Flexor tendon injury, management and rehabilitation

1. Flexor Tendon injury, Management
and Rehabilitation
Dr.Khadijah Nordin
Flexor
Tendon
anatomy
Flexor
Tendon
Healing
Flexor tendon
repair
Rehabilitation

2. Flexor
Tendon
anatomy
Tendon
anatomy
Flexor
tendon
Pulley
System
Tendon
Nutrition
Tendon
sheath
Flexor
Tendon
Excursion
Vincular
system
Flexor
tendon
Zone

3. Tendon Anatomy
• Tendon:
• part of the muscle that attaches the
muscle to bone and transfers forces
generated by muscle to bone that
produces movement at joint.
• 70% collagen (Type I)
• Extracellular components
• Elastin
• Mucopolysaccharides (enhance
water-binding capability)
• Endotenon – around collagen
bundles
• Epitenon – covers surface of
tendon
• Paratenon – visceral/parietal
adventitia surrounding tendons in
hand
• Synovial like fluid environment

5. Flexor tendon

6. FDS
*Origin
• 2 muscle bellies
- medial epicondyle
- radial shaft
* tendons arise form separated muscle bundles
act independently

7. FDP & FPL
* Origin
• ulna & interosseous membrane
* common muscle origin for several tendons
Act simultaneous flexion of
multiple digits

8. Flexor tendon zone

10. 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
2 annular pulley
interposed oblique pulley (most
important)

11. Tendon nutrition
1. Synovial fluid:
• produced within
tenosynovial sheath
2. Blood supply:
• provide by vincular
circulation

12. Vincular system
 Nutrition of tendon
 Suspensory ligament of tendon
 Stabilization of tendon

14. Flexor Tendon Excursion
• 9cm : wrist & digital flexion
• 2.5cm : full digital flexion with wrist neutral position

15. • Moment Arm:
• Increased distance of tendon from joint
center of rotation = higher moment arm
= less motion per muscle contraction
force
• Pulley system constrain govern these
parameters
• Loss of portions on flexor, intrinsic and
extensor tendon
• Loss of A2 or A4 pulley may diminish
motion/ power or lead to contracture of
IPjoint

16. 4 phases
Goal of
healing
Type of
healing

17. Re establish tendon fiber continuity
Restore gliding mechanism between tendon and surrounding
structure
Obtain a satisfactory return of digital motion

20. Two forms
–Intrinsic healing
• occur through the activity of the fibroblasts derived from the tendon.
–Extrinsic healing
• occurs by proliferation of fibroblasts from the peripheral epitendon
• adhesions occur because of extrinsic healing of the tendon and limit
tendon gliding within fibrous synovial sheaths
Balance between the two determines amount of extrinsic adhesion
vs intrinsic tendon healing

21. Timing of
repair
Incision
Repair
Techniques
Tendon
suture

22. Timing of repair
1.Primary repair
Golden period
With in 24hrs in a clean wound
Best results
2.Delayed primary repair
24-10 days
Done: suspicion of infection , viability questionable or came late
3.Secondary repair
-10-14days up to 4wks
4.Late secondary
After 4 wks
Delayed equal or better than emergent repair
Acute or subacute acceptable
Tendon deterioration/shortening after several wks
Delay several days if wound infected

23. Incision (Brunner incision)

24. Repair Techniques
• Ideal
• Gap resistant
• Strong enough to tolerate forces generated by early controlled active
motion protocols
• 10-50% decrease in repair strength from day 5-21 post repair in immobilized
tendons
• This is effect is minimized (possibly eliminated) through application of early
motion stress
• Minimal bulk
• Uncomplicated
• Minimal interference with tendon vascularity

25. Strickland stresses six characteristics of an ideal
tendon repair:
(1) easy placement of sutures in the tendon,
(2) secure suture knots,
(3) smooth juncture of tendon ends,
(4) minimal gapping at the repair site,
(5) minimal interference with tendon vascularity, and
(6) sufficient strength throughout healing to permit application of early
motion stress to the tendon.

