surface looks medially. The plane of the thumb lies at right angle to that of the other fingers. This makes the thumb able to oppose the other fingers. 2. Articular surfaces: the distal row of carpal bones articulate with the bases of the metacarpal bones in the following manner (Fig. 195): Trapezium articulates with the 1st metacarpal bone (of the thumb). Trapezoid articulates with the 2nd metacarpal bone (of the index). Capitate articulates with the 3rd metacarpal bone (of middle finger). Hamate articulates with the 4th and 5th metacarpal bones (of the ring and little fingers).  Joints of Upper Limb 1. Carpo-metacarpal joint of the thumb - Type: synovial, biaxial (saddle-shaped joint) (Figs. 195, 196) - Articular surfaces: the superior surface of rapezium articulates with the base of 1st metacarpal bone. The articular surface of each bone is concavo- convex (i.e., concave in one direction and convex in the other perpendicular direction). - Movements: it is a relatively freely mobile joint because the 1stmetacarpal bone lies at 90 degree to the plane of palm, in addition to a loose fibrous capsule. It allows the following movements (Fig. 185): A. Flexion and extension: occurs in a plane parallel to the palm. Flexion: 1. Flexor pollicis longus 2. Flexor pollicis brevis 3. Opponens pollicis Extension: 1. Extensor pollicis longus 2. Extensor pollicis brevis B. Abduction and adduction: in a plane at right angle to the palm. Abduction: 1. Aductor pollicis longus 2. Abductor pollicis brevis Adduction: 1. Adductor pollicis 2. First palmer interosseous (if exists) C. Opposition: the thumb is flexed, then rotated medially so that its palmar surface opposes the palmar surface of any of the other four fingers. 1. Opponens pollicis (main muscle) 2. Flexor pollicis brevis 3. Adductor pollicis D. Circumduction: is a combination of the upper four movements. N.B. The thumb is the most important finger because of its ability to oppose the other four finger~ performing fine movements. 2. Carpo-metacarpal joints of the medial four fingers - Type: synovial, plane variety. - Movement: minimal gliding movement. The little finger has an opponens muscle which can move its metacarpal bone forwards and laterally toward the thumb and helps in cupping the hand.  Joints of Upper Limb Inferior radioulnar joint Radiocarpal (wrist) joint Pisiform Carpo-metacarpal joint of thumb 1st metacarpal of thumb Fig. 195: Joints of the hand (Coronal section) Metacarpi ofttn.mb Trapezium Fig. 197: Saddle-shaped Fig. 196: Saddle-shaped joint of the carpo- joint with concavo-convex metacarpal joint of thumb articular surfaces  Joints of Upper Limb Metacarpo-Phalangeal Joints - Type: synovial ellipsoid joints between the convex heads of the metacarpal bone and the shallow concavities of the bases of the proximal phalanges. N.B. The metacarpo-phalangeal joint of the thumb is classified as hinge as abduction and adduction are restricted at this joint - Movements (Figs. 198 199): 1 1. Movements of metacarpo-phalangeal joints of the medial four fingers: A. Flexion: by lumbricals1 interossei/ flexor digitorum superficialis and profundus. B. Extension: by extensor digitorumr extensor indicis and digiti minimi. C. Adduction: by palmar interossei. D. Abduction: by dorsal interossei. N.B The fingers can be flexed at the metacarpo-phalangeal joints for 90 degrees but they can be slightly extended beyond the straight line/ i.e./ slightly hyperextended. Abduction and adduction at the metacarpo-phalangeal joints are free when the fingers are extended but they become gradually limited as the fingers are flexed until the hand is completely close~ abduction and adduction become impossible. 2. Movements of metacarpo-phalangeal joint of the thumb: A. Flexion: by flexor pollicis longus and brevis. B. Extension: by extensor pollicis longus and brevis. N.B. It allows only 60 degrees range of flexion and extension. Abduction and adduction are vety much restricted. Interphalangeal Joints - Type: synovial/ uniaxial (hinge) joints. - Movements (Figs. 200 201): they allow flexion and extension only. 1 1. In the medial four fingers: A. Flexion: 1. Flexor digitorum profundus (acting on both proximal and distal interphalangeal joints). 2. Flexor digitorum superficialis (acting only on proximal I/P joint). B. Extension: 1. Lumbricals 2. Interossei 3. Extensor digitorum 4. Extensor indicis 5. Extensor digiti minimi 2. In the thumb: A. Flexion: Flexor pollicis longus B. Extension: Extensor pollicis longus  Joints of Upper Limb Axial line Axial line Fig. 198: Abduction at metacarpo- Fig. 199: Adduction at metacarpo- phalangeal joint of the medial four phalangeal joint of the medial four fingers fingers Fig. 200: Flexion of the inter- phalangeal joints of the fingers (Lateral view) Fig. 201: Flexion & extension at metacarpo- phalangeal & interphalangeal joints  Joints of Upper Limb flexion of thumb extension of thumb abduction of thumb J adduction of thumb opposition of thumb Fig. 202: Movements of the thumb at the carpo-metacarpal joint  Joints of Upper Limb Formative Assessment I) M.C.Q: 1-The principal muscle concerned in lateral rotation of the shoulder: a. Pectoralis major. b. Deltoid anterior fibers. c. Teres major. d. Teres minor. 2- The ulnar co/latera/ligament: a. Attached to the medial epicondyle of the humerus. b. Attached to the lateral border of coronoid process of ulna. c. Attached to triceps and flexor carpi radialis. d. The ulnar nerve passes in front the ulnar collateral ligament. 3- Concerning pronation and supination: a. Pronation is more powerful than supination. b. Supination is done by biceps when the elbow is extended. c. They occur at the elbow joint. d. The ulna is fixed; the radius is the movable bone. II) Explain: 1. The shoulder joint is an unstable joint. 2. The shoulder joint has a wide range of movements Maha Mobarak Print Tel: 01001480892 - 01003325874  Anatomy of the Upper Limb SHEET Student name: Number ID: Date: Supervisor: Signature: Grade: AD BD cDnD