Hands

Question 1

Flexor Tendon Injuries

Phases of tendon healing [3]

Answer 1

Phase: Inflammatory

• Days 0-5
• Histology = cellular proliferation
• Strength = none

Phase: Fibroblastic

• Days: 5-28
• Histology = fibroblastic proliferation with disorganized collagen
• Strength = increasing

Phase: Remodeling

• Days : >28
• Histo: linear collagen organization
• Strength: will tolerate controlled active motion

Question 2

Jersey Finger

1. define

2. Epidemiology - finger most commonly involved and why?

3. Pathophysiology

Answer 2

1. Refers to an avulsion injury of FDP from insertion at base of distal phalanx
   * a Zone I flexor tendon injury
2. Epidemiology

• Ring finger involved in 75% of cases
  
  • during grip ring fingertip is 5 mm more prominent than other digits in ~90% of patients
    
    • therefore ring finger exposed to greater average force than other fingers during pull-away

3. Pathophysiology
   * FDP muscle belly in maximal contraction during forceful DIP extension

Question 3

Jersey Finger

Classification: Leddy and Packer Classification

Answer 3

Type I:

• FDP tendon retracted to palm. Leads to disruption of the vascular supply
• Rx: Prompt surgical treatment within 7 to 10 days

Type II

• FDP retracts to level of PIP joint
• Rx: Attempt to repair within several weeks for opitmal outcome

Type III

• Large avulsion fracture limits retraction to the level of the DIP joint
• Rx: Attempt to repair within several weeks for opitmal outcome

Type IV

• Osseous fragment and simultaneous avulsion of the tendon from the fracture fragment (“Double avulsion” with subsequent retraction of the tendon usually into palm)
• Rx: If tendon separated from fracture fragment, first fix fracture via ORIF then reattach tendon as for Type I/II injuries

Type V

• Ruptured tendon with bone avulsion with bony comminution of the remaining distal phalanx (Va, extraarticular; Vb, intra-articular)

Question 4

Jersey Finger

1. Treatment
2. Complications

Answer 4

Operative

• direct tendon repair or tendon reinsertion with dorsal button
  
  • indications : acute injury (< 3 weeks)
  • technique : advancement of > 1 cm carries risk of a DIP flexion contracture or quadrigia
  • postoperative rehab should include either:
    
    • early patient assisted passive ROM (Duran) or
    • dynamic splint-assisted passive ROM (Kleinert)
• ORIF fracture fragment
  
  • indications: types III and IV (for type IV then repair as for Type I/II injuries)
  • techniques: with K-wire, mini frag screw or pull out wire / examine for symmetric cascade once fixation completed
• two stage flexor tendon grafting
  
  • indications: chronic injury (> 3 months) in patient with full PROM of the DIP joint
• DIP arthrodesis
  
  • indicated as salvage procedure in chronic injury (> 3 months) with chronic stiffness

Complications

• Quadrigia
  
  • advancement of > 1 cm carries risk of a DIP flexion contracture or quadrigia

Question 5

Flexor Tendon Injuries

Muscles

blood supply

Answer 5

Anatomy: Muscles

• flexor digitorum profundus (FDP)
  
  • functions as a flexor of the DIP joint
  • assists with PIP and MCP flexion
  • shares a common muscle belly in the forearm
• flexor digitorum superficialis (FDS)
  
  • functions as a flexor of the PIP joint
  • assists with MCP flexion
  • individual muscle bellies exist in the forearm
    
    • FDS to the small finger is absent in 25% of people
• flexor pollicis longus (FPL)
  
  • located within the carpal tunnel as the most radial structure
• flexor carpi radialis (FCR)
  
  • primary wrist flexor\
  • inserts on the base of the second metacarpal
  • closest flexor tendon to the median nerve
• flexor carpi ulnaris (FCU)
  
  • primary wrist flexor
  • inserts on the pisiform, hook of hamate, and the base of the 5th metacarpal

Blood supply

• 2 sources exist
  
  • diffusion through synovial sheaths
    
    • occurs when flexor tendons are located within a sheath
    • it is the more important source distal to the MCP joint
• direct vascular supply
  
  • nourishes flexor tendons located outside of synovial sheaths

Question 6

Flexor Tendon Injuries

1. Campers Chiasm

2. Pulley System

Answer 6

Campers chiasm (image)

• located at the level of the proximal phalanx where FDP splits FDS

Pulley system

• digits 1-4 contain
  
  • 5 annular pulleys (A1 to A5)
  • 3 cruciate pulleys (C1 to C3)
    
    • A2 and A4 are the most important pulleys to prevent flexor tendon bowstringing
• thumb contains (image on title slide)
  
  • 2 annular pulley
  • interposed oblique pulley (most important)

Question 7

Flexor Tendon Injury

Classification

Answer 7

Zone1: Distal to FDS insertion

• ie: Jersey finger

Zone II: FDS insertion to distal palmar crease

• Zone is unique in that FDP and FDS in same tendon sheath (both injured within the flexor retinaculum)
• Direct repair of both tendons followed by early ROM (Duran, Kleinert). Be sure to preserve A2 and A4 pulley. This zone historically had very poor results but results have improved due to advances in postoperative motion protocols

Zone III : Palm

• Often associated with neurovascular injury which carries a worse prognosis
• Direct tendon repair. Good results from direct repair can be expected due to absence of retinacular structures (if no neurovascular injury)

Zone IV : Carpal tunnel

• Often complicated by postoperative adhesions due to close quarters and synovial sheath of the carpal tunnel
• Direct tendon repair. Transverse carpal ligament should be repaired in a lengthened fashion

Zone V : Wrist to forearm

• Often associated with neurovascular injury which carries a worse prognosis
• Direct tendon repair

Thumb: TI, TII, TIII

• Outcomes different than fingers. Early motion protocols do not improve long-term results and there is a higher re-rupture rate than flexor tendon repair in fingers
• Direct end-to-end repair of FPL is advocated. Try to avoid Zone III to avoid injury to the recurrent motor branch of the median nerve. Oblique pulley is more important than the A1 pulley; however both may be incised if necessary. Attempt to leave one pulley intact to prevent bowstringing

Question 8

Flexor Tendon Injury

Treatment

1. Nonoperative

• indications
• Outcomes

2. Operative

• indications
• Outcomes
• options

Answer 8

1. Nonoperative: wound care and early range of motion

• indications: partial lacerations < 60% of tendon width
• outcomes: may be associated with gap formation or triggering

2. Operative

• flexor tendon repair and controlled mobilization
  
  • indications: lacerations > 60% of tendon width
  • outcomes: depends on zone of injury
• flexor tendon reconstruction and intensive postoperative rehabilitation
  
  • indications:
    
    • failed primary repair
    • chronic untreated injuries
  • outcomes: subsequent tenolysis is required more than 50% of the time
• FDS4 transfer to thumb
  
  • single stage procedure
    
    • indication: chronic FPL rupture

Question 9

Flexor Tendon Injuries

Technique

1. Complete tendon rupture (this topic)

other topics (incl : partial rupture repair / wide awake repair / reconstruction - see https://www.orthobullets.com/topicview?id=6031 )

Answer 9

Flexor Tendon Repair of Complete Lacerations

• approach
  
  • incisions should always cross flexion creases transversely or obliquely to avoid contractures (never longitudinal)
• timing of repair:
  
  • perform repair within three weeks of injury (2 weeks ideal)
  • waiting longer leads to difficulty due to tendon retraction
• technique
  
  • # of suture strands that cross the repair site is more important than the number of grasping loops
    
    • linear relationship between strength of repair and # of sutures crossing repair
    • 4-6 strands provide adequate strength for early active motion
    • high-caliber suture material increases strength and stiffness and decreases gap formation
    • locking-loops decrease gap formation
    • ideal suture purchase is 10mm from cut edge
    • core sutures placed dorsally are stronger
    • meticulous atraumatic tendon handling minimizes adhesions
  • circumferential epitendinous suture
    
    • improves tendon gliding
    • improves strength of repair (adds 20% to tensile strength)
    • allows for less gap formation (first step in repair failure)
    • simple running suture is recommended
• sheath repair is controversial
  
  • theoretically improves tendon nutrition through synovial pathway
  • clinical studies show no difference with or without sheath repair
  • most surgeons will repair if it is easy to do
• pulley management
  
  • critical to preserve A2 and A4 pulleys in digits and oblique pulley in thumb
• FDS repair
  
  • in zone 2 injuries, repair of one slip alone improves gliding when compared to repair of both slips
• outcomes
  
  • repair failure
    
    • tendon repairs are weakest between postoperative day 6 and 12
    • repair usually fails at suture knots

Question 10

Flexor tendon injury

Post op Rehab

Answer 10

Postoperative controlled mobilization has been the major reason for improved results with tendon repair

• especially in zone II
• leads to improved tendon healing biology
• limits restrictive adhesions and leads to increased tendon excursion

Early active motion protocols

• moderate force and potentially high excursion
• dorsal blocking splint limiting wrist extension
• perform “place and hold” exercises with digits

Early passive motion protocols

• Duran protocol
  
  • low force and low excursion
  • active finger extension with patient-assisted passive finger flexion
• Kleinert protocol
  
  • low force and low excursion
  • active finger extension, dynamic splint-assisted passive finger flexion
• Mayo synergistic splint
  
  • low force and high tendon excursion
  • adds active wrist motion which increases flexor tendon excursion the most

Immobilize children and noncompliant patients

• Children should be immobilized following repair
• Casts or splints are applied with the wrist and MCP joints positioned in flexion and the IP joints in extension

Question 11

Flexor tendon injury

Complications

Answer 11

1. Tendon adhesions

• most common complication following flexor tendon repair

2. Rerupture

• 15-25% rerupture rate
• Treatment
  
  • if <1cm of scar is present, resect the scar and perform primary repair
  • if >1cm of scar is present, perform tendon graft
    
    • if the sheath is intact and allows passage of a pediatric urethral catheter or vascular dilator, perform primary tendon grafting
    • if the sheath is collapsed, place Hunter rod and perform staged grafting

3. Joint contracture

• rates as high as 17%

4. Swan-neck deformity

5. Trigger finger

6. Lumbrical plus finger

7. Quadrigia

Question 12

Extensor Tendon Injuries

1. Epidemiology

2. Mechanism of different zones (1 to 5)

Answer 12

Epidemiology

• Injury can be caused by laceration, trauma, or overuse
• most commonly injured digit is the long finger
• zone VI is the most frequently injured zone

Mechanism

• Zone I: forced flexion of extended DIP joint
• Zone II: dorsal laceration or crush injury
• Zone V:
  
  • commonly from “fight bite”
  • sagittal band rupture (“flea flicker injury”)
    
    • forced extension of flexed digit
    • most common in long finger

Question 13

Extensor Tendon Injuries

Zones of injury

Answer 13

Zone I

• Disruption of terminal extensor tendon distal to or at the DIP joint of the fingers and IP joint of the thumb (EPL)
• Mallet Finger

Zone II

• Disruption of tendon over middle phalanx or proximal phalanx of thumb (EPL)

Zone III

• Disruption over the PIP joint of digit (central slip) or MCP joint of thumb (EPL and EPB
• Boutonniere deformity

Zone IV

• Disruption over the proximal phalanx of digit or metacarpal of thumb (EPL and EPB)

Zone V

• Disruption over MCP joint of digit or CMC joint of thumb (EPL and EPB)
• “Fight bite” common
• Sagittal band rupture

Zone VI

• Disruption over the metacarpal
• Nerve and vessel injury likely

Zone VII

• Disruption at the wrist joint
• Must repair retinaculum to prevent bowstringing
• Tendon repair followed by immobilization with wrist in 40° extension and MCP joint in 20° flexion for 3-4 weeks

Zone VIII

• Disruption at the distal forearm
• Extensor muscle belly
• Usually from penetrating trauma
• Often have associated neurologic injury
• Tendon repair followed by immobilization with elbow in flexion and wrist in extension

Question 14

Extensor Tendon Injuries

what is Elsons Test ?

