Surgical Anatomy - Upper Limb

Front 1

Describe the landmarks and incision for an anterior approach to the shoulder

Back 1

1. Coracoid process - 1 in below the jct of the middle & outer 1/3 of the clavicle.
2. Deltopectoral groove - sometimes easier to see that feel.
3. Incision - Distally from above the coracoid distally centred over deltopectoral groove. Can also be approached by an axillary incision.

Front 2

What are the structures encountered in superficial dissection in the anterior approach to the shoulder?

Back 2

1. Skin
2. Subcutaneous fat.
3. Superficial layer of muscles: Deltoid[axillary n] and pectoral m [medial and lateral pectoral n]. The cephalic v lies in the groove between them. Utilise this internervous plane

Front 3

Describe the deep dissection associated with the anterior approach to the shoulder.

Back 3

1. Coracoid process + short head of biceps/ coracobrachialis is revealed in the early part of dissection.
2. Osteotomy of the coracoid and retract the coracobrachialis and short of biceps medially. Remain on the lateral side of the m (NV bundle and musculocutaneous n lie medially)
3. Now revealed is the subscapularis m. Incise the tendon 1in from insertion onto the lesser tuberosity. Remember to externally rotate the arm to increase the distance between the inferior border and the axillary n.

Front 4

What are the main NV dangers in the anterior approach to the shoulder ?

Back 4

SUPERFICIAL
1. Cephalic v - lies in the deltopectoral groove - retract either with the deltoid or pectoralis whilst developing the interval between them.

DEEP
1. Main NV bundle arm - lies medially and below the coracoid process - abducting arm brings these structures right against the coracoid, makes it dangerous when performing an osteotomy. Keep arm adducted.
2. Musculocutaneous n - enters medial side of the coracobrachialis - i.e. stay on the lateral side of the m while dissecting.
3. Axillary n - at the inferior border of the subscapularis. I.e. externally rotate the arm to increase distance btw the inferior border of the m and the nerve.

Front 5

Describe the landmarks and incision for the posterior approach to the shoulder ?

Back 5

1. Landmarks - Spine of the scapula and acromion
2. Posterior approach - Linear along the length of the scapular spine.

Front 6

What are the structures encountered in superficial dissection in the posterior approach to the shoulder?

Back 6

1. Skin
2. Superficial fat - no major sup N + V
3. Deltoid m - Detach the deltoid from the scapular spine and rotate it downwards.

Front 7

Describe the deep dissection associated with the posterior approach to the shoulder.

Back 7

1. First layer revealed in superficial dissection is the infraspinatus (suprascapular n) and teres minor m (posterior division of the axillary n).
2. Develop the interval between teres minor and the infraspinatus m.
3. Reach the posterior aspect of the glenoid cavity + scapular neck: incise the capsule for access to the joint.

Front 8

What are the main NV dangers in the posterior approach to the shoulder ?

Back 8

Most of the NV dangers are at the inferior border of the teres minor, most of these dangers can therefore be avoided by staying in the right plane.

1. Axillary n and posterior circumflex humeral a - between teres minor and major (above and below) and the long head of triceps / surgical neck of the humerus (medially and laterally)

2. Circumflex scapular a (subscapular a br) lies below teres minor (medial to the long head of the triceps.

3. Suprascapular n - runs around the base of the scapular spine from supra to infraspinous fossa. Can be impinged against scapula by over excited retraction of the infraspinatus medially.

Front 9

What are the landmarks and skin incision for the anterior approach to the AC joint and subacromial space?

Back 9

1. Landmarks - coracoid process and acromion
2. Incision - lateral corner of the acromion --> Just lateral of the coracoid.

Front 10

Describe the process of superficial dissection in the anterolateral approach to the subacromial space.

