Trauma Basics and Orthopaedic Infections Flashcards Preview

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Flashcards in Trauma Basics and Orthopaedic Infections Deck (77):

Three peak times of death following trauma

1. 50% first minutes (blood loss OR neuro injury)

2. 30% in first days (shock; hypoxia; neuro injury)

3. 20% days-weeks (multi-system failure AND infection)


1. What is the 'golden hour'

2. What % of preventable deaths occur during this time

1. Period of time when life/limb threatening injuries should be treated in order to decrease mortality

2. Estimated 60% of preventable deaths can occur during this time


Airbags in head on collision have been shown to significantly reduce: (4)

1. Closed head injury

2. Facial fractures

3. Thoracoabdominal injuries

4. Need for extraction


Primary Survery

Treat greatest threats to life first (pelvic # can be a life threatening intervened on by orthopedic surgeons)

- brief history -> ABCDE's (Airway-> incl. c-spine control ; Breathing and ventilation ; Circulation -> incl hemorrhage control and resus
- pregnant women should be placed in the left lateral decubitus position to limit positional hypotension


1. Secondary Survey

2. Tertiary Survey

Secondary survey=physical examination and updated history ALSO obtain indicated imaging studies

Tertiary survey=repeat physical examination and imaging as indicated when mental status has stabilized

**Note: formal tertiary survey decreases chances of missed orthopedic inury


1. Average adult has ______L of circulating blood?

2. Average child 2-10yr old has _______mL/kg blood

1. 4.7-5L

2. 75-80ml/kg
(eg. 30kg child has 2.2-2.4L blood


Methods of Resuscitation

1. Fluid

2. Blood options

3. Ratio of tranfusion (blood:platelet:plasma)

1. crystalloid isotonic solution

2. O negative blood (universal donor) ; Type specific blood; Cross-matched

3. 1 : 1 : 1


1. Most sensitive indicators of adequate resuscitation ?

2. Other indicators of adequate resuscitation? (3)

1. serum lactate levels (most sensitive indicator as to whether some circulatory beds remain inadequately perfused; normal < 2.5 mmol/L)

2a. urine output 0.5-1.0 ml/kg/hr (30 cc/hr)
2b. gastric mucosal ph
2c. base deficit (normal -2 to +2)


Risk of viral transmission with allogenic blood transfusion
1. HBV
2. HCV

1. 1 in 205,000

2. 1 in 1.8 million

3. 1 in 1.9 million


Non-hemorrhagic shock (3)

1. Cardiogenic shock (insufficient cardiac output due to pump failure)

2. Neurogenic shock = hypotension and relative bradycardia from loss of sympathetic tone following spinal cord injury

3. Septic shock
(note: septic shock= systemic vascular resistance is decreased VS. hypovolemic shock = vasc resitance increased)


Damage Control Orthopaedics (DCO)

1. definition

2. General concept

1. definitive treatment delayed until physiology has improved

2. Involves staging definitive management to avoid adding trauma to patient during vulnerable period

*** Note: the decision to operate and surgical timing on multiple injured trauma patients remains controversial


Parameters for patients treated with DCO principles

1. ISS >40 (without thoracic trauma)
2. ISS >20 with thoracic trauma
3. GCS of 8 or below
4. multiple injuries with severe pelvic/abdominal trauma and hemorrhagic shock
5. bilateral femoral fractures
6. pulmonary contusion noted on radiographs
7. hypothermia <35 degrees C
8. head injury with AIS of 3 or greater
9. IL-6 values above 500pg/dL


Optimal time of surgery in DCO

1. During what period should only life threatening injuries be treated ?

Patient are at increased risk of ARDS and multisystem failure during acute inflammatory window (period from 2 to 5 days characterized by a surge in inflammatory markers)


Optimal time of surgery in DCO

1. What injuries should be treated during high-risk period in DCO (7) ?

1. unstable pelvic fracture
2. compartment syndrome
3. fractures with vascular injuries
4. unreduced dislocations
5. traumatic amputations
6. unstable spine fractures
7. cauda equina syndrome
8. open fractures


DCO: Definitive treatment delayed for:

1. __to___ days for pelvic fractures

2. within _____ weeks for femur fractures

3. within __to__ days for tibita fractures

1. 7-10 days

2. within 3 weeks

3. 7-10 days


Open Fractures

1. Timing of surgery

2. Classifications (2)

1. In the absence of life-threatening injuries, there is NO clinical advantage to performing surgery within 6 hours of injury versus 6-24 hours

