Must know Flashcards
Nonop parameters for metacarpal shaft fractures
no rotational deformity
acceptable shaft shortening 2-5m
index/long finger >10 angulation
ring finger <20 angulation
little finger <30 angulation
nonop parameters for metacarpal neck fractures
- Index and middle = <10-15°
- Ring = <40°
- Small = <60°
- No rotation
acceptable shaft shortening 2-5m
how should malrotation of a MC fracture be assessed?
- with the fingers in flexion all should point towards the scaphoid tubercle without overlapping adjacent finger (compare to contralateral side)
- for patients who are unable to perform active flexion, the digital cascade can be observed through the tenodesis effect by flexing and extending the wrist
- each degree of rotation at the MC results in 5° of rotation at the fingertip, leading to 1.5cm of digital overlap in the closed fist
what is the reduction maneuver described for MC neck fractures
- Jahss Maneuver
- MCP and PIP joints are fully flexed and dorsal force is applied along the long axis of the proximal phalanx and volarly along the MC shaft to reduce the MC head from a flexed position
What is acceptable alignment for metacarpal head fractures?
No articular displacement acceptable
VACTERL
The following features are observed with VACTERL association:
V - Vertebral anomalies
A - Anorectal malformations
C - Cardiovascular anomalies
T - Tracheoesophageal fistula
E - Esophageal atresia
R - Renal (Kidney) and/or radial anomalies
L - Limb defects
physeal growth plate zones and associated conditions
Reserve zone (B)
Gaucher’s
Diastrophic dysplasia
Kneist
Proliferative zone (C)
Achondroplasia
Gigantism
MHE
Hypertrophic zone (D)
Zone of chondrocyte maturation, chondrocyte hypertrophy, and chondrocyte calcification
3 phases: maturation, degenerative, provisional calcification
SCFE (not renal)
Rickets (provisional calcification zone)
Enchondromas
Mucopolysacharide disease
Schmids
Fractures most commonly occur through zone of provisional calcification
primary spongiosa (E)
(metaphysis)
Metaphyseal “corner fracture” in child abuse
Scurvy
secondary spongiosa
(metaphysis)
Metaphyseal “corner fracture” in child abuse
Scurvy
most active physes in upper/extremity and lower extremity and mm/y
U/E
1. proximal humerus 7mm/y
2. distal radius 5.25mm/y
L/E
1. distal femur 9 mm/y
2. proximal tibia 6mm/y
3. distal tibia 5 mm/y
most common causative bacteria in PJI infections of the shoulder
- cutibacterium acnes (38.9%)
– gram-positive,facultative, aerotolerant, anaerobic rod that ferments lactose to propionic acid
– concentrated in the axilla within the dermal sebaceous glands
– forms biofilm within 18-90h (found on implant surface and on synovial tissue)»_space; planktonic
– Mean duration of culture incubation between 7-21 days - staph aureus 14.8%
- staph epidermidis (14.5%)
- coagulase-negative staph (14%)
RF of PJI of shoulder
- male
- higher BMI
- younger age
- immunosuppressed conditions and meds
- post-truma
- rTSA
- previous surgery
What is the cause of swan neck deformity & treatment
laxity/attenuation of volar plate
characterized by hyperextension of the PIP joint and flexion of the DIP joint due to an imbalance of muscle forces on the PIP.
- treatment
- volar plate advancement and PIP balancing with central slip tenotomy
what is the cause of boutoniere deformity
central slip rupture
Goutallier classification
0 Normal
1 Some fatty streaks
2 muscle>fat
3 fat = muscle
4 fat>musclemost tear articular sided, less strong
RC repair indications
- tear >50% M-L width of supra
- acute full-thickness
- bursal sided >3mm/>25% in depth
- PASTA >7mm of exposed bony footprint w/ >25% healthy bursal sided tissue
- young pt with acute traumatic tears
- older pt with degenerative tears
when do you do lat dorsi transfer
irreparable posterosuperior tears with intact subscap
* young laborer
* radial n + post branch of axillary n. at risk
massive RC retear RF
increased fatty infiltration,
decreased acromiohumeral space,
smoking,
size of RC tear, and
increase tension on repair
RF associated with lower tendon-bone RC healing following repair
- increase age
- osteoperosis (ind of age)
- smoker
- chronic tear
- large gap
- large size
- high tension repair
- low initial fixation strength
- fatty infiltration
- muscle atrophy
what are the indications for superior capsular reconstruction?
- massive irreparable supraspinatus and/or infraspinatus tear
- minimal to no arthritis
- functioning deltoid
- not suitable for rTSA (young, active)
what tendon transfers can be considered for irreparable RC tear?
- Lat dorsi for posterosuperior tears
- pec major for irreparable anterosuperior tears
Innervation of RC muscles
- supraspinatus
- suprascapular n.
- infraspinatus
- suprascapular n.
- teres minor
- posterior branch of axillary n.
- Subscapularis
- upper and lower subscap n.
what is the rotator crescent
thin, crescent-shaped sheet of rotator cuff comprising the distal portions of the supraspinatus and infraspinatus insertions.
rotator cable
thick bundle of fibers found at the avascular zone of the coracohumeral ligament running perpendicular to the supraspinatous fibers and spanning the insertions of the supra- and infraspinatus tendons.
triangular interval
3 syllable n.
3 word artery with ‘i’
superior: lower border of teres major
lateral: shaft of humerus
medial: long head of triceps
n: radial
v: profunda brachii artery
What are the boundaries of the quadrilateral space? What nerve and vessel run thru the quadrilateral space?
superiorly -teres major
Inferiorly - teres major
Laterally - surgical neck
Medially - long head of triceps
Axillary nerve
Posterior circumflex humeral artery
What are the borders and the contents of the Triangular Space?
3 word artery with ‘s’
Inferior - teres major
Lateral - long head of triceps
Superior - inferior border of teres minor
- CONTENTS - circumflex scapular artery
What is the primary stabilizer to valgus stress at elbow
which band
what is the origin & insertion
anterior bundle of medial collateral ligament
central band
origin: median epicondyle
insertion: sublime tubercle
primary statis stabilizer to valgus stress from 20-120 degrees of elbow flexion
superficial flexors of forearm and innervation and origin
PT, FCR, PL, FDS, FCU
all inervated by median n. except for FCU, supplied by the ulnar n.
all originate from common flexor origin on medial epicondyle
FDS also originates on anterior radius
deep flexors of forearm, innervation
FDP, FPL, PQ
all innervated by AIN
FDP has dual innervation (ulnar haf by ulnar n., radial half by AIN)
muscle of mobile wad and origin
brachioradialis, ECRL, ECRB
* The lateral supracondylar ridge of the humerus serves as an attachment point for the brachioradialis and ECRL, which also has attachments onto the superior aspect of the lateral epicondyle
* ECRB originates on the lateral epicondyle
* AllinnervatedbytheRadialn.
superficial extensors of forearm and origin
anconeus, EDC, EDM, ECU
all innervated by PIN except for anconeus, supplied by radial n.
ECU not innervated by ulnar n.
deep extensors of forearm
- Supinator
- Abductor Pollicis Longus
- Extensor Pollicis Brevis
- Extensor Pollicis Longus
- Extensor indicis proprius
all innervated by PIN
Sites of compression of the ulnar nerve at the cubital tunnel
Arcade of struthers
Medial intermuscular septum
Medial epicondyle
Osborne’s ligament
Between heads of FCU (fasica)
Aponeurosis of FDS
which ligament in the elbow is the primary stabilizer to varus and ER stress
LUCL
origin lateral humeral epicondyle
insertion tubercle of supinator crest of ulnar
Varus Posteromedial Rotatory Instability (VPMRI) vs.Valgus Posterolateral Rotatory Instabiliy (VPLRI)
1. radial head
2. coronoid fracture
3. MCL
4. LCL
5. P/E
- VPMRI
- No radial head fracture
- > 15% (anteromedial facet)
- Posterior band of MCL ruptured, anterior band intact (attached to anteromedial facet)
- LCL complex (includes LUCL) avulsion
- Valgus stress, moving valgus, milking maneuver
- VPLRI
- Radial head fracture
- < 15% (coronoid tip)
- Anterior band of MCL ruptured
- LCL complex (includes LUCL) avulsion
- Varus stress, chair rise, lateral pivot shift
approach for LUCL reconstruction
kocher approach
how to cast simple elbow dislocation post reduction
likely LUCL injury if any lig (most common)
cast in pronation
‘thumb away from injured side’
mechanism of injury of LUCL resulting in PLRI
FOOSH with axial compression, in supination and valgus
primary ligament injured that leads to PLRI
LUCL
P/E for PLRI
- lateral pivot-shift test
- patient lies supine with affected arm overhead; forearm is supinated and valgus stress is applied while bringing the elbow from full extension to 40 degrees of flexion
- with increased flexion, triceps tension reduces the radial head
- often more reliable on anesthetized patient
- posterior drawer test
- patient lies supine with affected arm overhead; forearm is supinated and the examiner’s index finger is placed under the radial head and the thumb over it.
