a complete overview of flexor tendon repair including healing methods,flexor tendon zones,flexor tendon repair techniques,flexor tendon suture metods,suture biomechanics, flexor tendon rehabilitation,

1. FLEXOR TENDON REPAIR.
DR.B.PUNITHAVASANTHAN
HAND AND MICRO SURGERY FELLOW
DEPARTMENT OF PLASTIC SURGERY
SKIMS-SOURA

2. DILEMMAS SURROUNDING
FLEXOR TENDON REPAIR
• Should both tendons be repaired or just the
FDP?
• Should the sheath be excised or repaired?
• What type of sutures should be utilized?
• What type of postoperative motion most
beneficial?

3. SYNOPSIS.
• FLEXOR TENDON HEALING.
• SUTURE TECHNIQUES.
• TENDON REPAIR ACCORDING TO ZONES.
• FLEXOR TENDON RECONSTRUCTION.
• REHABILITATION PROTOCOLS.

4. Flexor tendon healing
Intrinsic healing
- From prolifaration of tenocytes and
extracellular matrix from intrinsic cells.
- occurs without direct blood flow to the
tendon

5. Phases of Intrinsic healing
• 1.Inflammatory (0-5 days) : strength of the
repair is reliant on the strength of the suture
itself
• 2.Fibroblastic (5-28 days) : or so-called
collagen-producing phase
3.Remodelling (>28 days)

6. • Mobilized tendons showed progressively
greater ultimate load compared with
immobilized tendons
Early tendon motion has significant
role in favouring intrinsic healing.

7. 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 .
If intrinsic capacity is disabled such as in
excessive trauma, or in case of post surgical
immobilisation extrinsic healing is favoured

8. Suture principles and techniques
Ideal tendon repair
1.Easy placement of sutures in tendon
2. Secure suture knots
3. Smooth juncture of tendon ends
4. Minimal gapping at repair site
5. Minimal interference with tendon vascularity
6. Sufficient strength throughout healing to
permit application of early motion stress to
tendon.

9. • whereas early passive and early active motion
have been shown to prevent the initial
weakening, leading to progressively increased
repair strength, starting from the time of
repair
Immobilisation significantly decreases the
strength of repair by 10-50 % within the first
3 weeks of healing,

10. SUTURE CONFIGURATIONS:
Epitenon sutures
suture pull is parallel to tendon collagen
bundle, transmitting stress of repair
directly to opposing tendon ends.
Core suture
stress is transmitted directly across
juncture by suture material & depends on
strength of suture.
Pulvertaft technique
suture are placed perpendicular to
tendon collagen bundles & applied stress.

11. Core Sutures
• Strength proportional to number of strands
• Locking loops increase strength but may
collapse and lead to gapping
• Knots should be outside repair site
• Equal tension across all strands

12. • The optimal range of core suture purchase has
been determined as 1.0 cm with increased gap
resistance, ultimate force and stiffness
• The purchase of 0.5 cm results in very weak
repairs,
• whilst any increase over 1 cm does not
improve the biomechanical properties .

13. Locking loop
Transverse component crosses just superficial to the
longitudinal part of the suture.
Loop of suture locking around a small bundle of tendon
fibres so that when more tension is applied to the repair
site, the tighter the grip of the suture loop on these fibre
bundles

14. Several studies have demonstrated that
locking loops improve the ultimate
force and gap resistance compared to
grasping loops in flexor tendon repair
The locking loops of 25% reached the
highest gap resistance,highest repair
strength.

15. • Why we use 3-0 sutures for core suturing?
Because ,With 4–0 suture, the material
strength is inferior to the holding capacity of
the suture grips of the tendon, leading to
failure by suture rupture before the true
biomechanical properties of the locking loops
are obtained.

16. • What is the best suture material for tendon re
pair??
-Polyester suture demonstrates significantly
higher tensile strength than nylon and
polypropylene sutures .
- Maintains its tensile properties in the body
temperature, whilst the tensile strength of
both polypropylene and nylon suture has
been shown to decrease significantly
Braided polyblend polyethylene(New)>Coated braided
polyester >Monofilament polypropylene > monofilament
nylon.

27. Epitendinous suture
• Thought of a “tidying up” suture to improve
tendon gliding within the flexor sheath.
• It has now been shown that the peripheral
suture improves the gap resistance and
strength of repair

28. The strength and stiffness of the running
peripheral suture can be increased by:
• Taking deeper suture grasps
• Increasing suture purchase from 1 to 2 or
3 mm
• Increasing the number of suture passes

29. • It helps to decrease bulk by smoothing out the
repair site
• addition of peripheral suture itself contributes
up to 50% of ultimate load to failure and
potentially up to 50 N of strength.
• Several epitendinous configurations have
been suggested, Including simple running,
cross-stitch, interlocking cross-stitch, and
Interlocking horizontal mattress.

