Clinical Anatomy of the Upper Limb

Question 1

What are the regions of the upper limb as defined by a five year old?

Answer 1

• Shoulder
• Arm
• Elbow
• Wrist and hand

Question 2

What approach should one take when applying clinical knowledge of the upper limb?

Answer 2

• History
• Examination
• Investigation
• Management

Question 3

Suggest a diagnosis for the following case study:
• 25 year old male
• Playing rugby
• Injured whilst tacking another player
• Brought into Emergency Department for assessment
• Arm outstretched during tackle
• Upon impact felt “pop” and severe pain
• Says he can’t move his arm
• No PMH, DH, FH
• Look: Asymmetry of shoulders, no rounded contour
• Feel: Tender on palpation
• Move: Very painful to move,
unable to abduct
• Neuro: Able to move hand, skin of lateral shoulder numb

Answer 3

• Anterior dislocation of the glenohumeral joint
• Risk factors
• Repeated shoulder stress
• High energy injuries eg trauma
• Abducted, externally rotated, extended
shoulder
• Genetics e.g. ligamentous laxity 
• Previous dislocation

Deltoid doesn’t work + insignia patch numbness = damage to radial nerve

Question 4

What stabilises the shoulder joint?

Answer 4

• Tone of the rotator cuff muscles
• Ligaments and tendons (coracoacromial ligamnet, coracohumeral ligamnet, glenohumeral ligamnets)
• Glenoid labrum

Question 5

How does one manage a anterior dislocation of the glenohumeral joint?

Answer 5

• Analgesia
• Closed reduction
• Possibly surgery

Question 6

Suggest a diagnosis for the following case study:
• 25 year old male
• Brought to Emergency Department after a seizure • Very painful right shoulder which he can’t move
• Anteroposterior X-ray shows light bulb shape at proximal head of humerus

Answer 6

Posterior shoulder dislocation

Very common after seizures

Question 7

Suggest a diagnosis for the following case study:
• 18 year old male
• Had a pint at the union
• A few pints
• Challenges this guy to an arm wrestle
• Presents to Emergency Department with arm pain
—–
History
—–
• Arm wresting the Rock
• Shoulder and elbow flexed
• Performing internal rotation against resistance • Forced into external rotation
• Felt a sudden “crack”
• Immediate pain
• C/O swollen, painful arm • Notes hand is floppy
—–
• Look: arm bruised, swollen, deformed
• Feel: tender with a palpable step
• Move: able to move at shoulder and elbow, unable to extend wrist
• Neuro: 1st dorsal web space numb
• X ray shows fracture with most distal point of fracture on proximal half of the humerus notably distal to the most proximal point of fracture and vice versa

Answer 7

• Spiral fracture of mid-shaft humerus
• Rotational injury

He may not be able to extend his wrist due to radial nerve entrapment due to fracture
And so may be numb due to the superficial branch of the radial nerve no longer supplying the dermatome of the thumb + 2 1/2 fingers

As triceps function despite radial nerve supplying extensors then damage must be midshaftish as triceps brachii nerve supply branches off very proximally on the humerus

Therefore:

• Spiral fracture of mid-shaft humerus with radial nerve entrapment

Question 8

How does one manage spiral fracture of mid-shaft humerus with radial nerve entrapment?

Answer 8

• Analgesia
• Humeral brace
• Surgery
• Physiotherapy

Question 9

Suggest a diagnosis for the following case study:
• 4 year old girl
• Holding mum’s hand about to
cross the road
• They start to cross when a car suddenly cuts in front of them
• Mum pulls on her arm to save her
• Since incident girl is complaining of pain and not using the arm

• Sharp sudden pull to right arm
• Complaining of pain in right arm but cannot localise where
• Most of the history from mum – child not keen to engage
• Look: No obvious deformity. Watch child play with toys, right arm held against side, does not use this arm
• Feel: Tender to palpation at lateral elbow
• Move: Painful to pronate/supinate
• Neuro: Intact as best can tell

Answer 9

• Pulled elbow
• Dislocation/subluxati
on of radial head
• Investigations?
• Clinical diagnosis
• X-ray not usually required
• If concern for other injury (e.g. fracture) - x-ray

Question 10

How would one manage a pulled elbow + dislocation/subluxati

on of radial head

Answer 10

• Closed reduction
• Two methods
• Supination technique
• Hyper-pronation technique
• If successful
• Re-examine patient in 30
mins
• Pseudo-paralysis should resolve
• If unsuccessful • Re-evaluate
• X-ray
• Refer to Orthopaedics

Question 11

Suggest a diagnosis for the following case study:
• 57 year old female
• Presented to the GP with worsening issues with left hand

• Experiencing tingling, burning pain and numbness in left hand
• Notes this in her thumb, index and middle finger
• Lateral 3 fingers
• Progressively worsening over 6
months
• Professional pianist
• Symptoms often wake her at night

• Look: wasting at thenar eminence
• Feel: decreased muscle bulk
• Move: no deficit
• Neuro: weak grip and thumb, sensation altered over lateral 3.5 fingers, palm spared
• Special tests: Tinel’s and Phalen’s tests positive

Answer 11

• Carpal tunnel syndrome
  
  • Median nerve

Why is there weakness?
• 1⁄2 LOAF muscles:
• Lateral 2 lumbricals
• Opponens pollicis
• Abductor pollicis brevis
• Flexor pollicis brevis

Why is there numbness?
Median nerve supplies dermatome of over 1/2 of the palm and tips of fingers
So why is the palm spared?
Because the palmar cutaneous branch of the median nerve splits from the median nerve before it enters behind the transverse carpal ligament

Question 12

What is Tinels test?

Answer 12

It is performed by lightly tapping (percussing) over the nerve to elicit a sensation of tingling or “pins and needles” in the distribution of the nerve

When the nerve is not trapped behind a structure there will be a negative test and the patient will feel no pain. On the opposite when the nerve is trapped the patient will feel tingling’s in the distal area

Question 13

What is Phalens test?

Answer 13

a diagnostic test for carpal tunnel syndrome

The patient is asked to hold their wrists in complete and forced flexion (pushing the dorsal surfaces of both hands together) for 30–60 seconds. The lumbricals attach in part to the flexor digitorum profundus tendons. As the wrists flex, the flexor digitorum profundus contracts in a proximal direction, drawing the lumbricals along with it. In some individuals, the lumbricals can be “dragged” into the carpal tunnel with flexor digitorum profundus contraction. As such, Phalen’s maneuver can moderately increase the pressure in the carpal tunnel via this mass effect, pinching the median nerve between the proximal edge of the transverse carpal ligament and the anterior border of the distal end of the radius. By compressing the median nerve within the carpal tunnel, characteristic symptoms (such as burning, tingling or numb sensation over the thumb, index, middle and ring fingers) conveys a positive test result and suggests carpal tunnel syndrome. Because not all individuals will draw the lumbricals into the carpal tunnel with this maneuver, this test cannot be perfectly sensitive or specific for carpal tunnel syndrome.

Question 14

Suggest a diagnosis for the following case study:
• Experiencing tingling, burning pain and numbness in lateral 3 fingers of right hand
• Palm is affected
• Also ache in proximal volar forearm
• Worst when using a screwdriver

Answer 14

• Diagnosis: Pronator Syndrome

Median nerve course
• Can get impinged in other places
• Passes between humeral and ulnar heads of pronator teres muscle

Question 15

How would one manage pronator syndrome?

Answer 15

• Conservative
  
  • Splints
  • Physiotherapy
  • Analgesia
• Surgery