The document discusses flexor tendon injuries, including anatomy, classification by zones, surgical techniques for repair, and postoperative rehabilitation. It covers the superficial and deep flexor tendon groups, pulley system anatomy and its importance, and surgical approaches and repair methods for injuries in different zones of the hand. Primary goals of repair include restoring tendon continuity and gliding while preventing adhesions through techniques like circumferential suturing.

1. Flexors Tendon Injuries
Moderator : Assoc Prof Dr Suresh Uprety
Presenter : Dr Ajay Shah (Resident)
Department of Orthopedics and Trauma Surgery
IOM,TUTH

2. Anatomy
Superficial Group
• Pronator teres
• Flexor carpi radialis
• Palmaris longus
• Flexor digitorum superficialis
• Flexor carpi ulnaris
Deep Group
• Flexor digitorum profundus
• Flexor pollicis longus
• Pronator quadratus

4. Zones of Flexors Tendon
Verdan Classification
• Zone I: From middle of middle phalanx distally
• Zone II: From MCP joints to middle of middle
phalanx
• Zone III: Central palm
• Zone IV: Tendons in carpal tunnel
• Zone V: Tendons proximal to carpal tunnel
Thumb Zone
• TI: Distal to IP joint
• TII: From A1 pulley to IP joint
• TIII: Thenar eminence

5. Flexors Synovial
sheath

6. Muscles and Tendons According to Zones

7. Carpal Tunnel

8. Neurovascular Distribution According to Zones

10. Camper’s chiasm
• At A1 pulley FDS tendon splits and
rotates laterally then dorsally around
FDP tendon
• Two splits tendon join together
proximal to PIP joint at camper’s
chiasm
• Functions
Provides a pathway for FDP tendon
Increases the stability and balance of
PIP joint
Prevents hyperextension of PIP joint

11. No Man’s Land
• Historic derivation of “no man's land”
dates back to 14th century
• It was used to describe an area outside
London used for executions
• Sterling Bunnel used this term in hand
surgery who most probably derived it
with his experience in the World War 1

12. • He described it as no man's land because of perennial anatomical
characteristics
• This zone has a fibro osseous digital canal where both the tendons interweave
in a complex manner
• Multiple pulleys increase its complexity because minimal swelling of the
epitenon can impair free motion of the tendon
• Any infection, fibrosis, scarring, overcrowding can lead to dense adhesions and
hence compromising the results

13. Pulley system
• Digital flexors synovial sheath is reinforced by a system of fibrous pulleys
• 5 annular pulleys (A)
A1: 8-10 mm over MCPJ
A2: 18-20mm over proximal phalanx
A3: 2-4 mm over PIPJ
A4: 10-12mm over middle phalanx
A5: 2-4 mm over DIPJ

14. • 3 Cruciform pulleys (C)
C1, C2, C3 proximal to A3,A4, A5
Allow shortening of the pulley system in flexion
• A2 and A4 are considered most important.
• Their disruption leads to bowstringing, reduced mechanical
efficiency and decreased flexion

15. • Function of Pulley System
Keep the tendon close to bone , providing an inline pull of tendon along
the axis of digit and toward palm
Keep the tendon adjacent to the joints, maintaining a standard lever
distance from joint center of rotation
• Gaps between annular and cruciform ligaments are necessary to allow
flexion of fingers

16. Biomechanics of Pulley
• If the tendon is allowed to move away from joint center of rotation and force is pulled through
flexor system , lever distance increases, causing increase in work performance at joint leading to
excess flexion at DIP joint
• Degree of flexion is directly proportional to tendon excursion and inversely proportional to
moment arm

17. Tendon Nutrition
Tendon nutrition 2 basic sources:
• Synovial fluid produced within the tenosynovial sheath
• Blood supply provided through longitudinal vessels in the paratenon,
intraosseous vessels at the tendon insertion, and vincular circulation

18. Blood supply
• Suture placement in volar half of tendon
• Intratendinous placement of crisscross sutures
disturb the microcirculation

19. Tendon healing
Tendon healing is believed to occur through the activity of extrinsic and intrinsic
mechanisms
• Extrinsic: Through the activity of peripheral fibroblasts derived from tendon
sheath and seems dominant mechanism contributing to the formation of scar and
adhesions.
• Intrinsic: Through the activity of the fibroblasts derived from the tendon

20. Phases of Tendon healing
• Following laceration, tendon healing proceeds through 3 sequential but
overlapping phases

21. Examination
• General condition of patient
• Possibility of other injuries
• Neurologic examination
Assessment of light touch and static two point
discrimination
• Vascular examination
CRT of volar digital pulp and nail bed is assessed
When necessary, digital Allen test can be done

