Shoulder - Study Notes

Shoulder – classical anatomy Muscles of the back & shoulder (Left) 1. 2. 3. 4. 5. 6. 7. 8. Trapesius Latissimus dorsi - thoracodorsal(c6,7,8) Deltoid - axillary nerve (c5 & c6) Levator scapulae Supraspinatus Infraspinatus Teres minor Teres major Brachial plexus 1. 2. 3. 4. 5. 6. 7. 8. Arteries of the shoulder & upper arm 1. Thoracoacromial artery 2. Axiallary artery a. 1st sect proximal to Pec. Minor b. 2nd sect posterior to Pec. Minor c. 3rd sect inf Pec. Minor to inf Teres Maj à brachial artery 4 5 6 3 7 8 2 3. P o s t e r i o r h u m Musculocutaneous (C5-7) Axillary (C5,6) Radial (C5-T1) Median (C5-T1) Ulnar (C7-T1) Thoracodorsal (C6-8) Long thoracic (C5-7) Dorsal scapular (C5) erus circumflex artery 4. Brachial artery 5. Deep artery of the arm 6. Radial collateral artery 7. Radial recurrent artery 8. Radial artery 9. Ulnar artery 10. Common interosseus artery 11. Superior ulnar collateral artery 12. Circumflex scapula artery 13. Subscapular Shoulder - Functional Anatomy Sternoclavicular joint (SCJ) Saddle-shaped synovial joint that connects the medial clavicle, manubrium sternum, and cartilage of the first rib. The capsule is strengthened by the sternoclavicular (anterior and posterior) and interclavicular ligaments Acromioclavicular joint (ACJ) Plane synovial joint, angled to allow the clavicle to slide over the acromion Stability is due to the coracoclavicular ligament (comprising lateral 'trapezoid' and medial 'conoid' portions) and the acromioclavicular ligament The joint has sensory branches to the suprascapular and long thoracic nerves. Glenohumeral joint (GHJ) Multiaxial, spheroidal synovial joint The glenoid fossa is shallow & stability is mainly on the rotator cuff The joint is protected superiorly by the coracoacromial ligament The joint capsule has two openings; one allows the long head of the biceps tendon to enter the bicipital groove (taking an extension of the synovium with it as its sheath), the other permits an outpouching of the synovium to act as a bursa for the subscapularis ROTATOR CUFF provides joint stability Supraspinatus = abductor. Posterior to coracoid, but ant. to acromion – attaches to greater tubercle of humerus – innervated by suprascapular nerve (c4, c5, c6) Infraspinatus = lateral rotation. Inferior to acromion and supraspinatus – attaches to greater tubercle (post aspect) inferior to supraspinatus – innervated by suprascapular nerve (c5, c6) Teres minor = lateral rotation. Lies underneath infraspinatus (ish) – origin = lateral inf border of scapula, attachment = posteroinferior border of greater tubercle – innervated by axillary nerve (c5, c6) Subscapularis = medial rotation. lies on anterior portion of scapula – origin = most of scapula, attaches to lesser tubercle – innervated by upper & lower subscapular nerves (c5, c6, c7) A large subacromial bursa permits smooth movement between the rotator cuff and the undersurface of the acromion. Any tear of the rotator cuff (esp supraspinatus) can à communication with joint capsule (tendon runs through joint). The subcoracoid bursa, between the coracoid and the capsule, may be separate or communicate with the subacromial bursa. The suprascapular nerve supplies the superior and posterior parts of the joint and capsule and most of the rotator cuff; the axillary nerve supplies the anterior aspect of the joint and capsule. Symptoms SCJ pain is usually well localised, with little radiation (c). ACJ derives from C4 and produce pain close to its origin (b), with some radiation to the shoulder tip but no significant radiation to the arm. GHJ derives from C5 and produce pain maximal at the outer aspect of the upper arm close to the deltoid insertion; if severe, pain may radiate down the radial aspect of the forearm to the elbow (rarely to the wrist) and upwards to the shoulder (rarely to the neck). Such pain will be worsened by shoulder movements (d). Tendinitis of the long head of biceps also produces upper arm pain (C5/6) (c). Pain over the superior aspect of the shoulder and the C4/5 distribution may also be referred from the neck. Such pain may involve the whole length of the arm (± the hand), be worsened by neck movements (and only the extremes of shoulder movements), and be accompanied by sensory or motor impairment in the limb Radiation