Answer 14

Zone III

• Elson test
  
  • flex the patient’s PIP joint over a table 90 degrees and ask them to extend against resistance
    
    • if central slip is intact, DIP will remain supple
    • if central slip disrupted, DIP will be rigid

Other …

Zone V

• extensor lag and flexion loss common
• junctura tendinae (image) may allow partial/temporary extension by connecting with intact adjacent extensor tendons
• sagittal band rupture
  
  • rupture of stronger radial fibers of sagittal band may lead to extensor tendon subluxation
  • finger held in flexed position at MCP joint with no active extension

Question 15

Extensor Tendon Injury

Treatment

Answer 15

Treatment

1. Nonoperative

• immobilization with early protected motion
  
  • indications
    
    • lacerations < 50% of tendon in all zones if patient can extend digit against resistance

2. Operative

• immediate I&D
  
  • indications
    
    • fight bite to MCP joint
  • techniques
    
    • close loosely or in delayed fashion
    • treat with culture-specific antibiotics, although Eikenella corrodens is a common mouth organism
• tendon repair
  
  • indications
    
    • laceration > 50% of tendon width in all zones
• fixation of bony avulsion
  
  • indications
    
    • boney mallet finger with P3 volar subluxation
  • techniques
    
    • closed reduction and percutaneous pinning through DIP joint
    • extension block pinning
    • ORIF if it involves >50% of the articular surface

Question 16

Mallet Finger

• 1. Define*
• 2. Epidemiology (Risk factors/demographics/body location)*
• 3. Pathophysiology (MOI)*

Answer 16

1. A finger deformity caused by disruption of
   * the terminal extensor tendon distal to DIP joint the disruption may be bony or tendinous
2. Epidemiology

• Risk factors
  
  • usually occur in the work environment or during participation in sports
• Demographics
  
  • common in young to middle-aged males and older females
• Body location
  
  • most frequently involves long, ring and small fingers of dominant hand

3. Pathophysiology

• mechanism of injury
  
  • traumatic impaction blow
    
    • usually caused by a traumatic impaction blow (i.e. sudden forced flexion) to the tip of the finger in the extended position.
    • forces the DIP joint into forced flexion
  • dorsal laceration
    
    • a less common mechanism of injury is a sharp or crushing-type laceration to the dorsal DIP joint

Question 17

Mallet Finger

Classification (Doyle’s)

Answer 17

Type I

• Closed injury with or without small dorsal avulusion fracture

Type II

• Open injury (laceration)

Type III

• Open injury (deep soft tissue abrasion involving loss skin and tendon substance)

Type IV

• Mallet fracture
  
  • A = distal phalanx physeal injury (pediatrics)
  • B = fracture fragment involving 20% to 50% of articular surface (adult)
  • C = fracture fragment >50% of articular surface (adult)

Question 18

Mallet Finger

Treatment

Non-op VS Op

Answer 18

Nonoperative

• extension splinting of DIP joint for 6-8 weeks
  
  • indications
    
    • acute soft tissue injury (< than 12 weeks)
    • nondisplaced bony mallet injury
• technique
  
  • maintain free movement of the PIP joint
  • worn for 6-8 weeks
  • volar splinting has less complications than dorsal splinting
  • avoid hyperextension
  • begin progressive flexion exercises at 6 weeks

Operative

• CRPP vs ORIF indications absolute
  
  • indications
    
    • volar subluxation of distal phalanx
  • relative indications
    
    • >50% of articular surface involved
    • >2mm articular gap

Question 19

Sagittal Band Rupture

(traumatic extensor tendon dislocation)

1. Define
2. Epidemiology/demographics
3. Location
4. Mechanisms
5. Associated conditions

Answer 19

1. Define: Sagittal band (SB) rupture leads to dislocation of the extensor tendon

• also known as “boxer’s knuckle”

2. Epidemiology

• demographics
  
  • more common in boxers [amatuers/wall punchers and professionals]
    
    • index and middle finger in professionals
    • ring and little finger in amateurs
• location
  
  • the middle finger is most commonly involved
    
    • index 14%
    • middle 48%
    • ring 7%
    • little 31%
  • the radial SB is more commonly involved
    
    • radial:ulnar = 9:1
• Mechanisms
  
  • traumatic
    
    • forceful resisted flexion or extension
    • laceration of extensor hood
    • direct blow to MCP joint
  • atraumatic
    
    • inflammatory (e.g. rheumatoid arthritis)
    • spontaneously during routine activities
• Associated conditions
  
  • MCP joint collateral ligament injuries

Question 20

Sagittal Band Rupture

(traumatic extensor tendon dislocation)

Classification

1. eponymous name
2. types [1-3]

Answer 20

1. Rayan and Murray Classification of Closed SB Injury

2. Types [image]

• Type I
  
  • SB injury without extensor tendon instability
• Type II
  
  • SB injury with tendon subluxation
• Type III
  
  • SB injury with tendon dislocation

Question 21

Sagittal Band Rupture

(traumatic extensor tendon dislocation)

Anatomy

[image = MCP Girdle]

Answer 21

Extensor mechanism comprises:

• tendons
  
  • EDC/EIP/EDM
  • lumbricals
  • interossei
• retinacular system
  
  • sagittal bands [image]
    
    • the sagittal bands are part of a closed cylindrical tube (or girdle) that surrounds the metacarpal head and MCP along with the palmar plate
    • origin : volar plate and intermetacarpal ligament at the metacarpal neck
    • insertion : extensor mechanism (curving around radial and ulnar side of MCP joint)
• retinacular ligaments
• triangular ligament

Sagittal band

• function
  
  • the SB is the primary stabilizer of the extensor tendon at the MCP joint
    
    • juncturae tendinum are the secondary stabilizers [https://www.orthobullets.com/topicview?id=6029]
  • resists ulnar deviation of the tendon, especially during MCP flexion
  • prevents tendon bowstringing during MCP joint hyperextension
• biomechanics
  
  • ulnar sagittal band:
    
    • partial or complete sectioning does not lead to extensor tendon dislocation
  • radial sagittal band :
    
    • distal sectioning does not produce extensor tendon instability
    • complete sectioning leads to extensor dislocation
    • sectioning of 50% of the proximal SB leads to extensor tendon subluxation
• extensor tendon
  
  • instability after sectioning is greater with wrist flexion
  • instability after sectioning is greater in the central digits (than border digits)
    
    • the least stable tendon is the middle finger
    • the most stable tendon is the little finger
    • junctura tendinum stabilize the small finger

Question 22

Sagittal Band Rupture (traumatic extensor tendon dislocation)

Treatment

Answer 22

1. Nonoperative : extension splint for 4-6 weeks

• indications
  
  • acute injuries (within one week)

2. Operative

• direct repair (Kettlekamp)
  
  • indications
    
    • chronic injuries (more than one week) where primary repair is possible
    • professional athlete
• extensor centralization procedure
  
  • indications
    
    • chronic injuries (more than one week) where primary repair is NOT possible
    • professional athlete

Question 23

Pisiform Fracture

rare injury and often missed

Presentation

1. Symptoms
2. Physical exam
3. Imaging
4. Treatment

Answer 23

1. Symptoms: ulnar sided wrist pain after a fall / grip weakness

2. Physical exam: inspection - hypothenar tenderness and swelling / rule out associated injury to other carpal bones and distal radius

3. Imaging

• Radiographs recommended views [PA / lateral / ER oblique / carpal tunnel / best seen with ER oblique or carpal tunnel view]
• CT indications: may be required to delineate fracture pattern and determine treatment plan
• MRI : indications - suspected carpal fracture with negative radiographs
  
  • findings: may show bone marrow edema within the pisiform indicating fracture

4. Treatment

• Nonoperative: early immobilization
  
  • indications: first line of treatment
  • technique: short arm cast with 30 degrees of wrist flexion and ulnar deviation for 6-8 weeks
  • outcomes: most often go on to heal without posttraumatic osteoarthritis
• Operative: pisiformectomy
  
  • indications: severely displaced and symptomatic fractures / painful nonunion
  • outcomes: studies show a pisiformectomy is a reliable way to relieve this pain and does not impair wrist function

Question 24

Pisiform Fracture

rare injury and often missed

Epidemiology

1. incidence: Less than __% of carpal fractures
2. Pathophysiology: mechanism of injury
3. Associated conditions

Answer 24

1. <1% of carpal fractures
2. Pathophysiology: mechanism of injury

• usually occurs by direct impact against a hard surface
• fall on outstretched hand

3. Associated conditions

• 50% occur as isolated injuries
• 50% occur in association with other carpal fractures or distal radius fractures

4. Anatomy

• Pisiform Bone : osteology = pea shaped, seasmoid bone
• Location
  
  • most ulnar and palmar carpal bone in proximal row
  • located within the FCU tendon
• function: contributes to the stability of the ulnar column by preventing triquetral subluxation

Question 25

Seymour Fracture

1. define

2. Incidence

3. MOI

Answer 25

1. Displaced distal phalangeal physeal fracture with an associated nailbed injury
2. epidemiology / incidence

• 20% to 30% of phalangeal fractures involve the physis in children
• middle finger injury is most common
• type of the distal phalangeal physeal fracture:
  
  • metaphyseal fractures 1 to 2 mm distal to the epiphyseal plate
  • Salter-Harris I fractures
  • Salter-Harris II fractures
• type of nailbed injury:
  
  • nailbed laceration
  • nail plate subluxation
  • interposition of soft tissue at fracture site (usually germinal matrix)