- application of a posterior force will cause posterior subluxation of the radial head
- prone push up
- chair push up
- table top relocation test
Kocher approach
interval
indications
advantages
disadvantages
interval between the anconeus and extensor carpi ulnaris
indications: radial head #, excision, prosthesis, LUCL recon
advantages: low risk of PIN injury
disadvantage: distal extension may endager PIN
relatively more posterior and thus risks injuring the lateral collateral ligament complex.
kaplan approach
interval
indications
advantages
disadvantages
interval between the extensor carpi radialis brevis and extensor digitorum communis
Indications Radial head fractures – fixation, excision and prosthesis.
Advantages Good view of the anterior half of the radial head which is a common site of fracture.
No disruption of the LUCL.
Drawbacks Inadvertent injury to the PIN if the incision is too anterior.
Distal extension can endanger the PIN.
Remember: If there is a supinator crest of ulna fracture or LUCL avulsion as in 5% of terrible triad injuries, this approach should not be used.
EDC split approach
interval
advantages
EDC tendon is dissected directly longitudinally starting at its origin at the lateral epicondyle
The approach offers a slightly more anterior access than the Kocher’s approach.
Hotchkiss approach (over-the-top)
interval
indications
advantages
disadvantages
Interval: splits the flexor-pronator mass and elevates the anterior part (pronator teres (PT), flexor carpi radialis (FCR), and palmaris longus (PL)) along with brachialis from the anterior elbow capsule
Indications The Hotchkiss or ‘over-the-top approach’ is the most anterior of the medial approaches and provides good access to the tip of the coronoid process and the anterior elbow joint.
Advantages Good view of the coronoid tip fracture site.
Drawbacks Ulnar nerve exploration and visualisation is required.
Possible injury to medial antebrachial cutaneous nerve.
Flexor carpi ulnaris (FCU) splitting (Ring) approach
interval
indications
advantages
disadvantages
interval: between the heads of the flexor carpi ulnaris
Indications Coronoid fractures.
Advantages Good view of the fracture site especially the anteromedial facet.
Drawbacks Ulnar nerve exploration is required.
Possible injury to medial antebrachial cutaneous nerve.
Taylor and Scham approach
approach
interval
indications
advantages
disadvantages
Interval - For access to the base consider elevating the entire flexor-pronator mass from posterior to anterior
Indications This is a good approach for a medial plate fixation for a large basilar fracture of the coronoid.
Advantages Good view of the fracture site.
Drawbacks Ulnar nerve exploration is required.
Possible injury to medial antebrachial cutaneous nerve.
Which muscle shares the same origin site as the tendon that undergoes angiofibroplastic hyperplasia during the pathogenesis of tennis elbow?
anconeus
Lateral epidondylitis is classically thought to be caused by histopathologic angiofibroblastic hyperplasia at the origin of the extensor carpi radialis brevis. ECRB originates from the common extensor wad, that also includes ECRL, ED, ECU. The anconeus shares the same attachment site at the lateral epicondyle as the ECRB
which extensor muscle of the forearm originates on lateral supracondylar ridge
ECRL
what tendon is most commonly implicated in lateral epicondylitis
ECRB
- what is the underlying histopathology in lateral epicondylitis
- what are the histological findings in lateral epicondylitis
- tendinosis (degenerative condition) rather than tendinitis (inflammation)
- angiofibroblastic hyperplasia
- characterized by dense populations of fibroblasts, vacular hyperplasia and disorganized collagen
how to avoid iatrogenic injury to LUCL with lateral epicondylitis release
do not extend beyond equator of radial head
may lead to PLRI
what is valgus extension overload
- describes collection of injuries in the medial, lateral and posterior aspects of the overhead thrower’s elbow
- occurs as a consequence of the large valgus loads and rapid elbow extension during the throwing motion
what are the common presenting symptoms of valgus extension overload in over head thrower’s
- decreased performance (velocity, control, fatigue)
- posteromedial elbow pain with full extension of elbow
- locking/catching (loose bodies), loss of terminal elbow extension
- ulnar nerve symptoms (neuritis, subluxation)
- pain in deceleration of throwing phase
complication of surgical procedure for valgus extension overload syndrome
valgus instability - over-resection of posteromedial ostephy past its native margin or >3mm may lead to increased stress on the MCL and valgus instability
what are the components of the lateral collateral ligament of the elbow
- lateral ulnar collateral ligament
- inserts on the supinator crest
- radial collateral liagement
- inserts on the annular ligament
- annular ligament
- inserts on the supinator crest
- accessory lateral collateral ligament
- inserts on the supinator crest
what are the components of medial ulnar collateral ligaments of the elbow and which is the most important for valgus stability
-
anterior bundle
- strongest and most significant stabilizer to valgus stress
- insert - sublime tubercle
- provides stability between 30-120° flexion
- subdivides into anterior and posterior bands
- anterior band - 1° restraint to valgus stress, exhibiting nearly isometric strain during elbow ROM
-
posterior bundle
- greatest change in tension from flexion to extension
- tighter in flexion
- transverse bundle
what is the most sensitive test for diagnosis of medial elbow instability
moving valgus test (100% sensitive, 75% specific)
What are preventative strategies to avoid UCL injuries in pitchers?
- Limit pitching to 100 innings in a calendar year
- Do not pitch for multiple teams
- Do not pitch all year (3 month rest period advised)
- No pitching on consecutive days
- No pitching in a game or practice after being removed from a game
- No breaking pitches (curveballs/sliders) until puberty
- Proper pitching mechanics and year round conditioning should be stressed
- Avoid pitching while fatigued
where do partial distal biceps tendon tears primarily occur
on radial side of tubersosity footprint
RF for biceps tendon tear
high BMI, smoking, anabolic steroids
contents of antecubital fossa
medial) median nerve, brachial a., biceps tendon, radial n. (lateral)
when is LABC most at risk during surgery for biceps tendon repair
during surgical disseciton btw biceps and brachialis
distal biceps anatomy and insertion
- The tendon externally rotates 90°
- Brings the medial short head fibres anterior and the lateral long head fibres posterior
- The tendon inserts with:
- Short head fibres distal on the radial tuberosity
- Stronger flexor
- Long head fibres proximal
- Stronger supinator
- Short head fibres distal on the radial tuberosity
What are the reported deficits with nonoperative management of complete distal biceps tears?
Supination
- 79% endurance [50% loss]
- 21-55% strength [40% loss]
Flexion
- 10-40% strength [30% loss]
- 30% endurance
intervals for single incision technique for biceps repair
proxial - BR and brachialis
distal - BR and PT
intervals for single incision technique for biceps repair, how do you protect PIN
Forearm held in supination to protect the PIN and bring the radial tuberosity into view
If L4/L5 paracentral (posterolateral) disc herniation, what nerve is affected
affects traversing/descending/lower nerve root at L4/5 - affects L5 nerve root
most common PLL is weakest here
If L4/L5 foraminal disc herniation, what nerve is affected
less common (5-10%)
affects exiting/upper nerve root
at L4/5 affects L4 nerve root
- What are the sites of entrapment of the median nerve?
Pronator syndrome (SLAPS)
* **Struther’s ligament **Resisted Flexion at 120
* **Lacertus fibrosis **resisted flexion with supinated forearm
* **Arch of FDS **(sublimus arch) resisted FDS middle finger
* Pronator Teres (2 heads) resisted supination with elbow flexed
- What is the motor innervation of the median nerve?