22. Posture of Hand
• Normal flexion cascade: MCP joints slightly flexed – about 30 degrees in the
index, ranging to 70 degrees in the little
• Assure all fingers point to scaphoid area when flexed at PIPs joint
• When both flexor tendons of a finger are injured, the finger lies in an unnatural
position of hyperextension, especially compared with uninjured finger
• Passive extension of the wrist does not produce the normal flexion of the finger

23. Test for flexor digitorum profundus
Test for flexor digitorum superficialis
Test for flexor pollicis longus
Examination of individual Tendon

24. Objective of Tendon Repair
• Purpose of tendon suture
To approximate the ends of a tendon or to fasten one end of a tendon to
adjoining tendons or to bone
To hold this position during healing
• Pinching and grasping of the uninjured surfaces should be avoided

25. Principles of Tendon Repair
• All flexor tendons should be repaired at whatever level they are transected.
• Whenever possible the repair should be done primarily. When delayed a tendon
graft may be required
• A2 and A4 annular pulley areas of the flexor sheath should be preserved;
otherwise, tendon bowstringing and flexion deformity of the finger can develop
and excursion of the tendon becomes impaired.
• Tendon laceration of 60 % or more is treated as complete transection

26. • Initally dorsal epitenon sutures are placed then core sutures and then finally
volar epitenon sutures
• Diameter of the suture is also directly porportional to the strength of the
repair 3.0 to 4.0 calliber non absorbable suture is recommended

27. • Repair is supplemented with a running circumferential epitenon suture
technique.
Advantages:
smooth repair and improves tendon gliding
minimize the adhesion formation
less gap formation
• Suture technique must withstand gap formation of 3 mm at the repair site during
the initial 3 weeks following repair.

28. Strickland stressed six characteristics of an ideal tendon repair
• Easy placement of sutures in the tendon,
• Secure suture knots,
• Smooth juncture of tendon ends,
• Minimal gapping at the repair site,
• Minimal interference with tendon vascularity, and
• Sufficient strength throughout healing to permit application of early
motion stress to the tendon.

29. Timing of Flexor Tendon Repair
• Primary tendon repair
within the first 12 hours of injury
can be extended to within 24 hours of injury in rare situations
• Delayed primary repair: within 24 hours to approximately 10 days.
• Secondary after 10 to 14 days
• Late secondary repair after 4 weeks

30. Ideal properties of suture material
• Non reactive
• Hold securely when knotted
• Small caliber
• High tensile strength
• Easy to handle
Common material: Ethibond , Nylon, Prolene

31. Suture Configurations
Tendon repair types can be divided into three groups
• Group 1: Simple suture
• Group 2 : Bunnell suture
• Group 3: Pulvertaft technique (fish-mouth weave)

32. An abundance of research has shown that four-strand, six-strand, and
eight-strand core sutures
• Create stronger repairs
• Reduce the possibility of gap formation
• Permit greater active forces applied to the repaired tendons
• Allowing earlier active motion

33. End to End Suture Techniques
Kessler technique
• Modification of the Mason-Allen suture.
• Effective for tendon repair in the fingers and palm
• Knots being left exposed on the tendon surface.

34. Modified Kessler technique
• Modifications:
Only one knot inside the repair site
Knot is left in the cut surface of the tendon
• Easier to use a monofilament suture like a
4.0 Prolene to reapproximate tendon edges

35. Kessler Tajima stitch
• Separate sutures are used so that the tendon ends can be passed within the
flexor sheath using the free end of the suture as traction suture
• Knots are tied within the tendon
• However, use of two knots in the
repaired area could lead to a high risk of
early failure, suture slippage, and tendon torsion

36. Modified Kessler Tajima Suture (Strickland)
• Modified by addition of
 Peripheral epitenon suture
 Core mattress suture
• Knots are tied within the tendon
• Sutures are locked with each exit from
the tendon.

37. Pulvertaft Technique ( Fish mouth technique)
• Commonly used to suture tendons of unequal size
• Tendon of small diameter can be sutured to one of large diameter

38. End to Side Suture Technique
• Frequently used in tendon transfers when one motor must activate
several tendons

39. Tendon to Bone Attachment
• Frequently requires a pull-out technique (usually distal phalanx)
• For tendon to bone repairs ,core suture techniques used most often are
Kessler
Bunnell crisscross suture

40. Suture Anchor Tendon Attachment
• As effective as pull-out wire or suture but without
the potential complications with fingernail that
can occur with pull-out technique
• Two suture anchors are placed in the distal
phalanx from distal-volar to proximal-dorsal
• To purchase in the thickest portion of the distal
phalanx to provide greatest pullout strength