Pathophysiology

• mechanism of injury
  
  • direct trauma or crush injury (e.g. caught in door, heavy object or sport)
• pathoanatomy
  
  • similar mechanism to mallet finger in adults / injury causes flexed posturing of the distal phalanx
  • deformity results from an imbalance between the flexor and the extensor tendons at the level of the fracture
  • imbalance occurs due to different insertion sites of flexor and extensor tendons
    
    • extensor tendon inserts into the epiphysis of the distal phalanx
    • flexor tendon inserts into metaphysis of the distal phalanx
  • widened physis likely to have interposed tissue in the fracture site

Question 26

Seymour Fracture

1. Difference between mallet and seymour fracture ?

2. treatment

3. Prognosis

Answer 26

1. Mallet finger = pediatric mallet finger is usually osseous avulsion (SH III and SH IV)
   * mallet finger fracture line enters DIPJ, while Seymour fracture line traverses physis (does not enter DIPJ)
2. Prognosis

• operative intervention is warranted to ensure that there is no interposed tissue in the fracture site
• failure to recognize injury may result in:
  
  • nailplate deformity
  • physeal arrest
  • chronic osteomyelitis

3. Treatment

• Nonoperative
  
  • closed reduction and splinting
    
    • indications
      
      • minimally displaced, closed fracture
      • no interposition of soft tissue at fracture site
• Operative
  
  • closed reduction and pinning across DIPJ
    
    • indications
      
      • displaced, closed fracture
      • no interposition of soft tissue at fracture site
  • antibiotics, open reduction and pinning across DIPJ, nailbed repair
    
    • open management has fewer complications than closed management
      
      • indications
        
        • open fracture

Question 27

Hook of Hamate Fracture

1. Epidemiology : incidence = ___% of carpal fractures
2. Risk factors
3. Pathophysiology: MOI ?
4. Associated conditions [1]

Answer 27

1. Epidemiology
   * incidence = 2% of carpal fractures
2. Risk factors: often seen in athletes [golf / baseball / hockey]
3. Pathophysiology: typically caused by a direct blow [grounding a golf club / checking a baseball bat]
4. Associated conditions
   * bipartite hamate: will have smooth cortical surfaces

Question 28

Hook of Hamate Fracture

1. Anatomy
2. Boundaries of Guyons canal (roof / floor / radial border / ulnar border]

Answer 28

Hamate

• one of carpal bones, distal and radial to the pisiform
• articulates with:
  
  • fourth and fifth metacarpals
  • capitate
  • triquetrum
• hook of hamate
  
  • forms part of Guyon’s canal, which is formed by:
    
    • roof - superficial palmar carpal ligament
    • floor - deep flexor retinaculum, hypothenar muscles
    • ulnar border - pisiform and pisohamate ligament
    • radial border - hook of hamate
• one of the palpable attachments of the flexor retinaculum
• deep branch of ulnar nerve lies under the hook

Question 29

Hook of Hamate Fracture

Classification

Answer 29

Milch Classification

• Type I Hook of hamate fx (most common) [image this card]
  
  • Subtypes
    
    • I - avulsion
    • II - middle of hook
    • III - base of hook
• Type II: Body of hamate fx [image question card]
  
  • Subtypes
    
    • IIA - coronal
    • IIB - transverse

Question 30

Hook of Hamate Fracture

• Treatment
  
  • Non-operative
  • Operative
• Complications

Answer 30

• Nonoperative: immobilization 6 weeks
• Indications
  
  • body of hamate fx (rare)
  • acute hook of hamate fractures\
• Operative:
  
  • excision of hamate fracture fragment
    
    • indications
      
      • chronic hook of hamate fxs with non-union
  • ORIF
    
    • indications:
      
      • ORIF is possible but has little benefit

Complications

• Non-union
• Scar sensitivity
• Iatrogenic injury to ulnar nerve
• Closed rupture of the flexor tendons to the small finger

Question 31

Hook of Hamate Fracture

1. What is the hook of hamate pull test ?

2. other provocative maneuvers / exam findings ?

Answer 31

1. hook of hamate pull test:

• hand held in ulnar deviation as patient flexes DIP joints of the ulnar 2 digits, the flexor tendons act as a deforming force on the fracture site, positive test elicits pain
  
  • video @ https://www.orthobullets.com/topicview?id=6035

2. Physical examination

• provocative maneuvers
  
  • tender to palpation over the hook of hamate
  • hook of hamate pull test: (above)
  • motion and strength = decreased grip strength
  • neurovascular exam
    
    • chronic cases
      
      • parasthesia in ring and small finger
      • motor weakness in intrinsics

Question 32

Lunate Dislocation (Perilunate dissociation)

• Introduction : High energy injury with poor functional outcomes*
• Commonly missed (~25%) on initial presentation*
  1. Categories
• perilunate dislocation [4 types] ?
• lunate dislocation - define

2. Mechanism ?
3. Sequence of injury [5 sequential injuries leading to complete dislocation]

Answer 32

1. Categories

• perilunate dislocation [image Q. slide] : lunate stays in position while carpus dislocates
  
  • 4 types
    
    • transcaphoid-perilunate
    • perilunate
    • transradial-styloid
    • transcaphoid-trans-capitate-perilunar
• lunate dislocation
  
  • lunate forced volar or dorsal while carpus remains aligned

2. Mechanism

• traumatic, high energy
• occurs when wrist extended and ulnarly deviated
  
  • leads to intercarpal supination

3. Sequence of events [image] - CLOCKWISE

• scapholunate ligament disrupted –>
• disruption of capitolunate articulation –>
• disruption of lunotriquetral articulation –>
• failure of dorsal radiocarpal ligament –>
• lunate rotates and dislocates, usually into carpal tunnel

NOTE: dislocation can course through:

• greater arc - ligamentous disruptions with associated fractures of the radius, ulnar, or carpal bones
• lesser arc - purely ligamentous

Question 33

Lunate Dislocation (Perilunate dissociation)

1. classification

Answer 33

Mayfield Classification

• Stage I • scapholunate dissociation
• Stage II • + lunocapitate disruption
• Stage III • + lunotriquetral disruption, “perilunate”
• Stage IV: • lunate dislocated from lunate fossa (usually volar)
  
  • associated with median nerve compression

Question 34

Lunate Dislocation (Perilunate dissociation)

Xray

1. Guila’s arc - decribe

2. “Piece-of-pie sign”

Answer 34

1. break in Gilula’s arc -
2. “piece-of-pie sign”

• triangular appearance of lunate
• due to palmar rotation from dorsal force of carpus

other findings …

• lateral
  
  • loss of colinearity of radius, lunate, and capitate
  • SL angle >70 degrees
  • spilled teacup sign

MRI

• usually not required for diagnosis

https://www.orthobullets.com/topicview?id=6045

Question 35

Lunate Dislocation (Perilunate dissociation)

Treatment

1. Nonoperative [technique / indications / outcomes]

2. Operative

• Options
• Indications
• Outcomes

Answer 35

1. Nonoperative

• closed reduction and casting
  
  • indications
    
    • no indications when used as definitive management
  • outcomes
    
    • universally poor functional outcomes with non-operative management
    • recurrent dislocation is common

2. Operative

• emergent closed reduction/splinting followed by open reduction, ligament repair, fixation, possible carpal tunnel release
  
  • indications
    
    • all acute injuries < 8 weeks old
  • outcomes
    
    • emergent closed reduction leads to:
      
      • decreased risk of median nerve damage
      • decreased risk of cartilage damage
    • return to full function unlikely
    • decreased grip strength and stiffness are common
• proximal row carpectomy
  
  • indications
    
    • chronic injury (defined as >8 weeks after initial injury)
      
      • not uncommon, as initial diagnosis frequently missed
• total wrist arthrodesis
  
  • indications
    
    • chronic injuries with degenerative changes

Question 36

TFCC Injury

1. Mechanism - Type 1 vs Type 2

Answer 36

Mechanism of TFCC injury

• Type 1 traumatic injury
  
  • mechanism
    
    • most common is fall on extended wrist with forearm pronation
    • traction injury to ulnar side of wrist
  • traction injury to ulnar wrist
• Type 2 degenerative injury
  
  • associated with positive ulnar variance
  • associated with ulnocarpal impaction

Question 37

TFCC Injury

antomy

1. what structures make up TFCC [6]

2. Blood Supply

Answer 37

Anatomy

• TFCC made up of:
  
  • dorsal and volar radioulnar ligaments
    
    • deep ligaments known as ligamentum subcruentum
  • central articular disc
  • meniscus homolog
  • ulnar collateral ligament
  • ECU subsheath
  • origin of ulnolunate and ulnotriquetral ligaments
• Blood supply
  
  • periphery is well vascularized (10-40% of the periphery)
  • central portion is avascular
• Origin
  
  • dorsal and volar radioulnar ligaments originate at the sigmoid notch of the radius
• Insertion
  
  • dorsal and volar radioulnar ligaments converge at the base of the ulnar styloid

Question 38

TFCC Injury

1. classification

2. physical exam findings

3. DDx for ulnar sided wrist pain

Answer 38

Class 1 - Traumatic TFCC Injuries

• 1A = Central perforation or tear
• 1B = Ulnar avulsion (without ulnar styloid fx)
• 1C = Distal avulsion (origin of UL and UT ligaments)
• 1D = Radial avulsion

Class 2 - Degenerative TFCC Injuries

• 2A = TFCC wear and thinning
• 2B = Lunate and/or ulnar chondromalacia + 2A
• 2C = TFCC perforation + 2B
• 2D = Ligament disruption + 2C
• 2E = Ulnocarpal and DRUJ arthritis + 2D

Physical exam

• positive “fovea” sign
  
  • tenderness in the soft spot between the ulnar styloid and FCU tendon, between the volar surface of the ulnar head and the pisiform
  • 95% sensitivity and 87% specificity for foveal disruptions of TFCC or ulnotriquetral ligament injuries
• pain elicited with ulnar deviation (TFCC compression) or radial deviation (TFCC tension)

DDx (image)

Question 39

TFCC Injury

Imaging / Diagnosis

Answer 39

• Radiographs
  
  • usually negative
  • zero rotation PA view evaluates ulnar variance
• Arthography
  
  • joint injection shows extravasation
• MRI
  
  • has largely replaced arthrography
  • tear at ulnar part of lunate indicates ulnocarpal impaction
  • sensitivity = 74-100%
• Arthroscopy
  
  • most accurate method of diagnosis
  • indicated in symptomatic patients after failing several months of splinting and activity modification

Question 40

TFCC Injury

Treatment

1. non-op (indications)
2. Operative (options [6] and indications)

Answer 40

• Nonoperative
  
  • immobilization, NSAIDS, steroid injections
    
    • indications
      
      • all acute Type I injuries
      • first line of treatment for Type 2 injuries
• Operative arthroscopic debridement
  
