Shoulder muscle ruptures

Question 1

Describe the epidemiology of pectoralis major rupture?

Answer 1

• exclusively males
• often weight lifters
• most common occurs as tendon avulsion
• mechanism
  
  • excessive tenson on maximally eccentrically contracted muscle
  • maybe iatrogenic injury caused by RC repair

Question 2

Describe the anatomy of pectoralis major ?

Answer 2

• Origin
  
  • clavicle head, ant medial suface of medial half of clavicle. sternocostal head, ant surface of sternum, sup 6 costal cartilages
• Insertion
  
  • lateral tip of inertubercular groove of humerus
• action
  
  • adducts and medially rotates humerus, draws scapula anterior and inferiorly. acting alone- clavicular head flexes humerus and sternocostal head extends it.
• Innervated by lateral and medial pectoral nerves: clavicular head C5/6, sternocostal head( C7,8,T1)
• blood supply
  
  • pectoral branch of thoracoacromial trunk
• 2 heads
  
  • clavicular head
  • sternocostal head
  • one of 4 muscles connecting the upper limbto the thoracic wall others include
    
    • pectoralis minor
    • subclavius
    • serratus anterior
• Biomechanics
  
  • inferior fibres of sternal head at max stretch during final 30^o of humeral extension
  • position at which pectoralis major is most vunerable to rupture

Question 3

Describe the presentation of pectoralis major rupture?

Answer 3

• HX: reports a sharp tearing with resisted adduction and IR
• Pain and weakness of shoulder

O/E

• Swelling and ecchymosis
  
  • if localissed to anterior arm then humeral attachment rupture is more likely then musculotendinous junction rupture
• Palpable defect and deformity of the anterior axillary fold
• weakness with adduction and IR

Question 4

What imaging is useful in pectoralis major rupture?

Answer 4

• xrays normally normal
• MRI
  
  • may show avulsion of pect major tendon from humerus

Question 5

What is the tx of pectoralis major rupture?

Answer 5

• Non operative
  
  • intial sling, immobilisation, rest ice NSAIDs
    
    • for partial ruptures
    • trears in muscle or musculotendinous junction
    • low demand pts
• Oerative
  
  • open exploration and repair of tendon avulsion
    
    • tendon avulsed from bone/ high level athletes
    • http://www.orthobullets.com/video/view?id=144

Question 6

Describe the epidemiology of deltoid ruptures?

Answer 6

• Usually strains or partial tears
• complete tears are rare
• risk factors
  
  • rpt corticosteriods about the shoulder
  • RC tear
  • Trauma
• Mechanism
  
  • 2ary to rpt corticosteriods about the shoulder
  • Massive RC tear
    
    • prox migration of humeral head -> compression/abrasion of deltoid by geater tuberosity
  • Iatrogenic injury
    
    • during open RC repair
  • Trauma
    
    • sudden deltoid contracture
    • shoulder contusion

Question 7

Describe the anatomy of deltoid?

Answer 7

• origin
  
  • lateral 1.3 rd of clavicle, acromium, and spine of scapula
• insertion
  
  • Deltoid tuberosity
• action
  
  • anterior part- flexes and medially rotates arm
  • middle- abducts arm
  • posterior- extends and laterally rotates arm
• Innervation
  
  • axillary nerve C5/6
• Blood supply
  
  • deltoid branch of thoracoacromial artery

Question 8

What is the presentation of deltoid rupture?

Answer 8

• shoulder pain
• inspection
  
  • depression over deltoid
  • soft tissue mass distal to depression

Question 9

What is on imaging of deltoid rupture?

Answer 9

• Xrays
  
  • assoc cuff tear
• USS
  
  • deltoid gap with intact surrounding fibrers
• MRI​
  
  • Differentiates partial vs completee
  • find deltoid defect and assoc RC tear

Question 10

What is the tx of deltoid rupture?

Answer 10

Non operative

• Observation only
  
  • chronic injuries in elderly

Operative

• Early surgical repair
  
  • complete rupture
• Deltoplasty w mobilisation and anterior transfer of middle third of the deltoid
  
  • iatrogenic RC injury during RC repair

Question 11

Describe the anatomy of triceps brachii?

Answer 11

• Origin
  
  • long head - infraglenoid tubercle of scapula
  • lateal head- post surface of humerus, sup to radial groove
  • medial head- post surface of humerus, inf to radial groove
• Insertion
  
  • proximal end of olecranon process of ulna and fascia of forearm
• Action
  
  • chief extensor of forearm; long head steadies head of abducted humerus
• Innervation - Radial nerve (C6,7,8)
• Blood supply
  
  • ​branches of deep brachial artery

Question 12

Describe the epidemiology of tricep rupture?

Answer 12

• Usually males
• age 30-50
• usually in
  
  • competitive wieghtlifters
  • body builders
  • football players
• risk factors
  
  • systemic illness- renal osteodystophy
  • anabolic steriod use
  • local steriod injecions
  • flouroquiolone use
  • chronic olecranon burisitis
  • prev triceps surgery
• Mechanism
  
  • usually forceful eccentric contraction
• Pathoanatomy
  
  • rupture most common at insertion of medial /lateral head
  • les frequent thru muscle belly /musculotendinous junction

Question 13

What is the presentation of triceps rupture?

Answer 13

• Pt often not a painful pop
• loss of ability to extend elbow against gravity

O/E

• May have palpable gap
• swelling, ecchymosis and pain

Question 14

What is seen on imaging of triceps rupture?

Answer 14

• xray
  
  • lateral view may show flake sign
• MRI
  
  • determine loation and severity

Question 15

What is the tx of triceps rupture?

Answer 15

Non operative

• supportive tx
  
  • partial tears and able to extend against gravity
  • low demand pt with poor health

Operative

• Primary surgical repair
  
  • acute complete tears
  • partial tears (>50%) with significant weakness
  • delayed reconstruction may need tendon graft

Question 16

What are the complications of triceps rupture?

Answer 16

• Elbow stiffness
• Ulnar nerve injury
• failure of repair

Question 17

Describe the epidemiology of latissimus dorsi rupture?

Answer 17

• Rare
• cause of pain in throwers shoulder
• v rare condition
• pathophysiology
  
  • felt to be eccentric overload during the follow through of the throwing motion

Question 18

Describe the anatomy of latissmus dorsi?

Answer 18

• Origin
  
  • sipinous process of inferior 6 thoracic vertebrae, thoracolumbar fascia and inferior 3/4 ribs
• Inserts
  
  • floor of intertubercular groove of humerus
• action
  
  • extends, adducts and medially rotates humerus, raises body toward arms during climbing
• innervation
  
  • thoracocodorsal nerve C6,7,8
• ​Blood supply
  
  • ​thoracodorsal artery

Question 19

What is the presentation of latissimus dorsi rupture?

Answer 19

• Local tenderness & deformity over latissimus dorsi muscle
• pain with shoulder adduction and IR

Question 20

What imaging is useful in latissimus dorsi rupture?

Answer 20

• MRI
  
  • increase T2 signal and retractio of latissmus dorsi muscle

Question 21

What is the tx of latissimus dorsi rupture?

Answer 21

• Non operative
  
  • short period of rest followed by physio
  • physio aim is to restore shoulder motion/strength
  • throwing can be allowed
    
    • after full, painfree motion & gd strength
    • balance of RC and scapular R muscles
• Operative
  
  • Primary repair vs reconstruction
    
    • foe high demand athletes
    • early repair favoured to prevent retraction and scarring