2. (a) gustillo; (b) Tscherne


Open Fractures

1. antibiotic management

a) gustillo I/II

b) gustillo III

c) Farm injuries / heavily OR bowel contamination

d) water

a) 1st gen cephalosporin (or vanc or clinda if allergies)

b) 1st gen cephalosporin + aminoglycoside (eg. gentamicin)

c) as above and ADD high dose penicillin for anaerobic coverage (clostridium)

d) fresh = fluroquinolones (eg. cipro); salt = doxy OR fluroquinolone


Open Fractures: Timing of antibiotics

i. increased infection rate when antibiotics are delayed for more than ____hours from time of injury

ii. continue for _____ after wound closure (_____ in type III)

i. 3hrs

ii. 24hrs after closure (72hrs in type III wounds)


Open Fractures: tentanus

i. two forms of tetanus prophylaxis

ii. guideline for use based on what 3 factors?

i. Forms of tetanus prophylaxis
(1) toxoid dose 0.5 mL, regardless of age
(2) immune globulin dosing
- <5-years-old receive 75 U
- 5-10-years-old receive 125 U
- >10-years-old receive 250 U

ii. Guidelines for tetanus prophylaxis depend on 3 factors
(1) complete or incomplete vaccination history (3 doses)
(2) date of most recent vaccination (last 10 years)
(3)severity of wound


Open Fractures: emergency room management

Principles (5)

1. Antibiotics: initiate early IV antibiotics and ADT as indicated

2. Control bleeding
- direct pressure
- do not blindly clamp or place tourniquets on damaged extremities

3. Assessment:
- soft-tissue
- NV exam; +/- ABI (normal>0.9); vasc. sx consult and CT-angio) angiogram is warranted if ABI <0.9
consider saline load test if concern for traumatic arthrotomy (*contorversial)

4. Dressing:
- remove gross debris from wound, do not remove any bone fragments
- place sterile saline-soaked dressing on wound
- little evidence to support aggressive irrigation or irrigation with antiseptic solution in the ED (can push debris further into wound)

5. Stabilize
- splint, brace, or traction for temporary stabilization (decreases pain, minimizes soft tissue trauma, and prevents disruption of clots)


Open Fractures

Operating room management
i. Wash and debride principles

- thorough debridement is critical to prevent deep infection; remove FB's

- expose fracture by recreating mechanism of injury, extend wound proximally and distally in line with extremity

- low pressure is preferred over high pressure pulse lavage

- saline most effective irrigating agent
Rule: 3L of saline are used for each successive Gustilo type (Type I: 3L / Type II: 6L / Type III: 9L)

- bony fragments without soft tissue attachments should be removed


Open Fractures

i. Fracture Stabilisation

ii. Ex-Fix pin placement

iii. Staged wash/debride every __to__hrs PRN

i. internal fixation, ext-fix or IMN as indicated

ii. avoid placement of pins in proximity to planned definitive incisions

iii. 24-48hrs


Open Fractures: Soft tissue coverage in trauma

i. Timing - general

ii. Tibial coverage

iii. increased risk of infection after ___ days

iv. VAC dressings

v. ABx beads

i.Early coverage OR closure is ideal.

ii. Flap coverage for open tibial Fx is controversial but <5 days is desired

iii. 7 days

iv. VAC may be used during debridement until definitive coverage

v. for open,dirty wounds (made with methylmethacrylate with heat-stable antibiotic powder)


Open Fractures

Bone loss options (3)

1. Masquelet technique

2. Distraction osteogenesis

3. Vascularized bone flap/transfer


Open Fractures

What is the Masquelet Technique?

two-stage technique:

1st stage: debridement and filling of bone loss with an acrylic spacer
- original technique used external fixator, but new techniques use IM nail;

2nd stage: bone recon; filling with cancellous bone in the space left free (following cement removal) inside the so-called self-induced periosteal membrane


Open Fractures: Complications

1. Infection

2. NV Injury

3. Compartment Syndrome


Trauma Scoring Systems: Glasgow Coma Scale (GCS)

1. definition

2. Breakdown/scoring

3. Pros

1. quantifies severity of head injury by measuring CNS function

2. Motor 1-6 / Verbal 1-5 / Eye opening 1-4 = total 15
- Brain injury: <9= severe; 9-12 moderate; >/=13 minor

3. Reliably predicts outcomes for diffuse and local lesions


Injury Severity Scale (ISS)

What is ISS

Anatomical region and assigned number ?