- Motor
Order:
- Forearm
- Pronator teres
- FCR
- Palmaris longus
- FDS- Radial FDP [AIN] - Index and middle finger - FPL [AIN] - Pronator quadratus [AIN] - Hand - APB - FDB (superficial head) - OP - Lumbricals 1 & 2
what is the sensory innervation of median nerve
- Sensory
- volar wrist capsule, radial palm and palmar aspect of thumb, index, long and radial half of ring
- terminal AIN
- palmar cutaneous branch of median nerve
- terminal digital cutaneus branch
- volar wrist capsule, radial palm and palmar aspect of thumb, index, long and radial half of ring
median nerve course
- Lies medial to brachial a. at the elbow
- Passes between the two heads of the pronator
teres and then runs between FDS and FDP
Carpal tunnel borders and contents
- Carpal tunnel borders
- scaphoid tubercle and trapezium radially
- hook of hamate and pisiform ulnarly
- transverse carpal ligament palmarly (roof)
- proximal carpal row dorsally (floor)
- Carpal tunnel contents
- four flexor digitorum superficialis (FDS) tendons
- four flexor digitorum profundus (FDP) tendons
- flexor pollicis longus (FPL)
- most radial structure
- median nerve
what is Parsonage-Turner Syndrome
- bilateral AIN signs caused by viral brachial neuritis
- be suspicious if motor loss is preceded byintense shoulder pain and viral prodrome
AIN motor innervation
- FDP (index and middle finger)
- FPL
- pronator quadratus
pronator vs AIN syndrome
AIN Syndrome
* Forearm pain
* Weakness of grip and pinch - FPL, FDP 1&2, PQ
* * unable to make OK sign
* No sensory disturbance
Pronator Syndrome
* Pain in proximal, volar forearm
* Paresthesias in thumb, index, long fingers
* AIN Syndrome PLUS weakness of all digits & wrist flexion
* Exacerbated by resisted pronation
* Tinel’s at anterior elbow
AIN sites of compression
- potential sites of entrapment of AIN
- tendinous edge of deep head of** pronator teres**
- most common cause
** - fibrous arch of the FDS**
** - aberrant vessels**
** - accessory head of FPL(Gantzer’s muscle)**
- most common cause
- accessory muscle from FDS to FDP
- abberant muscles (FCRB, palmaris profundus)
- tendinous edge of deep head of** pronator teres**
how is pronator syndrome different to CTS
- should havecharacteristics differentiating from carpal tunnel syndrome (CTS)
- aching painover proximal volar forearm
- sensory disturbances over thedistribution of palmar cutaneous branch of the median nerve(palm of hand)
- arises 4 to 5 cm proximal to carpal tunnel
- lack of night symptoms
how is cubital tunnel different than ulnar tunnel
- less clawing
- sensory deficit to dorsum of the hand
- motor deficit to ulnar-innervated extrinsic muscles
- Tinel sign at the elbow
- positive elbow flexion test
boundaries of guyon’s canal
what are the contents
floor:Transverse carpal ligament, hypothenar muscles
roof: Volar carpal ligament
ulnar border: Pisiform and pisohamate ligament, abductor digiti minimi muscle
radial border: Hook of hamate
ulnar nerve, a/v
zones of guyon’s canal
- zone I - proximal to bifurcation (motor and sensory)
- zone II - deep motor branch (motor only)
- zone III - superifical sensory branch (sensory only)
ulnar nerve motor and sensory innervation
- Motor
- FCU
- Ulnar half of FDP
- All intrinsics except lateral 2 lumbricals and thenar muscles
- Except deep head of FPB
- Sensory
- Elbow joint
- Ulnar palm and dorsum of hand including small finger and ulnar half of ring finger
- Branches:
- Articular branch of the elbow
- Dorsal cutaneous branch
- Palmar cutaneous branch
- Only present in 58% of people
- Terminal superficial branch
ulnar nerve sites of compression
- Medial intermuscular septum
- Arcade of Struthers
- Triceps fascia
- Osborne ligament** (most common site)**
- Roof of cubital tunnel
- Medial epicondyle
- FCU
- Deep fascia
- Between two heads
- FDS/FDP fascia
- Anconeus epitrochlearis
- Anomalous muscle which arises from medial border of olecranon & adjacent triceps & inserts into the medial epicondyle
- Canal of Guyon
what is ulnar tunnel syndrome characterized by
- numbness/paresthesia of the small and ulnar half of ring finger (ulnar palm and dorsum are spared)
- intrinsic muscle weakness (thenar spared)
site of compression of radial n.
FREAS (radial nerve)
* Fascia superficial to radiocapitallar joint
* Radial Recurrent Vessels (Leash of Henry)
* ECRB tendinous proximal margin at origin
* Arcade of Frohse (prox aponeurotic/tendinous edge of sup, most common site of PIN entrapment)
* Supinator (distal edge of)
last muscle innervated by radial n.
EIP
radial tunnel borders
- Borders:
- Proximal border – begins at radiocapitellar joint
- Distal border – arcade of Froshe
- Roof – BR
- Medial border – brachialis and biceps tendon
- Lateral border – ECRB, ECRL, BR
characteristic features of radial tunnel syndrome
- Pain at lateral forearm distal to lateral epicondyle
- Lack motor and sensory changes
motor and sensory innervation of PIN
motor
common extensors
* ECRB (often from radial nerve proper, but can be from PIN)
* Extensor digitorum communis (EDC)
* Extensor digiti minimi (EDM)
* Extensor carpi ulnaris (ECU)
deep extensors
* Supinator
* Abductor pollicis longus (APL)
* Extensor pollicus brevis (EPB)
* Extensor pollicus longus (EPL)
* Extensor indicis proprius (EIP)
sensory
* sensory fibers to dorsal wrist capsule - provided by terminal branch which is located on the floor of the 4th extensor compartment
* no cutaneous innervation
motor innervation of radial n. proper
triceps brachii, anconeus, brachioradialis, extensor carpi radialis longus, brachialis
provocative test for radial tunnel syndrome
- Provocative maneouvers
- Pressure over supinator muscle in supinated position
- Pain with resisted wrist or long finger extension
potential sites of PIN compression
- fibrous tissue anterior to the radiocapitellar joint
- between the brachialis and brachioradialis
- “leash of Henry”
- are recurrent radial vessels that fan out across the PIN at the level of the radial neck
- extensor carpi radialis brevis edge
- medio-proximal edge of the extensor carpi radialis brevis
- “arcade of Fröhse”
- which is the proximal edge of the superficial portion of the supinator
- supinator muscle edge
- distal edge of the supinator muscle
characteristics and provocative maneovers of PIN compression syndrome
- Weakness of PIN innervated muscles
- Sparing of BR, ECRL
- Pain in dorsal radial forearm
- no sensory changes
- Wrist extension demonstrates radial deviation
- Intact ECRL
- resisted supination
- will increase pain symptoms
what is wartenburg syndrome
- Compression of the superficial radial nerve ~9cm proximal to radial styloid where the nerve passes between BR and ECRL
- Characterized by:
- Dorsal radial forearm pain radiating to dorsoradial hand
- more common inwomen
- SRN compressed by scissoring action ofbrachioradialisandECRL tendonsduringforearm pronation
- provocative test: wrist flexion, ulnar deviation and pronation for one minute- De Quervain’s tenosynovitis: pain is not aggravated by wrist pronation,
which ligament in the hand is not involved in dupuytrens disease
cleland’s ligament (c for feiling
- dorsal to digital nerve
which ligaments are critical to prevent bowstring
A2 and A4
What are the extensor compartments of the wrist and associated pathology?