of pain into the arm associated with numbness, or paraesthesia, suggests compressive neuropathy (e.g. thoracic outlet syndrome, suprascapular or axillary nerve entrapment). A typical rotator-cuff patient has often performed unaccustomed exercise with the involved arm (e.g. decorating the ceiling). Only noticed the following day as upper arm aching (a single regional pain syndrome). Pain is nonprogressive and is usually noted only during one or two movements of the arm (e.g. reaching up to a shelf): it is generally more an inconvenience than a major problem, and uncommonly interferes with sleep. Pain: Onset Pain: Progression Movements affected Rotator cuff Acute Non-progressive GHJ arthritis Insidious Variable, progressive Few Many Provoking factor Often apparent Localised problem Usually Severity ++ Absent Uncommonly ++++ Arthritis of the shoulder is usually part of an oligo- or polyarthritis that produces multiple regional pain problems. Pain is often insidious in onset without an obvious provoking event: it is variable but usually progressive, often keeps the patient awake, affects several (eventually all) shoulder movernents, and tends to interfere greatly with simple activities of daily living. Acute subacromial or subdeltoid bursitis is often characterised by its speed of onset, the patient being unable to abduct the arm within just a few days. Bursitis Diffuse pain in upper arm NB: rotator cuff tear can à 2o bursitis Bicipital Tendinitis Pain in upper anterior area of arm – well localised Usually from overusage of heavy mechanical work Pain on resisted active supination & palpation of bicipital grove Biceps tendon rupture Resisted active supination à fusiform swelling low in upper arm (popeye sign). But NO pain Usually due to severe inflammation or injection into inflamed tendon Capsulitis (frozen shoulder) Inflammation & pain worsening over several weeks à resolution à fibrosis, scarring & thickening of the capsule à no movement = frozen. After 12-18 months collagen remodels & movement regained O/E – early = joint line tenderness, stress pain, same on passive & active movement. Later = pain improves but progressive stiffness Risk factors – stroke / UMN lesion, rotator cuff / other local injury, late onset DM, previous contralateral capsulitis Differential ALWAYS includes sepsis Management – education (be optimistic – good long term outcome), analgesia, aggressive physio to stretch capsule & maintain movement Bony Pain Red Flags: Night pain, not related to movement/use, never radiates, progressively worse Paget’s disease – commonly targets upper arm / GHJ, slowly spreads along bone o 1 oesteonecrosis (avascular necrosis) – sudden death of bone. Commonly in proximal & distal heads of humerus & femur. Due to disruption of blood supply. Initial bony pain = Death of bone à inflammation à collapse 2-3 week later à disrupts cartilage & joint à arthritis à pain related to movement, all day, less well localised High dose steroids / alcohol à fat redistribution à bone marrow replaced with fat à compression of vessels in bone Sickle cells obstruct flow through capillaries à bony crises Benz à air bubbles in vessels à poor flow. Atrophy of deltoid Can occur if axillary nerve is severly injured (surgical neck of humerus #) à squaring of shoulder. Test by ability to abduct arm from 15o up Brachial plexus injuries C5-6 due to excess angle force between head & shoulder. à erb’s palsy = waiter’s tip position C8-T1 due to exess angle force between arm and trunk à damage to nerve supplying interosseous mm à claw hand (hyperextension of MCPs & flexion of IPJs) Other nerve injuries Musculocutanous nerve – usually due to knife / bullet. Paralysis of coracobrachialis, biceps & brachialis à weakened flexion of elbow & supination of forearm Radial nerve – wrist drop as extensors & supinators are affected Shoulder - Examination Inspection at rest – from in-front & behind Check shape of SCJ, ACJ & GHJ Inspect muscle bulk – esp deltoid (front) & supraspinatus, infraspinatus, trapezius & rhomboids (back) Inspect during movement Hands together behind head / neck, elbows back (testing abduction, external rotation, and flexion of the glenohumeral joint and the supraspinatus, infraspinatus, and teres minor muscles). Hands behind back (testing internal rotation, abduction