Disorders of the Shoulder

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[edit] Disorders of the Shoulder

John H. Bland

In a general medical practice, shoulder pain is a common complaint in the outpatient setting.As the link between arm and thorax, the shoulder is susceptible to injury that can masquerade as a nonarticular disorder.With the exception of dislocation, shoulder syndromes are more common after age 40.Shoulder lesions occur more often in men than in women.Lesions of the cervical spine, nerves, and blood vessels entering the upper extremity and even functional abnormalities of remote structures, diaphragm, and thoracoabdominal viscera may be perceived symptomatically in the shoulder.

On assumption of erect posture in evolutionary development, primates freed the upper extremity for prehension, sacrificing shoulder joint stability for remarkably increased mobility.No other joint has such extensive, free-ranging mobility.The shoulder joint is strikingly unstable, highly mobile, and continually subject to injury, strain, sprain, and a variety of diseases.^[1]

[edit] ANATOMY

Medically, the word shoulder means much more than the glenohumeral joint; it includes the complex mechanism of theentire shoulder girdle, each part of which plays an important role in the coordinated movements of the arm (Fig.125-1).The term shoulder joint is misleading because the shoulder includes three large bones (humerus, scapula, clavicle) and four joints (sternoclavicular, acromioclavicular, scapulothoracic, glenohumeral).Shoulder motion is a summation of movement resulting from synchronous movement of all these joints; no unit moves without the others.The scapula is free floating and suspended by its muscles; the only connection to the axial skeleton is the sternoclavicular joint.When shoulder movement is started, rhythm and coordinated motion occur as the muscles attached to clavicle, humerus, and scapula increase or decrease in contraction while the scapula seeks its position of greatest stability, the scapular setting phase.

Figure 125-1 Glenohumeral, acromioclavicular, and sternoclavicular joints.Thoracoscapular joint is between anterior scapular surface and chest wall.

The term scapulohumeral rhythm describes events noted on inspection of the normally moving scapula and humerus (Fig.125-2).This broad concept allows greater comprehension and interpretation in examination of the shoulder.

Figure 125-2 A, Examiner's thumb is at inferior angle of scapula, with bone prominent and in slight shrug and elbow in flexion. B, Scapula has moved anteriorly, upward, and laterally on passive abduction, elevation, and hyperabduction.Normal passive scapulohumeral rhythm.

The acromion is large and powerful to stabilize the joint as a non-weight-bearing, hypermobile, prehensile structure.The acromion functions like the mast of a derrick, providing attachment to the large deltoid muscle.The supraspinatus muscle, relatively small, is used to hold the boom, the humerus, on the fulcrum, the glenoid.The clavicle is also like a boom that holds the entire shoulder out away from the body, allowing extensive hypermobility, adduction, and abduction (Fig.125-3).

Figure 125-3 A, Gorilla shoulder has massive acromion, broad scapula, very large clavicle, relatively large deltoid muscle, and small supraspinatus muscle. B, Horse shoulder with long thin scapula positioned on side of thorax (rather than posteriorly as in humans), no clavicle, tiny acromion, and very large supraspinatus muscle that efficiently accelerates pendulum action of foreleg.Deltoid is absent. (From Codman EA:The shoulder: rupture of the supraspinatus tendon and other lesions in or about the subacromial bursa, Boston, 1934, Thomas Todd.)

[edit] Muscles

Three topographic groups of muscles act on the shoulder: from scapula to humerus (scapulohumeral group), from trunk to humerus (axiohumeral group), and from trunk to scapula.

The scapulohumeral group is the supraspinatus, infraspinatus, teres minor, subscapularis, deltoid, and teres major.The first four are commonly called the rotator cuff, or the short rotators; the first three insert on the greater tuberosity; and the subscapularis tendon inserts on the lesser tuberosity.The tendons are broad and flat, and about 1 inch (2.5 cm) in length.It is impossible to dissect the tendons from the capsule; it is useful to think of the capsule of the glenohumeral joint as a conjoined tendon containing insertions of the powerful capsular muscles.The subscapularis and teres major are medial rotators; the supraspinatus, infraspinatus, and teres minor are lateral rotators.The subscapularis, teres minor, and infraspinatus functional groups depress and rotate the head of the humerus (Fig.125-1 and 125-4).

Figure 125-4 A, Posterior view of the shoulder: surface muscles, all groups. B, Rotator cuff; subscapularis not shown (medial rotator).Rhomboids and levator scapula displace scapula medially toward midline, while scapulohumeral group rotates humerus laterally.