Back 10

1. Skin incision
2. Subcutaneous fat
3. Fibres of the deltoid: Incise these fibres longitudinally starting at the AC joint. Do not extend the split any more than 5 cm below the AC joint. Put stay sutures in the muscle split to avoid inadvertent distal tearing. This is to avoid damage to the axillary n.
4. Detach the deltoid from the AC joint and the acromion also.

Front 11

Describe the deep surgical dissection associated with the approach to the subacromial space.

Back 11

1. Detach the coracoacromial ligament at both ends of its attachment.
2. This manouvre exposes the supraspinatus m and its bursa.

Front 12

What are the dangers with the approach to the subacromial space?

Back 12

N -
Axillary n lies 5 cm below the acromion as it winds around the surgical neck of the humerus.

V -
Acromial branch of the thoracoacromial artery lies deep to the deltoid m and is damaged in incising the deltoid.

Front 13

What are the different approaches available to expose the humerus ?

Back 13

Anterior
Anterolateral approach to the distal humerus
Posterior
Lateral approach (distal humerus)

Front 14

What are the landmarks and incisions used for access in the anterior approach to the humerus ?

Back 14

1. Landmarks
- Coracoid process
- Long head of the biceps
- Lateral border of the biceps m.

2. Incision
- Proximal - along the deltopectoral groove.
- Distal - along the lateral border of the biceps m.

Front 15

What internervous planes are used in the anterior approach to the humerus ?

Back 15

1. Proximal - btw deltoid (axillary n) and pectoralis major m (medial and lateral pectoral n)
2. Distal - Between the medial and lateral halves of the brachialis m (i.e. between the radial and musculocutaneous n)

Front 16

Describe the superficial surgical dissection in the anterior approach to the humerus.

Back 16

1. Skin
2. Superficial fascia - Main danger is the cephalic vein.
3.Proximal- Develop the interval between the pectoralis major and the deltoid m. Develop this interval as far distally as possible.
4. Distal - develop the interval between the brachialis and the biceps brachii.

Front 17

Describe the deep dissection in the anterior approach to the humerus

Back 17

1. Proximal - cut the periosteum at the lateral margin of the pectoralis major insertion into the humerus. Continue incision proximally along the lateral border of the long head of the biceps.

2. Distal - incise the middle of the brachialis in line with its fibres - down to the bone.

Front 18

What are the dangers of dissection in the anterior approach to the humerus

Back 18

1. Proximal -
- Anterior circumflex humeral vessels - pass transversely across the humeral shaft deep to the deltoid. Where you want to incise the periosteum. Cannot avoid ligating them.
- Axillary n - lies on the undersurface of the deltoid m.

2. Distal -
- Musculocutaneous n (lies between the biceps brachii and brachialis), develop this interval with blunt dissection.
- Radial n - in danger in 2 main places during this approach.
i) In the spiral groove (middle 1/3 of the humeral shaft) - in danger from pins applied in the AP direction with anterior plates.
ii) Anterior compartment of the arm - it lies btw the brachialis and brachioradialis once it pierces the IM septum (incise the brachialis in the middle - use the m as a cushion between the retractor and the nerve.

Front 19

Describe the process of the minimal access approach to the anterior humeral shaft.

Back 19

Develop a proximal window and distal window
1. Proximal window - develop the interval of the deltopectoral groove. Develop the interval down to the bone remaining at the lateral border of the long head of the biceps m.

2. Distal window - develop the interval between biceps brachii and brachialis. Incise the middle of brachialis in line with the m down to bone.

3. Connect the 2 windows through blind dissection in an epiperiosteal plane - remain close to the anterior surface of the bone. Can work through both windows till they meet each other.

Front 20

Describe the dangers of surgical dissection in the minimal acess approach to the anterior humeral shaft.

Back 20

PROXIMAL
- Anterior circumflex humeral vessels - wind around the upper 1/3 of the humerus - deep to the interval between pec major and deltoid.


DISTAL
- Radial n - lies btw brachialis and brachioradialis
- Musculocutaneous n - lies medially btw biceps brachii and brachialis.
- Incise the middle of the brachialis to avoid drama with any of the nerves.