32. • -
It should be noted that the
repair strength of the core
stitch and epitendinous
suture are not summative
and can fail independently.

33. Tendon repair according to zones

34. ZONE 1- distal to the insertion of
superficialis
• ZONE 2- no mans land b/w the
distal palmar crease and insertion of
the sublimis
• ZONE 3- lumbrical region b/w distal
palmar crease and the distal end of
transverse carpal ligament
• ZONE 4- zone covered by the flexor
retinaculum
• ZONE 5- proximal to the flexor
retinaculum

35. RULES OF REPAIR
• All flexor tendons when severed should be
repaired irrespective of whatever is the zone.
• When delayed repair is done, may need a
tendon graft
• A2 and A4 pulleys of the flexor sheaths should
be preserved to prevent bowstringing and
flexion

36. • Timing of flexor tendon injuries:
• Primary: repair within 24 hours
(contraindicated in case of high grade
contamination i.e. human bites, infection)
• Delayed Primary: 1-14 days when the wound
can be still pulled open without incision
• Early Secondary: 2-5 weeks.
• Late Secondary : after 5 weeks i.e. tendon
substitution techniques/salvage process

37. Incisions
Avoid crossing joints and
creases at 90 deg.
Existing lacerations
-zigzag
-mid lateral

38. Should we do tendon sheath repair??
Advantages
• Barrier to extrinsic adhesion formation
• More rapid return of synovial nutrition
• Tendon within the sheath have an intrinsic
capacity for healing
Disadvantages
Technically difficult
• Presently, no clearcut advantage to sheath repair
has been established

39. ZONE 1 flexor
Tendon injuries.

40. Profundus Tendon Avulsion
• Avulsion of FDP from its insertion by forced
hyperextension
• Most common in the ring finger
Leddy and Parker classification
• Based on the level to which the tendon
retracts
• Status of the tendon vascular anatomy

41. Type I
• Profundus has retracted proximally into the
palm
• Surgery should be done in 7-10 days before a
fixed muscular contracture develops
• Least common

42. Type II
• Profundus retracts to PIP,
• Disruption of Vinculum Breve
• Nutrition is maintained by Vinculum longum
• May be repaired up to 3 months
• Delay may convert type II into a type I if
viniculum longum subsequently ruptures

43. Type III
• Attached bone fragment that fractures off
the volar base of distal phalanx
• A4 pulley prevents proximal retraction
• Both Vinculae are preserved
• type IV was later added to the classification in
which there is a fracture of the distal phalanx
and the tendon, which has retracted Into the
palm, is no longer attached to this fragment.

44. • Vincular blood supply to types II and Ill
remains intact, and these injuries can be
repaired even after considerable delay
• Tendons in types I and IV Injures, on the other
hand, are separated from the blood supply.
Type 1 & 4 require early surgical repair,
within 7 to 10 days of injury, to prevent
ischemic contracture.

45. Direct repair:
If laceration is more than 1 cm from FDP insertion
• Entire A4 annular pulley preserved
• proximal tendon Retrieved by feeding tube and
passed underneath A4 pulley
Tendon advancement: if the laceration is less
then 1 cm from insertion.
Old cases: tendon grafting, arthrodesis, tenodesis

47. Removed after 6
weeks
Internal suture methods:
suture
anchors or other methods
to affix
the tendon directly to the
bone

48. In zone 1 look out for Quadriga effect
Over advancement of the
FDP (> 1 cm)
- weak grasp in
remaining fingers due to
FDP tethering;
- if one FDP is
tethered, the others can
not shorten;
- there is loss of
flexion in other digits and
patient may be unable to
make a full fist

49. Zone 2 flexor tendon injuries.
May involve both the FDS and FDP tendons.
Repair should ideally be performed within 7 to 14
days of injury
Exposure of the tendons can be performed through
either a Bruner zigzag incision or a midlateral
Incision. which incorporates the laceration
It is necessary to open either the C1 (between A2
and A3) or C2 (between A3 and A4) cruciate-
synovial sheath
Dissection proceeds with identification and
protection of the digital nerves and arteries

50. Should both tendons be repaired or only FDP??
Henry M et al, Zone II: Repair or reset the flexor
digitorum superficialis? J Hand Surg Am. 2011
• repair only the FDP tendon if both the slips of FDS
tendon are to be repaired underneath A2 pulley
• Repairs FDS if the injury is proximal or distal to A2
pulley in zone 2.
• Most hand surgeons prefer to repair the FDP and one
slip of FDS as the repair of both slips of FDS may
produce overcrowding within the sheath and pulleys
and compromise the results.
• If only one slip of FDS is cut then the chiasma should
be opened from that side and the FDP should be
delivered from the same side.

