C14 -T

Question 1

Blood supply to the talus

Answer 1

1. Posterior Tibial Artery
   
   1. artery of tarsal canal
   2. deltoid branch
2. Anterior tibial artery
3. Artery of tarsal sinus

• *posterior tibial artery**
• via artery of tarsal canal (dominant supply) supplies majority of talar body

deltoid branch of PT supplies medial portion of talar body

may be only remaining blood supply with a displaced fracture

anterior tibial artery -suplies head and neck

perforating peroneal artery via artery of tarsal sinus suplies head and neck

Question 2

List specific things evaluated in an AP pelvis radiograph in the trauma setting.

Answer 2

Symphysis pubis <5 mm in width
Sacroiliac joint 2-4 mm in width
Pelvic ring should have no disruption
Obturator ring should have no disruption
Sacral foraminal arcs should be visible
Check TPs of lower lumbar vertebrae for fracture
Check the fat stripes: gluteal, iliopsoas, obturator
internus
Iliopectineal or arcuate line disruption # anterior column
Ilioischial line disruption # posterior column
Radiographic U or teardrop
Acetabular roof Sorcil
Anterior rim of the acetabulum
Posterior rim of the acetabulum

Line of Klein drawn along superior edge of femoral neck
should intersect epiphysis
Shenton line - smooth continuous arc

6 radiographic landmarks of the acetabulum:

1. iliopectineal line (anterior column)
2. ilioischial line (posterior column)
3. anterior rim
4. posterior rim
5. teardrop
6. weight bearing roof

Question 3

List all potential sources of bleeding in pelvic fractures. And give a alogorythm to appoach hemorrahgic shock in pelvic fractures.

Answer 3

Basic algorithm

1. Is there massive blood loss - >2L (0-5 minutes)

if yes the OR

2. ATLS performed

Question 4

List the 4 SC joint ligaments (4)

Answer 4

1. Posterior Capsule (most important)
2. Anterior Capsule
3. Interclavicular (attaches across notch to other SC)
4. Costoclavicular (holds it to first rib)

Question 5

Which AC joint ligaments provide horizontal stability (AP)? (2)

Which ones provide vertical stability ?

Answer 5

Superior & Posterior Ligaments- horizontal

Conoid & Trapazoid Ligaments - Vertical

Question 6

What x-ray is the money view for AC joints?

Answer 6

Zanca view

• performed by tilting the x-ray beam 10° to 15° shooting caudal to cephalic direction and using only 50% of the standard shoulder anteroposterior penetration strength.

Question 7

How do you position hemi in type 4 proximal humerus fractures?

Height?

Version?

Answer 7

Preop

1. Template unsing other arm

interop

1. 5.6mm above superior border of pec major tendon
2. Restore gothic arch (fluoro,xrays)
3. GT 5-9 mm below superior aspect of head

Retroversion

1. 20-40 degrees retroverted (30)
2. bicipital groove is on average, angled approximately 30° more retroverted than the humeral head with respect to the epicondylar axis.

Question 8

Describe deltopectoral approach.

What is the internervous plane?

Answer 8

Internervous plane

1. axillary nerve - Laterally
2. medial and lateral pectoral nerve - Medially

• Incision 8-10-cm extending inferiorly and laterally from the tip of the coracoid process toward the deltoid tuberosity
• deltopectoral fascia - cephalic vien(lateral w deltoid)
• substantial hematoma, which should be evacuated
• pectoralis major insertion is preserved
• conjoined tendon coracobrachialis & SHbiceps is identified
• clavipectoral fascia is incised just lateral to SH-biceps superiorly to the coracoacromial ligament
• finger swept medially, deep to CJ tendon, superiorly-inferiorly
• identify axillary nerve - passes superficial to the subscapularis muscle belly toward the quadrilateral space.
• musculocutaneous nerve passes thru CJ-tendon approx 5-6 cm distal -tip of the coracoid
• biceps sheath ident. inf. portion - superior to pectoralis major
• pec-major inserts on lateral lip - bicipital groove
• biceps traced superiorly to transverse humeral ligament, which is preserved
• soft-tissue split parallel-ant border of supraspinatus all the way to the glenoid
• biceps is then tenodesed-pec-major
• joint accessed - GT fracture line & split at anterior border SS
• heavy nonabsorbable suture- bone-tendon junction GT & LT most lateral extent on each

Question 9

Indications for Prosthetic humeral head replacement in trauma (3)

Answer 9

1. head-splitting fractures
2. fracture-dislocations
3. four-part fractures with significant initial varus displacement (>20°).