and extension of the glenohumeral joint, and principally, the subscapularis muscle). NB: If can do both then the rotator cuff & GHJ are probably normal Test for painful arc Independent movement first, assist if required Ask the patient to raise the arm slowly through 180° towards the ceiling, and then slowly to lower it again. Initial 90° - glenohumeral abduction Next 70° - principally scapula rotation Final 20° - further glenohurneral movement. Painful middle arc (a) Pain at end of initial GH abduction. The greater tuberosity of the humerus rises relative to the acromion and can squeeze the intervening structures (supraspinatus tendon and subacromial bursa). As the arm is further elevated the greater tuberosity drops relative to the acromion and relieves the pressure. Occasionally, patients with supraspinatus lesions have no painful arc on moving their arm upwards, but on slowly lowering the arm they experience a painful catching sensation in the middle-arc range, which causes them to quickly drop the arm to their side This arc is characteristic of a supraspinatus lesion or subacromial bursitis. Supination of the hand may decrease impingement of the humerus on the acromion and reduce or eliminate the pain in the middle arc. Painful superior arc (ACJ) Pain in top 20-30o of arc where maximum stress on ACJ – suggesting lesion at ACJ Palpation From behind with patient seated SCJ – confirm by shrugging shoulders. Check for position, crepitus, subluxation, tenderness, swelling, temperature AJC – 2 finger breadth medial from coracoid. Confirm by shrugging shoulders. Check for position, crepitus, subluxation, tenderness, swelling, temperature. If pain do scarf test – cross arm across chest to reproduce pain GHJ – Below distal clavicle. Check for soft swelling – press & observe filling to check for GHJ effusion. Check for anterior joint line ternderness. Move joint & feel for crepitus (esp abduction & ext rotation). Stand behind & feel joint & scapula movement as patient abducts through arc - observe range of movement before scapula moves (should be 80-90). If painful then move arm passively. If pain less then muscular / tendon, if same then joint. Identify grove between greater & lesser tuberosity = biceps tendon. Tenderness on pressing incidates biceps tendonitis Resisted active movements To detect rotator cuff lesions Resisted active abduction – Supraspinatus --> pain in upper arm Resisted active external rotation - infraspinatus/teres minor Resisted internal rotation - subscapularis muscle/tendon lesion Weakness = from pain / partial / total tear of cuff. Inject lignocaine & repeat test. If still weak then = major tear Test for glenohumeral instability With the patient standing, and the arm hanging relaxed by their side, fix the scapula and shoulder girdle from behind with one hand while gripping the top of the humerus with the other. Move the humeral head backwards and forwards in the glenoid fossa, noting the degree of movement and any palpable clicks which may signify labral pathology. Next, position the patient with their shoulder abducted to 90° and the elbow flexed. Gently, passively extend and externally rotate the glenohumeral joint: a positive test for anterior instability is when the patient experiences apprehension as an external rotation force is applied Elbow – classical anatomy Left 1. 2. 3. 4. 5. Ulnar (radial notch, coronoid process, trochlear notch, olecranon) Radius Trochlear notch Tuberosity Humerus Right 1. 2. 3. 4. 5. 6. 7. 8. 9. Capitulum Head Tuberosity Tuberosity Neck Head Olecranon Lateral epicondyle Olecranon fossa Bones of forearm (left) 1. Radial head 2. Neck of radius 3. Radial Tuberosity 4. Interosseous membrane 5. Styloid process of ulna 6. Ulnar tuberosity 7. Trochlear notch 8. Olecranon 9. Dorsal tubercle 10. Styloid process Upper arm muscles 4 2 3 5 1. Biceps brachii Flexor & supinator C5-6 2. Coracobrachialis Flexor & adductor C6-7 3. Brachialis Powerful flexor C5,6,7 4. Triceps brachii Elbow extensors C7-8 5. Anconeus . Elbow extensors C7-8 Nerve of the arm 1. 2. 3. 4. 5. 6. 7. 8. 