26. • Direct repair:
• if laceration is more than 1 cm
• from FDP insertion
• Tendon advancement:
• if the laceration is less then 1 cm from insertion.

27. Tendon suturing
• Suture Material
• Suture Configuration
• Suture Technique

28. Suture material
• Monofilament
• Non absorbable
• Synthetic

29. Suture strength
• Taras et.al
• Noted a 49% increase in suture strength when caliber was increased from 4-0 to 3-0.
 the strength of a braided, nonabsorbable suture is related to its cross-sectional area
• Nelson et.al
• Primary factors
• core suture caliber,
• number of core suture strands,
• peripheral suture purchase
• Secondary factors
• core suture purchase
• peripheral suture caliber

30. Suture strength
• Winters et al
• 8-strand repair is stronger than 4-strand repair
• at 3 weeks (49% greater ultimate load)
• at 6 weeks (117% greater ultimate load)
• 8-strand 3-0  difficult in practice
• 3-0 suture
• mechanically advantageous
• 8-strand 4-0 suture
• 43% stronger than 4-strand 3-0

31. Suture configuration
3 Groups
• Group 1
• Ex : simple sutures;
• the suture pull is parallel to the tendon collagen bundles, transmitting the stress of
the repair directly to the opposing tendon ends.
• Weakest
• Group 2
• Ex : Bunnell suture;
• stress is transmitted directly across the juncture by the suture material and depends
on the strength of the suture itself.
• Group 3
• Ex : Pulvertaft technique (fish-mouth weave);
• sutures are placed perpendicular to the tendon collagen bundles and the applied
stress
• Strongest & most suitable

32. Chapter 66 : Flexor and Extensor Tendon Injuries. Campbell’s Operative Orthopaedic, 12th. Ed

33. Suture configuration
• Multiple-strand modifications
• Savage (six strands)
• Lee (four strands)
• The Tang and cruciate repairs
• better tensile strength and elastic properties
• compared with the Silfverskiöld, Robertson, and modified Kessler repairs
• A four-strand adaptation of the Kessler repair (Smith-Evans
modification)
• significantly stronger than the Kessler technique

35. Suture configuration
• Epitenon-first technique
• 22% stronger than the modified
Kessler technique
• Circumferential suture :
• Interlocking horizontal mattress
suture
• highest load to failure,
• greatest resistance to gap formation,
• highest stiffness
best overall

36. Suture technique
• End-to-End
• End-to-Side
• Tendon-to-Tendon
• Tendon-to-Bone

37. End to end technique

38. SUTURE TECHNIQUE
End-to-End (Crisscross Bunnel)

39. SUTURE TECHNIQUE
End-to-End
• Kleinert (Bunnel crisscross
modification)
• easier to insert
• probably causes less intratendinous
ischemia.
• Because of the single crisscross,
• “straightening” of the suture within
the tendon and gap formation are
possible.

40. SUTURE TECHNIQUE
End-to-End
• Kessler
• A modification of the Mason-Allen suture.
• Effective for tendon repair in the fingers and palm.
• In the fingers, (-) knots being left exposed on the tendon surface
• Modified Kessler (Smith-Evans modification)
• (+)
• A single piece of suture material is used.
• Another advantage is that the knot is left in the cut surface of the tendon.
• minimize the problem of exposed suture material
• (-)
• difficulty of sliding the tendon on some suture materials to achieve
satisfactory approximation of the tendon ends.

42. SUTURE TECHNIQUE End-to-End
• Tajima
• Allows the placement of two
pieces of suture material in the
ends of the cut tendon.
• This permits the use of the suture
for traction to pass the tendon
through the sheath and beneath
the pulleys in difficult locations.
• It also has the advantage of
allowing the knots to be placed
within the cut surface of the
tendon

43. SUTURE TECHNIQUE
End-to-End
• Strickland (Modified Kessler-Tajima)
• incorporates several advantages of each.
• Separate sutures are introduced in each tendon end at distance of 0.5 to 1 cm
• so that the tendon ends can be passed within the flexor sheath, using the free ends of
the suture as traction sutures.
• The knots are tied within the tendon.
• The sutures are locked with each exit from the tendon