  • indications
    
    • type 1A
    • diagnostic gold standard
• arthroscopic repair
  
  • indications
    
    • type 1B, 1C, 1D
    • best for ulnar and dorsal/ulnar tears
    • generally acute, athletic injuries more amenable to repair than chronic injuries
  • outcomes
    
    • patient should expect to regain 80% of motion and grip strength when injuries are classified as acute (<3 months)
• ulnar diaphyseal shortening
  
  • indications
    
    • Type II with ulnar positive variance is > 2mm
    • advantage of effectively tightening the ulnocarpal ligaments and is favored when LT instability is present
• Wafer procedure
  
  • indications
    
    • Type II with ulnar positive variance is < 2mm
    • type 2A-C
• limited ulnar head resection
  
  • indications
    
    • type 2D
• Darrach procedure
  
  • indications
    
    • contraindicated due to problems with ulnar stump instability

Question 41

Metacarpal Fractures

Anatomy : tendons inserting on metacarpals

Answer 41

• Metacarpal anatomy
  
  • concave on palmar surface
  • 1st, 4th, and 5th digits form mobile borders
  • 2nd and 3rd digits form stiffer central pillar
    
    • index metacarpal is the most firmly fixed, while the thumb metacarpal articulates with the trapezium and acts independently from the others
  • three palmar and four dorsal interossei muscles arise from metacarpal shafts
• Insertional anatomy
  
  • extensor carpi radialis longus/brevis
    
    • insert on the base of metacarpal II, III (respectively); assist with wrist extension and radial flexion of the wrist
  • extensor carpi ulnaris
    
    • inserts on the base of metacarpal V; extends and fixes wrist when digits are being flexed; assists with ulnar flexion of wrist
  • abductor pollicis longus
    
    • inserts on the trapezium and base of metacarpal I; abducts thumb in frontal plane; extends thumb at carpometacarpal joint
  • opponens pollicis
    
    • inserts on metacarpal I; flexes metacarpal I to oppose the thumb to the fingertips
  • opponens digiti minimi
    
    • inserts on the medial surface of metacarpal V; Flexes metacarpal V at carpometacarpal joint when little finger is moved into opposition with tip of thumb; deepens palm of hand.

Question 42

Metacarpal Fractures

acceptable angulation

Answer 42

Acceptable Shaft Angulation (degrees)

• IF / LF = 10-20
• RF = 30
• LF = 40

Acceptable Shaft Shortening (mm)

• IF / LF = 2-5 mm
• RF = 2-5 mm
• LF = 2-5 mm

Acceptable Neck Angulation (degrees)

• IF / LF = 10-15
• RF = 30-40
• LF = 50-60

Question 43

Metacarpal Fractures

Treatment indications

Answer 43

• Nonoperative
  
  • immobilization
    
    • indications
      
      • must be stable pattern
      • no rotational deformity
      • acceptable angulation & shortening (see table)
• Operative
  
  • general indications
    
    • open fx
    • intra-articular fxs
    • rotational malalignment of digit
    • significantly displaced or angulated fractures (see above criteria)
    • multiple metacarpal shaft fractures
    • loss of inherent stability from border digit during healing process
  • postoperative
    
    • early motion is critical
    • remove pins/ cast at ~ 4 weeks

Question 44

Metacarpal Fractures

Question 45

Thumb Collateral Ligament Injury

1. Types & mechanism

2. Epnonyms for UCL injury [3]

3. What is a Stener Lesion ?

Answer 45

1. Thumb collateral ligament injuries include

• radial collateral ligament
  
  • rare
• ulnar collateral ligament
  
  • most common
• Mechanism = hyper abduction or extension at the MCP joint

2. eponyms for ulnar collateral ligament (UCL) injury are

• Gamekeeper’s thumb for chronic injury
• skiers thumb for acute injury
• Stener lesion

3. Stener lesion (image)

• avulsed ligament with or without bony attachment is displaced above the adductor aponeurosis
• will not heal without surgical repair

Question 46

Thumb Collateral Ligament Injury

1. Anatomy: UCL composed of: [2]

2. Physical exam findings

Answer 46

1. Anatomy

• UCL is composed of
  
  • proper collateral ligament
    
    • resists valgus load with thumb in flexion
  • accessory collateral ligament and volar plate
    
    • resists valgus load with thumb in extension
    • valgus laxity in both flexion and extension is indicative of a complete UCL rupture

2. Physical exam

• stress joint with radial deviation both at neutral and 30° of flexion
  
  • instability in 30° of flexion indicates injury to proper UCL
  • instability in neutral indicates injury to accessory and proper UCL and/or volar plate
    
    • compare to uninjured thumb MCP joint

XR Finding - UCL avulsion [image]

Question 47

Thumb Collateral Ligament Injury​

• Treatment:
  
  • Non-op
    
    • indications
  • Operative
    
    • indications
    • techniques

Answer 47

Nonoperative

• immobilization for 4 to 6 weeks
  
  • indications
    
    • partial tears with < 20° side to side variation of varus/valgus instability

Operative

• ligament repair
  
  • indications
    
    • acute injuries with:
      
      • > 20° side to side variation of varus/valgus instability
      • >35° of opening
    • Stener lesion
      
      • avulsed ligament with or without bony attachment is displaced above the adductor aponeurosis
      • will not heal without surgical repair
  • technique
    
    • can use suture, suture anchors, or small screw to repair ligament
• reconstruction of ligament with tendon graft, MCP fusion, or adductor advancement
  
  • ​indications
    
    • chronic injury

Question 48

Thumb CMC Dislocation

define

epidemiology

pathophysiology/MOI

pathoanatomy

Answer 48

• Thumb CMC dislocation is mostly dorsal
  
  • volar dislocation is rare
• Epidemiology
  
  • incidence
    
    • makes up <1% of hand injuries
• Pathophysiology
  
  • mechanism
    
    • axial force on a flexed thumb (more common)
    • dorsal force applied in 1st web space (e.g. handlebar driven into a motorcyclist’s thumb on impact) (less common)
• pathoanatomy
  
  • dorsoradial ligament is torn
  • anterior oblique ligament is stripped/peeled off the 1st metacarpal base but remains continuous
• Treatment - if stable (AOL intact) = nonop - if unstbale (AOL torn) = operative

Question 49

Base of Thumb Fractures

1. Types / Classification [image]

2. incidence: __% of thumb fractures involve the metacarpal base

3.MOI (bennett/rolando)

addit: Volar beak ligament ? [image this slide]

Answer 49

1. Classification

• Extra-articular oblique : oblique fracture line not involving the articular surface
• Extra-articular transverse : a pure TV Fx not involved the articular surface
• Intra-articular Bennett : Intra-articular fracture with a palmar radial fragment
• Intra-articular Rolando : Y or T shaped complete intra-articular fracture
• Intra-articular comminuted : comminuted complete intra-articular fracture

2. 80% of thumb fractures involve the metacarpal base; the most common pattern is extraarticular epibasal fracture

3. mechanism of injury: most Bennett and Rolando are fractures caused by axial force applied to the thumb in flexion

volar beak ligament : spans the tuberosity of the trapezium to the volar edge of the 1st metacarpal; keeps trapezium connected to the volar-ulnar base fragment

dorsoradial ligament: spans the dorsoradial tubercle of the trapezium to the dorsal base of the 1st metacarpal

Question 50

Base of Thumb Fractures

Anatomy

1. osteology (joint type and motion)

2. deforming forces

3.

Answer 50

1. Osteology

• CMC joint is a saddle-shaped joint composed of the trapezium and the base of the thumb (1st) metacarpal [image]
  
  • flexion-extension motion
  • abduction-adduction motion

2. Muscles : three muscles provide deforming forces at the base of the thumb

• abductor pollicis longus (PIN)
  
  • proximal, dorsal, and radial force on the shaft fragment
• extensor pollicis longus (PIN)
  
  • proximal, dorsal, and radial force on the shaft fragment
• adductor pollicis (Ulnar n.)
  
  • supination and adduction force on the shaft fragment

Ligament volar beak ligament

spans the tuberosity of the trapezium to the volar edge of the 1st metacarpal

keeps trapezium connected to the volar-ulnar base fragment

dorsoradial ligament

spans the dorsoradial tubercle of the trapezium to the dorsal base of the 1st metacarpal

Biomechanics

very limited axial rotation

average flexion-extension of 53 degrees

average abduction-adduction of 42 degrees

Question 51

Base of Thumb Fractures

Treatment

Nonoperative

• closed reduction and thumb spica casting
  
  • indications ? [2]

Operative

• closed reduction and percutaneous k-wire fixation
  
  • indications [4]
• open reduction internal fixation
  
  • indications
• distraction and external fixation
  
  • indications

Answer 51

Nonoperative:

1. closed reduction and thumb spica casting

• indications
  
  • extra-articular fractures with <30 degrees of angulation following closed reduction
  • Bennett fractures with <1mm displacement
• modalities
  
  • a reduction is achieved with longitudinal traction, palmar abduction, and pronation

2. thumb spica casting

• indications
  
  • fractures greater than 3 weeks old that will no motion at fracture site should be treated allowance of step-off and casting

Operative

1. closed reduction and percutaneous k-wire fixation

• indications
  
  • extra-articular fractures with >30 degrees of angulation following closed reduction
  • inability to maintain reduction <30 degrees with thumb spica
  • Rolando fracture <1mm displacement
  • small fracture fragments that are not amenable to screw fixation

2. open reduction internal fixation

• indications
  
  • >1mm of displacement in Bennett, Rolando, and severely comminuted fractures with large fracture fragments amenable to fixation

3. distraction and external fixation

• indications
  
  • Rolando fracture with >1mm displacement and major soft tissue injury
  • severely comminuted fractures with major soft tissue injury or impacted articular fragments
  • Bennett, Rolando, or severely comminuted fractures with fragments too small for ORIF

Question 53

Phalanx Fractures

Common hand injuries that can be broken into the following injuries

• proximal phalanx
• middle phalanx
• distal phalanx

1. Epidemiology: incidence / demographics

2. Pathophysiology

• Mechanism of injury
• Associated conditions

Answer 53

1. Epidemiology

• incidence
  
  • most common injuries to the skeletal system
    
    • accounts for 10% of all fractures
• demographics
  
  • more common in males 2:1
• location
  
  • distal phalanx > middle phalanx > proximal phalanx
  • small finger is most commonly affected (accounts for 38% of all hand fractures)
• Pathophysiology
  
  • mechanism of injury
    
    • depends on age
      
      • 10-29 years old - sports is most common
      • 40-69 years old - machinery is most common
      • >70 years old - falls are most common
• Associated conditions
  