- EPB + APL = De Quervain’s tenosynovitis
- ECRB + ECRL = intersection syndrome
- EPL = drummer’s wrist, traumatic rupture with DR #
- EDC + extensor indicis = extensor tenosynovitis
- EDM = Vaughn-Jackson syndrome
- ECU = snapping ECU
what is the disi deformity and findings on xray
-
DISI (dorsal intercalated segmental instability)
- Division of the dorsal component of the SLIL results in gradual collapse of the scaphoid into flexion, while the lunate is pulled into extension to form the dorsal intercalated segment instability pattern
- Diagnosis of DISI deformity can be made with lateral wrist radiographs showing
- a scapholunate angle > 70 degrees. (N 30-60)
- DISI defined by radiolunate angle >15°
signs on xrays of SL ligament injury
- Widened SL distance
- gap >3mm with clenched fist view (terry thomas sign)
- Cortical ring sign
- caused by schaphoid malalignment
- Shortening of the scaphoid
- Scapholunate angle >70° (normal = 30-60)
- Lunate extension
- DISI defined by radiolunate angle >15°
which SL ligament component is the strongest
dorsal
most common pattern of wrist arthritis
SLAC 55%
what is SLAC wrist and radiographic classification
- scapholunate advanced collapse
- describes a pattern of wrist arthritis that occurs following a scapholunate ligament injury
Watson Classification
Stage I - radial styloid
Stage II - radioscaphoid joint
Stage III - capitolunate joint
[Stage IV - pancarpal involvment (controversial)]
Treatment of SLAC
- Stage I - scaphoid and radial styloid arthritis
- radial styloidectomy
- PIN and AIN denervation
- Stage II - scaphoid/scaphoid facet of radius arthritis
- proximal row carpectomy
- contraindicated with caputolunate arthritis because capitate articulates with lunate fossa of the distal radius
- contraindicated if there is an incompetent radioscaphocapitate ligament
- advantages - greater postop ROM (flexion, extension, total flexion/extension arc), lower complication rate
- others - earlier ROM no hardware
- scaphoid excision and 4 corner fusion
- advantages - greater radial deviation ROM, greater grip strength
- proximal row carpectomy
- Stage III - pan carpal arthritis
- scaphoid excision and 4 corner fusion
- wrist fusion
- wrist fusion gives best pain relief and good grip strength at the cost of wrist motion
what is the most common complication following PRC
synovitis and significant edema
major blood supply of scaphoid
-
major blood supply isdorsal carpal branch (branch of the radial artery)
- enters scaphoid in a nonarticular ridge on the dorsal surface and supplies proximal80% of scaphoidvia retrograde blood flow
- supplies proximal80% of scaphoidvia retrograde blood flow
- minor blood supply fromsuperficial palmar arch (branch of volar radial artery)
- entersdistal tubercle andsupplies distal 20% of scaphoid
pathomechanics of SNAC wrist development?
- In the normal wrist:
- Scaphoid links the proximal and distal carpal rows
- Proximal row moves with the scaphoid
- Scaphoid has a tendency to assume a flexed posture
- Capitate longitudinal load on the lunate is eccentric causing the lunate and triquetrum to extend
- These forces are balanced as long as the link between the scaphoid and lunate are intact
- Scaphoid links the proximal and distal carpal rows
- With scaphoid nonunion
- The distal scaphoid flexes
- The proximal scaphoid extends with the lunate and triquetrum
radiographic stages of SNAC wrist
- Stage I - radial styloid
- Stage II - proximal scaphocapitate joint
- Stage III - capitolunate joint
- Initially, degeneration occurs between the radial styloid and radial side of the distal scaphoid fragment
- Degeneration does not progress proximally in the radioscaphoid joint because the proximal scaphoid relationship with the lunate is maintained
- Degeneration progresses to the midcarpal joint starting with the proximal scaphocapitate joint then the capitolunate joint
which MC is the plate for wrist arthrodesis placed
3rd metacarpal shaft
optimal position of wrist fusion
10-15° of extension, slight ulnar deviation
What are the ulnar-sided procedures that can be considered in context of distal radius malunion?
- Hemiresection-interposition
- Ulnar shortening osteotomy
- ‘Wafer’ resection
- Sauve-Kapandji
- DRUJ fusion with proximal pseudoarthrosis
- Darrach
- Complete distal ulna resection
- Arthroplasty
describe humpback deformity of scaphoid
humpback deformity (distal pole flexes over the volar radioscaphocapitate ligament)
results from volar angulation of the proximal and distal poles of the scaphoid in the setting of scaphoid fracturethrough the waist
The dorsal component forms a ‘humpback’ which can be palpated
What is the treatment algorithm for scaphoid nonunion based on specific fracture characteristics?
- Delayed union (<6 months)
- Established nonunion without humpback
- Nonunion with humpback deformity; no AVN
- AVN without humpback deformity
- AVN with humpback deformity
- Delayed union (<6 months)
- ORIF with headless compression screw- Established nonunion without humpback
- ORIF with headless compression screw + bone graft (cancellous ICBG or distal radius)
- Nonunion with humpback deformity; no AVN
- ORIF via volar approach + corticocancellous bone graft
- AVN without humpback deformity
- Vascularized bone graft via volar or dorsal approach
- AVN with humpback deformity
- Vascularized medial femoral condyle bone graft via volar approach
- Established nonunion without humpback
Classification of Kienbock disease
- Lichtman Classification
- Stage I
- Normal xray
- MRI decreased signal T1
- Bone scan positive
- Stage II
- Lunate sclerosis
- Stage IIIa
- Lunate collapse (no scaphoid rotation)
- Carpal height maintained
- Stage IIIb
- Lunate collapse
- Carpal collapse
- Scaphoid rotation (hyperflexed, RS angle >60°)
- Cortical ring sign
- Capitate migrates proximal
- Decreased carpal height
- Stage IV
- Pancarpal arthritis (Kienbock’s disease advanced collapse)
- Stage I
treatment options for Kienbock’s disease based on stage of disease?
- Stage I (normal xray, mri decreased signal t1)
- Nonoperative (3 months immobilization)
- Stage II (lunate sclerosis)
- Radial shortening osteotomy
- If ulnar negative or neutral
- Capitate shortening
- If ulnar positive
- (vascularized bone graft)
- Radial shortening osteotomy
- Stage IIIa (lunate collapse)
- Same as Stage II
- Vascularized bone graft (dorsal pedicle)
- 4,5 ECA graft
- Vascularized pisiform
- Free vascularized medial femoral condyle
- Stage IIIb (lunate/capitate collapse and scaphoid rotation)
- Scaphocapitate fusion
- STT fusion
- PRC
- Stage IV (pancarpal arthritis)
- PRC
- Total wrist arthrodesis
What vascularized bone graft would you use for kienbock disease
dorsal 4 + 5 extensor compartment artery (ECA) pedicled VBG
What are surgical management options for DRUJ arthritis
- what are surgical management options for DRUJ arthritis
- darrach procedure
- indications
- preferred for low demand and nonreconstructable joint
- technique
- subperiosteal distal ulna exposure
- distal ulna resection just proximal to sigmoid notch
- preserve soft tissue
- TFCC, ECU sheath, periosteum
- indications
- hemiresection
- indications -required intact TFCC
- technique
- classic -resection of articular distal ulna with remainder left insitu including TFCC attachment
- hemi-resection interposition technique (HIT)
- resection as classic
- soft tissue interposition into void to prevent radioulnar convergence (capsular flap or free tendon)
- sauve-kapandji procedure
- indications - preferred for young, active patient with nonreconstructable joint
- technique
- dorsal or ulnar approach preserving soft tissue
- identify and protect the dorsal cutaneous branch of the ulnar nerve
- ulnar neck resection just proximal to sigmoid (~10-15mm)
- sigmoid notch and ulnar head prepared for fusion (Cancellous bone)
- DRUJ fusion with 2 k-wires or 3.5mm screw (neutral ulnar variance)
- pronator quadratus interposed in osteotomy site (prevents re-ossificaiton)
- FCU slip can be tenodesed through drill hole in ulnar stump to prevent instability
- partial ulnar head arthroplasty
- indication - isolated DRUJ arthritis without instability
- failed HIT