How is it calculated

1. First scoring system to be based on anatomic criteria

2. Based on 9 anatomical regions [1.head 2.face 3.neck 4.thorax 5.abdo/pelvis 6. spine 7. UL 8. LL 9. External

ISS = sum of squares for the highest AIS grades in the three most severely injured ISS body regions [ISS = A2 + B2 + C2]


Systemic Inflammatory Response Syndrome (SIRS)

A generalized response to trauma characterized by ◾an increase in cytokines
◾an increase in complement
◾an increase in hormones

◦heart rate > 90 beats/min
◦WCC <4000cells/mm³ OR >12,000 cells/mm³
◦ RR> 20 or PaCO2< 32mm
◦Temp<36 deg or >38deg


Mangled Extremity Severity Score (MESS)

1. utility?

2. variable?

◦used to predict necessity of amputation after lower extremity trauma

- skeletal and soft tissue injury (energy/MOI graded 1-4)
- limb ischemia (graded 1-3)
- shock (0-2) with persistent hypotension = 2
- age (<30=0; >50=2)
(>7 = high risk of amputation)


Amputations: Prognosis

1. Outcomes of Lower Extremity Assessment Project (LEAP study) ?
[Higgins TF1, Klatt JB, Beals TC.Orthop Clin North Am. 2010 Apr;41(2):233-9]

* Leap study looked at amputation vs reconstruction decision making

Two big outcomes:

1. Factors influencing decision to amputate limb

i. severe soft tissue injury = highest impact on decision-making process

ii. absence of plantar sensation (2nd highest impact on decision)
; NOT an absolute contraind. to recon

2. Outcome measure:

i. SIP (sickness impact profile) and return to work not significantly different between amp and recon @ 2yrs in limb-threatening injuries
ii. most important factor to determine patient-reported outcome is the ability to return to work


Compartment Syndrome: etiology (leg)


1. trauma (fractures =69% of cases / crush injuries / contusions / gunshots
2. tight casts, dressings, or external wrappings
3. extravasation of IV infusion
4. burns
5. postischemic swelling
6. bleeding disorders
7. arterial injury


Compartment Syndrome Leg: Anatomy

Deep posterior compartment
i. muscles (3)
ii. nerve (1)
iii. arteries (1)

i. tibialis posterior / flexor digitorum longus / flexor hallucis longus

ii. Tibial nerve

iii. Peroneal artery and vein / post tibial artery and vein


Compartment Syndrome Leg: Anatomy

Sup. posterior compartment
i. muscles (3)
ii. nerve (1)
iii. arteries (2)

i. muscles
- gastrocnemius
- soleus
- plantaris

ii. median cutaneous nerve

iii. Peroneal artery and vein


Compartment Syndrome Leg: Anatomy

Anterior compartment
i. muscles (3)
ii. nerve (1)
iii. arteries (2)

i. tibialis anterior / extensor hallucis longus / extensor digitorum longus / peroneus tertius

ii. DPN

iii. anterior tibial artery


Compartment Syndrome Leg: Anatomy

Lateral compartment
i. muscles (3)
ii. nerve (1)
iii. arteries (2)

i. muscles
- peroneus longus
- peroneus brevis

ii. SPN

iii. nil


Compartment Syndrome Leg: Treatment


1. observation (ind. diastolic differential (delta p) is > 30)
and presentation not consistent with CS

2. bi-valving cast etc
(splinting ankle neutral to resting PF (~37 deg) can decrease intracompartment pressures

3. hyperbaric oxygen therapy (increases O2 diff grad)


Compartment Syndrome Leg: Treatment

Anterolateral incision
1. Structure @ risk
Posteromedial incision
2. structure @ risk

1. SPN

2. Saph vein and nerve


Osteomyelitis - Adult

1. definition

2. Risk factors

1. Infection of bone characterized by progressive inflamm destruction and apposition of new bone

2. recent trauma or surgery; immunocompromise; IVDU; poor vasc supply; systemic conditions (DM; sickle cell); peripheral neuropathy