The axioscapular group consists of the trapezius, rhomboids, serratus anterior, and levator scapulae.The trapezius rotates the scapula, raising the point of the shoulder and holding the scapula at a certain distance from the vertebral border, important to the setting phase of scapular fixation.The serratus anterior and levator scapulae originate on the transverse processes of the cervical vertebrae and upper eight or ten ribs, inserting on the vertebral border of the scapula.These muscles are also important for scapular fixation.The rhomboids, antagonists to the trapezius, pull the shoulders backward; they arise from the ligamentum nuchae and the spine of the seventh cervical (C7) and first to fifth thoracic (T1 to T5) vertebrae and insert on the medial border of the scapula.The trapezius overlies the rhomboids (see Fig.125-4).

The axiohumeral group consists of the pectoralis major, pectoralis minor, and latissimus dorsi, the muscles connecting the humerus to the trunk.The pectoralis major arises from the manubrium and body of the sternum and medial clavicle and inserts into the lateral lip of the bicipital groove of the humerus.The pectoralis minor arises from the third, fourth, and fifth ribs under the pectoralis major and inserts into the coracoid process.The latissimus dorsi forms the posterior axillary fold and arises from the lower six thoracic vertebrae and the heavy lumbar fascia, inserting into the floor of the bicipital groove of the humerus (Fig.125-5).

Figure 125-5 Interior view of the shoulder: surface muscles and deep layer of muscles.

The biceps and triceps are a special category, connecting the scapula and the bones of the forearm.If the arm is externally rotated, the bicipital tendon is restored to its original position and can abduct the shoulder.The triceps arises by three heads, with lateral and medial heads from the humerus and a long head from the intraglenoid tubercle of the scapula, inserting into the posterior proximal humeral olecranon and the deep fascia on either side of it.

[edit] Bursae

Bursae provide easy gliding movement in areas with extensive movement but no need for a complete diarthrodial joint, such as where two muscles cross each other in opposite directions or where tendon or muscle must move on one another without real articular contact.Synovial sacs are formed, allowing smooth gliding movement.The only significant bursa around the shoulder is the subacromial bursa; such designations as subdeltoid, subcoracoid, and supraspinatus bursae describe extensions of the subacromial bursa or the glenohumeral capsule.Some of the subacromial bursal base covers the bicipital grooves; the roof is attached to the underside of the acromion and the coracoacromial ligament.The roof and base are in intimate contact.This bursa is an essential component of the shoulder mechanism.The subacromial bursa normally provides a smooth gliding mechanism between the coracoacromial arch above and the rotator cuff tendons below.When bursal surfaces are inflamed, the friction is so painful as to preclude arm abduction or rotation.Adhesive bursitis grossly limits serviceable motion (Fig.125-6).

Figure 125-6 Left, Subacromial bursa in normal anatomic position: supraspinatus insertion.After normal anatomic position: acromion (A) and greater tuberosity/supraspinatus insertion (B).Right, Position of bursa in extreme abduction; deltoid muscle (A) and greater tuberosity of humerus (B).

[edit] Coracoacromial Arch

The coracoacromial ligament is a tough, triangular structure joining the coracoid and the acromion, overhanging the humeral head anteriorly (Fig.125-7).The combination of the bony acromial roof and this ligamentous arch protects both the rotator cuff tendons and the humeral head from direct trauma.However, the close relationship of the humeral head in abduction reduces the space available for rotator cuff tendons to glide beneath.Chronic impingement and tendon attrition with or without calcific tendinitis may result in a painful arc on abduction.The subacromial bursa may be secondarily inflamed by calcific deposits in the tendon, ultimately rupturing into the bursal sac or rotator cuff.Tendon tears may result in spread of inflammation to the bursa (see Fig.125-6, A).

Figure 125-7 Ligaments of the shoulder joint. 1, Capsule blends with rotator cuff tendon;2, acromioclavicular ligament;4, coracoclavicular ligament;5, trapezoid ligament;6, conoid ligament;7, coracoacromial ligament or arch;8, 9, superior and inferior transverse ligament;10, coracohumeral ligament;11, glenohumeral ligament;12, transverse humeral ligament.

[edit] Articular Capsule

The capsule of the glenohumeral joint has a demonstrated volume twice as large as that of the humeral head, allowing unusual mobility and some obvious instability.The capsule arises from the glenoid labrum and surrounding bone and inserts into the upper anatomic neck and the periosteum of the humeral shaft.It is lined with synovium around the periphery of the articular cartilage.Synovial membrane extends into the lining of the biceps tendon sheath, an extension of the joint cavity.

Some areas of the fibrous capsule are thickened to ligamentous proportions.The coracohumeral ligament arises from the lateral edge of the coracoid process and extends over the top of the humerus to insert on the greater tuberosity.Thecapsule thickens anteriorly, forming the superior, inferior, and middle glenohumeral ligaments.These ligaments have variable recesses formed between them, sometimes quite large and redundant.If the fibrous capsule is attached to the neck of the scapula rather than the glenoid, a large anterior pouch appears.The middle glenohumeral ligament is absent or too thin; anterior dislocations may occur (Fig.125-8).