Front 21

Describe the superficial dissection in the anterolateral approach to the distal humerus.

Back 21

1. Skin
2. Superficial fascia - identify the MC nerve piercing the deep fascia above the level of the elbow: avoid damaging it.
3. Incise the deep fascia - along the lateral border of the biceps.
4. Retract the biceps brachii medially; exposing underlying brachialis m.
5. Develop the interval between the brachialis and the brachioradialis next. (Radial n lies in the slit and should be dissected out)

Front 22

Describe the deep dissection in the anterolateral approach to the distal humerus

Back 22

1. Staying medial to the radial n; incise the brachialis m lateral part. Keep going until you reach bone.
2. Incise periosteum then strip brachialis off the front of the distal humerus subperiosteally.

Front 23

What are the major NV dangers in the anterolateral approach to the humerus and how do we avoid these ?

Back 23

Nerves mainly endangered
1. MC nerve - between biceps and brachialis. In danger in initial mobilisation
2. RADIAL N - btw biceps and brachioradialis - follow this upwards to where it pierces the IM septum.

Front 24

Describe the superficial dissection in the posterior approach to the humerus

Back 24

1. Skin
2. Superficial fascia
3. Deep fascia
4. Divide superficial part of triceps (i.e. separate the lateral and long heads) - above this can be done by blunt dissection and below this needs to be done with sharp dissection.
5. This reveals the medial head of the triceps and the Radial n + profunda brachii in the groove between medial and lateral heads.

Front 25

Describe the deep dissection in the posterior approach to the humerus

Back 25

Split the medial head in line with its fibres to expose the posterior aspect of the humerus. Strip the medial head from the bone in an epi-periosteal plane.

Front 26

What are the major NV dangers in the posterior approach to the humerus and how do we avoid these ?

Back 26

1. Radial n
- In the spiral groove it is vulnerable
- If it is identified in the groove between lateral and medial heads it is safe to proceed.

2. Ulnar n
- Lies between medial head and IM septum
- Keep in an epiperosteal plane during deep dissection to avoid damaging the nerve.

Front 27

Describe the superficial dissection the lateral approach to the distal humerus.

Back 27

1. Skin
2. Superficial fascia
3. Deep fascia - incise the fascia btw triceps and brachioradialis
4. Develop the 'internervous plane' between the brachioradialis and triceps: to the bone.

Front 28

Describe the deep dissection in the lateral approach to the distal humerus ?

Back 28

1. Remove triceps m fibres from humerus if further exposure is required of the humerus.
2. Remove common extensor origin from the lateral epicondyle if further exp is needed.

Front 29

What NV structures are in danger in the lateral approach to the distal humerus ?

Back 29

RADIAL N
1. Pierces the lateral IM septum in the distal 1/3 of the arm. (I.e. lies in the ant compt of the arm)
2. Avoid the n by avoiding extension of dissection proximally.

Front 30

Describe the landmarks used for the incision in the posterior approach to the elbow.

Back 30

LANDMARKS
1. Olecranon

INCISION
1. 5cm above olecranon
2. Change direction so it passes along the lateral side of the olecranon.
3. Curve the line medially back to subcut border of the ulna

Front 31

Describe the superficial dissection involved in the posterior approach to the elbow.

Back 31

1. Skin
2. Superficial fascia
3. Cut the deep fascia over the ulnar n - mobilise this nerve fully.
4. Osteotomise the olecranon process.

Front 32

Describe the deep dissection involved in the posterior approach to the elbow.

Back 32

1. Free the attachments from the medial and lateral sides of the olecranon.
2. Reflect olecranon osteotomy superiorly - exposing posterior aspect of elbow joint and the distal humerus.
3. Dissect subperiosteally around the humerus to expose all surfaces of the humerus.

Front 33

Describe the main NV dangers in the posterior approach to the elbow.