Osteomyelitis - Adult

Modes of spread (3)

1) Hematogenous
- 20% of OM
- vertebrae most common
- S. aureus is most common

2) Contiguous-focus
- assoc. with previous surgery, trauma, wounds, or poor vascularity
- can be bacterial (most common), mycobacterial, or fungal

3) Direct-inoculation
- penetrating injuries OR surgical contamination


Osteomyelitis - Adult

what is 'biofilm' ?

extracellular polymeric substance or exopolysaccharide that covers necrotic bone and hardware (produced by bacteria --> antibiotics have difficulty penetrating)



most common organisms by age:
1. Newborns
2. Children 4mth-4y
3. Child/adolescent 4-12y
4. Adult
5. Sickle Cell

1. S. aureus, Enterobacter species, and grp A/B Strep

2. S. aureus, group A Strep, Kingella kingae, Enterobacter spp

3. S. aureus (80%), Grp A Strep, H. influenzae, Enterobacter spp

4. S. aureus, Enterobacter spp (occasional Strep spp)

5. S. aureus most common, BUT Salmonella spp is pathognomonic


Osteomyelitis - Adult


Timing classification

◦acute ◾within 2 weeks

◦subacute ◾within one to several months

◦chronic ◾after several months

*also Cierny classification Stage 1-4 (location) and type A-C (host health)


Osteomyelitis - Adult: Imaging

Radiograph Findings:
1. ____________
2. ___________
3. Bone loss must be __to__% before seen on XR
4. What is 'sequestrum'
5. What is 'involuvrum'

1. lytic region surrounded by an area of sclerosis

2. may mimic neoplasia

3. 30-40%

4. sequestrum: devitalized bone that serves as a nidus for infection

5. involucrum: formation of new bone around an area of bony necrosis


Osteomyelitis - Adult: diagnosis / Studies

1. WCC often ______ in acute OM; may be ______ in chronic OM
2. ESR usually _______ in acute and chronic
3. ESR drop with treatment is ______________
4. CRP ________ faster than ESR

1. blood cultures used to guide Rx ______ OM

2. sinus tract cultures_____ to guiding antibiotic therapy

3. _______ is gold-standard for guiding antibiotic Rx

1. elevated; normal
2. elevated
3. favorable prognostic indicator
4. decreased faster with treatment

1. hematogenous
2. not reliable
3. Bone biopsy


Osteomyelitis - Adult: Prognosis/Outcomes

1. Success in the treatment is dependent on various factors (5)

1. patient factors (immunocompetence; nutrition; compliance)

2. Injury factors (severity of injury as demonstrated by segmental bone loss)

3. Infection location (metaphyseal infections heal better than mid-diaphyseal)

4. Residual foreign materials and/or ischemic and necrotic tissues

5. Appropriate antibiotic coverage


Osteomyelitis - Adult: Treatment Principles


1. IV or oral antibiotic therapy for 4-6 weeks ◾indications = initial therapy in almost all situations
◾outcomes = rate of recurrence can be as high as 30%

2. hyperbaric oxygen therapy
◾indications = can be used as adjunct in refractory osteomyelitis


Osteomyelitis - Adult: Treatment Principles


1. Irrigation and debridement followed by organism specific antibiotics
◾indications= stage III and IV osteomyelitis; abscess; draining sinus

2. Surgical fixation techniques
◾Ilizarov technique
◾intramedullary nail with or without external fixation
◾Masquelet technique
◾free tissue transfer
◾in situ reconstruction

3. outcomes
◾when combined with postoperative antibiotics tailored to specific organism, treatment is often successful


Osteomyelitis - Adult: Treatment Principles

Surgical technique

1. debride (all devitalized/necrotic tissue
◾extensive debridement is essential to eradicate infection
◾sequestrum must be eliminated from the body, or infection is likely to recur

◾hardware removal ◾any non-essential hardware should be removed

◾dead space management ◾goal is to replace dead bone and scar tissue with vascularized tissue
◾options include
◾vascularized bone grafts
◾local tissue flaps or free flaps
◾antibiotic-impregnated acrylic beads (PMMA)
◾vacuum-assisted closure


VAC Therapy: Mechanism of Action

◾vacuum-assisted closure
VAC dressings improve wound healing and dead space closure in multiple ways
◾remove interstitial fluids
◾eliminate superficial purulence or slime
◾allow arterioles to dilate, which allows granulation tissue to proliferate
◾decrease in capillary afterload to promote inflow of blood
◾mechanical force on wound edges draws them in