- indication - isolated DRUJ arthritis without instability
- total ulnar head arthroplasty
- indications - painful instability after failed resection, isolated instability
- requires stability from native soft tissues
- total DRUJ arthroplasty
- indications - incompetent native soft tissues, salvage option after failed distal ulnar resection
- darrach procedure
which tendon could inhibit reduction of DRUJ
ECU
stabilizing structures of DRUJ (8)
- bone contour (sigmoid notch of radius and ulnar head)
- TFCC
- ulnocarpal ligament complex
- ECU
- ECU tendon sheath
- pronator quadratus
- interosseous membrane
- DRUJ joint capsule
management options for DRUJ instability
- nonop
- acute dislocation
- closed reduction and splinting in stable position for 6 weeks
- dorsal radioulnar ligament injury - splint midsupination
- volar radioulnar dislocaiton - splint midpronation
- closed reduction and splinting in stable position for 6 weeks
- acute dislocation
- operative
- acute DRUJ instability indications
- irreducible
- open reduction +/- DRUJ pinning +/- TFCC repair +/- ulnar styloid fracture fixation
- associated fractures
- ORIF of associated fractures often resolves the instability
- if remains unstable pin in reduced position
- TFCC tear
- open or arthroscopic repair
- open - dorsal interval between 5 & 5 compartment, TFCC repaired to distal ulnar with anchor or suture tunnels
- reconstruction if repair fails
- open or arthroscopic repair
- irreducible
- chronic DRUJ instability
- in absence of arthritis
- distal radius malunion
- indications for correction = >20° of dorsal angulation (controversial)
- correct distal radius malunion then assess DRUJ stability
- if still unstable reconstruct the DRUJ
- reconstruction
- indications - TFCC or radioulnar ligament repair failure, unrepairable
- Adams procedure +/- notchplasty (if flat lesser sigmoid)
- dorsal approach between 5-6 compartments and PL graft radius and ulna
- bain procedure
- indication
- chronic DRUJ instability with a TFCC foveal tear and stable radial attachment
- positive arthroscopic hook and trampoline test
- technique
- dorsal approach via 5th extensor compartment, PL graft in TFCC and ulna
- indication
- distal radius malunion
- in presence of arthritis
- darrach with ulnar stump stabilization
- sauve-kapandji
- in absence of arthritis
- acute DRUJ instability indications
xrays to assess for ulnocarpal abutment syndrome
- recommended views
- AP radiograph with wrist in neutral supination/pronation and zero rotation
- required to evaluate ulnar variance
- pronated grip view
- increases radiographic impaction
- AP radiograph with wrist in neutral supination/pronation and zero rotation
- findings
- ulna positive variance
- sclerosis of lunateand ulnar head
surgical management of ulnocarpal abutment syndrome
- Ulnar shortening osteotomy
- Technique
- Subcutaneous approach to the ulna
- Osteotomy at junction of distal and middle 1/3
- Compression plate
- Volar surface preferred
- Goal of 0 to -1mm ulnar variance
- Advantages
- Addresses ulnar styloid carpal impaction concomitantly
- Decreases dorsal subluxation of distal ulna
- Larger shortening can be achieved compared to wafer
- Stabilizes ulnar ligament complex
- Preferred if associated LT ligament injury
- Disadvantages
- Nonunion
- Hardware irritation
- Technique
- Wafer procedure
- Technique
- Open or arthroscopic
- Resection of thin wafer of dome of ulnar head
- Advantage
- Less revision compared to shortening osteotomy (hardware removal)
- No nonunion
- Disadvantage
- Limit resection to 2-3mm
- Does not address associated ulnar styloid carpal impaction
- Does not improve dorsal ulnar subluxation
- Does not tighten ulnar ligament complex
- Technique
What are the components of TFCC
- Articular disc
* Extends between the volar and dorsal radioulnar ligaments (hammock) - Meniscus homologue
- Volar and dorsal radioulnar ligaments
* Superficial and deep (ligamentum subcruentum)
* Major stabilizers of the DRUJ - Sheath of ECU
- Ulnar capsule (ulnar collateral ligament)
* Arises from the ulnar styloid and extends between the ulnotriquetral ligament and the ECU sheath - Ulnolunate and ulnotriquetral ligaments (volar)
P/E Findings for TFCC
- Prominent ulna
- Fovea sign
- Palpation of the depression volar between ulnar styloid, FCU and pisiform
- Tenderness suggests:
- Tear of ulnotriquetral ligament
- Foveal disruption of TFCC
- Chondromalacia of ulnar aspect lunate
- Suggestive of ulnocarpal impaction
- Ulnocarpal stress test
- Ulnar deviation with axial loading in alternating supination and pronation
- Positive grind test
- Clicking, crepitus or pain with passive supination and pronation
- Lunotriquetral shuck test
- Pain and laxity when examiner grasps the pisiform/triquetrum and lunate with opposite hands and translates volar and dorsal
common mechanism for TFCC tear
extended wrist with forearm pronation
Treatment of TFCC tears
- Nonoperative
- Most tears are initially treated nonoperative
- Operative
- Contraindications:
- Severe OA
- Previous infection
- Severe osteoporosis of ulnar head
- Open
- Indicated when fixing distal radius fracture or surgeon not familiar with arthroscopy
- Arthroscopic
- Palmar 1A – debridement
- Palmer 1B, C, D – repair
- Transosseous or suture anchor fixation
- Ulnar positive wrists
- Perform ulnar shortening osteotomy or wafer procedure at time of TFCC repair
- Better outcomes
- Perform ulnar shortening osteotomy or wafer procedure at time of TFCC repair
- Contraindications:
What are the components of the UCL and RCL ligaments in thumb
[JAAOS 2011;19:287-296]
- Proper collateral ligament
* Taut in flexion - Accessory collateral ligament and volar plate
* Taut in extension
What is a Stener lesion?
[JAAOS 2011;19:287-296]
- Distal edge of the avulsed UCL is displaced proximal to the adductor aponeurosis
* Blocked from reapproximation to its insertion on the proximal phalanx - Surgical management is recommended
classification for CMC arthritis
Eaton and Littler Classification of Basilar Thumb Arthritis
- Stage I
- Normal joint with widening
- Synovitis, effusion, ligamentous laxity
- Normal joint with widening
- Stage II
- Mild joint narrowing
- Mild subchondral sclerosis
- Subchondral cysts and/or periarticular debris
- Stage III
- Severe joint space narrowing
- Subchondral sclerosis/cysts
- Larger periarticular debris
- Stage IV
- Involves scaphotrapezial joint
What is the direction of trapeziometacarpal (TM) dislocation and ligament most commonly injured
[J Hand Surg Eur Vol. 2015 Jan;40(1):42-50]
Dorsoradial
dorsoradial ligament
What is the pattern of injury in a Bennett fracture dislocation?
[J Hand Surg Eur Vol. 2015 Jan;40(1):42-50]
- Anteromedial (volar-ulnar) fragment
- Smaller (less articular surface area)
- Nondisplaced, attached to volar oblique ligament
- Metacarpal fragment
- Larger (greater articular surface area)
- Displaced
- Proximal, dorsal and radial
What are the deforming forces of the metacarpal fragment in a Bennett fracture?
[J Hand Surg Eur Vol. 2015 Jan;40(1):42-50]
- APL = proximal, dorsal, radial
- Adductor pollicis = narrowing of 1st web space
What is the open approach for fixation of a Bennett fracture?
Wagner approach
- Junction of the glabrous and nonglaborus skin
- Elevate thenar muscles and perform capsulotomy
What is the mechanism of injury for dorsal fracture dislocation of the PIP joint?
[JAAOS 2013;21:88-98]
- Extension (most common)
- Axial load of a flexed PIP joint
What structures are injured in a dorsal fracture dislocation of the PIP joint?
[JAAOS 2013;21:88-98]
- Volar plate rupture or avulsion of volar base off middle phalanx
- Volar avulsion of variable size (loss of buttress effect)
How is the stability of a dorsal PIP fracture dislocation determined?
[JAAOS 2013;21:88-98]
- Stable
- Articular surface <30% involvement
- Clinical stability = stable throughout ROM
- Tenuous
- Articular surface = 30-50% involvement
- Clinical stability = Requires ≤30° of PIP flexion to maintain reduction
- Unstable
- Articular surface >50% involvment
- Clinical stability = Requires >30° of PIP flexion to maintain reduction
What is the management of dorsal PIP fracture dislocations based on stability?