51. Zone 3 flexor tendon injuries.
-Both tendon should be repaired.
Lumbrical muscle bellies usually are not sutured
because this can increase the tension of these
muscles and result in a “lumbrical plus” finger
(paradoxical proximal interphalangeal
extension on attempted active finger flexion).

52. Zone 4 and 5 flexor tendon injuries.
• Be aware of median ,ulnar nerve or ulnar or
radial vessel injury.
• Here vessels and nerves should be repaired
first and the tendons last

53. Complications
Adhesion
• Most common complication despite early
motion protocols
Tendon Rupture
• Noted by the patient at “popping” in the hand
• 7-10 days postop when tensile strength is
weakest
• MRI may help in diagnosis

54. Triggering and entrapment
• Especially when sheath is not repaired
Post traumatic regional pain syndromes
• Cold intolerance
• RSD
FDP advancement more than 1 cm may
lead to flexion contracture and weakened
hand grip because of quadrigia effect

55. FLEXOR TENDON RECONSTRUCTION

56. Tenolysis
Indication -tendon adhesion
Preop evaluation
Discripency exists between passive and active
range of motion after hand therapy has
platued
Timing – 3-6 mos. Post repair (minimum)
Anesthesia – Local with sedation , Allows
patient participation

57. Technique
• Zig zag incisions
• Adhesions divided maintaining non-limiting
adhesions
• Pulleys reconstructed as needed
• On post op- active range of motion should
begin immediately
If extensive or not possible convert to
staged reconstruction

58. Boyes’ grading scale of
flexor tendon injury
provides a guideline in
determining the
achievable outcome
after flexion tendon
reconstruction
Single Stage Tendon Grafting

59. Principles of tendon grafting include
• Place only one graft in each finger
• Never sacrifice intact FDS
• Use a graft of smaller caliber
• Perform the junctions outside the tndon
sheath
• Ensure adequate graft tension.

60. Indications
-Injuries resulting in segmental tendon loss.
- Delay in repair that obviates primary repair, such
as laceration that have been neglected for 3 to
6 weeks and show tendon degenerations
-Zone 2 injury where large section of tendon
have been damaged and surgeon belives
delayed grafting is better option
- Delay presentation of FDP avulsion injury
associated with significant tendon retraction
-Supple joints with adequate passive ROM

61. Before sx Look for ..
-wound should be well healed with no extensive
scarring
-Joint should be free of contracture and maximum
passive range of motion shd have been attained
-Circulation is satisfactory
-At least one digital nerve in affected digit is intact
-Pts with joint contacture shd undergo hand
therapy regimen to achive maximum possible
passive range of motion
In case of extensive scarring,pulley
incompitance,joint contacture single stage
grafting is contraindicated.

62. Donor choices.
• Palmaris longus- tendon present in
approximately 85% of all individuals of
sufficient length and size .
• Plantaris when graft length is important.
present in about 93% of population
• EDL
• EI
• EDM
• FDS of unaffected finger

63. DISTAL JUNCTURE
If enough stump is available
If sufficient stump is not available

64. Proximal juncture
-Tendon weave in any area outside the
flexor sheath
- Stronger than the end-to-end suture
techniques
- Allow to modulate graft tension
In zone 2 -Proximal
juncture into the FDP
tendon just distal to the
lumbrical origin.

65. • If FDP is of poor quality,FDS may be used for
proximal juncture.
• Occasionaly FDP of uninjured neigbour digit may
be used as end to side proximal juncture.
• For zone 3,4,5 distal end junction is taken just
proximal to lumbrical origin.
• If intact FDS,and FDP injured ,arthrodesis of DIP is
done in OLD age group.
In young FDP reconstruction is offered
Keep 1-2 cm of distal fds stump as it provides
a favourable bed for graft,stability to PIP,and
prevents swan neck

66. Tension adjustment
-Proximal weave is
adjusted.
-Wrist is extended and
flex
the fingers into the
cascade of the hand
-Overcorrect slightly
because some stretching
occurs after surgery

67. • Post op care
• Early motion exercise have been used
• Protected passive range of motion can be
instituted after 2 to 3 days of sx if the juncture
are strong enough to withstand the tesile
strength
• Post op splint- static dorsal bloking splint with
wrist positioned in neutral,MP in 45 degree
flexion, Ipin neutral. And worn for 6 weeks
after sx

68. Two Stage Reconstruction
Hunter and salisbury introduced in 1971.
They noted silicon rod placement helped in
forming soft,flexible,translucent sheath.
Indications
Crushing injuries a/w # or skin damage
Damaged pulley system
Excessive scarring of the tendon bed
Failure of previous operations
Contracted joint.