Question 10

Vascularity to the Humeral Head

Answer 10

anterior humeral circumflex artery

• anterolateral ascending branch (of AHCA)
• arcuate artery - terminal branch

posterior humeral circumflex artery

• recent studies suggest it is the main blood supply to humeral head

Question 11

Describe the Neer classification (4)

Answer 11

Based on anatomic relationship of 4 segments:

1. greater tuberosity
2. lesser tuberosity
3. articular surface
4. shaft

separate part - displaced > 1 cm 45° angulation

valgus impacted is not true 4 part.

Question 12

Approach to radial nerve palsy in humerus fractues.

What Tendon transfers are typically preformed.

Question 13

Describe Hawkins classification and Osteonecrosis rates (4)

Answer 13

Hawkins 1: Nondisplaced 0-13%
Hawkins 2: Subtalar dislocation 20-50%
Hawkins 3: Subtalar and tibiotalar dislocation 20-100%
Hawkins 4: Subtalar, tibiotalar, and talonavicular dislocation 70-100%

Question 15

What x-ray provides optimal view of talar neck?

Answer 15

Canale View

technique:

• maximum equinus,
• 15 degrees pronated,
• Xray 75 degrees cephalad from horizontal

Question 16

List all 10 types of Periacetabular fractures

Answer 16

Elementary

1. Posterior wall
2. Posterior column
3. Anterior wall
4. Anterior column
5. Transverse

Associated

1. Associated Both Column
2. Transverse + Post. Wall
3. T shaped
4. Anterior column or wall + Post. hemitransverse
5. Post. column + Post. wall

Question 17

What is this?

Answer 17

Extensive soft-tissue calcifications are noted bilaterally in
the lower extremities of this patient with dermatomyositis.

Question 18

Describe the Young-Burgess classification.

Answer 18

Anteroposterior compression (APC)

• A) APC type I - wide pubic symphasis <2.5cm
• B) APC type II- no sacrotuberous, sacrospinous& ant.SI ligaments; post. SI ligaments remain intact >2.5cm
• C) APC type III -dissociated SI or displacedvnonimpacted posterior fracture

Lateral compression (LC)

• D) LC type I - buckle # sacral ala & Rami #
• E) LC type II - near comp post disruption crescent #
• F) LC type III - rollover or windswept pelvis

G)Vertical shear - Comple disruption of SI

arrows indicates direction of force

Question 19

In open pelvis fracture management what are the important intitial steps.

Answer 19

1. Hemodynamically unstable at presentation.
2. Pack open wounds & apply pelbic binder
3. Broad spectrum Abx & tetnus
4. While continuing resescitation - assess other sorces of Bleeding
5. Plan for OR control of other bleeds plus I&D of wound Ex fix and Fecal diversion - Colostomy
6. ICU likely needed

Question 20

Although not definitive what could one predict with blood transfusion requirements in trauma using Young-Burgess & Letounal classifications. (JOT2007)

Answer 20

Most blood required:

1. APC III avg -12.6 units
2. tansverse (13)
3. both columns (8.8)

Most likely need transfusion

1. all APCs
2. LC III
3. VS
4. combined pelvis & acetabulum
5. all acetabulum except ant wall may require blood

• Nearly 50% (10 of 25) of APC II, APC III, or LC III
• patients with acetabular fractures are just as likely to require transfusion
• High enegy patterns require more - transverse (13.0), both column (8.8 units) & AC post. hemi-T (6.4 units)

Question 21

what is PUDA?