  • nail bed injuries
  • associated with distal phalanx fractures

Question 54

Distal Phalanx Fractures

Most common phalanx fracture

1. Classification

2. Mechanism

Answer 54

Classification

• tuft fractures
  
  • mechanism = is usually crush injury
    
    • usually stable due to nail plate dorsally and pulp volarly
    • often associated with laceration of nail matrix or pulp
• shaft fractures can be
  
  • transverse
  • longitudinal
• base fractures
  
  • usually unstable
  • mechanism can be
    
    • shearing due to axial load, leading to fracture involving > 20% of articular surface
    • avulsion due tensile force of terminal tendon or FDP, leading to small avulsion fracture
  • can be further classified into
    
    • volar base
    • dorsal base
• Seymour fractures
  
  • epiphyseal injury of distal phalanx
  • resuls from hyperflexion
  • presents as mallet deformity (i.e. apex dorsal) due to
    
    • terminal tendon attaches to proximal epiphyseal fragment
    • FDP attaches to distal fragment

Nonoperative

• closed reduction +/- splinting
  
  • indications
    
    • most cases
  • nail matrix may be incarcerated in fracture and block reduction

Operative

• remove nail, repair nailbed, and replace nail to maintain epi fold
  
  • indications
    
    • distal phalanx fractures with nailbed injury
      
      • see nail bed injuries
• CRPP vs. ORIF
  
  • indications
    
    • displaced or irreducible shaft fractures
    • dorsal base fractures with > 25% articular involvement
    • displaced volar base fractures with large fragment and involvement of FDP
    • non-unions
  • techniques
    
    • longitudinal or crossed K wires
    • extension block pinning
    • minifragment fixation with lag screws

Question 55

Middle Phalanx Fractures

1. Classification

2. Treatment

Answer 55

Classification:

• head fracturescan be further classified into:
  
  • type I - stable with no displacement
  • type II - unstable unicondylar
  • type III - unstable bicondylar or comminuted
• neck fractures
  
  • ​deformity is usually apex volar angulation
    
    • proximal fragment in flexion (due to FDS)
    • distal fragment in extension (due to terminal tendon)
• shaft fracturescan be
  
  • transverse
  • short oblique
  • long oblique
  • spiral
• deformity can be
  
  • apex volar angulation
    
    • if distal to FDS insertion
  • apex dorsal angulation
    
    • if proximal to FDS insertion
  • without angulation
    
    • due to inherent stability provided by an intact and prolonged FDS insertion
• base fractures
  
  • ​deformity is usually apex dorsal angulation
    
    • proximal fragment in extension (due to central slip)
    • distal fragment in flexion (due to FDS)
  • can be further classified into
    
    • partial articular fractures
      
      • volar base
        
        • results from hyperextension injury or axial loading
        • represents avulsion of volar plate
        • unstable if > 40% articular surface involved
      • dorsal base
        
        • results from hyperflexion injury
        • represents avulsion of central tendon
  • lateral base
    
    • represents avulsion of collateral ligaments
  • complete articular fractures
    
    • know as pilon fractures
    • unstable in all directions

Nonoperative

• buddy taping vs. splinting
  
  • indications
    
    • extraarticular fractures with < 10° angulation or < 2mm shortening and no rotational deformity
    • non-displaced intraarticular fractures
  • technique
    
    • 3 weeks of immobilization followed by aggressive motion

OperativeCRPP vs. ORIF

• indications
  
  • extraarticular fractures with > 10° angulation or > 2mm shortening or rotational deformity
  • displaced intraarticular fractures
  • irreducible or unstable fracture pattern
• techniques
  
  • crossed K wires
  • extension block pinning
  • collateral recess pinning
  • minifragment fixation with plate and/or lag screws
  • volar plate arthroplasty

Question 56

Proximal Phalanx Fractures

1. Classification
2. Treatment

Answer 56

Classification

• head fractures can be further classified into :
  
  • type I - stable with no displacement
  • type II - unstable unicondylar
  • type III - unstable bicondylar or comminuted
• neck/shaft fractures can be
  
  • transverse
  • short oblique
  • long oblique
  • spiral
• deformity is usually apex volar angulation
  
  • proximal fragment in flexion (due to interossei)
  • distal fragment in extension (due to central slip)
• base fractures can be
  
  • extra-articular
  • intra-articular
    
    • lateral base

Nonoperative: buddy taping vs. splinting

• indications
  
  • extraarticular fractures with < 10° angulation or < 2mm shortening and no rotational deformity
  • non-displaced intraarticular fractures
• technique
  
  • 3 weeks of immobilization followed by aggressive motion

OperativeCRPP vs. ORIF

• indications
  
  • extraarticular fractures with > 10° angulation or > 2mm shortening or rotational deformity
  • displaced intraarticular fractures
  • unstable or irreducible fracture pattern
• techniques
  
  • crossed K wires
  • Eaton-Belsky pinning through metacarpal head
  • minifragment fixation with plate and/or lag screws
    
    • lag screws alone indicated in presence of long oblique fracture

Question 57

Pyogenic Flexor Tenosynovitis

*Infection of the synovial sheath that surrounds the flexor tendon*

• 1. incidence (% of all hand infections)*
• 2. Risk factors [3]*
• 3. Pathophysiology - mechanism of infection*
• 4. Cause - mirco ?*
• 5. What is a horseshoe abscess ?*

Answer 57

1. incidence 2.5 to 9.4% of all hand infections
2. risk factors: diabetes / IV drug use / immunocompromise
3. Pathophysiology: mechanism

• penetrating trauma to the tendon sheath
• direct spread from:
  
  • felon
  • septic joint
  • deep space infection

4. Mircor

• S. aureus (40-75%) most common
• MRSA (29%) IVDU
• other common skin flora (s. epi / Beta-hem strep / pseudomonas)
• mixed flora and gram negative organsims = in immunocompromised patients
• Eikenella = in human bites
• Pasteurella multocida = in animal bites

5. “horseshoe abscess” [image]

• may develop from spread pyogenic flexor tenosynovitis
  
  • of many individuals have a connection between the sheaths of the thumb and little fingers at the level of the wrist
  • infection in one finger can lead to direct infection of the sheath on the opposite side of the hand resulting a “horseshoe abscess”

Question 58

Pyogenic Flexor Tenosynovitis

1. Kanavels Signs [4]

2. Anatomical variation in sheaths

Answer 58

Kanavel signs (4 total)

1. flexed posturing of the involved digit
2. tenderness to palpation over the tendon sheath
3. marked pain with passive extension of the digit
4. fusiform swelling of the digit

2. Variation common [image]

• Around 70% have thumb - 5th connection with no connection btwn 2/3/4

Question 59

Pyogenic Flexor Tenosynovitis

treatment

technique

Answer 59

1. Treatment

Nonoperative (rare)

• hospital admission, IV antibiotics, hand immobilization, observation
• indications = early presentation
• outcomes = if signs of improvement within 24 hours, no surgery is required

Operative: I&D followed by culture-specific IV antibiotics

• indications
  
  • low threshold (orthopaedic emergency)\
  • late presentation
  • no improvement after 24 hours of non-operative treatment (confirmed diagnosis)

2. Technique : I&D of flexor tendon

• Approach
  
  • full open exposure using long midaxial or Bruner incision
  • two small incisions placed distally at A5 pulley and proximally at A1 pulley and using an angiocatheter

Question 60

Nail Bed Injury

3 types = Subungal Haematoma / nail bed laceration / nail bed avulsion]

Anatomy [6 structures]

Answer 60

Nailbed and surrounding tissue

• perionychium [1]
  
  • nail
  • nailbed
  • surrounding skin
• paronychium [2]
  
  • lateral nail folds
• hyponychium [3]
  
  • skin distal distal and palmar to the nail
• eponychium [4]
  
  • dorsal nail fold
  • proximal to nail fold
• lunula [5]
  
  • white part of the proximal nail
• matrix [6]
  
  • sterile matrix
    
    • soft tissue deep to nail
    • distal to lunula
    • adheres to nail
  • germinal matrix
    
    • soft tissue deep to nail
    • proximal to sterile matrix
    • responsible for most of nail development
    • NB: insertion of extensor tendon is approximately 1.2 to 1.4 mm proximal to germinal matrix

Question 61

Nail Bed Injury

3 types

1. Subungal Haematoma [this card]
2. Nail bed laceration
3. Nail bed avulsion

Answer 61

Most commonly caused by a crushing-type injury

• causes bleeding beneath nail

Treatment

• Drainage of hematoma by perforation
  
  • indications
    
    • less than 50% of nail involved
  • techniques
    
    • puncture nail using sterile needle
    • electrocautery to perforate nail
• Nail removal, D&I, nail bed repair
  
  • indications
    
    • > 50 % nail involved
  • technique
    
    • nail bed repair

Question 62

Nail Bed Injury

3 types

1. Subungal Haematoma

2. Nail bed laceration [this card]

3. Nail bed avulsion

Answer 62

Nail Bed Lacerations

• Laceration of the nail and underlying nail bed
  
  • usually present with the nail intact and a subungual hematoma greater than 50% of nail surface area
• Treatment
  
  • nail removal with D&I, nail bed repair
    
    • indications
      
      • most cases
    • modalities
      
      • tetanus and antibiotic prophylaxis

Question 63

Nail Bed Injury

3 types

1. Subungal Haematoma
2. Nail bed laceration

3. Nail bed avulsion [this card]

Answer 63

Avulsion of nail and portion of underlying nail bed

• Mechanism
  
  • usually caused by higher energy injuries
• Associated conditions
  
  • commonly associated with other injuries including:
    
    • distal phalanx fracture
      
      • if present reduction is advocated
• Treatment
  
  • nail removal, nail bed repair, +/- fx fixation
    
    • indications
      
      • avulsion injury with minimal or no loss of nail matrix, with or without fracture
  • technique
    
    • always give tetanus and antibiotics
    • fracture fixation depends on fracture type
• nail removal, nail bed repair, split thickness graft vs. nail matrix transfer, +/- fx fixation
  
  • indications
    
    • avulsion or crush injury with significant loss of nail matrix
• technique
  
  • always give tetanus and antibiotics
  • nail matrix transfer from adjacent injured finger or nail matrix transfer from second toe
  • fracture fixation depends on fracture type

Question 64

Nail Bed Injury

1. Technique (surgery)

2. Complications

a. What is Hook nail ?
b. What is Split nail ?

