Extensor tendon injuries hand

1. Extensor Tendon Injuries
-nousfier
-Mod:Dr Kumaran Chettiyar sir

2. Introduction
• Vulnerable to injury – Superficial location
• Small variations in tendon length and
suture tension can have sub optimal
results.

3. Anatomy
• 12 extensor muscles
• All innervated by Radial nerve or its
terminal motor PIN .
• Brachio radialis , Anconeus, ECRL –
Radial Nerve
• ECRB – Radial nerve / PIN
• All others – PIN

4. Origin
• BR, ECRL , ECRB - lateral supra condylar
ridge of humerus and lateral
epicondyle.
• ED, EDM, ECU, anconeus – commmon
extensor origin (lat
epicondyle humerus)
• Other muscles – more distally in the
forearm

6. Arrangement in forearm
• Superficial : Anconeus, ECRL ,ECRB , ED,
EDM, ECU
• Deep : Supinator, APL , EPB, EPL , EIP

9. Arrangement in Wrist
• Tendons under the extensor retinaculum
• 6 compartments ( 5 fibro osseous, 1
fibrous)
• 5th compartment (EDM) – only fibrous
compartment.

13. • EIP and EDM tendons are ulnar to the ED
tendons and insert at the MCP joint.
• Tendons become thinned over dorsum of
prox phalanx and trifurcates.

14. • 2nd and 3rd compartment separated
by listers tubercle
• Listers Tubercle acts as a
pivot point for EPL
• Juncturae Tendinum – EDC
interconnections.
(Cl : Proximal Lacerations )

15. Extensor Expansion

23. • Central portion – Central slip – base of
middle phalanx
• Lateral slips join tendons of interosseii and
lumbricals and inserts to base of distal
phalanx

24. • Transverse Retinacular ligament- prevents
dorsal subluxation of lateral bands
• Triangular ligament- prevents volar
subluxation of lateral bands
• Oblique retinacular ligament (
Landsmeer)– (origin A2 Pulley) – extends
DIP joint when PIP is extended.

29. Intrinsic Muscles
• 7 interosseii
• 4 lumbricals
• 3 palmar interosseii : arise from medial
side of 2 , 4, 5 metacarpals
• 4 dorsal interosseii: two heads each from
the adjacent sides of the five metacarpal
bones

31. • Lumbricals arise from radial side of FDP
at level of metacarpals.

32. Function- Intrinsic muscles
• Interosseii : Flex MP and extend IP
When MP joint is in extension – IP joint is
extended
When MP joint is flexed – loses extension
capabilty distally.
• Lumbricals : Extend PIP and DIP even
when MP is flexed.

33. Function – Extrinsic muscles
• Component which Extends proximal
phalanx
• Normally counter acted by intrinsic
muscles
• Hence paralysis ex. Ulnar nerve palsy –
hyperextension at MP joints
• Claw hand
• For complete extension of IP joints,
intrinsic muscle function is mandatory.

34. Movements
• Proximal Phalanx: Extrinsic extensors,
flexors, Intrinsics
• Middle phalanx: Extrinsic extensors,
Flexors, Oblique retin ligament

35. Diagnosis of Extensor tendon
injury
• EDC : extend MP joint against resistance.
• EPL : Lift thumb off table
• Elsons test – for closed central slip rupture
after flexing PIP jt, examiner asks to
extend PIP against resistance. In central slip
rupture minimal extension power felt over
PIP but more power at DIP due to intact
lateral bands.

38. • An extensor tendon division b/w PIP & DIP
active extension of DIP is lost.
• Initially, a gross mallet finger deformity may
be absent  surrounding capsule and other
soft tissues have not yet been stretched

39. • When the extensor tendon is divided just
proximal to the MCP joint, PIP & DIP can be
extended by the lateral bands and their
connecting transverse fibers, but extension of
the MCP is incomplete.

40. • Partial or complete extension of the finger
may be possible when a single extensor
tendon is divided at the wrist because of the
presence of accessory communicating
tendons (juncturae tendinum)

41. CLINICALEVALUATION N
Testing for EDC, EIP &
EDM
musculotendinous
function
The proprius tendon to
the index & little finger
are capable of
independent extension.
Their function together can
be evaluated with the
middle & ring finger flexed
into the palm , the proprius
tendons can extend the ring
& little finger

42. TESTING PROPRIUS TENDONS
With the middle & ring
fingers flexed into the
palm, the Proprius tendon
can extend the index and
little fingers

43. EPB tendon can be
checked by placing a
finger in the
anatomical snuff box
and asking the patient
to extend the thumb in
a flat position
APL tendon can be
checked by asking
the patient to abduct
the thumb against
resistance

44. Evaluation of wrist
extensors & deviators

45. TestingtheEPLtendon

46. Zones of Injury
• Kleinert and Verdan -8
zones
• Doyle – 9th zone(forearm
extensor muscle belly)
• Odd no zones are located
on a joint
• Even no zones are in
between over bones

48. Patient selection
• Explore lesions proximal to zone 6 only in
OT
• Use loupe (magnification)
• Wide awake surgery – Tumuscent
anesthesia and no
tourniquet

49. Suturing Techniques
• Depends on location of injury
• In zone 6 and proximal – resembles flexor
tendons – core suture + running epi
tendon suture
• In distal zones –core sutures are difficult
due to flattening of tendon.