Back 33

NERVES
1. Ulnar n - always dissect the nerve out from its posn behind medial epicondyle (to protect it.
2. Radial n - pierces the lat im septum and is related to the middle 1/3 of the post aspect of the humerus. Avoid damage by keeping dissection below the lower 1/4 of the humerus.
3. Median n - lies in front of distal humerus - avoid damage to the n by dissecting m away from bone in a subperiosteal plane.

Front 34

What are the landmarks for the incision in the medial approach to the elbow.

Back 34

Curved incision centred on the medial epicondyle.

Front 35

Describe the superficial dissection involved in the medial approach to the elbow.

Back 35

1. Skin
2. Supeficial fascia - be aware of the anterior and posterior branches of the medial cutaneous n of the forearm.
3.Incise the deep fascia over the ulnar n and dissect this n out fully. Retract fascial flaps.
4. Develop the IN plane between the brachialis (mc nerve) from the pronator teres (median n)
5. Create an osteotomy of the medial epicondyle and retract this laterally with the common flexor tendon to reveal the underlying brachialis tendon.

Front 36

Describe the deep dissection associated with the medial approach to the elbow.

Back 36

1. Retract Brachialis from front of elbow joint capsule
2. Cut elbow joint capsule to expose the internal apsect of the joint.

Front 37

Describe the dangers in the medial approach to the elbow

Back 37

1. Nerves
* Ulnar n - lies behind the medial epicondyle and is at risk when osteotomising the medial epicondyle. Avoid danger by mobilising the nerve from behind the epicondyle early.
2. Median n - passes between the 2 heads of pronator and can be damaged if the flexor pronator group is pulled too rigorously laterally to expose underlying brachialis.

Front 38

What are the landmarks and incision for the lateral approach to the radial head?

Back 38

LANDMARKS
1. Radial head
2. Lateral epicondyle of humerus
3. Ulna subcutaneous border

INCISION
1. Lateral epicondyle ->> Subcutaneous border of ulna 6cm distal to the tip of the olecranon

Front 39

What is the superficial dissection associated with the lateral approach to the radial head ?

Back 39

1. Skin
2. Superficial fascia
3. Deep fascia
4. Develop the interval between the anconeus and the ECU muscle
5. Reveals the supinator m.

Front 40

What is the deep dissection associated with the lateral approach to the radial head?

Back 40

Incise the supinator m from its ulnar origin to expose the radial head which it wraps around.

Front 41

What NV dangers are associated w/ the lateral approach to the radial head ?

Back 41

PIN is the major danger.
Lies in the substance of the supinator as it winds around the neck of the radius.

Avoid danger by
1) Pronating forearm - taking the nerve as far away from the incision as possible
2) Do not incise distal to the annular ligament

Front 42

What are the landmarks and incision for the anterolateral approach to the elbow?

Back 42

LANDMARKS
1. Brachioradialis
2. Biceps tendon

INCISION
1. Above elbow - along lateral border biceps
2. Across elbow - obliquely across skin flexion line
3. Below elbow - along medial border of Brachioradialis n

Front 43

What are the steps in the superficial dissection in the anterolateral approach to the elbow?

Back 43

1. Skin
2. Superficial fat - Watch out for the lateral cutaneous n of the forearm as it pierces the fascia lateral to the biceps tendon.
3. Deep fascia - Cut the deep fascia along the medial border of the brachioradialis
4. Develop the plane between -
I) BR + Pronator teres - distally
II) BR + Brachialis - proximally.

5. Reveals
i) Supinator (Distally)
ii) Anterior aspect of humerus and elbow joint (Proximally)

Front 44

What are the steps in deep dissection, in the anterolateral approach to the elbow?

Back 44

1) Detach the supinator from bone to expose proximal radius
2) Cut through periosteum and elbow joint capsule to expose distal humerus.

Front 45

What are the NV dangers of the anterolateral approach to the elbow ?