Figure 125-8 A, Examiner palpates under shelving edge of posterior acromion for tenderness of rotator cuff or swelling and tenderness of subacromial bursa. B, Anterior aspect is exposed to examining fingers with arm in extension or with hand behind back in marked medial rotation.

[edit] Glenoid Fossa

The scapular glenoid fossa, broad below and narrow above, is surrounded by the glenoid labrum, a fibrocartilaginous rim giving stability to the glenohumeral joint.The articular surface of the humeral head is oriented posteriorly, medially, and upward; only a fraction of the surface is in contact with the glenoid surface at any time.The greater tuberositydirected laterally forms the outer wall of the bicipital groove, and the lesser tuberosity forms the inner wall.New bone formation in and around the bicipital groove may result in damage, fraying, and even rupture of the long head of the biceps tendon.

[edit] Blood Supply

Six major arteries supply the shoulder: the suprascapular, anterior circumflex humeral, and posterior circumflex humeral are always present; the thoracoacromial, suprahumeral, and subscapular arteries are present less often.An area of severe undervascularization exists in the distal part of the supraspinatus tendon proximal to its insertion in the greater tuberosity.The infraspinatus and subscapularis tendons may also show hypovascularization but less frequently.This is the critical zone, and the pathogenetic assumption is that the ischemic area is subject to cellular hypoxia, fiber tears, release of lysozymes with further destruction of tendons, and spread of traumatic inflammation.Such areas have limited repair potential for attritional tears.A further contributing force to tendon damage is the sharp angulation of the rotator cuff tendons over the humeral head, with vessel compression in the tissue of the tendon.

[edit] Nerve Supply

Only two sensory nerves supply the shoulder region: the axillary, or circumflex, and the suprascapular.The axillary nerve courses to the anterior surface of the capsule, sending branches into the joint from below.The suprascapular nerve separates from the superior division of the brachial plexus, courses laterally and downward under the trapezius muscle to the upper border of the suprascapular notch, passes under the supraspinatus muscle, and penetrates the infraspinatus fossa, where it divides into terminal branches.The suprascapular nerve supplies the superior and posterior portions of the joint capsule, most of the tendon sheath, and the acromioclavicular joint.Both nerves supply the coracoclavicular, coracoacromial, coracohumeral, and glenohumeral ligaments.The long thoracic nerve sends a branch to the coracoid process and the acromioclavicular joint.Cartilage and bone are not very pain sensitive.The tissues of the shoulder can be listed in decreasing degree of pain sensitivity: tendons, bursae, ligaments, synovial tissue, joints, their capsular reinforcements, and muscles.

[edit] PATIENT EVALUATION

[edit] History

Details of the patient's history should include type of pain of onset, location of initial pain, pain behavior from onset, history and nature of injury, type and degree of pain, rapidity of onset, magnitude of disability, spread of symptoms and their precise timing, true appearance of reproducible signs, relieving or aggravating factors, effect of position, relationship to time of day or night, effect of passive or active movements, and presence or absence of neurologic symptoms or signs.The patient's age, habitus, occupation, body type, posture, mental state, and intellectual status are important.Emotional tension, complaint threshold, anxiety states, and hysteria affect shoulder complaints.

Pain is most often in the lower part of the deltoid area, the referral area for the supraspinatus tendon.Although the lesion may be only millimeters in size, the pain can be great, often involving most of the deltoid area and the proximal arm.Pain at the acromioclavicular joint area indicates a problem in and around that joint.Pain in any other part of the arm, shoulder, or neck or in the C5 sclerotome is common to all other possible shoulder lesions (Fig.125-9).

Figure 125-9 A, Fifth cervical (C5) sclerotome distribution of pain. B, Dermatomes and sclerotomes for pain distribution in upper extremities. (B, From Lance JW, McLeod JG:A physiological approach to clinical neurology, ed 2, Reading, Mass, 1975, Butterworth.)

Initial symptoms in supraspinatus tendinitis are pain in the deltoid insertion area initiated by abduction, especially active but also on passive abduction.Spread of inflammation to the subacromial bursa is characterized by extension of the pain to the distal arm and into the forearm.Pain involving the forearm as far as the wrist indicates that the process has spread to the capsule and has been present for 3 to 6 months.If the entire arm is painful with severe limitation of motion, the inflammation has spread to involve the capsule and synovium, and a frozen shoulder is developing or already present.