Septic Arthritis - Adult: Location (most->least common)

knee (~ 50% of cases) >

◾hip > shoulder > elbow > ankle > ◾SCJ

(IVDU / p. aeruginosa was most common pathogen in 1980's ◾s. aureus now most common in all patients, incl. IVDU)


Septic Arthritis - Adult

Classification: Staphylococcus species 1. staph _____ ◾most common and accounts for ____ of cases
2. Other common causes include _____ and staph ______

1. aureus / 50%

2. MRSA / Staph epi


Septic Arthritis - Adult

Classification: N.gonorrhea

1. account for ____ of cases

2. Most common organism in what group?

1. ~20%

2. otherwise well young, exually active men

Note: Manifests as a bacteremic infection ◾arthritis-dermatitis syndrome in ~60% of cases
◾localized septic arthritis in ~40% cases


Septic Arthritis - Adult

Classification: Gram -ve bacilli

1. account for __to__% of cases
2. pathogens include ? (4)

3. risk factors (4)

1. 10-20%

2. E coli / proteus / klebsiella / enterobacter

- neonates
- IV drug users
- elderly
- immunocompromised patients with diabetes


Septic Arthritis - Adult

Classification: Streptococcus

1. Strep _____ most common

2. Group __ (eg. strep ______) has a predilection for infants, elderly and diabetic patients

1. streptococcus pyogenes (Group A)

2. group B streptococcus (e.g., agalactiae) ◾predilection for infants, elderly and diabetic patients


Septic Arthritis - Adult

Associated organism
1. shoulder surgery
2. patients with sickle cell disease
3. patients with HIV
5. dog or cat bite
6. human bite
7. immunocompromised host

1. propionibacterium acnes
2. salmonella or streptococcus pneumoniae
3. bartonella henselae
4. p.aeruginosa
5. pasteurella multocida
6. eikenella corrodens
7. fungal/candida


Septic Arthritis - Adult

Joint fluid aspirate
1. WCC > ___ in normal joint and

2. WCC> __ in prosthetic joint

indicates infection

1. >50,000

2. >1,100

Other: blood WCC>10K (left shift) / ESR>30 / CRP most helpful


Wound and Hardware Infection:

1. Incidence in traumatic fracture up to ____%

2. Pathophysiology

1. 16%

2. direct (eg. open fx) OR indirect (eg. haematogenous spread)


Wound and Hardware Infection:

chronic suppression with antibiotics
risk of surgical treatment outweighs the benefit to the host
immunosuppressed, elderly, etc.
presence of an infected but incompletely healed fracture following internal fixation
ESR and CRP levels used to assess adequacy of treatment


Wound and Hardware Infection: Non-operative

1. What percentage of chronic infected nonunions persist OR get worse despite suppression?

2. 32%


Wound and Hardware infection: Treatment

Operative: Surgical debridement

1. indications

2. technique

1. indications
any active infection

2. Tecnique:
- hardware should be maintained if stability at risk with removal

- low-pressure irrigation with normal saline

- thorough identification and debridement of infection key to success

- deep bony specimens should be obtained for culture as well as biopsy


Wound and Hardware infection: Treatment

Operative: Surgical debridement

1. ___% success seen with debridement and antibiotics for early acute postoperative infection

2. Risk factors for failure (2)

1. 71%

2.Risk factors for failure include:
- intramedullary nail
- open fracture


Necrotising Fasciitis

1. Definition

2. Risk Factors (3 broad groups)

1. Necrotizing fasciitis is a life threatening infection that spreads along soft tissue planes

2. Risk factors:
i) immune suppression (DM/AIDS/Cancer)

ii) Bacterial introduction (IVDU/iatrogenic/cuts etc)

iii) Other host factors (obesity)


Necrotising Fasciitis

1. Mortality correlates with ________ ?

2. Overall mortality of ___%?

1. Time to surgical intervention

2. 32%


Necrotising Fasciitis


Type 1: Polymicrobial (80-90% of cases)

Type 2 Monomicrobial (5% of cases; Grp A Strep most common)