51. ZONEIINJURY
 Occurs at the DIP joint of the
finger or the IP joint of the
thumb
 Mechanism of injury is
usually forced flexion of an
actively extended DIP
 aka Mallet finger, Base ball
finger, Dropped finger, or
Extension lag

52. MALLET FINGER
Mechanism : a blow from a thrown ball
strikes the tip of the finger--- ‘forced
flexion’.
It tears the extensor tendon from its
insertion
Clinically , there is extensor lag with
localized DIP joint tenderness . The
athlete is unable to extend the DIP
Investigation : radiographs to rule
out fracture with volar subluxation

54. Zone 1 injury

55. Zone 1-DIP
• Mallet finger
flexion at distal phalanx due to extensor
lesion at DIP jt.
Rx: Conservative , immobilize DIP joint in
extension sparing PIP
6-8 wks. Then 4 wks splinting at night.then
passive exercises
Sx: only if fragment size > 1/3 joint surface.
Transfix DIP jt by K wire.

56. • Treatment of an open injury of the extensor
tendon insertion at DIP requires repair of the
tendon
• Use roll sutures
• Dermo-teno-dermal sutures

57. • Mallet finger deformities in children may be
caused by traumatic separation of the
epiphysis
• finger is splinted for 3 to 4 weeks, and healing
is rapid compared with injury of the extensor
tendon itself
Type 4A

58. Type 4B and 4C
• Operative treatment with
extension block pinning
or
• Non operative with
splinting

59. Zone 2
• MC lacerated wounds over middle phalanx
• Explore
• If more than 50 % of tendon substance is
found to be involved – SUTURE
• If <50%-suture skin only
• Silfverskiöld cross-stitch
• DIP splinted for 4-6 wks
• Avoid shortening tendon coz
flexion of DIP aff

60. Doyle’s repair : Sharp laceration of zone II repaired with a
running suture and over sewn by a Silverskiold cross
stitch

61. Zone 3
• At the level of PIP joint
• Disruption of extensor apparatus @ or just
prox to PIP jt
• Forced flexion at PIP-damages the central
slip
• Early : inability to actively extend PIP (
passive possible)
• LATE :Boutonniere deformity : hyper
extended DIP , flexed PIP

62. • After central slip disruption-
triangular lig stretches over time
shifting lateral bands in volar
direction
• Head of prox phalanx buttonholes
through ext mechanism causing
Boutonniere deformity
• Lateral bands fall volar-PIP joint
flexes instead of extension and
DIP continuing extension

63. May be acute or chronic

65. Rx zone 3 injuries
• Closed Injuries
check extension of PIP against
resistance.
Rx: Splinting PIP. ( avoid splinting DIP
….flexing DIP helps in dorsal migration of
lateral bands ) encourage DIP movt.
6 weeks
Sx : if large fragment.

66. • Open injuries
Explore
Snows technique :
Retrograde tendon flap
To bridge the defect

67. • Aiaches technique:
splitting lateral
Bands- join in mid

68. Central slip laceration with sufficient tendon to repair
with core suture & over sew with silverskiold
epitendinous suture

69. When the tendon laceration is distal, leaving a small
stump of central slip; the core suture can be
passed through a trough in the base of the middle
phalanx

70. Chronic Boutonniere
Deformity
 Burton & Melchior classification:
Stage 1: supple, passively
correctable deformity
Stage 2: fixed contracture:
contracted lateral bands
Stage 3: fixed contracture: joint
fibrosis, collateral ligament &
palmar plate contractures

71. Treatment plan in Boutonniere
deformity



• Acute closed: extension splinting of
PIP joint
• Acute open: primary repair (Snow’s,
Aiache’s methods)
• Chronic:
• Stage 1 & 2- therapy-active assisted
extension of the PIP+passive flexion
of the DIP jt.
• Stage 3-Tenotomy, Tendon grafting,
Tendon relocation

73. ReconstructionofBoutonnière
A. Theboutonnieredeformitywiththelateral
bands&ORL volartothePIPjoint
B. Dorsalzigzag incision
C. TheORL isseparatedfromthelateralbands
&atenotomyof thelateralbandsisdone
distaltothecentralslipinsertion
D. If activePIP extensionisstillnotpossible,
thelateralbandsaresuturetogether,dorsal
tothePIP joint
E. Sequenceof events
F. ThePIP jointisfixedwithatransarticularK
wire
G. Themechanicsof thereconstruction