[JAAOS 2013;21:88-98]
- Stable
* Buddy taping - Tenuous
- Extension block splinting (if no hinging)
- Prevents extension of the PIPJ into the range where it is unstable while permitting motion within the stable range
- Unstable
- Operative options
- Extension block pinning or transarticular pinning +/- percutaneous pinning of large fracture fragment
- Indicated when concern for closed reduction failure or digit will not accommodate extension block splint (swollen, short, small digit)
- Dynamic distraction and external fixation (Suzuki splint)
- ORIF
- Large fragments
- Volar plate arthroplasty
- Comminuted and impacted volar fragment
- <50% articular surface involvement
- Hemi-hamate resurfacing arthroplasty
- Comminuted and impacted volar fragment
- >50% articular surface involvement
- Extension block pinning or transarticular pinning +/- percutaneous pinning of large fracture fragment
What is the mechanism of injury for volar PIP fracture dislocation?
- Hyperflexion
- Axial load of an extended PIP joint
What structures are injured in a volar PIP fracture dislocation?
- Central slip rupture or avulsion of dorsal base of middle phalanx
- Dorsal avulsion of variable size
What is the management of volar PIP fracture dislocation?
- Stable and small minimally displaced fracture
- <50% articular surface and <2mm displacement
- PIP joint splinting
- Stable and large or displaced fracture
- >50% articular surface and >2mm displacement
- CRPP or ORIF
- Unstable with minimally displaced fracture
* Dynamic distraction and external fixation
What is the usual deformity of proximal phalanx fractures?
Apex volar
- Proximal fragment flexes due to interosseous attachments
- Distal fragment extends due to extensor central slip
What is the usual deformity of middle phalanx fractures?
- Apex dorsal if fracture proximal to FDS insertion
- Apex volar if fracture distal to FDS insertion
what is a seymour fracture
- displaced distal phalangeal physeal fractures with an associated nailbed injury.
- resuls from hyperflexion
- presents asmallet deformity(i.e. apex dorsal) due to
- terminal tendon attaches to proximal epiphyseal fragment
- FDP attaches to distal fragment
Describe the pulley system for FDP and FDS tendons?
[JAAOS 2018;26:e26-e35]
A1 - MCP volar plate
A2 - proximal phalanx
C1 - between A2-A3
A3 - PIP volar plate
C2 - between A3-A4
A4 - middle phalanx
C3 - between A4-A5
A5 - DIP volar plate
What flexor pulleys are most important for digital motion and power?
[JAAOS 2018;26:e26-e35]
A2 and A4
Describe the pulley system for FPL?
[JAAOS 2018;26:e26-e35]
A1 - MCP volar plate
Oblique pulley - proximal half of proximal phalanx
A2 - IP volar plate
What pulley is most important for preventing bowstringing of the FPL?
[JAAOS 2018;26:e26-e35]
Oblique pulley
What are the 5 zones of the flexor tendon system?
[JAAOS 2018;26:e26-e35]
Zone 1 - distal to FDS insertion
Zone 2 - FDS insertion to proximal A1 pulley
Zone 3 - proximal A1 pulley to distal transverse carpal ligament
Zone 4 - carpal tunnel
Zone 5 - proximal transverse carpal ligament to musculotendinous junction
What are the pathways and phases of (flexor) tendon healing?
[JAAOS 2018;26:e26-e35]
Pathways
- Intrinsic = tenocytes within the tendon
- Extrinsic = inflammatory cells outside the tendon
- Implicated in adhesions/scarring
Phases
- Inflammatory (0-72h)
- Strength of repair is equivalent to strength of suture repair
- Proliferative (72h-4 weeks)
- Type III collagen laid down
- Strength increases
- Remodeling phase (>4 weeks - 112 days)
- Type I collagen laid down
- Strength increases
- Does not reach preinjury
What are the pathological changes that occur in the tendon and the tendon sheath in trigger finger (stenosing tenosynovitis)?
[JAAOS 2015;23:741-750]
- Tendon sheath
- Fibrocartilaginous metaplasia
- Cartilage degradation
- Vascular ingrowth
- Tendon
- Chronic degenerative tears
- Absence of inflammatory cells
What pulley is most commonly involved in trigger finger?
[JAAOS 2015;23:741-750]
A1 pulley
What are the four cardinal signs of Kanavel in flexor tendon sheath infections?
[JAAOS 2012;20:373-382]
- Symmetric swelling of entire digit
- Tenderness along course of tendon sheath
- Semiflexed posture
- Pain with passive extension of digit
What is the most commonly involved cord in the hand in Dupuytren disease?
[JAAOS 2011;19:746-757]
Pretendinous cord
[Normal fascial bands become pathologic cords]
What are the clinically relevant cords in Dupuytren Disease?
- Pretendinous cord = MCP contracture
- Central cord = PIP contracture
- Lateral cord = PIP or DIP contracture
- Natatory cord = web space contracture
- Spiral cord = displaces NV bundle superficial and to midline
* MCP and PIP contracture
Patients with bilateral Dupuytren disease commonly have Garrod nodes (knuckle pads over PIP) which is associated with increased incidence of which ectopic diseases?
[JAAOS 2011;19:746-757]
- Peyronie disease (penile fibromatosis)
- Ledderhose disease (plantar fibromatosis)
What is the management of caput ulna syndrome?
[JAAOS 2006;14:65-77] [J Hand Surg Am. 2011;36(4):736–747]
- Darrach procedure
- Favoured in low demand, elderly patients
- Main concern in RA is ulnar translation of carpus (weak ligamentous support)
- Sauve-Kapandji
- Favoured in active, younger patients
- Main concern in RA is less predictable fusion
What are two clinical poor prognostic signs for reimplantation?
[JAAOS 2015;23:373-381]
- Red line sign
- Red stripe along the mid lateral aspect of the avulsed digit
- Represents hemorrhage along the vessel
- Ribbon sign
- Tortuous, spiraled blood vessels are seen
- Indicates significant intimal injury
What is the most reliable test to diagnose a Boutonniere deformity?
[JAAOS 2015;23:623-632]
Elson test
- The examiner holds the PIP joint in 90° of flexion and instructs the patient to actively extend the DIP joint
- With an intact extensor mechanism, holding the PIP joint in 90° of flexion causes slack in the lateral bands as they are held distally by their attachments to the central slip
- The patient is unable to generate any extension power at the DIP joint
- With a boutonnière injury, flexion of the PIP joint does not advance the lateral bands distally secondary to disruption of the central slip
- Tension is generated in the terminal tendon because of the disrupted central slip
- Therefore, the patient is able to generate an abnormal amount of active extension at the DIP joint with the PIP joint held in flexion
What test is used to assess for intrinsic muscle tightness (ie. in Swan neck deformity)?
[JAAOS 2015;23:623-632]
Bunnell test
- A patient with intrinsic muscle tightness will have a decrease in passive and active flexion of the PIP joint with the MP joint held in extension
What is the classification of postaxial polydactyly?
[JAAOS 2018;26:75-82]
Type A
- Well-formed digit with osseous connection
Type B
- Incompletely-formed with soft tissue connection
- Nonfunctional
What is the Wassel classification of preaxial polydactyly?
[JAAOS 2018;26:75-82]
Type I
- Bifid distal phalanx
Type II
- Duplicated distal phalanx (2nd most common)
Type III
- Bifid proximal phalanx
Type IV
- Duplicated proximal phalanx (most common)
Type V
- Bifid metacarpal
Type VI
- Duplicated metacarpal
Type VII
- Any triphalangeal thumb
What are the radiographic parameters to be assessed on plain film for craniocervical dissociation?
[JAAOS 2014;22:718-729]
- Harris lines (Harris rule of 12s)
- Basion-dens interval
- Normal = <12mm
- Distance from basion to tip of dens
- Basion-axis interval
- Normal = 4-12mm
- Distance between line parallel to posterior cortex of C2 and basion
- Powers ratio [Orthobullets]
- Distance from basion to posterior arch C1/distance from opisthion to anterior arch C1
- Normal = 1
- >1 = anterior dislocation
- <1 = posterior dislocation, dens fracture, ring of atlas fracture
- Wackenheim line
- Line parallel along the posterior portion of the clivus to the upper cervical spine
- Normal = tip of dens is <1-2mm from Wackenheim line
What are the radiographic parameters to assess for atlas fractures?