Answer 64

1. Techniques: Nail bed repair

• nail removal
  
  • soak nail in Betadine while repairing nail bed
• nail bed repair
  
  • repair nail bed with 6-0 or smaller absorbable suture
  • RCT has demonstrated quicker repair time using 2-octylcyanoacrylate (Dermabond) instead of suture with comparable cosmetic and functional results
• splint eponychial fold
  
  • splint eponychial fold with original nail, aluminum, or non-adherent gauze

Complications

• Hook nail [image] : caused by advancement of the matrix to obtain coverage without adequate bony support
  
  • Treatment
    
    • remove nail and trim matrix to level of bone
• Split nail: caused by scarring of the matrix following injury to nail bed
  
  • Treatment
    
    • excise scar tissue and replace nail matrix
      
      • graft may be needed

Question 65

High-Pressure Injection Injuries

Characterized by extensive soft tissue damage associated with a benign high-pressure entry wound

1. demographics

2. location - most common

3. pathophysiology

4. Prognosis - Severity of injury based on 4 factors

Answer 65

1. most common in laborers in industry using paint, automotive grease, solvents and diesel oil

2. location

• the non-dominant index finger is the most commonly affected

3. Pathophysiology

• force delivered from 3,000 to 10,000 PSI and up to 400mph
• leads to dissection along planes of least resistance (along neurovascular bundles)
• vascular occlusion may lead to local soft tissue necrosis

4. Prognosis = Up to 50% amputation rate for organic solvents (paint, paint thinner, diesel fuel, jet fuel, oil)

• severity of the injury is dependent on:
  
  • time from injury to treatment [1]
  • force of injection [2]
  • volume injected [3]
  • composition of material [4]
    
    • grease, latex, chloroflourocarbon & water based paints are less destructive
    • industrial solvents & oil based paints cause more soft tissue necrosis

Question 66

High-Pressure Injection Injuries

treatment

Answer 66

1. Nonoperative: ADT + ABx + elevation + early mobilization & monitoring for compartment syndrome

• indications
  
  • for injection of air and water

2. Operative : Irrigation & debridement, foreign body removal and broad-spectrum antibiotics

• indications
  
  • most cases require immediate surgical debridement
• technique
  
  • it is important to remove as much of the foreign material as possible
  • broad spectrum antibiotic coverage is important to reduce risk of post operative infection
• outcomes
  
  • higher rates of amputation are seen when surgery is delayed greater than 10 hours after injury

Question 67

Tendon Transfer Principles

• Specific Transfers and Indications (Card 1 of 2)*
• 1. Musculocutaneous Palsy*
• 2. Radial Palsy*

Answer 67

Musculocutaneous nerve palsy

• Elbow flexion :
  
  • Working / transfer from : pectoralis major, latissimus dorsi
  • Deficient / transfer to : to biceps
• Elbow flexion
  
  • Working / transfer from : common flexor mass
  • Deficient / transfer to : point more proximal on humerus (Steindler flexorplasty)

Radial nerve & PIN palsy

• Elbow extension
  
  • working / transfer from : deltoid, latissimus dorsi, or biceps
  • Deficient / transfer to : to triceps
• Wrist extension
  
  • Working / transfer from : PT
  • Deficient / transfer to : ERCB
• Finger extension
  
  • Working / transfer from : FDS, FCR, or FCU
  • Deficient / transfer to : EDC
• Thumb extension
  
  • Working / transfer from :PL or FDS
  • Deficient / transfer to : EPL
• • • working / transfer from :
• Deficient / transfer to :

Question 68

Tendon Transfer Principles

basic principles [5]

pronosis [2]

Answer 68

Basic principles

1. donor must be expendable and of similar excursion and power
2. one tendon transfer performs one function
3. synergistic transfers rehabilitate more easily
4. it is optimal to have a straight line of pull
5. one grade of motor strength is lost following transfer

Prognosis

• age
  
  • leading prognostic factor
  • worse after age 30
• location
  
  • distal is better than proximal

Question 69

Tendon Transfer Principles

Specific Transfers and Indications (Card 1 of 2)

1. Musculocutaneous Palsy

2. Radial Palsy

Answer 69

Low median nerve palsy

• Thumb opposition and abduction
  
  • Working / transfer from : FDS (ring)
  • Deficient / transfer to : base proximal phalanx or APB tendon (use FCU as pulley - classic Bunnell opponensplasty)
  • Working / transfer from : EIP
  • Deficient / transfer to : APB (pulley around ulnar side of wrist)

High median nerve palsy

• Thumb IP flexion
  
  • Working / transfer from : BR
  • Deficient / transfer to : FPL
• Index and long finger flexion
  
  • Working / transfer from : FDP of ring and small finger (ulnar nerve)
  • Deficient / transfer to : FDP of index and middle (side-to-side transfer)

Ulnar nerve palsy

• Thumb adduction
  
  • Working / transfer from : FDS or ECRB
  • Deficient / transfer to : adductor pollicis
• Finger abduction (index most important)
  
  • Working / transfer from : APL, ECRL, or EIP
  • Deficient / transfer to : 1st dorsal interosseous
• Reverse clawing effect
  
  • Working / transfer from FDS, ECRL (must pass volar to transverse metacarpal ligament to flex proximal phalanx)
  • Deficient / transfer to :lateral bands of ulnar digits

Question 70

Carpal Tunnel Syndrome

Anatomy

1. Borders

2. Contents

3. Branches of median nerve

Answer 70

1. Carpal tunnel defined by:

• scaphoid tubercle and trapezium radially
• hook of hamate and pisiform ulnarly
• transverse carpal ligament palmarly (roof)
• proximal carpal row dorsally (floor)

2. Carpal tunnel consists of

• nine flexor tendons
• one nerve (median nerve)
• FPL is the most radial structure

3 . Branches of median nerve

• palmar cutaneous branch of median nerve
  
  • lies between PL and FCR at level of the wrist flexion crease
• recurrent motor branch of median nerve
  
  • 50% are extraligamentous with recurrent innervation
  • 30% are subligamentous with recurrent innervation
  • 20% are transligamentous with recurrent innervation
    
    • cut TV lig far ulnar to avoid cutting if nerve is transligamentous

Note: Carpal tunnel is narrowest at the level of the hook of the hamate

Question 71

Carpal Tunnel Syndrome

Most common compressive neuropathy

Note: pathologic (inflamed) synovium most common cause of idiopathic CTS

1. affects _____% of general population
2. Risk factors [12]
3. Associated conditions
4. Prognosis : good prognostic indicators [4]

Answer 71

1. Affects 0.1-10% of general population
2. Risk factors : female / obesity / pregnancy / hypothyroidism / rheumatoid arthritis / > age / CRF / smoking / ETOH / repetitive motion activities / mucopolysaccharidosis / mucolipidosis

3. Associated conditions : diabetes / hypothyroidism / RA / pregnancy / amyloidosis

4. Good prognostic indicators include

• night symptoms
• short incisions
• relief of symptoms with steroid injections
• not improved when incomplete release of transverse carpal ligament is discovered

Question 72

Carpal Tunnel Syndrome

1. Symptoms

2. Physical exam

Answer 72

1. Symptoms

• numbness and tingling in radial 3-1/2 digits
• clumsiness
• pain and paresthesias that awaken patient at night
• self administered hand diagram
  
  • the most specific test (76%) for carpal tunnel syndrome

2. Physical exam

• inspection may show thenar atrophy
• Carpal tunnel compression test (Durkan’s test)
  
  • is the most sensitive test to diagnose carpal tunnels syndrome
  • performed by pressing thumbs over the carpal tunnel and holding pressure for 30 seconds.
    
    • onset of pain or paresthesia in the median nerve distribution within 30 seconds is a positive result.
• Phalen test : wrist volar flexion for ~60 sec produces symptoms
• Tinel’s test : provocative tests performed by tapping the median nerve over the volar carpal tunnel
• Semmes-Weinstein testing :
  
  • ​most sensitive sensory test for detecting early carpal tunnel syndrome
  • measures a single nerve fiber innervating a receptor or group of receptors
• innervation density test
  
  • static and moving two-point discrimination
  • measures multiple overlapping of different sensory units and complex cortical integration
  • the test is a good measure for assessing functional nerve regeneration after nerve

Question 73

Carpal Tunnel Syndrome

Treatment

Answer 73

Nonoperative

• NSAIDS, night splints, activity modifications
  
  • indications
    
    • first line of treatment
  • modalities
    
    • night splints (good for patients with nocturnal symptoms only)
  • activity modification (avoid aggravating activity)
• Steroid injections
  
  • indications
    
    • adjunctive conservative treatment
    • diagnostic utility in clinically and electromyographically equivocal cases
  • outcomes
    
    • 80% have transient improvement of symptoms (of these 22% remain symptoms free at one year)
    • failure to improve after injection is poor prognostic factor
      
      • surgery is less effective in these patients

Operative

• carpal tunnel release
  
  • ​indications
    
    • failure of nonoperative treatment (including steroid injections)
      
      • temporary improvement with steroid injections is a good prognostic factor that the patient will have a good result with surgery)
    • acute CTS following ORIF of a distal radius fx
  • outcomes
    
    • pinch strength return in 6 week
    • grip strength is expected to return to 100% preoperative levels by 12 weeks postop
    • rate of continued symptoms at 1+ year is 2% in moderate and 20% in severe CTS
• Revision CTR for incomplete release
  
  • indications
    
    • failure to improve following primary surgery
      
      • incomplete release most common reason
  • outcomes
    
    • only 25% will have complete relief after revision CTR
    • 50% some relief
    • 25% will have no relief

Question 74

AIN Compressive Neuropathy

1. What is Parsonage-Turner Syndrome
2. Anatomy

Answer 74

Parsonage-Turner Syndrome

• bilateral AIN signs caused by viral brachial neuritis
• be suspicious if motor loss is preceded by intense shoulder pain and viral prodrom

Anatomy

• AIN is terminal motor branch of median nerve
  
  • AIN arises from the median nerve approximately 4-6 cm distal to the medial epicondyle
  • Travels between FDS and FDP initially, then between FPL and FDP, then it lies on the anterior surface of the interosseous membrane traveling with the anterior interoseous artery to pronator quadratus
  • Terminal branches innervate the joint capsule and the intercarpal, radiocarpal and distal radioulnar joints.
• AIN has principally motor innervation (no cutaneous sensory) and innervates 3 muscles
  
  • FDP (index and middle finger)
  • FPL
  • pronator quadratus

Question 75

AIN Compressive Neuropathy

1. A compressive neuropathy of the AIN that results in: [2]

2. Potential sites of entrapment [7]

patient with complete AIN palsy should have no motor function to all muscles innervated by AINpatients with incompletes palsies or with Martin-Gruber anastamoses (anomalous anatomy in 15% of population where axons of AIN may cross over and connect to ulnar nerve and innervate other muscle groups)

present with intrinsic weakness

Associated conditionsParsonage-Turner Syndrome

bilateral AIN signs caused by viral brachial neuritis

be suspicious if motor loss is preceded by intense shoulder pain and viral prodrome