Other joint involvement suggests rheumatoid arthritis, gout, or some systemic rheumatic disease.Osteoarthritis rarely involves the shoulder primarily.If preceding injury has occurred, osteoarthritis may gradually develop.Tears in the supraspinatus tendon or capsule and other injuries to the shoulder may appear later, long after the primary injury.The more the arm is involved by pain, the more extensive is the lesion.Tendinitis evolves into subacromial bursitis, which becomes capsulitis and then synovitis.Pain when lying on the side of the affected shoulder suggests supraspinatus tendinitis.Spontaneous pain indicates an extensive spread, from tendinitis to bursitis and later capsulitis.Head, neck, chest, or upper abdominal pain suggests a lesion separate from the shoulder, such as diaphragmatic hernia, cervical spondylosis, or cardiac involvement.

[edit] Physical Examination

Inspection should include the head, cervical spine, shoulder, arm, forearm, wrist, and hand, including the area the patient designates as the painful site.The effect of gravity is an important consideration (Fig.125-10).

Figure 125-10 Effect of gravity on shoulder (full trunk and hip flexion) separates pain-sensitive structures, relieving pain.

[edit] Cervical Spine.

The cervical spine is examined by active flexion, extension, lateral flexion, and rotation to determine if any of these movements causes pain.Passive flexion, extension, lateral flexion, and rotation of the cervical spine are then demonstrated to determine if these movements produce the characteristic pain.The aim is to determine whether mobile structures (muscles and tendons) are pain sensitive or whether capsules, ligamentous structures, joints, osteophytes, and anterior and posterior longitudinal ligaments are the source of pain.To identify pain-sensitive structures by selective tension, the patient flexes, extends, laterally flexes, and rotates the cervical spine against resistance.These maneuvers also identify lesions at the origin and insertion of muscle.

[edit] Shoulder.

The examiner inspects the painful shoulder anteriorly, laterally, and posteriorly, comparing it to the unaffected side.Observations of scapulohumeral, claviculohumeral, and arm trunk rhythm may be revealing and often diagnostic.Key characteristics are atrophy, loss of muscle tone, fasciculations, reflex changes, and sensory alterations.The entire upper limb should be inspected for color change, swelling, skin changes, and abnormal posturing.

Full range of active motion is then inspected.Shoulder flexion, extension, adduction, abduction, and medial and lateral rotation are observed anteriorly, posteriorly, andlaterally.The examiner notes whether abduction is accomplished by shrugging and observes the clavicular movements.Posterior inspection centers on the scapular motion, the scapulohumeral rhythm, and the lower angle of the bone moving out or in as it seeks stability.At about 45 degrees the outward movement accelerates laterally, forward, and upward as the serratus anterior muscle moves (Fig.125-11).

Figure 125-11 A, Normal anatomic position. B, Arms abducted just above 90 degrees until humeri are medially rotated (palms facing down).Next 60 degrees of abduction cannot occur. C, With palms facing, scapulae have rotated, allowing 60 degrees more; last 30 degrees, with distal arm touching head, are achieved by abduction of humerus across front of scapula, coracoid, and acromion.

If the glenohumeral or acromioclavicular joint is fixed, the humerus and scapula move as one, and abduction to as much as 60 degrees occurs by the shrugging mechanism.The lateral view focuses on the deltoid muscle.A look from above with the patient seated is helpful, with occasional inspection in supine and prone positions to see the relaxed musculature and conformation of the shoulders.

The full range of these motions is noted passively, with the examiner lifting the shoulder and arm through its motions.Full passive motion, gently and slowly done, is common in shoulder problems, even with marked limitation of various active ranges of motion in the presence of muscle and tendon lesions.In tears or ruptures of the rotator cuff, active abduction may be impossible or grossly limited, whereas with assisted complete passive motion, abduction to 90 degrees can be shown.When the support is removed, however, marked weakness in holding the abduction is noted, the drop-arm sign. Rotation of the humeral head in the glenoid should be shown in both adduction and abduction (to 90 degrees).Humeral rotation must be distinguished from pronation and supination of the hand.To study lesions at the origin and insertion of tendons and ligaments, the patient demonstrates the ranges of motion against resistance.

[edit] Palpation.

All landmarks are palpated: sternoclavicular and acromioclavicular joints, coracoid process, spine of scapula and clavicle, acromion around its periphery, rotator cuff, and muscles of the shoulder joint (adductors, latissimus dorsi, teres major, pectoralis major and minor, deltoid).The posterior aspect of the rotator cuff is readily palpable with the arm adducted across the chest.

Acromioclavicular lesions are detected by pain in the superior aspect of the shoulder, referral to the neck and jaw, and local joint tenderness exaggerated by adduction of the arm across the chest. Crepitus is elicited by placing the palmof the examiner's hand over the top of the patient's shoulder while the other hand rotates the humerus at various angles of adduction, abduction, and rotation.Crepitus is indicative of severe rotator cuff disease with secondary osteoarthritis of the glenohumeral joint.The painful arc is pain production at about 60 degrees of abduction, with freedom from pain before and after this level.This indicates impingement of the greater tuberosity under the acromion, a supraspinatus tendinitis with or without calcific deposits (Fig.125-12).