74. tenotomyof thelateralbandsisdone distal
tothecentralslipinsertion

75. Zone 4
• MC : partial lacerations-bcoz extensor
mechanism is flat and curves around the
prox phalanx
• Modified Kessler repair
• Early active mobilization-passive
extension and active flexion

76. Zone 5
• At level of MP joint
• Complete division of extensor mechanism
uncommon-owing to width
• Partial laceration with division of central
tendon-common
• Core suture with running epitendinous
suturing
• splint:wrist extension,30* MCP flexion-->
IP jt is allowed active motion

77. Sagittal band injuries
• Result in subluxation of the
tendon to the side opposite to
the injury(>>ulnar side
subluxation)
• Closed>open injuries
• Subluxation if >2/3 of prox
band cut
• Open:simple matress suture
f/b buddy strapping-allowing
gentle mobilisation

78. • Closed sagittal band injuries can occur following blunt
trauma or resisted extension of the digit
• Patient complains of
– snapping sensation on flexion due to the tendon subluxing,
– finger may be adducted ulnarly
– difficulty initiating extension when the MCPJ is in full
flexion even though the tendon is in a central position
during full extension
• Rx: within 3 weeksFlexion block splints that limit
flexion of the MCPJ and allow the tendon to heal in the
reduced position (MCP PIP jt movement is allowed)
upto 8 weeks
• After 3weeks/failed splint: surgery

81. HUMAN BITE INJURIES
• ‘Punch’ to mouth- teeth penetrating injury in zone 5
• External wound small,history often omit by patient
• Most involve MCPJ
• Expolre=breach in dorsal capsule= debridement and
washout the joint
• Tendon repair deferred till wound clean
• Failure to recognize= septic arthritis

82. Zone 6
• Better prognosis: broad, extra synovial,
• Dx: MP joint extension against resistace.
( however juncturae tendinum )
• Complete laceration of an EDC tendon in
zone 6 may not result in an extensor lag at
the MCPJ because of the juncturae
tendinae that interconnect the EDC
tendons
• Core sutres with running epi tendinous

83. Zone 7
• At level of extensor retinaculum-open it to
gain access
• ‘z’ or oblique incision to facilitate repair
• Core suture with running epi tendinous
• Sensory branch of ulnar and radial nerve
prone to injury here- repair
• EPL rupture associated with distal radius
fracture / RArthritis

84. Zone 8 + 9
• Injuries to the muscle belly and musculo
tendinous jn.
• Adequate repair of muscle and tendons –
difficult(poor suture holding)
• Muscle sutures have no tensile strength
• Hence post op immobilization protocol is
followed for 4 weeks.
• PIN should be explored if prox lesions

85. Post op
• Immobilization although allows tendon
healing, promotes loss of motion due to
adhesions
• But immobilization protocols are the main
stay in
mallet finger, closed zone 3 injuries,
zone 8 ,9 injuries.
• Other zone injuries are managed by early
active mobilization protocols

86. • Evans protocol – 3 splints
-affected digit is immmobilized between
training sessions in an extension splint. 0 deg ext at
DIP PIP
-Every waking hour , splint removed, another
splint is put on to block flexion of PIP 30 deg, and
DIP 25 deg.
-20 repetitions done of active and passive
motion within limits.
-3rd splint is then put with PIP joint in 0 deg
extension sparing DIP.
-active flex and ext of DIP 20 times

87. • Dynamic mobilization for zones 5- 7
injuries
• Passive extension by rubber band sytem
with active flexion of affected digit.
• (reverse washington / reverse kleinert
regimen)
• Active flex + passive extens
10 times hourly for 3 weeks

88. Complications
• MC compication – Adhesions
• Clinically PIP joint flexion is limited when
MP jt is flexed
• Hand therapy, splinting – 4-6 months
• If no improvement - Tenolysis

89. Swan-neck deformity

90. • Cause : Volar plate rupture at the PIP+
accompanying triangular ligament rupture.
• Pathology :Lateral bands drift dorsally
+hyperextension at the PIP joint. They
become ineffective in extension at the DIP
joint
• unopposed action of the profundus causes
flexion at the DIP joint.
• Clinically : Causes “jamming” dislocations
Immediately noticeable, if not immobilized
will become surgical finger.
• Treatment : involves SORL reconstruction

91. Swan Neck Deformity
• Hyper extension PIP, flexion at DIP and MCP
• Pathology
• PIP joint : synovitis – dorsal translation of
lateral bands
• MCP joint: synovitis – weakening of extensor
attatchment at proximal phalanx , hence force
transmitted to middle phalanx
• DIP jt: rupture of terminal extensor
• Wrist- synovitis-carpal collapse-lax long
flexors and extensors-overaction of intrinsic

93. • Thank you