Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”
SHOULDER
Anterior approach: Delto-Pectoral (Evidence by Chin Hsien Wu et al Injury 2011 vs.
deltoid split)
Interneural plane (axillary and medial and lateral pectoral nerves)
Surface markings:

Coracoid process and oblique incision inferiorly between deltopectoral region
Dangers:
1. Musculocutaneous nerve
a. 2-5cm under coracoid and coracobrachialis medially (do not over retract)
2. Axillary Nerve
a. Length of PIPJ to tip of index finger under Coracoid
b. Adduction brings axillary nerve towards joint
3. Brachial Plexus
4. No medial instruments to humeral neck to avoid AVN
Waymarkers:




Cephalic vein
o marks plane between deltoid and pectoralis muscles
o Ligate tributaries and mobilise vessel
Tip of Coracoid
o Lateral side of conjoint tendon is “safe side”
o Conjoint tendon made up from SH of biceps and coracobrachialis
o Proximal extension improves
Leash of vessels at inferior margin of subscapularis
o Lowest safe margin – brachial plexus below
To open joint split subscapularis tendon
o Externally rotate humerus to improve visualisation
Important Notes:


Quadrangular space
o Laterally – humerus
o Medially – Triceps tendon
o Superiorly – Teres minor
o Inferiorly – Teres major
To open joint split subscapularis tendon aided with external rotation
Page 1 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”
Mackenzie Approach to the Shoulder: for access to proximal humerus, rotator cuff and
subacromial space
Muscle splitting
Surface markings:

5cm vertical incision from acromion down line of arm
Dangers:

Axillary nerve – runs 3-7 cm (average 5cm) horizontally distal to acromion
Waymarkers:

Split deltoid in line of fibres – place a suture in apex distally to prevent split
propagation
Important Notes:

Identify axillary nerve before making a 2nd vertical incision distally
Posterior Approach to the Shoulder: glenoid fractures
Interneural plane
Surface markings:


Longitudinal incision along scapular spine
Extending to lateral acromion boarder
Dangers:
1. Axillary nerve - laterally
2. Circumflex Scapular artery – medially
3. Suprascapular nerve supplying infraspinatus – goes around spine of scapular
Waymarkers:



Junction between infraspinatus – multipennate muscle covered in fascia
(Suprascapular nerve) and Teres Minor – a unipennate muscle (Posterior division of
axillary nerve)
Peel off infraspinatus proximately watch for suprascapular nerve
Can gain access to capsule proximately
Important Notes:


Rotator interval – between subscapularis and supraspinatus
Ligaments found in the interval
Page 2 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”


Subscapular bursa
o Communicates with glenohumeral joint via foramen of Rouviere
o Constantly found between superior and middle glenohumeral ligament
Scapula nerve supplies infraspinatus and goes around the scapula spine
Posterior arthroscopic to the shoulder:
Surface markings:



Lateral inferior corner of the acromium
2cm inferior and medial
Soft area aiming for coracoid
Dangers:
1. Axillary nerve - laterally
2. Circumflex Scapular artery - medially
Important Notes:



Rotator interval – between subscapularis and supraspinatus
Ligaments found in the interval
Subscapular bursa
o Communicates with glenohumeral joint via foramen of Rouviere
o Constantly found between superior and middle glenohumeral ligament
HUMERUS
Anterior approach to the humerus: Upper 2/3 of humerus approach can extend
proximately via deltopectoral approach and further access by elevating deltoid anteriorly
Indications:




Open #
Vessel injury
Pathological
Floating elbow
Interneural plane (as Brachialis has dual innervation)
Surface markings:


Lateral side of biceps tendon with arm flexed
Proximal extension into deltopectoral and elevate
deltoid from bone
Dangers: MUST STICK SUBPERIOSTEALLY TO AVOID
NERVES
Page 3 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”
 Radial nerve laterally – identify before brachialis is split
 Ulnar nerve medially
 Musculocutaneous nerve sub biceps

Waymarkers:

Split Brachialis (lateral 1/3 supplied by radius and medial 2/3 by musculocutaneous)
Important Notes:


Distally radial nerve is found between brachioradialis and Brachialis
Cannot extend distally
Anterolateral approach to the humerus: use for radial nerve exploration distal humerus or
shantz pin
Interneural plane
Surface markings:

Lateral to biceps muscle
Dangers:

Radial nerve (and the superficial branch)

Lateral cutaneous nerve of forearm (5cm from
elbow crease)
Waymarkers:




Retract Biceps medially and retract lateral antebrachial cutaneous nerve with it.
Between Brachialis (Radial & musculocutaneous nerve) and Brachioradialis (radial
nerve)
Develop intermuscular plane between these 2 muscles
Brachialis also goes medially with the biceps muscle and tendon
Posterior Approach to the humerus: for inferior 2/3rds of humerus
Stanley 1999 JBJS approach with both splitting and reflection of the triceps
Surface markings:

8 cm proximal to olecranon skirting to the ulnar aspect and continuing 8cm distally
along the ulnar subcutaneous boarder
Dangers:
Page 4 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”


Radial nerve
o nerve crosses posterior aspect of humerus at 20-21 cm proximal to medial
epicondyle and 14-15 cm proximal to lateral epicondyle
o from posterior cord of brachial plexus
o Passing through triangular interval distal to teres major
o Pierces lateral intermuscular septum between brachialis and brachioradialis
Ulnar nerve – decompressed superficially
Waymarkers:
 split fascia between long and lateral head of triceps
 Split the triceps tendon 75% laterally and 25% medially continue distally past the
olecranon for further 6-7cm
 Elevate medial triceps and periosteum over olecranon as single unit continuing over
medial epicondyle
 Laterally subperiosteally elevate the flap, lifting off the triceps attachment from the
olecranon and anconeus from the lateral ulnar
 Reattachment of the soft tissues to the olecranon can occur with suture and drill holes
as required.
 radial nerve found in spiral groove proximately
Lateral Approach to the humerus: for Holsteine Lewis fracture of distal 1/3 of humus with
radial nerve palsy ideal for exploring
Muscle splitting plane
Surface markings:

Lateral supracondylar ridge between brachioradialis in upper 1/3 and ECRL in lower
1/3
Dangers:


Radial nerve pierces lateral septum between proximal 2/3rds and distal 1/3rd
proximately
PIN distally
Waymarkers:



Muscle plane between triceps (radial nerve) and
brachioradialis (radial nerve)
Reflect triceps posteriorly and brachioradialis
anteriorly
Deeper common extensor origin and triceps can be
elevated
Page 5 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”
Important Notes:

DISTAL EXTENSION Interneural plane between aconeus (radial) and ECU (PIN)
ELBOW:
Posterolateral or Kockers Approach to the Radial head:
Interneural interval – between aconeus and ECU
Surface markings:

Lateral epicondyle to end of proximal ulna
Dangers:

PIN – keep arm pronated to prevent injury
Waymarkers:

Aconeus (radial nerve) is fan shaped proximately and vertical distally

ECU (PIN)
Important Notes:

PIN is found between the muscle planes of EDC and ECRL interval
Boyd - Sub aconeus approach to radial head:
Surface markings:

From lateral side of olecranon towards radial styloid (whilst supinated)
Dangers:
Page 6 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”

PIN distance increased by pronation
Waymarkers


Aconeus (radial nerve) is fan shaped proximately and vertical distally
Elevate subperiosteally off ulna until radial head / neck exposed
Medial approach to elbow:
Surface markings:

Anteriorly directly in front of medial epicondyle
Dangers:

Ulnar nerve
Waymarkers:


Lift up corridor anterior to MCL fibres
MCL attached distal to medial epicondyle – access to this must lift off flexors from
epicondyle
Anterior Approach to elbow
Surface markings:



Horizontal skin incision across skin crease
Proximal incision lateral to biceps tendon
Distal incision towards radial styloid
Dangers:




Musculocutaneous nerve – lateral to biceps tendon
Superficial radial nerve – medial boarder of brachioradialis
PIN – Supinator
Brachial artery – medial to biceps tendon
Waymarkers:

Incise supinator ulnarly to find insertion of biceps tendon on proximal radius
Triceps Split
Surface markings:

Start 5cm proximal to olecranon and then curve medially around olecranon to middle
of ulna distally
Page 7 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”
Dangers:



Ulnar nerve dissected out and protected if access is required to medial column
Median nerve – stay subperiosteal anteriorly will protect nerve
Radial nerve – runs 14-15cm proximal to lateral epicondyle as is travels from
posterior to anterior compartments in the arm
Waymarkers:





Incise fascia over midline and split muscle down to olecranon fossa
o Retrograde humeral nail insertion
Identify ulnar nerve and dissect out
Chevron the olecranon making sure the olecranon is mountain shape
Split with an osteotome to aid anatomical reduction after
Subperiosteal elevation laterally and medially allows access to distal 4th of humerus.
Important Notes:

Distally the ulnar nerve is found between the 2 heads of FCU
FOREARM
Volar Approach: Henry’s approach
Interneural plane
Surface markings:

Radial side of biceps tendon to radial styloid
Dangers:




Lateral antebrachial cutaneous nerve
Radial artery and superficial radial nerve – under brachioradialis
(mobile wad) most easily injured as it leaves mobile wad
PIN – enters supinator via arcade of Frohse – this is the most
superior and superficial layer of the supinator muscle
Median nerve – under surface of FDS
Waymarkers:

Develop plane between brachioradialis – the mobile wad (radial nerve) and flexor
carpi radialis (median nerve)
Page 8 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”





Start distal to proximal identify superficial radial nerve under brachioradialis and
ligate branches of radial nerve to aid lateral retraction of brachioradialis
Proximately the bursa on the radial aspect of the biceps tendon can be incised to gain
access (the radial artery lies ulnar side of biceps tendon TAN)
Proximal 1/3
o Keep arm supinated to avoid PIN.
o The supinator is mobilised from ulnar to radial side
Middle 1/3
o Pronate to bring into view pronator teres and incise and mobilise from radially
to ulnar.
Distal 1/3
o Semi supinate arm and elevate periosteum radially to FDS and PQ
Important Notes:



Proximately supinator needs to go ulnarly
Middle Pronator teres can be peeled off radius in neutral position
Distally plane is between FCR and Brachioradialis
Dorsal Approach: Thompson’s Approach
Internervous plane
Surface markings:

Lateral epicondyle to Lister’s tubercle – for access
to proximal 1/3 of radius
Dangers:

PIN
Waymarkers:
Superficial dissection


Proximal 1/3 – ECRB (radial N) & EDC (Pin) plane
Distal 1/3 – ECRB and EPL (Pin) plane
Deep dissection

Proximal 1/3 Must identify PIN as it leaves the Supinator muscle belly in
SUPINATION
o Either dissect nerve out of muscle
o Or Subperiosteally lift supinator off bone to protect nerve
Page 9 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”

Middle 1/3 Abductor pollicis longus and extensor pollicis brevis muscles are retracted
off bone
Important Notes:

PIN usually injured in retraction though 25% actually are in direct contact with the
proximal radius
HIP:
Direct Lateral Approach: Hardinge
Splits gluteus medius distal to superior gluteal nerve
Surface markings:

Longitudinal incision centred over GT and curving posteriorly
Dangers:

Superior gluteal nerve 4-5cm above tip of GT
Waymarkers:





Skin, subcutaneous tissues down to fascia lata
Take GM off GT and go proximately laterally <4cm for access
Extend incision inferiorly through VL
Gluteus minimus is excised off anterior GT
Expose anterior joint capsule and perform T shaped capsulotomy down to fibrous rim
Important Notes:

Leave sufficient cuff on bone to help reattach GM tendon
Anterolateral Approach: Watson Jones
Inter muscular plane
Surface markings:

15cm incision centred over GT
Dangers:

Femoral vessels
Waymarkers:
Page 10 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”





Same approach as Modified Hardinge
Find plane between GM and TFL (both superior gluteal nerve)
Develop this interval and externally rotate hip to find origin of vastus lateralis
Detach abductor mechanism
In front of the joint capsule will lie rectus femoris and psoas which may need
elevating and retracting
Anterior Approach: Smith Peterson – Hoyter Modification
Interneural plane
Surface markings:


ASIS to lateral side of patella for 8-10 cm
Incision can be extended proximately underneath line of ilium
Dangers:



Lateral cutaneous femoral nerve - Hospodar et al 1999
o Passes 1-2cm medial to and inferior ASIS under inguinal ligament
o Anterior to iliacus muscle and superficially onto of TFL fascia
Femoral nerve
o Medial side of Sartorius muscle (forms lateral wall of femoral triangle)
Ascending branch of lateral femoral circumflex artery
o Ligate to avoid excessive bleeding
Waymarkers:







Identify gap between Sartorius (femoral N) and TFL (Superior gluteal N)
Subcutaneous fat will have lateral cutaneous femoral nerve
Incise fascia on medial side of TFL
Detach origin of TFL to develop plane and identify and ligate lateral femoral
circumflex artery
Deeper identify plane between rectus femoris (femoral N) & gluteus medius
(superior gluteal N)
Detach rectus femoris from attachment and retract medially with psoas, GM can go
laterally to expose capsule
Externally rotate hip also to aid this
Posterior Approach (Moore or Southern)
Inter muscular pane splitting of gluteus maximus (inferior gluteal nerve)
Page 11 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”
Surface markings:


Posterior curvilinear approach centred over GT
Can mark this out by flexing hip to 900 and draw a straight line in line with the
femur, when the leg straightens it is now curvilinear
Dangers:




Sciatic nerve – can split look around piriformis to see if there is another branch
Inferior gluteal artery – leaves pelvis under piriformis
Perforating branch of profunda femoris – can be cut whilst releasing gluteus maximus
insertion
Anterior to acetabulum are the femoral vessels
Waymarkers:
Superficial


Split fascia in line with incision to visualise vastus lateralis and gluteus fan shaped
incision proximately
Split maximus in line with its fibres
Deep


Internally rotate hip to place tension on short rotators
Detach piriformis and obturator internus 1cm from femoral insertion.
FEMUR
Lateral
None splits vastus lateralis
Surface markings:

Lateral thigh with leg internally rotated 15 degrees
Dangers:

Perforating vessels of profunda femoris artery – bleeding ++
Waymarkers


Fascia lata
Fascial covering to VL
Page 12 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”


Split VL
Subperiosteal dissection to expose femur
Posterolateral
Interneural plane
Surface markings:

Posterior aspect of femoral condyle up the femoral shaft
Dangers:


Perforating branches of the profunda femoris artery
Superior lateral geniculate artery and vein
Waymarkers



Deep fascia of thigh
Feel intermuscular septum go anteriorly between VL (femoral N) & hamstrings
(sciatic N)
Reach the linea aspera
KNEE
Medial para-patella – relative CI is previous lateral para-patella
None
Surface markings:

5cm above superior pole of patella down to tibial tubercle
(either straight or curvilinear)
Dangers:


Superior lateral geniculate artery
Infra-patella branch of saphenous nerve
o Subcutaneous after leaving fascia lata
Waymarkers
Superficial



Deepen dissection between vastus medialis and quads tendon
Medial arthrotomy medial to patella tendon
Excise fat pad
Deep
Page 13 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”


Reflect patella laterally
If difficult extend incision proximately
Antero-lateral Tibial plateau: Lobenhoffer and Frosch 2010 for knee approaches
None
Surface markings:

Curvilinear incision - Half way between patella tendon and biceps femoris
Dangers:


LCL
Common peroneal nerve behind fibula – head osteotomy increases exposure
Waymarkers



Fascia
Stick subperiosteally and peel off extensor muscle bellies to expose plateau
Horizontal capsulotomy to expose joint
Antero-medial Tibial plateau:
Surface markings:

Curvilinear incision - Half way between patella tendon and MCL
Dangers:


MCL
Saphenous nerve and vein
Waymarkers



Fascia
Stick subperiosteally and peel off extensor muscle bellies to expose plateau
Horizontal capsulotomy to expose joint
Dorsolateral Tibial Plateau:
Surface markings:

Straight incision lateral side of gastrocnemius
Dangers:


CPN – posterior to biceps tendon
Distal extension is 4cm due to anterior tibial artery piercing interosseous membrane
Page 14 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”
Waymarkers



Fascia
Lateral side of gastrocnemius
Peel soleus and popliteus off posterolateral aspect of tibia - subperiosteally
Dorsomedially Tibial Plateau:
Surface markings:

Straight incision medial side of gastrocnemius
Dangers:

Popliteal artery if Subperiosteal dissection not carried out
Waymarkers



Fascia
Medial side of gastrocnemius
Mobalise popliteus muscle subperiosteally.
Posterior Knee: Popliteal fossa
None
Surface markings

Lazy S incision starting proximately over biceps femoris and extending medially over
medial head of gastrocnemius
Dangers



Short saphenous and sural nerve
Common peroneal
Tibial vessels from superficial to deep (nerve, artery, vein)
Waymarkers
Superficial




Find Sural and short saphenous vein distally
Follow vessels into fascia between gastrocnemius heads
Common peroneal nerve proximately
Release medial head of gastrocnemius if more exposure required
Deep

Ligate geniculate vessles to mobilise tibial neurovascaurl structures
Page 15 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”

PCL attachment superior to popliteus (enters capsule via arcuate ligament)
ANKLE
Lateral ankle
None
Surface markings:

Centre incision over fracture make long enough to avoid skin tension
Dangers:



Superficial peroneal nerve – 6-12 cm proximal to tip of fibula from posterior to
anterior (junction between middle and distal 1/3)
Short saphenous vein
Sural nerve runs along posterior aspect of fibula
Waymarkers


Blunt dissection in subcutaneous tissues
Stick to bone and stay subperiosteally when clearing fracture site
Anteromedial ankle
None
Surface markings:

8-10cm incision curving anteriorly centred over anterior 1/3 of malleolus
Dangers:

Saphenous nerve – numbness over medial foot and vein
Waymarkers



Skin flap blunt dissection in subcutaneous tissues
Stick to bone and lift out fracture to expose joint
Longitudinal split to bring screw to bony tip
Posterolateral ankle: - for posterior malleolus fracture size is not necessarily an issue by
note mechanism – if axial or shearing it should be fixed
None
Surface markings:
Page 16 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”



Begin 12cm proximal to lateral malleoli tip
Half way between tendon and fibula
Curve to posterior fibula and then follow peroneal tendons to 2cm below and anterior
to malleolar tip
Dangers:


Sural nerve half way between Achilles and fibula
Deep are the posterior n/v bundles going posterior to the medial malleolus
Waymarkers


Aim to go between muscle bellies of peroneals either side depending on access
Meat to the heal is FHL
Anterior to ankle:
None inter-tendinous all supplied by deep peroneal nerve
Surface markings:

Lateral to EHL is where the anterior tibial artery and deep
peroneal nerve
Dangers:


Anterior tibial artery
Deep peroneal nerve
Waymarkers

Incise fascia and locate EHL – n/v bundle lateral to this
TALUS
Anteromedial approach:
None
Surface markings:

Medial malleolus to navicular N spot
Dangers:




Saphenous nerve and vein
Tibialis posterior tendon attaches onto Navicular
EHL
Medial malleolus can undergo osteotomy to improve access
Page 17 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”
Waymarkers

Straight down to capsule onto bone
Anterolateral approach:
None
Surface markings:

Fibula to 5th metatarsal base
Dangers:

Peroneal nerves
Waymarkers


Down to peroneus brevis
Anteriorly through capsule
Posterior para Achilles approach:
None
Surface markings:

Medial of lateral side to Achilles tendon
Dangers:


Medially
o Posterior tibial artery and nerve
Laterally
o Sural nerve
Waymarkers

Straight down to achilles fat pad then capsule onto bone
CALCANEUM
Posterolateral:
Medial approach:
None
Surface markings:
Page 18 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”



Junction of sole to lateral skin of the foot extending proximately half way between
fibular and achilles
Keep angle of flap >1000
Full thickness flap elevate off bone
Dangers:


Peroneal tendons
Sural nerve proximately
Waymarkers

Straight down onto bone
Surgical approach for assessing limb alignment: Buckley et al 2011 showed a 50%
malrotation in the MIPO technique despite every effort being made intra-operatively
Leg length

Prep both legs and check leg length
Varus/valgus (coronal)

Centre of the femoral head to centre of the knee to centre of the ankle (>100 correct)
Recurvatum (sagittal)


Excessive notch on AP confirms recurvatum
Place drapes under distal femur to allow flexion of distal femoral condyles
Rotation



Flex knee and check IR and ER for symmetry
Symmetry of foot position with leg straight
Lesser trochanter sign
o IR increases size (LT is a Anteromedial structure)
Surgical exposure for IM nailing
Humeral nailing:


Antegrade via deltoid and supraspinatus splitting
o Modern nails go through articular cartilage
o Axillary nerve damaged with locking screws best done via open approach
Retrograde via triceps muscle splitting approach down to olecranon fossa – excise fat
o Radial nerve damaged in distal locking screws best avoided via open
dissection down to bone
Page 19 of 20
Notes on anatomy surgical exposure
“Anatomy without clinical is dead. Clinical without anatomy is deadly”
Tibial nailing:


Must be midline entry no evidence parapatella is better than transpatella
Anatomical studies show
o 30% of time lateral meniscus damaged
o 20% of time nail is intra-articular
Femoral nailing:


Antegrade via GT or piriformis fossa
o Incise 5-7cm proximal to GT
Retrograde with knee flexed 30-600
o Through patella tendon nail inserted through femoral trochlear 7-15% of
articular surface destroyed
o Can use in intra-articular fractures by fixing intra-articular fragment first
Page 20 of 20