Figure 125-12 Right arm abduction to just 30 degrees when pain is felt.

[edit] Special Procedures.

In rotator cuff lesions, most muscles around the shoulder develop varying degrees of spasm, itself a source of pain.The pain frequently disappears in full trunk and hip flexion, allowing the arm to hang limp; the weight of the arm separates the inflamed area from the acromion and the coracoacromial arch.The muscles then relax on passive swinging and pendular movements of the arm, so-called pendulum exercises (see Fig.125-10).

With partial rupture the patient swings the arm forward and the examiner holds it there; the patient then returns to an erect position with the arm in full abduction, or elevation.Thus the shoulder can be put through a full range of painless motion.Pain in rotator cuff tendinitis may also be relieved by supporting the forearm in flexion, putting the arm at about 30 to 40 degrees abduction, and exerting gentle traction downward.

Lidocaine (Xylocaine) infiltration in the tissues of suspected involvement is often helpful, diagnostically and therapeutically.In rotator cuff tears, with the pain gone, painless movements allow determination of loss of power.With normal movement and power after lidocaine infiltration, nonsurgical therapy is promising.

[edit] Systematic Clinical Plan

A systematic clinical approach to identification of the pain-sensitive structure leads to a precise diagnosis and successful management in the vast majority of patients.With the exception of the acromioclavicular joint (derived from the C4 sclerotome embryologically), all structures of the shoulder, which include subacromial bursa, capsule, synovium, glenohumeral joint, periosteum, biceps tendon (long head), and rotator cuff muscles and tendons, are derived entirely or partially from the C5 sclerotome, and thus shoulder pain originating in any structure is perceived only in its distribution (see Fig.125-9, A).Pain arising from structures deep to the deep fascia is referred in a segmental distribution not following the dermatome distribution.The area of pain is always very large, severe, and never perceived at the site of the lesion.Rhomboid muscle irritation causes severe transient pain over the shoulder region anteriorly and posteriorly, following the deep segmental sensory distribution of the C5 root.Irritation of the periosteum of the humerus near the capsule insertion causes diffuse, severe pain over the same segmental area.Thus in disorders of deep structures (muscles, ligaments, capsules, tendons, fascia), broad intrasegmental distribution of pain occurs.Thus pain caused by shoulder lesions is felt in some part of the C5 sclerotome.Pain may also arise as referred pain from the cervical spine, intrathoracic structures, diaphragm, and even intraabdominal structures, as noted later.

Initially a survey is made of all the segments possibly involved.Pain in the scapular area, shoulder, or arm indicates a lesion in one of the tissues forming the C5 to T2 sclerotomes (see Fig.125-9, B).Thus a survey of the segments from neck to fingertips tells the examiner whether there is a lesion of tissues in and around the shoulder, a lesion perceived in the shoulder but not arising from shoulder tissues, or pain referred from a distant site, visceral or somatic; hysteria, anxiety state, and psychoneurosis are detectable through clinical inconsistencies.The patient is first asked to actively flex, extend, laterally flex, and rotate the cervical spine; next to shrug the shoulders maximally and actively elevate the scapula (C3 to C4); next the shoulder is taken through a full range of active motion (C5); then the elbow is examined in flexion, against resistance and in extension against resistance to study C5 to C7; next the wrist is examined in resisted extension (C6) and resisted flexion (C7); then the thumb is examined in resisted extension (C8) and resisted adduction (C8); and last the fifth finger is examined in adduction against resistance (T1).The patient is instructed during all these maneuvers to describe pain occurring at any point.The examiner should then know whether the tissues of the shoulder are the cause, whether tissues peripheral to that area are involved, or whether the problem is nonorganic or psychogenic.The following 12 movements, systematically done, determine the pain-sensitive structure:

• Elevation of the arm. The arm is abducted to 90 degrees, and the patient notes pain in the process.The glenohumeral joint abducts normally to 90 degrees, at which point the greater tuberosity impinges under the coracoid and the coracoacromial arch.The next 60 degrees of elevation result from scapular rotation, and the last 30 degrees constitute adduction of the humerus across the front of the scapula (seeFig.125-11).Psychogenic symptoms can be identified in this process, since the degree of elevation minus 60 degrees represents the abduction range at the glenohumeral joint.If marked discrepancy is noted later, psychogenic mechanisms may be invoked.
  
• Passive elevation. The examiner goes through the same motions as in step 1.Pain is noted, and the “end feel” is observed (i.e., whether the movement comes to an abrupt or gradual stop at the extreme of the range, a perception that comes with experience).
  
• Painful arc. The patient abducts the shoulders.Pain between 60 and 120 degrees indicates impingement between the acromion, the greater tuberosity, and the supraspinatus tendon (Fig.125-12).
  