Answer 75

1. A compressive neuropathy of the AIN that results in:

• motor deficits only
• no cutaneous sensory changes

2. Potential sites of entrapment

• tendinous edge of deep head of pronator teres (most common cause)
• FDS arcade
• edge of lacertus fibrosus
• accessory head of FPL (Gantzer’s muscle)
• accessory muscle from FDS to FDP
• abberant muscles (FCRB, palmaris profundus)
• thrombosed ulnar radial or ulnar artery

Note: patient with complete AIN palsy should have no motor function to all muscles innervated by AINpatients with incompletes palsies or with Martin-Gruber anastamoses (anomalous anatomy in 15% of population where axons of AIN may cross over and connect to ulnar nerve and innervate other muscle groups) – present with intrinsic weakness

Associated conditionsParsonage-Turner Syndrome

bilateral AIN signs caused by viral brachial neuritis

be suspicious if motor loss is preceded by intense shoulder pain and viral prodrome

Question 77

AIN Compressive Neuropathy

Presentation

1. Symptoms
2. Physical exam

Answer 77

1. Symptoms

• motor deficits only
• no complaints of pain, unlike other median compression neuropathies (carpal tunnel syndrome and pronator syndrome)

2. Physical exam

• weakness of grip and pinch, specifically thumb, index and middle finger flexion
• patient unable to make OK sign (test FDP and FPL)
• pronator quadratus weakness shown with weak resisted pronation with elbow maximally flexed
• distinguish from FPL attritional rupture (seen in rheumatoids) by passively flexing and extending wrist to confirm tenodesis effect in intact tendon
  
  • if tendons intact, passive wrist extension brings thumb IP joint and index finger DIP joint into relatively flexed position

Question 78

PIN Compression Syndrome

A compressive neuropathy of the PIN which affects the nerve supply of the forearm extensor compartment

1. incidence: reported as ___ per 100,000 people yearly
2. More common in: [3]
3. Mechanism of injury [4]

Answer 78

1. 3 per 100,000 people yearly

2. More common in : manual laborers / males / bodybuilders

3. Mechanism of injury:

• microtrauma : from repetitive pronosupination movements
• trauma : fracture/dislocation (e.g., monteggia fx, radial head fx, etc)
• space filling lesions: e.g. ganglion, lipomas, etc
• inflammation: e.g. rheumatoid synovitis of radiocapitellar joint
• iatrogenic (surgery)

Question 79

PIN Compression Syndrome

Question 80

PIN Compression Syndrome

Question 81

PIN Compression Syndrome

A compressive neuropathy of the PIN which affects the nerve supply of the forearm extensor compartment

Answer 81

Five potential sites of compression include: [image]

1. Fibrous tissue anterior to the radiocapitellar joint

• between the brachialis and brachioradialis

2. “Leash of Henry”

• are recurrent radial vessels that fan out across the PIN at the level of the radial neck

3. Extensor carpi radialis brevis edge

• medio-proximal edge of the extensor carpi radialis brevis

4. “Arcade of Fröhse”

• which is the proximal edge of the superficial portion of the supinator

5. Supinator muscle edge

• distal edge of the supinator muscle

Question 82

PIN Compression Syndrome

PIN is a branch of the radial nerve that provides motor innervation to the extensor compartment​

Anatomy

1. Course

2. Motor

3. Sensory

Answer 82

Course

• passes between the two heads of origin of the supinator muscle
• direct contact with the radial neck osteology
• passes over abductor pollicis longus muscle origin to reach interosseous membrane
• transverses along the posterior interosseous membrane

innervation

• 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

Question 83

Ulnar Tunnel Syndrome

Ulnar nerve compression neuropathy caused by direct compression in Guyon’s canal

also known as handlebar palsy (seen in cyclists)

1. Causes of compression include [11]

Answer 83

Causes of compression include:

1. ganglion cyst (80% of nontraumatic causes)
2. lipoma
3. repetitive trauma
4. ulnar artery thrombosis or aneurysm
5. hook of hamate fracture or nonunion
6. pisiform dislocation
7. inflammatory arthritis
8. fibrous band, muscle or bony anomaly
9. congenital bands
10. palmaris brevis hypertrophy
11. idiopathic

Question 84

Ulnar Tunnel Syndrome

Ulnar nerve compression neuropathy caused by direct compression in Guyon’s canal

also known as handlebar palsy (seen in cyclists)

Anatomy : Guyon’s canal

1. course

2. contents

3. boundaries and zones

Answer 84

1. Course

• is approximately 4 cm long
• begins at the proximal extent of the transverse carpal ligament and ends at the aponeurotic arch of the hypothenar muscles

2. Contents

• ulnar nerve bifurcates into the superficial sensory and deep motor branches
• boundaries and zones (see table below)

3. Boundaries

• Floor : Transverse carpal ligament, hypothenar muscles
• Roof : Volar carpal ligament
• Ulnar border : Pisiform and pisohamate lig, abductor digiti minimi muscle belly
• Radial border : Hook of hamate

4. Zones

• Zone 1
  
  • Locations: Proximal to bifurcation of the nerve
  • Common cause of compression: Ganglia and hook of hamate
  • Symptoms: Mixed motor and sensory
• Zone 2
  
  • Locations: Surrounds deep motor branch
  • Common cause of compression: Ganglia and hook of hamate fracture
  • Symptoms: Motor only
• Zone 3
  
  • Locations: Surrounds superficial sensory branch
  • Common cause of compression: Ulnar artery thrombosis or aneurysm
  • Symptoms: Sensory only

Question 85

Ulnar Tunnel Syndrome

Ulnar nerve compression neuropathy caused by direct compression in Guyon’s canal

also known as handlebar palsy (seen in cyclists)

1. classification

2. symptoms

3. physical exam and special tests

Answer 85

Classification : Presentation varies based on location of compression within Guyon’s canal and may be:

• Motor only
• Sensory only
• Mixed Motor & Sensory

Presentation

• Symptoms
  
  • pain and paresthesias in ulnar 1-1/2 digits
  • weakness to intrinsics, ring and small finger digital flexion or thumb adduction
• Physical exam
  
  • inspection & palpation
    
    • clawing of ring and little fingers
      
      • caused from loss of intrinsics flexing the MCPs and extending the IP joints
    • Allen test : helps diagnose ulnar artery thrombosis
  • neurovascular exam
    
    • ulnar nerve palsy results in paralysis of the intrinsic muscles (adductor pollicis, deep head FPB, interossei, and lumbricals 4 and 5)
    • weakened grasp
      
      • from loss of MP joint flexion power
    • weak pinch
      
      • from loss of thumb adduction (as much as 70% of pinch strength is lost)
  • Froment sign = IP flexion compensating for loss of thumb adduction when attempting to hold a piece of paper
    
    • loss of MCP flexion and adduction by adductor pollicis (ulnar n.)
    • compensatory IP hyperflexion by FPL (AIN)
  • Jeane’s sign = a compensatory thumb MCP hyperextension and thumb adduction by EPL (radial n.)
    
    • compensates for loss of IP extension and thumb adduction by adductor pollicis (ulna n.)
  • Wartenberg sign [image]
    
    • abduction posturing of the little finger

Question 86

Ulnar Tunnel Syndrome

Ulnar nerve compression neuropathy caused by direct compression in Guyon’s canal

also known as handlebar palsy (seen in cyclists)

Treatment

Techniques (local surgical options)

Answer 86

Nonoperative

• Activity modification, NSAIDS and splinting
  
  • indications
    
    • as a first line of treatment when symptoms are mild

Operative

• Local decompression
  
  • indications
    
    • severe symptoms that have failed nonoperative treatment
• Tendon transfers
  
  • indications
    
    • correction of clawed fingers
  • loss of power pinch
  • Wartenberg sign (abduction of small finger)
• Carpal tunnel release
  
  • indications
    
    • patients diagnosed with both ulnar tunnel syndrome and CTS

Techniques

• Local surgical decompression
  
  • release hypothenar muscle origin
  • decompress ganglion cysts
  • resect hook of hamate
  • vascular treatment of ulnar artery thombosis
  • explore and release all three zones in Guyon’s canal

Question 87

Cubital Tunnel Syndrome

A compressive neuropathy of the ulnar nerve

2nd most common compression neuropathy of the upper extremity

1. Sites of compression

• • common [3] /* less common [6]
• • External sources of compression [4]*

2. Associated conditions [4]

Answer 87

1. Sites of entrapment

• most common
  
  • between the two heads of FCU/aponeurosis (most common site)
  • within arcade of Struthers (hiatus in medial intermuscular septum)
  • between Osborne’s ligament and MCL
• less common sites of compression include
  
  • medial head of triceps
  • medial intermuscular septum
  • medial epicondyle
  • fascial bands within FCU
  • anconeus epitrochlearis (anomalous muscle from the medial olecranon to the medial epicondyle)
  • aponeurosis of FDS proximal edge
• External sources of compression
  
  • fractures and medial epicondyle nonunions
  • osteophytes
  • heterotopic ossification
  • tumors and ganglion cysts

2. Associated conditions

• cubitus varus or valgus deformities
• medial epicondylitis
• burns
• elbow contracture release

Question 88

Cubital Tunnel Syndrome

A compressive neuropathy of the ulnar nerve [2nd most common compression neuropathy of the upper extremity]

1. Anatomy

- Ulnar nerve course

- Borders of cubutal tunnel

Answer 88

Ulnar nerve

• pierces intramuscular septum at arcade of Struthers 8 cm proximal to the medial epicondyle as it passes from the anterior to posterior compartment of the arm
• enters cubital tunnel

Cubital tunnel

• Roof
  
  • formed by FCU fascia and Osborne’s ligament (travels from the medial epicondyle to the olecranon)
• Floor
  
  • formed by posterior and transverse bands of MCL and elbow joint capsule
• Walls
  
  • formed by medial epicondyle and olecranon

Question 89

Cubital Tunnel Syndrome

A compressive neuropathy of the ulnar nerve [ 2nd most common compression neuropathy of the upper extremity]

Presentation

1. Symptoms

2. Exam Findings

Answer 89

Symptoms

• paresthesias of small finger, ulnar half of ring finger, and ulnar dorsal hand
  
  • exacerbating activities include
    
    • cell phone use (excessive flexion)
    • occupational or athletic activities requiring repetitive elbow flexion and valgus stress
• night symptoms
  
  • caused by sleeping with arm in flexion

Physical exam

• inspection and palpation
  
  • interosseous and first web space atrophy
  • ring and small finger clawing
  • observe ulnar nerve subluxation over the medial epicondyle as the elbow moves through a flexion-extension arc
• sensory
  
  • decreased sensation in ulnar 1-1/2 digits
• motor
  
  • loss of the ulnar nerve results in paralysis of intrinsic muscles (adductor pollicis, deep head FPB, interossei, and lumbricals 4 and 5) which leads to:
    
    • ​weakened grasp
      
      • from loss of MP joint flexion power
    • weak pinch
      
      • from loss of thumb adduction (as much as 70% of pinch strength is lost)
    • Froment sign = compensatory thumb IP flexion by FPL (AIN) during key pinch
      
      • compensates for the loss of MCP flexion by adductor pollicis (ulna n.)
        