Type 3: Marine Vibrio vulnificus

Type 4: MRSA


Necrotising Fasciitis

Type 1 : Polymicrobial

1. Seen in which patient group?
2. Accounts for __to__% of cases
3. Organisms

1.Most common (80-90%)
1. Immunosuppressed (diabetics and cancer patients)

2. 80-90%

3. Bacteria involved
- Non-Group A Strep
- anaerobes incl Clostridia
- facultative anaerobes
- enterobacteria
(**Synergistic virulence between organisms)


Necrotising Fasciitis: Type 2 - monomicrobial

1. Most commmon bug

2. What % of all NF cases?

3. What group of patients are classically affected?

4. Seen in what body region normally

1. Group A β-hemolytic Streptococci

2. 5% of cases

3. Seen in healthy patients

4. Extremities


Necrotising Fasciitis: Presentation

1. Early Symptoms

2. Late Symptoms

3. Examination findings

1. Symptoms: early
- localized abscess or cellulitis with rapid progression
- minimal swelling
- no trauma or discoloration

2. Symptoms: late findings
- severe pain
- high fever, chills and rigors
- tachycardia

3. Physical exam
- skin bullae
- discoloration (ischemic patches/cutaneous gangrene)
- swelling, edema
- dermal induration and erythema
- subcut emphysema (gas producing organisms)


Necrotising Fasciitis:

Histolgical findings

Histological findings
- necrosis of fascial layer
- microorganisms within fascial layer
- PMN infiltration
- fibrinous thrombi in arteries and veins and necrosis of arterial and venous walls


Necrotising Fasciitis: LRINEC Scoring system (6 categories)

Score > 6 has PPV of 92% of having necrotizing fasciitis

1. CRP (mg/L): ≥150: 4 points
2. WBC count:
- <15: 0 points
- 15–25: 1 point
- >25: 2 points
3. Hemoglobin (g/dL):
- >13.5: 0 points
- 11–13.5: 1 point
- <11: 2 points
4. Sodium (mmol/L): <135: 2 points
5. Creatinine (umol/L): >141: 2 points
6. Glucose (mmol/L): >10: 1 point


Necrotising Fasciitis: Treatment

1. 1st line treatment

2. operative findings

1. Operative
emergency radical debridement with broad-spectrum IV antibiotics

2. Operative findings:
- liquefied subcutaneous fat
- dishwater pus
- muscle necrosis
- venous thrombosis


Necrotising Fasciitis: Antibiotics

1. Initial antibiotics
- start empirically with penicillin, clindamycin, metronidazole, and an aminoglycoside

2. definitive antibiotics
- penicillin G for strep or clostridium

- imipenem or doripenem or meropenem for polymicrobial

- add vancomycin or daptomycin if MRSA suspected


Scapulothoracic Dissociation

1. Definition

A traumatic disruption of the scapulothoracic articulation often associated with:
- severe neurologic injuries
- vascular injuries
- orthopaedic injuries


Scapulothoracic Dissociation

1. Mechanism

2. Prognosis

a) Mortality of ___%

b) Functional outcome dependent on _______?

1. Usually caused by a lateral traction injury to the shoulder girdle; involves significant trauma to heart, chest wall and lungs

2a. 10%

2b. neurologic injury
(**note: if return of neurological function is unlikely, early amputation is recommended)


Scapulothoracic Dissociation

1. Associated orthopaedic injuries

2. Flail extremity seen in ___% of ST dissociation

1. scapula fractures; clavicle fractures; AC disloc/separation; sternoclavicular dislocation

2. 52% (complete loss of motor and sensory function rendering the extremity non-functional)


Scapulothoracic Dissociation

1. Associated vascular injuries

2. Associated neurological injuries?

3. Associated neurological injury seen in up to ____%

1. subclavian artery most commonly injured > axillary artery

2. ipsilateral brachial plexus injury (often complete)
(note: *** neurologic injuries more common than vascular injuries)

3. 90%


Scapulothoracic Dissociation

Anatomy: Scapulothoracic joint:
1. Type of joint ?

2. Articulates with ribs __to__

3. moves into abduction at __:__ ratio
- GH joint ___°
- ST joint __°

1. a sliding joint
2. ribs 2-7

3. Moves into abduction at 2:1 ratio
- GH joint 120°
- ST joint 60°

(* known as scapulohumeral rhythm = 2 degrees of humeral flexion/abduction to 1 degree of scapular upward rotation)