44. Strickland 1983 :
• Separate sutures are introduced in each
tendon end at distance of 0.5 to 1 cm.
• Approximately 25% of diameter of tendon is
grasped by separate needle passage and
locked on side of tendon.
• Suture is passed transversely behind knot
across tendon, where second-needle pass-
and-lock suture is used to grasp tendon side.
• Finally, suture is passed behind second knot
and down tendon-to-tendon end.
• After placement of similar suture in opposite
end, two tendon ends can be brought
together, and repair usually is tidied up by
small circumferential suture.
• When in place in end of given tendon,
protruding suture ends can be used to pass
tendon through tendon sheath and position
it for repair without needing to damage
tendon with further instrumentation
Chapter 66 : Flexor and Extensor Tendon Injuries. Campbell’s Operative Orthopaedic, 12th. Ed

45. Strickland 1995 :
• Perform the Strickland
modification of the Kessler-
Tajima core sutures as
described previously.
• Add a running-lock dorsal
epitendinous suture of 5-0 or
6-0 nylon.
• On completion of the back wall
suture, add a horizontal
mattress suture of 4-0 braided
polyester to the core suture
configuration.
• Tie all knots of the core
sutures.
• Complete the palmar (volar)
running-lock peripheral
epitendinous suture.
Chapter 66 : Flexor and Extensor Tendon Injuries. Campbell’s Operative Orthopaedic, 12th. Ed

46. SUTURE TECHNIQUE
End-to-End
• Double-right Angled
• To suture the severed ends of a
tendon together without
shortening,
• (+)
• useful proximal to the palm.
• easier and is used more often
when several tendons have been
severed in the distal forearm and
proximal palm.
• (-)
• apposition of the tendon ends is
not neat.
Chapter 66 : Flexor and Extensor Tendon Injuries. Campbell’s Operative Orthopaedic, 12th. Ed

47. SUTURE TECHNIQUE
End-to-End
• Fishmouth (Pulvertaft)
• A tendon of small diameter can be sutured to one of large diameter.
• commonly used to suture tendons of unequal size.
Chapter 66 : Flexor and Extensor Tendon Injuries. Campbell’s Operative Orthopaedic, 12th. Ed

48. SUTURE TECHNIQUE
End-to-Side
• Used in tendon transfers
• when one motor must
activate several tendons.
Chapter 66 : Flexor and Extensor Tendon Injuries. Campbell’s Operative Orthopaedic, 12th. Ed

49. SUTURE TECHNIQUE
Roll-Stitch
• especially useful for suturing extensor tendons over or near the
metacarpophalangeal joints
Chapter 66 : Flexor and Extensor Tendon Injuries. Campbell’s Operative Orthopaedic, 12th. Ed

50. SUTURE TECHNIQUE
Pull-out Technique
• For Tendon repairs or grafting
• Tendon-to-tendon repair
• in children
• to avoid physeal injury.
• Tendon-to-bone repairs,
• the core suture techniques
• Kessler
• modification of the Bunnell crisscross suture
• the pull-out wire is looped over a straight needle that is passed transversely through the
tendon approximately 10 mm from the cut end.
 pull-out wire attached to a loop of the suture proximally in the tendon to be passed into the
bone distally

51. Tendon-to-Tendon Suture
Chapter 66 : Flexor and Extensor Tendon Injuries. Campbell’s Operative Orthopaedic, 12th. Ed

52. Tendon-to-Bone Attachments
Chapter 66 : Flexor and Extensor Tendon Injuries. Campbell’s Operative Orthopaedic, 12th. Ed

53. Tendon Attachment in Fingers
Chapter 66 : Flexor and Extensor Tendon Injuries. Campbell’s Operative Orthopaedic, 12th. Ed

54. One method of attaching
tendon to bone.
• A, Small area of cortex is
raised with osteotome.
• B, Hole is drilled through
bone with Kirschner wire
in drill.
• C, Bunnell crisscross stitch
is placed in end of
tendon, and wire suture is
drawn through hole in
bone.
• D, End of tendon is drawn
against bone, and suture
is tied over button
Chapter 66 : Flexor and Extensor Tendon Injuries. Campbell’s Operative Orthopaedic, 12th. Ed