9. Musculocutaneous Radial (deep & superficial branches) Median nerve Recurrent motor to thenar mm Common palmar digital branches of median nn Superficial branch of Ulnar nerve Median nerve Ulnar nerve Radial nerve MEDIAN – lateral and medial cords (c5 – t1) runs anteriorly along arm & forearm, through carpal tunnel à hand Innervates flexor mm in forearm (except flexor carpi ulnaris, ulnar ½ of flexor digitorum profundus and 5 hand muscles) Sensory info to most of hand ULNAR – medial cord (C8 & T1) Runs distally, anterior to triceps, passes posterior to medial epicondyle of humerus Innervates 1 & ½ of flexor muscles in forearm, most small muscles in hand, and skin of little and ½ of ring finger Elbow – Clinical Anatomy Carrying angle In the anatomical position the elbow has a natural valgus angle. Males 5o, Females 10-15o. Can be increased = cubital valgus as developmental abnormality (e.g. turners) Pain is usually felt maximally at the elbow, close to its origin: severe arthropathy may cause radiation of pain down the forearm and, to a lesser extent, proximally to the upper arm Lateral epicondylitis ('tennis elbow') is usually maximal close to the epicondyle, radiating down the outer aspect of the forearm towards the wrist (128): it is particularly marked during power grip with the wrist extended. Medial epicondylitis (golfer's elbow') causes pain maximum around the medial epicondyle, radiating down the flexor aspect of the forearm towards the wrist (129). Olecranon bursitis is well localised, usually showing no clear relationship to passive or resisted elbow movement: it may be provoked by leaning the elbow on a table, or on flexion at the elbow when tight clothing is worn. Humeral # Common in surgical neck in falls on elbow with arm abducted Transverse fractures result from direct blow to the arm Risk of nerve damage Surgical neck – axillary nerve Radial grove – radial nerve Distal humerus – median nerve Medial epicondyle – ulnar nerve Radius & Unlar #s Ulnar shaft angulates posteriorly Radial shaft is pronated & pulled medially by muscles # of distal end of the radius is the most common # in people over 50 Colles # - distal radius without ulnar involvement. Distal fragment is usually displaced dorsally à dinner fork deformity Elbow – Examination Inspection at rest From behind & in front for… Skin changes erythema (confined in bursitis or over the whole joint), scars: the extensor aspect is a common site for psoriasis, nodules, and pressure sores Swelling Synovial swelling is most apparent over the radial head anteriorly, and over the para-olecranon grooves posteriorly (medial > lateral. Olecranon bursitis causes localised smooth swelling around the olecranon Defortmity In particular, cubitus valgus or varus, and fixed extension (from in front); and posterior subluxation of the olecranon on the humerus (from behind). Attitude A capsular pattern of restriction usually affects flexion more than extension, with supination/ pronation affected last: in the presence of synovitis or effusion the patient is therefore most comfortable with the elbow positioned in flexion (about 45 70°). Inspection during movement Bend the elbow Supinate & Pronate (with elbows flexed at 90o) Palpation Increased warmth Swelling, tenderness – inc balloon sign if joint swelling Deformity – Medial & lateral epicondyles + olecranon should be straight line in extension & equilateral triangle in flexion Crepitus Periarticular structures Movement Proximal radioulnar joint (tenderness, laxity, crepitus, passive movement) Passive movement humeroulnar joint Epicondylar tenderness, resisted active movements Tennis elbow - tenderness over the common extensor origin at the lateral epicondyle. Resisted active wrist extension reproduces the pain. Golfer's elbow - tenderness over the medial epicondyle at the insertion of the wrist flexor/pronator group. Resisted active wrist flexion with the hand supinated reproduces the pain Additional tests Collateral ligament stability – flex elbow to 20-30o & apply varus & valgus force Tinel's sign – light percussion over ulnar nerve in medial para-olecranon groove produces tingling Elbow flexion test - elbow in full flexion for 5 min. Tingling in an ulnar distribution again suggests a cubital tunnel syndrome Pinch grip test - oppose the tips of the index finger and thumb. If the normal tip-to-tip pinch is replaced by a pulp-to-pulp pinch anterior interosseus nerve is trapped between heads of pronator teres. If flexors also weak then median nerve is also involved