L11 Clinical Anatomy of Upper Limb Flashcards
What needs to be identified and released to allow insertion of a shoulder replacement?
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anterior inter-nervous plane: b/w deltoid and pectoralis major
- cephalic vein lies there - deltoid and pectoralis major get pushed apart
- coracoid process: fasica underneath is incised
- subscapularis: gets cut
- humeral head and glenoid
What are things to look out for when operating around the shoulder joint?
- brachial plexus → not caught in retractors
- musculocutaneous nerve → not streched when coracobrachialis is cut away
rotator cuff injuries
- usually supraspinatous gets torn (due to spur of acromium causing inflammation)
- continued wear: infraspinatous and subscapularis gets torn
What procedures can be done when inflammation caused by acromium occurs?
- open acromiosplasty → older procedure
- athroscopic acromioplasty → more common
What kind of procedures can be done when the clavicle is fractured?
- pin inserted into hollowed out clavicle bones
- pin and plate: be wary of pin lengths
When fixing the clavicle, what are some structures that may be endangered?
- axillary artery/subclavian artery
- axillary vein/subclavian vein
- brachial plexus
arcuate artery
- branch of anterior humeral circumflex artery
- branches via greater tuberosity
- supplies humeral head
If blood vessels to the humeral head are damaged, what could occur?
- bone in humeral head will necrose, avascular necrosis
- cartilage will then also die
- joint becomes arthritic
How much of the proximal humerus does the anterior circumflex artery provide blood supply to?
3/4 of proximal humerus
How much of the proximal humerus does the posterior circumflex artery provide blood supply to?
1/4 → 1/3 of proximal humerus
How does the parts of fractures affect the rate of avascular necrosis?
- 3-part: 12-25%
- 4-part: 21-75%
- Valgus (lateral displacement) 4-part: 8-26%
What are some predictors of ischemia in the humeral head?
- metaphyseal head extension (calcar) < 8mm
- loss of integrity of medial higne
- fracture pattern (anatomical neck) → more fracture pattern = worse
SLAP tear and grades of SLAP tears
- Superior Labral Anterior Posterior lesion
- I: little damage to biceps insertion
- II: torn off insertion - can be sewn back
- III: labrum flaps and causes catching in shoulder
- IV: tears running into biceps tendon
What can occur due to a torn glenoid labrum? What can be the consequence of this?
- cysts can occur
- can cause impingement of supraspinatous nerve
- impingement syndrome
- weakness of supraspinatous and infraspinatous
What are the grades of AC joint dislocation?
- I: sprained ligaments
- II: conoid and trapezoid ligaments aren’t torn
above: can be healed by physiotherapy
- III: tear of ligaments but displacement is small → can be healed with physiotherapy, however 20% of grade III displacements need surgery
- IV & V: tear of ligaments with greater (V: and greater) displacement → requires surgery
- VI: distal clavicle displaced behind tendon of biceps and coracobrachialis - not common though
What are some procedures that can be done to fix AC joint dislocations?
- tightrope fixation surgery - liable to breakage, but allows for mobility
- bosworth screw - old method and rigid - breaks easily as AC joint is meant to be mobile
- lateral clavicular plate: attached under acromium (could affect subacromial space - SITS), is usually removed after ligaments are healed
What are some treatments for fractures of the clavicle in the lateral third?
similar to AC joint dislocation treatment (physio or in worse cases, surgery with lateral clavicular plate)
When repairing distal biceps tendon tears, what structures are at risk of being endangered?
posterior interosseous nerve (branch of radial nerve) - goes round the two heads of supinator
When placing a plate along the whole length of the humerus, what structures may be damaged?
- axillary nerve (near the head)
- radial nerve (runs across the shaft of the humerus)
- plate needs to be placed under the radial nerve
- if plate is placed over, can cause wrist drop due to damage
- ulnar nerve (elbow)
Holstein Lewis humeral fracture
- fracture at where radial nerve crosses through lateral intermuscular septum
- radial nerve at danger of getting trapped in the fracture
What can cause damage to the axillary nerve?
- dislocated shoulder
- proximal humeral fracture
If the axillary nerve is damaged, what are the consequences?
- if stretched → axillary nerve palsy
- numbness at deltoid insertion
- deltoid palsy
- if prolonged injury → 2° deltoid wasting
Hilton’s Law
Nerve that supplies muscles that move a joint also innervates articular branches of said joint and the skin overlying the insertion of the muscle
Hill-Sach’s deformity
- shoulder dislocation → humeral head hits edge of glenoid → Hill-Sachs impaction fracture (can include bleeding in joint)
What can be done when a Hill-Sach’s impaction fracture occurs? Or when a more severe shoulder dislocation occurs?
- arthroscopic repair
- detach ligaments (usually anterior and inferior glenohumeral ligament - which attach to glenoid via glenoid labrum)
- then repair arthroscopically - stops shoulder dislocation
- with recurrent shoulder dislocation - mini open procedure
- similar to shoulder replacement surgery
What can be done to manage humeral head defects?
based on severity of damage
- 20-30%: engaging lesion Bristow or Laterjet
- 33%: osteochondral allograft - transfer infraspinatous rotational osteotomy
- >40%: arthroplasty
Done by surgery via internervous plane b/w teres minor and infraspinatous
- injury usually at the back of the humeral head (posterior)
What can be a consequence of plating the distal radius? How can this complication be fixed?
- screws may rupture extensor pollicis longus
- can be repaired with extensor indicis
De Quervain’s tenosynovitis
- occurs in 1st compartment when extensor pollicis brevis and abductor pollicis longus get inflammed via 1st compartment tunnel
- pain with the Finkelstein test - pressing the thumb into the palm and getting the patient to counter it
- fixed with surgery on radial styloid
How to fix radius and ulna midshaft fracture
-
radius: Henry’s approach ⇒ incision b/w radial styloid and lateral epicondyle (of humerus) → find internervous plane b/w brachioradialis and forearm flexor (flexor carpi radialis) and reflect → find pronator teres and attach plate
- warning! be aware of radial artery - it runs in the same plane
- ulna: find internervous plane b/w flexor carpi ulnaris and extensor carpi ulnaris