        • adductor pollicis muscle normally acts as a MCP flexor, first metacarpal adductor, and IP extensor
    • Jeanne sign = compensatory thumb MCP hyperextension and thumb adduction by EPL (radial n.) with key pinch
      
      • compensates for loss of IP extension and thumb adduction by adductor pollicis (ulna n.)
    • Wartenberg sign
      
      • persistent small finger abduction and extension during attempted adduction secondary to weak 3rd palmar interosseous and small finger lumbrical
    • Masse sign
      
      • palmar arch flattening and loss of ulnar hand elevation secondary to weak opponens digiti quinti and decreased small finger MCP flexion
• Extrinsic weakness
  
  • ​Pollock’s test
    
    • shows weakness of two ulnar FDPs
• Provocative tests
  
  • Tinel sign positive over cubital tunnel
  • elbow flexion test
    
    • positive when flexion of the elbow for > 60 seconds reproduces symptoms
  • direct cubital tunnel compression exacerbates symptoms

Question 90

Cubital Tunnel Syndrome

A compressive neuropathy of the ulnar nerve

2nd most common compression neuropathy of the upper extremity

Treatment

1. Non-op

2. Operative [3 techniques]

Answer 90

Nonoperative

• NSAIDs, activity modification, and nighttime elbow extension splinting
  
  • indications
    
    • first line of treatment with mild symptoms
  • Technique
    
    • night bracing in 45° extension with forearm in neutral rotation
  • Outcomes
    
    • management is effective in ~50% of cases

Operative

• in situ ulnar nerve decompression without transposition
  
  • approach : elbow medial approach
  • indications : when nonop Rx fails / before motor denervation occurs
  • technique : open release of cubital tunnel retinaculum / endoscopically-assisted cubital tunnel release [favorable early results but lacks long-term data]
  • outcomes:
    
    • ​meta-analyses have shown similar clinical results with significantly fewer complications compared to decompression with transposition
    • 80-90% good results when symptoms are intermittent and denervation has not yet occurred
    • poor prognosis correlates most with intrinsic muscle atrophy
• Ulnar nerve decompression and anterior transposition
  
  • indications: failed in situ release / throwing athlete / patient with poor ulnar nerve bed from tumor, osteophyte, or heterotopic bone
  • technique
    
    • subcutaneous, submuscular, or intramuscular transposition
  • outcomes
    
    • similar outcomes to in situ release but increased risk of creating a new point of compression
    • Improved outcomes with unstable nerves in the pediatric population
• Medial epicondylectomy
  
  • Indications
    
    • visible and symptomatic subluxating ulnar nerve
  • technique
    
    • in situ release with medial epicondylectomy
  • outcomes
    
    • risk of destabilizing the medial elbow by damaging the medial ulnar collateral ligament

Question 91

Replantation

Indications for replantation after trauma

1. primary indications [5]

2. relative indications [3]

Contraindications for replantation after trauma

3. primary contraindications [4]

4. relative contraindications [5]

Answer 91

INDICATIONS

1. Primary indications

• thumb at any level
• multiple digits
• through the palm
• wrist level or proximal to wrist
• almost all parts in children

2. Relative indications

• individual digits distal to the insertion of flexor digitorum superficialis [FDS] (Zone I)
• ring avulsion
• through or above elbow

CONTRAINDICATIONS

3. Primary contraindications

• severe vascular disorder
• mangled limb or crush injury
• segmental amputation
• prolonged ischemia time with large muscle content (>6 hours)

4. Relative contraindications

• single digit proximal to FDS insertion (Zone II)
• medically unstable patient
• disabling psychiatric illness
• tissue contamination
• prolonged ischemia time with no muscle content (>12 hours)

Question 92

Replantation

Operative : time to replantation

1. proximal to carpus

• warm ischemia time < ___ hours
• cold ischemia time < ___ hours

2. distal to carpus (digit)

• warm ischemia time < ___ hours
• cold ischemia time < ___ hours

3. Operative : general operative sequence of replantation [steps 1 to 8]

Answer 92

Operative: time to replantation

• [1] proximal to carpus
  
  • warm ischemia time < 6 hours
  • cold ischemia time < 12 hours
• [2] distal to carpus (digit)
  
  • warm ischemia time < 12 hours
  • cold ischemia time < 24 hours
• [3] General operative sequence of replantation
  
  • Step 1: vascular shunt first (for proximal replantation with large muscle mass to minimize warm ischemia time)
  • Step 2: bone fixation +/- shortening (after irrigation and debridement of soft-tissue and bone)
  • Step 3: extensor tendon repair
  • Step 4: artery repair(repair second after bone if ischemic time is >3-4 hours)
  • Step 5: venous anastomoses
  • Step 6: flexor tendon repair
  • Step 7: nerve repair
  • Step 8: skin +/- fasciotomy

NOTE : Finger order = thumb, long, ring, small, index

Question 93

Replantation

Postoperative Care

1. Environment
2. Replant monitoring
3. Anticoagulation
4. Arterial Insufficiency
5. Venous congestion

Answer 93

1. Environment

• keep patient in warm room (80°F)
• avoid caffeine, chocolate, and nicotine

2. Replant monitoring

• Skin temperature most reliable
  
  • concerning changes include a > 2° drop in skin temp in less than one hour or a temperature below 30° celsius
• pulse oximetry
  
  • < 94% indicates potential vascular compromise

3. Anticoagulation

• adequate hydration
• medications (aspirin, dipyridamile, low-molecular weight dextram, heparin)

4. Arterial Insufficiency

• treat with:
  
  • release constricting bandages
  • place extremity in dependent position
  • consider heparinization
  • consider stellate ganglion blockade
  • early surgical exploration if previous measures unsuccessful
• thrombosis secondary to vasospasm is most common cause of early replant failure

5. Venous congestion

• treatment
  
  • elevate extremity
  • leech application
    
    • releases Hirudin (powerful anticoagulant)
    • Aeromonos hydrophila infection can occur (prophylax with Bactrim or ciprofloxacin)
  • heparin soaked pledgets if leeches not available​

Question 94

Replantation

Complications [7]

Answer 94

Complications

• Replantation failure
  
  • most frequently cause within 12 hours is arterial thrombosis from persistent vasospasm
• Stiffness
  
  • replanted digits have 50% of total motion
  • tenolysis is most common secondary surgery
• Myonecrosis
  
  • greater concern in major limb replantation than in digit replantation
• Myoglobinuria
  
  • caused by muscle necrosis in larger replants (forearm and arm)
  • can lead to renal failure and be fatal
• Reperfusion injury
  
  • mechanism thought to be related to ischemia-induced hypoxanthine conversion to xanthine
  • allopurinol is the best adjunctive therapy agent to decrease xanthine production
• Infection
• Cold intolerance

Question 95

Extremity Flap Reconstruction

1. Definition of flap

2. Definition of pedicle

3. Indications for flap coverage [broad]

4. Prognosis

Answer 95

1. Definition of flap

• unit of tissue transferred from a donor site to a recipient site while maintaining its own vascular supply

2. Definition of pedicle

• vascular portion of the transferred tissue
• usually contains one artery and one or more veins

3. Indications for flap coverage = soft tissue injury with exposed

• bone
• tendons
• cartilage
• orthopaedic implants

4. Prognosis

• free tissue transfer within 72 hours for severe trauma in the upper extremity has been shown to decrease complication rates

Question 96

Extremity Flap Reconstruction

Classification

1. Blood supply classification [3]
2. Tissue type classification [5]
3. Mobilization type classification [4]

Answer 96

Blood supply classification

• Axial pattern local flaps
  
  • ​contain single arteriovenous pedicle (a “named vessel”)
  • indications:
    
    • primary/secondary closure not advisable and
    • area cannot support STSG or FTSG and length-width ratio needed > 2:1
• Random pattern flaps
  
  • supported by numerous microcirculation with no single arteriovenous pedicle
  • indications
    
    • primary/secondary closure not advisable andarea cannot support STSG or FTSG and
    • length-width ratio needed < 2:1
• Venous flap
  
  • uses veins as inflow and outflow of arterial blood

Tissue type classification

• Cutaneous
  
  • include skin and subcutaneous tissue
• Fascial flap
  
  • include fascia with no overlying skin [eg. temporoparietal flap]
• Muscle flaps
  
  • usually requires additional transfer of a skin graft to cover muscle
  • alternatively, muscle can be transposed as part of a musculocutaneous flap (composite flap)
  • if motor nerve is not preserved the flap will atrophy to 50% of its original size
• Bone flaps
  
  • Free fibula [based on peroneal artery pedicle – useful for diaphyseal reconstruction]
  • Free iliac crest [based on deep circumflex iliac vessels – useful for metaphyseal reconstuction]
• Composite flaps
  
  • consists of multiple tissue types [eg. radial forearm flap (fasciocutaneous)]​

Mobilization type classification

• Local flap
  
  • tissue transferred from an area adjacent to defect
• Distal random pattern flap
  
  • transfer of tissue to a noncontiguous anatomic site
  • indications
    
    • surrounding tissue will not support a local flap
    • length-width ratio needed < 2:1
• Distal axial pattern flap
  
  • indications
    
    • surrounding tissue will not support a local flap
    • length-width ratio needed > 2:1
• Free tissue transfer
  
  • indicatoins
    
    • local or distant tissue not sufficient for distal axial and random pattern flaps

Question 97

Extremity Flap Reconstruction

Techniques

1. Ladder of reconstruction

Answer 97

Ladder of reconstruction

• in order of increasing complexity
  
  • primary closure
  • secondary closure
    
    • healing by secondary intention
  • skin graft
  • local flap
  • regional flap
  • free tissue transfer

2. Complications

• Flap Failure
  
  • inadequate arterial flow
    
    • treatment = immediate return to operating room
  • inadequate venous outflow
    
    • treatment
      
      • loosen dressings, removal of selected sutures
      • return to operating room if not relieved by above measure
• Donor site morbidity
  
  • may be cosmetically unacceptable
  • pain related to grafting
  • seroma
    
    • treatment = aspiration / excision if encapsulated
• Nonunion for vascularized bone transfer
  
  • incidence
    
    • may be as high as 32% if no additional bone graft is used

Question 98

Radial TunnRadial TuRadial Tunnel Syndromennel Syndromeel Syndrome

Question 100

Extremity Flap Reconstruction

Question 101

Extremity Flap Reconstruction