• Passive scapulohumeral abduction. The thumb is placed at the lower angle of the scapula to determine whether it moves.The other hand elevates the arm until the examiner feels the scapula begin to rotate.This occurs normally at 90 degrees (seeFig.125-2).
  
• Passive lateral rotation. The patient's elbow is bent at a right angle, and the forearm (as a lever) rotates it outward in the sagittal plane.Normal range is 90 degrees; range, end feel, and pain are noted.
  
• Passive medial rotation. The examiner rotates the humerus medially, noting how far behind the patient's back the forearm can be placed.Normal range is 90 degrees; restriction and pain are noted.
  
• Resisted abduction. With the elbow tight against the body, the patient is asked to abduct against resistance by the examiner, who prevents the joint from moving.Resisted abduction examines the deltoid and supraspinatus.Since the deltoid muscle rarely if ever has painful lesions, pain with abduction generally indicates supraspinatus tendinitis (Fig.125-13,A).
  
• Resisted medial rotation. With the elbow fixed against the body, the patient is asked to rotate medially against resistance, testing pectoralis major, teres major, latissimus dorsi, and subscapular muscles (Fig.125-13,B).
  
• Resisted lateral rotation. This rotation tests the infraspinatus and teres minor muscles; if lateral rotation results in pain, only the infraspinatus tendon is at fault (Fig.125-13,C).
  
• Resisted adduction. This adduction tests the thoracohumeral group of muscles (Fig.125-13,D).
  
• Resisted flexion at the elbow. Resisted flexion tests biceps and brachialis function, but if supination against resistance is painful, the lesion is bicipital.
  
• Resisted extension at the elbow. This extension tests triceps function (Fig.125-13,E).
  

Figure 125-13 A, Abduction against resistance: supraspinatus muscle and tendon. B, Medial rotation against resistance: subscapular muscle and tendon; also pectoralis major, teres major, and latissimus dorsi. C, Lateral rotation against resistance: infraspinatus and teres minor. D, Resisted adduction: thoracohumeral muscle group; flexion against resistance at elbow (not shown). E, Extension against resistance at elbow: triceps.

[edit] Shoulder Range of Motion.

The shoulder lends itself well to measurements of range of motion: extension, 35 degrees from neutral; flexion, 95 to 100 degrees from neutral; adduction, 25 to 30 degrees; abduction, 90 degrees before gross scapular movement; and medial and lateral rotation, either from neutral or 90 degrees of abduction and 90 degrees both ways.In the superior plane the hands are placed behind the head and the elbow braced backward as far as possible; with palms facing and extending maximally vertically over the head, arms touch the sides of the head.In the inferior plane the dorsum of the hand is noted reaching variably up the back, the buttock, the small of the back, or up between the shoulder blades, all reflecting varying degrees of shoulder mobility (Fig.125-14).

Figure 125-14 Parameters of progress. A, Hand at buttock only. B, Hand can reach to flank. C, Hand can reach to interscapular area. A B C

[edit] Muscle Power.

Each muscle or muscle group can be tested for power by having the patient make the appropriate effort against resistance.Weakness may result from loss or impairment of nerve supply, rupture of tendons, or pain too severe to allow movement.

[edit] Laboratory Studies.

Few laboratory studies are needed in studying the painful shoulder.Erythrocyte sedimentation rate (Westergren), latex fixation, antinuclear antibody, serum calcium, phosphorus, alkaline phosphatase, quantitative immunoglobulins, culture of joint fluids, synovial fluid analysis, and various metabolic and endocrine studies may be helpful in the diagnosis of rheumatoid arthritis, thyroid and parathyroid disease, septic arthritis, and neoplasms involving the shoulder.

[edit] Radiologic Studies.

Most shoulder problems are diagnosed and treated using the history and physical examination.For more difficult presentations or cases of tendinitis with persistent disability, radiographs are useful.The standard views are anteroposterior (AP); the beam is centered on the coracoid process, with both medial and lateral rotation views of the humerus.These views document and locate a calcific deposit in the cuff or in the bursa (Fig.125-15).Plain films may suggest a full-thickness rotator cuff tear.Subluxation of the acromioclavicular joint occurs as the patient laterally rotates the arm (Fig.125-16, A).The freed humeral head drives the acromion upward.Full-thickness tears may appear simply as a narrowing of the acromiohumeral gap.Superior migration of the humeral head is a direct consequence of the loss of supraspinatus function (Fig.125-16, B).The acromioclavicular joint is best studied with the beam passing anteroposteriorly, with 30 to 35 degrees angulation upward.

Figure 125-15 A, Calcific tendinitis localized by AP radiographs.Supraspinatus tendon with extensive calcific deposit. B, Subscapularus tendon with calcific deposits; deposit moves across front of humeral head on medial rotation.