Back 45

The main dangers are:
1) Radial nerve
2) Posterior interosseus n
3) Lateral cutaneous n of the arm
4) Radial recurrent a (Deep to brachialis - must be ligated to avoid haematoma formation)

RADIAL N
1. Radial n: lies in the IM interval between the BR and the brachialis
2. Must be identified before this interval is fully developed.

PIN
1. Winds around neck of radius within supinator
2. Protect by removing supinator from the radius at its anterior attachment - fully supinate the forearm to reveal this.
3. Remove the rest of the m from bone in the subperiosteal plane.

LATERAL CUTANEOUS N OF FOREARM
1. Identify the nerve at the lateral border of the biceps tendon and follow it proximally to the MC nerve lying between the brachialis and biceps.

Front 46

What are the landmarks and incision for the dorsal approach to the wrist.

Back 46

LANDMARKS
1. Radial styloid
2. Ulnar styloid

INCISION
1. 8cm incision on the dorsum 1/2 way between radial and ulnar styloids.

Front 47

What is the superficial dissection associated with the dorsal approach to the wrist ?

Back 47

1. Skin
2. Superficial tissues - subcutaneous fat
3. Extensor retinaculum is now exposed.

Front 48

What is the deep dissection associated with the dorsal approach to the wrist?

Back 48

1. Incise extensor retinaculum over extensor digitorum communis tendons.
2. Separate tendons of this compartment to reach dorsal radiocarpal ligament
3. Incise dorsal radiocarpal ligament; elevate the ligament and the extensor tendons are elevated from the back of the radius to expose the distal end of the bone and the carpals.

Front 49

What are the NV dangers of the dorsal approach to the wrist ?

Back 49

SUPERFICIAL
1. Superficial branch of radial n: pierces deep fascia behind BR just above wrist.
* Incision usually lies between this n and the dorsal cutaneous br of the ulnar n.
* Protect n by taking incision to extensor retinaculum and then incising it to create the flaps that are elevated.

DEEP
1. Radial a
* Lies in relation to the lateral aspect of the wrist joint.
* Stay in a subperiosteal plane to avoid damage to this structure.

Front 50

What are the landmarks and incision for the volar approach to the wrist ?

Back 50

LANDMARKS
1. Thenar crease - @ the base of the thenar eminence.
2. Transverse skin crease of wrist joint.
3. Tendon of palmaris longus

INCISION
1. Just ulnar to the thenar crease
2. At wrist curve incision to the ulnar side of forearm to avoid crossing flexion crease at right angles.
3.

Front 51

Describe the superficial dissection associated with the volar approach to the wrist ?

Back 51

1. Skin
2. Superficial fascia - watch out for palmar cutaneous br of median n
3. Palmaris longus lying in front of the transverse carpal ligament (Flexor retinaculum)
4. Incise the ligament to open the carpal tunnel.
5. Retract median n laterally; FDS tendons medially to expose the anterior aspect of wrist joint capsule.

Front 52

Describe the deep dissection associated with the volar approach to the wrist.

Back 52

1. Incise the capsule of the wrist joint and elevate this off bone in the radial and ulnar directions.

Front 53

What are the NV dangers of the volar approach to the wrist ?

Back 53

SUPERFICIAL
1. Palmar cutaneous br of median n - runs downwards along the medial border of the FCU tendon to the wrist.
* Avoid danger by carrying incision to the ulnar side of the forearm.

DEEP
1. Median n
2. Superficial palmar arch

Median n
1. Most superficial structure in carpal tunnel. Particularly motor branches which leave its thenar side just distal to the retinaculum.
2. Avoid damage by cutting retinaculum nearer to the ulnar side.

Superficial palmar arch
1. Lies across the palm at the distal level of the outstretched thumb
2. Avoid damage by not taking incision of flexor retinaculum too far distally.

Front 54

Describe the exposure of the median nerve in the carpal tunnel.