69. Patient selection
Motivated
Absence of neurovascular injury
Good passive joint motion
Balance benefits of two additional procedures in
an already traumatized digit with
amputation/arthrodesis.
Primary grafting likely to give poor result, but
salvage of functioning finger still desirable

70. Stage 1
Excision of tendon remnants
Distal 1 cm of FDP left intact, remainder excised
to lumbrical level
FDS tail preserved for potential pulley
reconstruction
Incision proximal to wrist
FDS removed/excised
Hunter rod then placed through pulley system
and fixed distally

71. • Rod extends proximally to distal forearm in
plane between FDS and FDP
• Test glide
• Reconstruct pulleys as needed if implant
bowstrings
• Start physiotheraphy from next day and plan
stage 2 after 3 months.
• Complications of stage 1-
infection,synovitis,rod migration,rupture of
distal end of rod ,rod buckling.

72. Stage 2
• implant removal and tendon graft insertion
• Distal and proximal incisions opened
• Implant located proximally and motor selected
(FDP middle/ring/small, FDP index)
• Graft harvested, sutured to proximal implant
and delivered distally
Fixed to distal phalanx with pull out wire over
button
Postop Early controlled motion x 3 wks,
then slow progression to active motion

73. Thumb flexor tendon reconstruction.
Direct repair is possible upto 3-6 weeks if the
tendon ends have not widely seperated.
Recostruction is indicated when satisfactory IP
joint motion is present.
Options available ;
1)Single stage tendon grafting.
Tension setting:wrist neutral.IP joint 30 degree
flexion.

74. 2)Staged tendon reconstruction;
when pulleys are damaged,
3 ) single stage FDS transfer
from RF,
In stage 2 a FDS transfer can also be done
after removing silicon rod.
For Precise tensioning at distal juncture ,the
FDS is woven through the stump of FDP

75. Secondary Reconstruction
• Zone 1 (functioning FDS) – Eg. Late
presentation of FDP avulsion
DIP fusion
• Tendon graft Risks damaging FDS function
through injury/adhesions in a very functional
finger
• Young patients, supple joints, need for active
DIP flexion

76. • Zones 2,3, 4 and 5
Usually associated with 3 – 5 cm gap
Interposition graft
FDS to FDP transfer
End to side profundus juncture

77. • FDS finger or PIP joint finger,
Salvage procedure in cases of DIP joint
damage,pulley failure even after 2 attempts at
pulley reconsrution,
Tendon graft is attached to middle phalynx
through pullout sutures.

78. • Complication after flexor tendon reconstruction.
• Adhesions
• Mechanical failure of implant(Dacron reinforced
silicon helps in suture pull out)
• Graft rupture
• Pulley disruption,
• Quadriga syndrome(too much tension)
• Hyper extension of PIP (due to Absent FDS)
• Lumbrical plus finger(insufficient tension)
• Synovitis,infection,
• Late flexion deformity,(inadequate pulleys,wound
contractures,splinting )

79. Flexor tendon rehabilitation
• All protocols employ a dorsal shell with the wrist,
MCPs, and IP joints extended or flexed.
• Active extension and passive flexion are encouraged
after the first postoperative day,
• After 2 to 3 weeks, “place and hold no power” can be
initiated along with protected passive motion to
maintain joint mobility and avoid contractures
especially the PIP joint.
Differential gliding of the uninjured tendons can also
start at this time.

80. • Isolated active tendon differential gliding of
the injured tendon begins by atleast 4 to 6
weeks and active, assisted, complete fist and
passive range of motion.
• Protective splinting may continue with
progressive resistance exercises for upto 8
weeks total.
• Gradually increased active resistance-
strengthening exercises up to 12 weeks

81. Rehabilitation involve mainly 3 objects:
• 1. Immobilization method and positions
• 2. Type and timing of mobilization
• 3. Time of splint removal and return to full
unprotected functioning.

82. Zone 1 Rehabilitation
Immobilization:
Apply dorsal splint with wrist and MP joints
flexed and PIP and DIP joints at 0 to 10 degrees
flexion.
Mobilization:
The rehabilitation protocol generally follows the
same progression as for zone 2 injuries.
Return to Activities:
The patient may return to full activity at 4 to 6
months after surgery.