Figure 125-16 A, Normal film in lateral rotation. B, Humeral head is elevated 2 years later; patient had full-thickness tear.

A chest film offers diagnostic clues to the origin of shoulder pain.It may reveal a cervical rib, a past clavicular fracture with malalignment, or an apical lung tumor (Pancoast's tumor).

Shoulder arthrography demonstrates the shape and capacity of the glenohumeral joint space (Fig.125-17).A contrast study is the only way to distinguish between complete and incomplete tears of the rotator cuff.Complete ruptures can be surgically repaired.Arthrography may be helpful in adhesive capsulitis and recurrent shoulder dislocations.It is not helpful in bicipital rupture.

Figure 125-17 Normal radiographic contrast study, with dye in biceps sheath (straight arrows) and subscapular recess (curved arrow).

[edit] THE PAINFUL SHOULDER

Pain syndromes arising from structures in and around the shoulder joint have a surfeit of names in textbooks and the published literature, with subsequent confusion of terminology, diagnosis, and treatment.The following syndromes refer to the same basic process: supraspinatus tendinitis, rotator cuff tendinitis, subacromial bursitis, subdeltoid bursitis, painful arc syndrome, calcific tendinitis, calcific bursitis, and impingement syndrome.Overlapping and usually following these are a group of names also referring to the same process: periarthritis, adhesive capsulitis, frozen shoulder, adhesive bursitis, periarticular adhesions, and check rein shoulder.

The great majority of painful nontraumatic lesions and syndromes around the shoulder are caused by tendinitis of the rotator cuff. There are four rotator cuff tendons inserting into the greater and lesser tuberosities.The long head of the biceps tendon passes through the intertubercular groove to insert on the superior rim of the glenoid.The supraspinatus tendon is usually the first and ultimately the most involved of the cuff tears.The initial lesion is almost always a localized supraspinatus tendinitis with subsequent extension to other members of the rotator cuff and the subacromial bursa, later extending to the joint capsule and intraarticular and extraarticular structures and leading to frozen shoulder.The pathologic process of rotator cuff tendinitis may be a continuum of inflammation, degeneration, and attrition ofthe rotator cuff by impingement on the anterior edge of the acromial process, the coracoacromial ligament, and sometimes the acromioclavicular joint.The wear and attritional tears of the cuff occur on the supraspinatus tendon and may extend into the infraspinatus tendon and the long head of the biceps tendon (Box 125-1).Most cases of rotator cuff tendinitis improve with time, and conservative management is usually advised.

Some experts conclude that stiff and painful shoulders all improve regardless of treatment, whereas others strongly advocate localized steroid injections in all cases of both intracapsular and extracapsular lesions affecting tendons, their sheaths, and bursae.

The term periarthritis has become an umbrella term to describe inflammatory syndromes involving all structures about the shoulder.It describes a continuum of pathology with many subsets of sufficient clinical distinction to separate them, culminating in the frozen shoulder.Most physicians specializing in shoulder syndromes believe that the continuum should be interrupted and reversed before it reaches the extreme of this disabling condition.

Inflammation of the supraspinatus or bicipital tendon may spread by contiguity to the tendon sheaths, other tendons andtheir sheaths (tenosynovitis), the bursa, capsule, synovium, cartilage, bone, and surrounding muscles.

Box 125-2 lists the differential diagnosis of shoulder pain.Uncomplicated supraspinatus tendinitis and tenosynovitis (with or without extension to other members of the rotator cuff) and bicipital tendinitis and tenosynovitis are associated with the normal range of passive motion.Involvement of the capsule (adhesive capsulitis), the bursa, muscles, and synovium is associated with limited range of motion.^[2]

[edit] SUPRASPINATUS TENDINITIS, TENOSYNOVITIS, AND ROTATOR CUFF LESIONS

The first pathologic event occurs in the supraspinatus tendon.After the fifth decade of life, thinning, fraying, fissuring, and fibrillation of the distal tendon in the critical zone of hypovascularity result from the mechanical disadvantage and the constant stress on the tissue by humeral impingement against the coracoacromial arch.Traumatic inflammation occurs, possibly with an autoimmune mechanism producing antibody against denatured collagen and other structural proteins, and spreads to the contiguous tendon sheath, subacromial bursa, and other joint structures.

The patient is usually over 45 years of age with an occupation or leisure activity that entails unusual shoulder stress.The pain is a dull ache in the deltoid insertion area, often over a wider area, even the entire C5 sclerotome, with acute and severe pain on certain movements (abduction to 60 degrees or more, reaching over the head, putting on a coat).There is usually no arm or neck radiation.Night pain is characteristic, and the patient cannot lie on the affected side in bed because of increased pain.The patient often grabs theaffected shoulder with the opposite hand, complaining of a “catch,” or a severe twinge in the shoulder.The shoulder is diffusely tender, especially over the humeral head lateral and posterior to the acromion and over the supraspinatus insertion.More posterior tenderness suggests teres minor and infraspinatus involvement.Pain in resisted medial rotation suggests subscapularis involvement.The anterior and superior aspects of the rotator cuff can be examined by having the patient reach behind the low back.