Answer 21

Proximal ulna dorsal angulation

exists in 96% of population

6 +/- 3 ° - 5 cm from tip of olecranon

5 degrees malreduction = radial head instability

varus angle proximal ulna (N) = 14 ° +/- 4°

Question 22

Describe how to apply an External fixator to pelvis.

Question 23

list the Principles of Tendon Transfer (8)

Answer 23

1. Supple joint: joint must have max pROM otherwise transfer will fail. Need aggressive physio or even surgical releases PRIOR to tendon transfer procedure
2. Soft tissue equilibrium: want healthy soft tissue bed free from edema, inflammation, scar so do not get adhesions which will result in poor outcome of tendon transfer. Either need to wait or excise scar or even consider flap coverage
3. Expendable donor: do not want to regain one function at expense of losing another function
4. Donor of adequate excursion (=max linear distance). Wrist flexors/extensors = 33mm, finger extensors = 50mm, finger flexors = 70mm

5.Donor of adequate strength: FCR/wrist extensors/pronator teres/finger flexors strength = 1; brachioradialis/FCU strength = 2; finger extensors strength = 0.5; APL/EPB/EPL/PL strength = 0.1

a. Lose one grade of strength with a transfer
6. Straight line of pull: direction changes weaken force of pull
7. Synergy: certain muscle groups work together ex. Wrist flexion & finger extension, wrist extension & finger flexion. Finger flexion & extension not synergistic, so try to avoid.
8. Single function: if try to restore multiple functions, compromise strength & movement

Question 24

Whats the diffrence between High and Low radial nerve palsy clinically?

Answer 24

High radial nerve palsy = injury proximal to elbow = radial nerve proper

Lack wrist/finger/thumb extension

Lack sensation 1st webspace/dorsoradial hand (not critical to normal hand function)

Low radial nerve palsy (PIN) = injury distal to elbow = posterior interosseous nerve

Lack finger/thumb extension

Have sensation 1st webspace/dorsoradial hand

Wrist extension preserved (ECRL is radial nerve proper), although may have radial deviation in extension if proximal PIN injury and ECU affected

Question 25

What are the tendon transfers preformed for high radial nerve palsy?

Answer 25

Wrist extension: pronator teres to ECRB

• Harvest insertion of pronator teres & flap of periosteum to achieve enough length
• Reroute superficial to brachiradialis

End-to-end if no recovery expected; end-to-side if using as internal splint & expect recovery

Thumb extension: Palmaris longus OR ring FDS to EPL

Finger extension: FCR OR FCU OR middle FDS to EDC

Question 26

What are the tendon transfers for Low radial nerve palsy (PIN)?

Answer 26

1. Thumb extension: Palmaris longus OR ring FDS to EPL
2. Finger extension: FCR OR middle FDS to EDC
3. Wrist extension preserved (ECRL is radial nerve proper), although may have radial deviation in extension if proximal PIN injury and ECU affected

Question 27

Describe Seddon’s classification. (3)

Answer 27

1. Neurapraxia
2. Axonotmesis
3. Neurotomesis

Question 28

Describe Sunderland classification (5)

Answer 28

• Type 1 - neuropraxia - local myelin damage recovers -
• Type 2 - Axonotomesis- loss of continuity of axons
• Type 3 - loss of continuity in axons and endoneurium
• Type 4 loss of continutiy in axons, endonuerium, perineurium ; epineurium intact
• Type 5 - complete disruption of nerve trunk

Question 29

List sources of autologous nerve graft used.

Question 30

Describe EMG findings both in acute and chronic denervation.

Answer 30

Acute Denervation

• Prominent fibrillations and PSWs

Chronic Denervation

• High amplitude–long duration MUPs
• Collateral sprouting from adjacent healthy axons

Results in increased muscle fiber activation by stimulation of one motor unit (= high amplitude)

Early on, new sprouts not myelinated, thus conduct slowly (will see polyphasicity). After sprouts mature synchronization of muscle fiber discharges improves; polyphasicity tends to be reduced.