83. Zone II injury Rehabilitation
Immobilization: the wrist flexed (20 to 30
degrees) and MP joints flexed (50 to 70
degrees), and PIP and DIP joints at zero or
slight flexion.
Return to Activities
The patient may return to unrestricted
activity at 4 to 6 months after surgery

84. • Rehabilitation divided into 3 groups according
to protocol used in 1st 3-4 wks :
1. Immobilization:
2. Early Controlled Motion
– Duran & Houser
– Kleinert & Chow
3. Active Mobilization
– Silfversksold & May
– Strickland

85. Kleinert & Chow protocol:
• A controlled active extension–passive flexion
motion protocol.
• The wrist is palmary flexed with a dorsal
protective splint with 30–40° wrist flexion,
50–70° MCP joint flexion, and the IP joints are
allowed full extension.

86. • Original Kleinert regime had been changed to Modified
Kleinert regime (Chow) due to rubber band traction
was found to lead to flexion contractures of the finger.
Modified Kleinert regime (Chow) differ by:
1. a palmer bar at the level of the MCP joint as a pulley
for the rubber bands to create greater flexion of both
the PIP and DIP joints.
2. the elastic band is detached at night and the fingers
are strapped into extension within the splint to
minimize the risk of flexion contractures of the
fingers.

88. • All fingers should be included in the rubber band
traction to ensure added FDP protection and to
promote better tendon excursion also decrease
risk of PIP contracture through more efficient
action of EDC.
• mobilization program is begun 1 to 3 days
postoperatively.
• The finger to be actively extended within the
limitations of the splint.
The patient is instructed to perform this exercise 10
times every waking hour.

89. • At 3 weeks, the splint is altered to further
extend the metacarpophalangeal joints with
the wrist neutral.
• At 4 weeks, the dorsal splint can be removed,
leaving the line/rubber band attached to a
wristlet. Wrist exercises are encouraged.
at 5th week, the rubber band is discontinued;
the patient actively flexes without resistance.

90. Duran–Houser method
• This is a controlled passive finger flexion
protocol without traction of rubber bands.
• Dorsal splint is applied with the wrist in 20°
flexion, the MCP joint in 50° flexion, and the IP
joints are allowed full extension .
Full isolated passive flexion of DIP joint.
Full isolated passive flexion of PIP joint.
Full passive flexion of MP, PIP, and DIP joints.

92. Advantages:
• decreased the frequency of PIP joint
contracture seen with Kleinert’s rubber band
traction.
• Better differential gliding.
• Improved protection between exercise time.
Disadvantages:
• Greater tension on repair site.
• Patient may not be able to resist temptation
to flex against volar strap.

93. Early controlled Active Mobilization
• All early active mobilization technique require strong
tendon repair at least 4 strand core stitches with strong
epitendinous repair.
Strickland indiana protocol(Controlled “place-and-hold”):
• A traditional dorsal blocking splint that positions the wrist
in 20 degrees of palmer flexion, MP joints in 50 degrees
of flexion, and IP joints in extension is applied.
A another tenodesis splint with a wrist hinge is fabricated

95. Silfversksold & May:
All fingers are placed in dynamic traction with
palmer bar and the patient use their uninjured
hand to ensure complete flexion.

96. Differential gliding exercises

97. What type of postoperative motion
most beneficial?
Flexor Tendon Repair Rehabilitation Protocols: A Systematic Review harlan.m.starr et
all,ASSH SCIENTIFIC ARTICLE| VOLUME 38, ISSUE 9, P1712-1717.E14, SEPTEMBER
01, 2013
After analysing 170 articles,
Early passive range of motion protocols had a statistically significantly decreased risk
for tendon rupture but an increased risk for postoperative decreased range of
motion compared to early active motion protocols.
However, modern improvements in surgical technique, materials, and rehabilitation
may now allow for early active motion rehabilitation that can provide better
postoperative motion while maintaining low rupture rates.
Strength of repair good -fair—early passive range of
motion protocols.
Strength of repair excellent-- early active motion protocols.

98. 1)Early tendon motion has significant role in favouring intrinsic healing.
2)Immobilisation significantly decreases the strength of repair by 10-50 %
within the first 3 weeks of healing,
3)Dissection proceeds with identification and protection of the digital nerves
and arteries.
4)In cases of extensive injuries ,do staged tendon reconstruction.
5)Quadriga syndrome(too much tension)
6)Hyper extension of PIP (due to Absent FDS)
7)Lumbrical plus finger(insufficient tension)
8)Early active vs early passive is (excellent vs good repair)
Take home messages