[JAAOS 2014;22:718-729]
- Atlanto-dens interval (ADI)
- Distance between anterior dens and posterior aspect of anterior arch of C1
- Normal = <3mm in adults
- >3mm indicates transverse ligament disruption and C1-C2 instability
- Lateral atlanto-dens interval
- Distance between the lateral surface of the dens and the medial surface of the lateral mass of C1
- Normal = <2mm of asymmetry
- Combined lateral mass overhang
- Combined horizontal distance from lateral border of C1 to lateral border of C2 on open mouth radiographs or coronal CT
- Normal = <7mm
- >7mm indicates transverse ligament rupture and C1-C2 instability
What is the classification system for atlas (C1) fractures?
[Orthobullets]
Landells Classification
- Type I - isolated anterior or posterior arch fracture
- Type II - Jefferson burst fracture (bilateral anterior and posterior arch fractures)
- Type III - unilateral lateral mass fracture
What is the classification system for Odontoid fractures?
[JAAOS 2010;18:383-394]
- Anderson and D’Alonzo Classification
- Type I - odontoid tip fracture
- Oblique fracture due to bony avulsion of the alar ligament
- Type II - base of the dens fracture
- Does not involve the C2 superior articular facet
- High non-union rate due to watershed area
- Type III – C2 body fracture
- Does involve the C2 superior articular facet
- Grauer modification
- Type IIA - transverse fracture, <1mm displacement
- Type IIB- oblique fracture extending from anterosuperior to posteroinferior
- Type IIC- oblique fracture extending from anteroinferior to posterosuperior
- May be associated with significant anterior comminution
What is the treatment based on odontoid fracture type?
[JAAOS 2010;18:383-394]
- Type I
- Stable fractures (at least one alar ligament and the transverse ligament is intact)
- Cervical collar
- Unstable fractures (associated craniocervical dissociation)
- Posterior C0-C2 fusion
- Type II
- Young patient
- No risk factors for nonunion = halo immobilization
- Risk factors for nonunion = surgery
- Elderly patient
- Surgical candidate = surgical stabilization
- Posterior C1-C2 fusion
- Not surgical candidate = cervical orthosis
- Results in fibrous union in most cases
- Halo vest is associated with high rate of morbidity and mortality in elderly
3. Type III
- Surgical candidate = surgical stabilization
- Cervical orthosis
What is the classification for traumatic spondylolisthesis of the axis (Hangman’s Fracture)?
Levine and Edwards Classification
- Type I
- Minimally displaced pars interarticularis fracture
- Translation <3mm of C2, no angulation
- MOI = axial load and hyperextension
- Type Ia
- Oblique fracture through one pars interarticularis and anterior to the pars within the body of the contralateral side (unstable)
- Type II
- Translation >3mm of C2
- MOI – axial load and hyperextension followed by flexion
- Type IIa
- Angulation (kyphosis) more than translation
- MOI = flexion-distraction
- Type III
- Similar pars fracture as type I plus C2/C3 facet dislocation
- MOI = flexion distraction followed by hyperextension
- ***Note: hyperextension causes the pars fracture and flexion causes PLL and disc rupture
What is the treatment of traumatic spondylolisthesis of the axis (Hangman’s Fracture)?
[JAAOS 2014;22:718-729]
Type I - hard cervical orthosis (12 weeks)
Type Ia - halo immobilization
Type II - halo immobilization (12 weeks)
Type IIa
- C2-C3 ACDF or posterior fixation [JAAOS 2014;22:718-729]
- Reduction with gentle axial load + hyperextension, then compression halo immobilization for 6-12 weeks [Orthobullets]
Type III - posterior reduction and stabilization
- C2-C3 or C1-C3 fusion
What is the classification system for subaxial cervical spine trauma?
- Allen and Ferguson
- 6 classes based on mechanism of injury and static radiographs (used in research)
- Flexion-compression, vertical compression, flexion-distraction, extension-compression, extension-distraction, lateral flexion
- Subaxial Injury Classification System (SLIC)
- Three components
- Morphology
- Integrity of the discoligamentous complex
- Neurological status
- Score dictates treatment
- <4 = conservative treatment
- 4 = treatment at discretion of surgeon
- >4 = surgical treatment
Describe the Denis three-column model of spinal stability
[Rockwood and Green 8th ed. 2015]
- Anterior column = anterior half/part of vertebral body/disc and ALL
- Middle column = posterior half/part of vertebral body/disc and PLL
- Posterior column = posterior elements including pedicles, facets, lamina, spinous process and ligaments
***NOTE – based on this system fractures extending into the middle column are largely considered unstable
What is the classification system for thoracolumbar spine injuries?
[JAAOS 2010;18:63-71]
- Thoracolumbar Injury Classification and Severity Score (TLICS)
- 3 injury characteristics
- Injury morphology
- Neurological status
- Integrity of PLC
- Score dictates treatment
- <4 = nonsurgical
- 4 = nonsurgical or surgical
- >4 = surgical
- AO Thoracolumbar Classification (Morphology)
- TYPE A = Compression Injuries
- A0 = Minor, nonstructural fractures
- Fractures which do not compromise the structural integrity of the spinal column (eg. transverse process and spinous processes)
- A1 = Wedge-compression
- Fracture of a single endplate without involvement of the posterior wall of the vertebral body
- A2 = Split
- Fracture of both endplates without involvement of the posterior wall of the vertebral body
- A3 = Incomplete burst
- Fracture with any involvement of the posterior wall; only a single endplate fractured
- Vertical fracture of the lamina is usually present and does not constitute a tension band failure
- A4 = Complete burst
- Fracture with any involvement of the posterior wall and both endplates
- Vertical fracture of the lamina is usually present and does not constitute a tension band failure
- A0 = Minor, nonstructural fractures
- TYPE B = Distraction Injuries
- B1 = Transosseous tension band disruption (Chance fracture)
- Monosegmental pure osseous failure of the posterior tension band
- B2 = Posterior tension band disruption
- Bony and/or ligamentary failure of the posterior tension band together with a Type A fracture
- Type A fracture should be classified separately
- B3 = Hyperextension
- Injury through the disc or vertebral body leading to hyperextended position of the spinal column
- Commonly seen in ankylotic disorders
- Anterior structures, especially ALL are ruptured but there is a posterior hinge preventing further displacement
- B1 = Transosseous tension band disruption (Chance fracture)
- TYPE C = Translation Injuries
- C = Displacement/dislocation
- There are no subtypes because various configurations are possible due to dissociation/dislocation
- Can be combined with subtypes of A or B
- C = Displacement/dislocation
What is the ASIA spinal cord injury scale?
Asia A: Complete
- No motor or sensory function preserved in sacral elements
Asia B: Incomplete
- Sensory but not motor function preserved below neurological level
Asia C: Incomplete
- Greater than half the muscles below affected level are < antigravity power (<3/5)
Asia D: Incomplete
- Greater than half the muscles below affected level are > antigravity (>3/5)
Asia E: Normal
What are the clinical features of an upper motor neuron vs lower motor neuron lesion?
What is the kyphosis line (K-line) on a lateral radiograph and what is its significance in OPLL?
[JAAOS 2014;22:420-429]
- Line from center of the spinal canal at C2 to center of canal at C7
- Assesses the affect of the size of OPLL and the cervical lordosis
- Negative K-line = OPLL protrudes posterior to the K-line
- Positive K-line = OPLL protrudes anterior to the K-line
- Significance = negative K-line is a negative predictor of outcome for posterior surgery alone
What are the locations of lumbar disc herniations?
[Orthobullets]
- Central
- Causes back pain
- Can cause cauda equina
- Paracentral (posterolateral)
* Affects the descending nerve root (L4/5 affects L5) - Foraminal (far lateral)
* Affects the exiting nerve root (L4/5 affects L4)
What are the 3 lumbar disc herniation morphologies?
[AAOS comprehensive review 2, 2014]
- Protrusion
* Eccentric bulging through an intact anulus fibrosus - Extrusion
* Disc material crosses the disrupted anulus fibrosus but is continuous with the disc space - Sequestered
- Free fragment
- Disc material is not continuous with the disc space
What are the radiographic features of Rheumatoid spine?