55. Quadrigia effect
• Tendon advancement shortens the FDP & completes
• the grip before the normal fingerd and limit their
• flexion and thus week grip

56. Rehabilitation
Goal promote intrinsic tendon healing & minimize extrinsic scarring to
optimize tendon gliding & functional range of motion
Early post-repair motion stress
_ biologically alter the process of scar formation and maturation at the repair
site such that collagen is laid down parallel to the axial forces (increase
strength), and decrease adhesions :tendon adhesions are stretched
(increased tendon glide)
– Load at failure for mobilized tendons twice that for immobilized tendons at 3
wks (Gelberman)

57. FLEXOR TENDON MANAGEMENT
3 methods of post-op flexor tendon
management are:
•Immobilization,
•controlled passive motion
•early active motion

58. Immobilization
• Complete immobilization of tendon for 3 ½ weeks after Surgery
• May not yield consistently good results due to production of scar
adherence
• May lead to a greater incidence of tendon rupture
• May be necessary if other injuries are present (e.g., a fractured
phalanx that cannot be moved)
• May be selected if patient appears unable to participate fully in
treatment (e.g., child or a person with cognitive impairments)

60. CONTROLLED PASSIVE MOTION
• Durand and Houser protocol allows 3 to 5 mm of tendon excursion
after repair
• On 3rd postoperative day, patient begins twice-daily exercise regimen
of passive flexion and extension (6 to 8 motions per tendon)
• Keep wrist flexed and MCPs in 70 degrees of flexion
• After 4 ½ weeks, protective dorsal splint is removed and rubber band
traction is attached to a wristband.
• Active extension and passive flexion are done 1 additional week and
gradually increased over next several weeks.
• Found sufficient to prevent adherence of the repaired tendons

62. Duran and Houser

63. EARLY ACTIVE MOTION
• Kleinhert and Washington protocols use early active extension but passive flexion
• Indian and MAMTT (minimal-active muscle-tendon tension) protocols allow early gentile
supervised active flexion of tendon
• Rubber bands are attached to fingernails of the involved digits
• Dorsal blocking splint with MCP joints held in ~ 60 degrees of flexion and PIPs in
gentile flexion
• Patient wears splint 24 hours a day for 3 weeks and is instructed to actively
extend fingers several times a day in splint, allowing rubber bands to pull fingers
into flexion
• Patient must be able to fully extend IP joints actively within splint to prevent joint
contractures
• Splint is removed at 3 weeks, depending on the surgeon’s judgment
• Method minimizes scar adhesions while enhancing tendon nutrition and blood
flow

64. Kleinert splint with palmar pulley
Kleinert (1950s)
– Posterior splint, wrist in flexion
– Rubber bands from fingernails to volar
wrist area hold fingers in flexion
– Patient able to actively extend against
rubber bands (within confines of
splint)
– Fingers pulled passively back into
flexion
– Used widely since with some
modifications
– Showed superior results with primary
repair vs delayed grafting

67. POSTACUTE FLEXOR TENDON REHAB
• Once active flexion is begun out of splint (after postoperative management), patient
should be instructed in exercises to facilitate differential tendon gliding
• Wehbe recommends 3 positions—hook fist, straight fist, and composite fist
• Tendon glide exercises should be repeated 10x’s in each position, 2-3x’s daily
• Isolated exercises to assist tendon gliding may be performed with a blocking splint
or by using opposite hand
• MCP joint is held in extension during blocking, so intrinsic muscles that act on it
cannot overcome power of repaired flexor tendons
• After 6 to 8 weeks, passive extension may be started (cylindrical plaster splint or
volar finger splint may be necessary to correct flexion contracture at PIP joint)
• After ~ 8 weeks, patient may begin light resistive exercises, light ADL, and other
activities; patient must avoid lifting with or applying excessive resistance to affected
hand
• Activities such as working with soft clay, woodworking, and macramé are excellent