Back 54

Same as the superficial dissection in the volar approach to the wrist
1. Skin
2. Superficial fascia - avoiding palmar cutaneous br of the median n.
3. Flexor retinaculum (with palmaris longus overlying it) : incise it near its ulnar border
4. Exposure of median n within carpal tunnel

Front 55

Describe how the median n can be accessed in the forearm?

Back 55

LAYERS OF DISSECTION

1. Skin
2. Superficial fascia
3. Deep fascia
4. Muscle 1: Palmaris longus retracted in ulnar direction >> reveals underlying FDS.
5. Muscle 2: Lift FDS upwards from its medial side; the median nerve is stuck to the undersurface of the m by connective tissue.

Front 56

Describe the landmarks and incisions in the approach to the ulnar n @ the wrist.

Back 56

LANDMARK
1. Transverse skin crease of the wrist
2. Hypothenar eminence

SKIN INCISION
1. Curved incision following the radial border of the hypothenar eminence
2. Crosses skin crease at wrist at 60 degrees.
3. Continues up into the volar aspect of the forearm.

Front 57

What is the approach to dissection of the ulnar n @ the wrist?

Back 57

1. Skin
2. Superficial fascia - deepen in line with skin incision.
3. Expose the FCU tendon in the proximal part of the wound
4. Incise fascia on the radial border of the FCU tendon and find the ulnar n + artery here.
5. Follow artery and n distally - incise overlying volar carpal ligament. Nerve in the canal of guyon is now decompressed.

Front 58

How do we avoid complications in the approach to the ulnar n @ the wrist ?

Back 58

Be careful during -
1. Incising fascia at radial border of the FCU tendon.
2. Incising volar carpal ligament to expose nerve + vessel.

Front 59

How can we expose the ulnar nerve in the forearm?

Back 59

1. Skin incision - curved - overlying palmaris longus
2. Superficial fascia - deepen incision in line with skin
3. Deep fascia - in line with skin incision
4. Muscle layer
* Retract FCU in an ulnar direction and the underlying FDS radially
* This manouevre should reveal the ulnar n + vessels lying on the underlying FDS.

Front 60

What is the canal of guyon and what are its boundaries ?

Back 60

Canal through which the ulnar n passes through at the wrist.

BOUNDARIES
1. Floor - flexor retinaculum
2. Lateral wall - hook of hamate
3. Medial - pisiform
4. Roof - thickened fascia of volar carpal ligament.

Front 61

What is the incision for the volar approach to the flexor tendons of the finger ?

Back 61

Zig zag approach
LANDMARKS
* Interphalangeal creases (just proximal to the joints)

INCISION
* Cut across the phalanges in a diagonal incision
* Make sure incision lines are at least 90 degrees to each other; any narrower = endangers skin at the corners

Front 62

What is superficial dissection necessary in the volar approach to the flexor tendons of the finger ?

Back 62

1. Skin
2. Superficial fascia - if skin incision is very far dorsally on the medial / lateral aspects of the finger then the NV bundle is at direct risk during dissection.Otherwise it is at risk as we dissect fat away from the fibrous tissue laterally. Be sure to identify and preserve the bundles.

Front 63

What are the zones of the flexor tendons in the hand ? In which zone is tendon injury the most dangerous ?

Back 63

Zone 1 - FDP tendon in flexor sheath just before insertion

Zone 2 - FDP + FDS tendon in flexor sheath just before insertion of FDS

Zone 3 - Hands where the lumbricals originate from the FDP tendons.

Zone 4 - Carpal tunnel

Zone 5 - distal forearm

Injury to tendons in zone 2 is associated with the worst prognosis - this is because 1) it is a fixed rigid space and 2) Function requires tendons to be able to glide over one another which may not occur with scarring.

Front 64

What are the pulleys in the flexor tendon sheath in the hand ?

Back 64

Pulleys are thickenings in the fibrous flexor sheaths that hold down the flexor tendons.