[JAAOS 2005;13:463-474]
- Atlantoaxial impaction
- McCrae’s line
- Line between basion and opisthion
- Normal = tip of dens should be below line
- McGregor’s line
- Line between hard palate and base of the occiput
- Abnormal = tip of dens 4.5mm above line
- Ranawat Index
- Distance from midpoint of C2 pedicle along centre of odontoid to horizontal line through C1
- Abnormal = <15mm in males, <13mm in females
- Cervicomedullary angle (MRI)
- Angle between anterior aspect of cervical cord and anterior medulla
- <135° indicates impending neurological impairment
- Clark’s station
- C2 divided into thirds (1 is superior, 3 is inferior)
- Abnormal = anterior ring of C1 is in the 2nd or 3rd station
- Simplest method to use as the relationship does not change in flexion, extension or neutral
- ***McRae and McGregors inaccurate with odontoid erosion
2. Atlantoaxial instability - ADI (atlantodental interval)
- Distance between the anterior dens and the posterior anterior arch of C1
- Abnormal = >3.5mm
- >5mm suggests instability
- >10mm suggests complete loss of ligamentous integrity
- PADI/SAC
- Posterior atlantodental interval/space available for the cord
- Distance between the posterior dens and the posterior arch of C1
- Abnormal = ≤14mm is an indication for surgery
- Need 14mm for canal (10 cord, 1 dura, 1 CSF)
- <10mm assoc with poor neuro outcomes
- ≥14mm assoc with excellent neuro outcomes
- Better predictor of neuro outcomes than ADI
- ***ADI and PADI can not evaluate cord compression by soft tissues (i.e. pannus)
3. Subaxial instability - C2/3 and C4/5 most commonly involved
- Kyphosis
- “staircase” when multiple levels involved
- Facet joint erosions and widening
- Spindling of the spinous processes
- Subluxation
- Abnormal = >4mm or 20% listhesis of vertebral body diameter
What are the indications for surgery in Rheumatoid Spine?
[JAAOS 2005;13:463-474]
- Intractable pain
- Neurologic deficits
- ADI >10 [Orthobullets]
- PADI ≤14mm
- Dens migration ≥5mm rostral to McGregor’s line
- Subaxial subluxation with canal diameter ≤14mm
- Cervicomedullary angle <135°
***Increased function and lifespan compared to non-op
What are the differentiating features of DISH compared to Ankylosing Spondylitis?
[Orthobullets]
What scoring system can help predict prognosis and guide treatment decisions in metastatic spine disease?
[JAAOS 2015;23:38-46]
Modified Tokuhashi scoring system
* high score is good, low score is bad
- 6 components
- Karnofsky performance status
- Number of extraspinal metastases foci
- Number of metastases in the vertebral body
- Metastases to the major internal organs
- Primary site of cancer
- Palsy (neurological status)
- Score:
- 0-8 = life expectancy ≤ 6 months
- Conservative treatment versus palliative
- 9-11 = life expectancy ≥ 6 months
- Palliative surgery
- 12-15 = life expectancy ≥1 year
- Excisional surgery
- 0-8 = life expectancy ≤ 6 months
What classification system can predict spinal instability in spine tumors?
[JAAOS 2015;23:38-46]
SINS (Spinal Instability Neoplastic Score)
- 6 components
- Location
- Pain
- Bone lesion
- Radiographic spinal alignment
- Vertebral body collapse
- Posterolateral involvement of spinal elements
- Score:
- 0-6 = stable
- 7-12 = impending instability
- 13-18 = unstable
What is the NOMS framework?
[The Oncologist 2013;18:744 –751]
- A decision making framework for making treatment decisions in patients with spinal metastasis
- Considers 4 factors:
- Neurologic
- Degree of spinal cord compromise
- Radiographic assessment (degree of epidural spinal cord compression)
- Degree of spinal cord compromise
- Oncologic
- Radiosensitive vs. radioresistant tumors
- Mechanical (instability)
- Mechanical pain (movement related)
- SINS score
- Systemic
- Ability of patient to tolerate intervention
- Determines treatment options based on above factors including:
- Ability of patient to tolerate intervention
- Conventional external beam radiation
- Stereotactic radiosurgery
- Decompression/separation surgery
- Stabilization surgery
What is the classification system for adolescent idiopathic scoliosis?
[AOfoundation]
Lenke classification
- Requires upright AP and lateral and supine left and right bending
- 4 steps
- STEP 1 – divide spine into 3 regions
- Proximal thoracic – Apex at T3, T4 or T5
- Main thoracic – Apex between T6 and the T11-T12 disc
- Thoracolumbar/Lumbar – T/L apex between T12 and L1, and lumbar apex between the L1-L2 disc and L4
- STEP 2 – determine the major and minor curves
- Curve with largest Cobb angle is the major curve
- Other curves are minor
- STEP 3 – determine if minor curves are structural or nonstructural
- Curve is structural if:
- Residual curve >25° in coronal plane on the bending film
- Kyphosis >20 in sagittal plane (regardless of coronal flexibility)
- Curve is structural if:
- STEP 4 – based on above information determine the curve type
- For LENKE 4 – Main Thoracic OR TL/L can be the Major Curve
- STEP 5 – determine lumbar and sagittal modifiers
- Lumbar modifier – draw the CSVL and compare to lumbar apical vertebra
- A = line is between pedicles of apical vertebra
- B = line touches pedicle
- C = line does not touch vertebra or pedicle
- Sagittal modifier – assess kyphosis from T5-T12
- ‘-‘ (hypo) = kyphosis <10
- ‘N’ (Normal) = kyphosis 10-40
- ‘+’ (hyper) = kyphosis >40
- Lumbar modifier – draw the CSVL and compare to lumbar apical vertebra
- STEP 1 – divide spine into 3 regions
What are the radiographic parameters to be evaluated during surgical planning in AIS?
[Scoliosis Research Society]
- Cobb angle
* Superior endplate of the upper end vertebra, to the inferior endplate of the lower end vertebra - End vertebra
- Define the ends of a curve in a frontal or sagittal projection
- Cephalad EV – first vertebra from apex whose superior surface is tilted maximally toward the concavity of the curve
- Caudal EV – first vertebra from apex whose inferior surface is tilted maximally toward the concavity of the curve
- Neutral vertebra
* Vertebra without axial rotation - Stable vertebra
* Thoracic or lumbar vertebra cephalad to a lumbar scoliosis that is most closely bisected by CSVL assuming the pelvis is level - Apical vertebra
* Vertebra most deviated laterally from the CSVL
What are the indicators of curve progression in early onset idiopathic scoliosis?
[JAAOS 2006;14:101-112]
- Rib-Vertebra Angle Difference (RVAD)
- AKA Mehta angle
- Most reliable indicator
- RVAD = angle formed between a line perpendicular to the end plate of the apical vertebra and a line from the midpoint of the rib head to the midpoint of the rib neck
- Concave RVA – Convex RVA = RVAD
- RVAD >20° = high risk of curve progression
- RVAD <20° = curve more likely to resolve
2. Phase 2 relationship - Rib head overlaps the apical vertebra
- Implies that progression is certain
- Cobb angle >20o
What are the causes of congenital scoliosis?
[OKU Spine 5]
- Failure of vertebral body formation
- Hemivertebra (unilateral formation failure)
- Fully segmented, partially segmented, unsegmented
- Segmented if normal disc present
- Incarcerated or nonincarcerated
- Incarcerated = within the curve
- Pedicle of hemivertebra is inline with adjacent pedicles
- Adjacent vertebral bodies conform in their shape
- Less disruption of spinal curvature
- Nonincarcerated = outside of the curve
- Pedicle of hemivertebra is outside the line of adjacent pedicles
- Typically fully segmented
- More disruption of spinal curvature (adjacent vertebrae do not accommondate)
- Incarcerated = within the curve
- Fully segmented, partially segmented, unsegmented
- Wedge vertebra (unilateral partial formation failure)
- Failure of vertebral body segmentation
- Block vertebra
- Unilateral bars
- Unilateral bars with contralateral hemivertebra
- Multiple congenital rib fusions (thoracogenic)