The posterior aspect of the rotator cuff can be best examined by adducting the arm across the chest.Downward pull on the relaxed arm is painful because of tension in the rotator cuff.Adduction and forward-backward swing cause no pain.Scapulohumeral rhythm is reversed, with the patient shrugging to rotate the scapula with the least glenohumeral adduction.The pain is greatly increased by forced abduction against resistance, and there is a painful arc of 10 to 15 degrees just beyond 60 degrees' abduction (as the tendons and cuff impinge over the coracoacromial arch).Passive range of motion is normal.

Radiographs are usually not helpful, although calcific densities may be seen later; bony flakes, spicules, sclerosis, and osteophytosis of the tuberosities occur, followed by eburnation and cystic changes.Infiltration of the cuff with 1% lidocaine with relief of pain, especially the arc of pain, is both diagnostic and therapeutic (see Figs.125-15 and 125-16).

Management of rotator cuff tendinitis includes (1) extensive patient education with definition of the problem, prognosis, and reassurance regarding recovery; (2) heat as well as cold intermittently; (3) pendulum exercises (see Fig.125-10); (4) range of motion exercises; (5) nonsteroidal antiinflammatory drugs; (6) injection of steroid and local anesthetic agents;(7) pain medication; and (8) occasionally, a short course of steroids (e.g., prednisone, 15 mg in the morning and at supper for 5 days, reduced by 5 mg every 5 days until cessation).About 90% of patients recover with this therapy.

Boxes 125-3,125-4,125-5,125-6,125-7,125-8,125-9 to 125-10 summarize calcific tendinitis,^[3] rupture of the rotator cuff, bicipital syndromes (Fig.125-18), frozen shoulder^[4][5][6](Fig.125-19), acromioclavicular syndromes, reflex sympathetic dystrophy syndrome,^[7] neurovascular syndromes, and visceral and somatic lesions.^[8]

Figure 125-18 Note “lump” in right biceps (left side of photograph) compared with left biceps.Long head of biceps tendon is completely ruptured.

Figure 125-19 Sequence of events terminating in frozen shoulder. A, Normal structures of the shoulder. B, Supraspinatus tendinitis, sometimes calcific, in the “critical zone.”C, Spread of inflammation to the tendon sheath and a bulge into the floor of the subacromial bursa. D, Rupture into the subacromial bursa and extension of the inflammatory process as an osteitis into the humeral head and greater tuberosity. E, Frozen shoulder with involvement of tendons, bursa, capsule, synovium, and muscle with fibrous contracture and markedly diminished volume of the shoulder joint space.

[edit] SHOULDER ARTHROCENTESIS AND INTRAARTICULAR INJECTION

Shoulder arthrocentesis is best accomplished with the patient seated and the shoulder internally rotated.The skin is marked just medial to the head of the humerus and slightly inferior and just lateral to the coracoid process; both structures are readily palpable with practice.Using strict sterile skin preparation, a wheal is raised in the skin using a syringe with lidocaine and a 26-gauge needle at the marked spot.A 20-to 22-gauge needle is then directed posteriorly, slightly superiorly, and laterally.Ideally, the physician should feel the needle enter the joint space.If bone is hit, the physician should pull back and redirect the needle at a slightly different angle^[9](see Fig.125-1).

For injection into the subacromial bursa the physician follows the clavicle laterally to palpate the shelving edge of the acromion process, which is usually readily identified; the needle is directed under the edge.Entry into the bursa can usually be perceived.A lateral approach to both the shoulder joint and the subacromial bursa can also be used, inserting the needle between the acromion process of the scapula and the head of the humerus.

Corticosteroids are often mixed with a local anesthetic, typically procaine or lidocaine.Package inserts from the major pharmaceutical manufacturers advise against this practice.Most local anesthetics contain preservatives thatmay result in flocculation of the corticosteroid.Lidocaine for intravenous use does not contain a preservative.A conservative approach is advised.A short-or intermediate-acting steroid preparation such as triamcinolone diacetate or methylprednisolone acetate is recommended for periarticular injections.A long-acting preparation such as triamcinolone hexacetonide may be used for intraarticular injection (see Chapter 123 ).No consensus exists on the ideal volume and dose of corticosteroid for injection into joints.The shoulder is a large joint with considerable intrasynovial volume; 2 to 3 ml is advised (Box 125-11).^[9]

[edit] REFERENCES