There are annular pulleys and cruciate pulleys

A1 - A4:
* A1 - MCP joint
* A2 - Proximal end of proximal phalanx
* A3 - PIP joint
* A4 - Middle of middle phalanx

C1 - C3
* C1 : distal end of proximal phalanx
* C2 : proximal end of middle phalanx
* C3 - distal end of middle phalanx.

Front 65

Describe the incision and dissection in the mid lateral approach to the flexor tendons in the fingers.

Back 65

INCISION
* Flex the finger completely
* Connect the distal ends of the interphalangeal creases with one another.

DISSECTION
1. Skin
2.Superficial fascia - dissect perpendicularly straight to bone. Expose the NV bundle in the anterior flap and preserve it. The dorsal branch of the nerve /artery lies in the dorsal flap
3. Incise the fibrous flexor sheath longitudinally to expose the flexor tendons.

Front 66

Describe the landmarks and skin incision for the volar approach to the scaphoid

Back 66

LANDMARKS
* Tuberosity of the scaphoid (Felt just distal to the distal skin crease for the wrist joint)
* FCR tendon (lateral to the palmaris longus)
* Radial pulse (lateral to the FCR tendon)

INCISION
* Start at scaphoid tubercle
* Extend proximally between the FCR + radial artery

Front 67

Describe the superficial dissection in the volar approach to the scaphoid.

Back 67

1. Skin
2. Superficial fascia - watch out for the palmar cutaneous br of the median n (medial to FCR)
3. Deep fascia - incise lateral to the FCR tendon
4. Deep tissues - retract the Radial artery w/ lateral skin flap. Dissect out the FCR from where it pierces the flexor retinaculum; retract it medially. This set of manouvres exposes the volar aspect of the wrist joint.

Front 68

Describe the deep dissection in the volar approach to the scaphoid.

Back 68

Incise the wrist joint capsule and dorsiflex the wrist to expose the scaphoid.

Front 69

Describe the neurovascular dangers in the volar approach to the scaphoid

Back 69

NERVES
* Superficial palmar cutaneous br of the median n is endangered if you stray medial to FCR
* Deeper: median n lies medial to the FCR above wrist.

VESSELS
* Radial a lies in the lateral part of the incision - identify it early to avoid damage.

Front 70

Describe the landmarks and skin incision for the dorsolateral approach to the scaphoid

Back 70

LANDMARKS
1. Radial styloid
2. Anatomical snuffbox
3. Base of the 1st MC

INCISION
1. Start @ base of 1st MC
2. Curve incision over snuffbox
3. End incision 3cm above snuffbox

Front 71

Describe the superficial dissection in the dorso-lateral approach to the scaphoid.

Back 71

1. Skin
2. Superficial fascia - watch out for superficial radial n which crosses snuffbox.
3. Deep fascia - identify EPL, EPB and abductor pollicis brevis deep to fascia - incise the deep fascia over the drop box.
4. Deep tissues - retract the EPL dorsally and the EPB ventrally to reveal radial artery + dorsal carpal branches, Retract the artery out of the way.

Front 72

Describe the deep dissection in the dorso-lateral approach to the scaphoid.

Back 72

Superficial dissection exposes the dorsal aspect of the radiocarpal joint capsule.

Front 73

Describe the neurovascular dangers in the dorsolateral approach to the scaphoid

Back 73

NERVES
* Superfical radial n - overlies the EPL tendon and snuffbox and should be dissected and preserved.
VESSELS
* Radial a - avoid the a, its dorsal carpal branch. Also be aware that most branches enter the scaphoid from the dorsal aspect and need to be preserved.

Front 74

Detail the drainage of paronychia

Back 74

Paronychia is infection of the nail fold. Usually represents pus stuck between the cuticle and the nail base. Some may be between the nail bed and nail.

Incise skin longitudinally @ the lateral border of the nail. Elevate skin flaps, i.e. develop the space between cuticle and nail base. Drain puss as appropriate. Remove half the nail to drain pus deep to the nail itself if necessary.