41. Surgical Incision
• Incisions should not compromise viability of skin flaps
• Should not create contractures or cosmetically unsightly scars
• Less exposure needed distally than proximally
• Zigzag (Brunner),mid radial ,mid ulnar or midline oblique incisions

42. Zone I Repair
• Contains only the FDP tendon
• Direct repair (primary tenorraphy): laceration >1 cm from FDP insertion
• Proximal tendon retrieved by feeding tube and passed underneath A4
pulley

43. Tendon advancement (<1cm stump)
• Pull-out suture
Free ends of sutures are passed
through or around distal phalanx, tied
over dorsum of fingernail with button.
Removed after 6 weeks
• Internal suture methods
Suture anchors or other methods to
affix the tendon directly to the bone

44. When the diagnosis of interruption of FDP tendon is delayed, and the tendon has
retracted into the palm, its vinculum has been disrupted and a decision must be
made regarding repair depending upon types
• Type I: FDP tendon is avulsed from its
insertion and retracts into palm
• Type II: Avulsed from its insertion but
stump remains within digital sheath
• Type III: Avulsed bony fragment attached
to tendon stump, remains within flexor
sheath

45. Modified Leddy and Packer classification for FDP avulsion
Type IV avulsions were first described by Robins and Dobyns in 1974. Inclusion
of type V avulsions in the classification was proposed by Al-Qattan in 2001

46. • Type 1, if it is within 7 to 10 days of the injury, the tendon should be threaded
back into the finger and reattached with a pull-out wire into distal phalanx
• Type 2, despite the passage of a few months, these tendons can be reattached as
well because circulation is thought to be maintained
• Type 3, usually fracture repair with k-wire or miniature screw fixation
• Type 4, fracture fixation followed by advancement of tendon to distal phalanx
• Type 5, FDP tendon with avulsed bone fragment is reduced using a pull-out
technique, and a K-wire is placed for avulsed fragment

47. Zone II Repair
Primary repair at this level frequently fails because of adhesion in the area of
pulley
Technical concerns during the repair procedure includes
• Management of lacerations of FDP and FDS tendons
• Appropriate orientation of the FDP with FDS slips
• Attachment of the FDS slips in the thin flat area
• Management of the flexor sheath, including annular thickening (pulleys)
• Postoperative management,
• Timing and technique for tenolysis

48. • Care should be taken when FDS has been injured in area just proximal to PIP joint
• Care also should be taken to deliver FDP tendon through the split portion of FDS
when profundus tendon has retracted proximally

49. • Method of repair however is controversial but following are the different options
of treatment:
Repair of the FDP tendon only with debridement of the FDS stump
Repair of both tendons or
Repair of FDP with repair of one slip of FDS tendon
Most hand surgeons prefer to repair the FDP and one slip of FDS , reasonably a
good option as the repair of both slips of FDS may produce overcrowding within the
sheath and pulleys and compromise the result
Coats RW, 2nd, Echevarría-Oré JC, Mass DP. Acute flexor tendon repairs in zone II. Hand Clin. 2005;21:173–9

50. • Core suture with two or more strands, locking components, and buried knots is
usually preferred
• A running, circumferential 5-0 or 6-0 suture is used to complete a smooth repair
and to minimize adhesion formation to the sheath
• Tenolysis may be required in an estimated 18% to 25% of patients after flexor
tendon repair
• Three months is considered to be earliest time for flexor tenolysis, assuming no
improvement in motion in previous 1 to 2 months
• Function in the finger can be improved by 50% by tenolysis

51. Strickland technique for flexor tendon injury in Zone II

52. Zone III Repair
• If both tendons are lacerated, both are repaired, end to end with circumferential
re-enforcing sutures
• Muscles bellies of lumbricals and tendon are frequently affected so additional
incision often needed to expose further area
• If conditions permit, primary repair of sharply severed nerve is crucial
• If wound condition preclude tendon and nerve repair, the ends of the tendon and
nerve are sutured to adjacent fascia to prevent undue retraction
• Lumbricals muscle bellies usually are not sutured, causes lumbrical plus finger

53. Zone IV Repair
• Associated with median ,ulnar nerve or ulnar/radial vessel injury
• If the laceration occurs beneath the transverse carpal ligament, partial or complete release
of the transverse carpal ligament may be required
• Preserve, if possible, a portion of the transverse carpal ligament to avoid bowstringing
postoperatively
• If it cannot be preserved, release it in a Z-lengthening configuration
• Best suture configuration is intratendinous one with a locking core
• Immobilize the wrist in about 45 degrees of flexion, 50 to 60 degrees of flexion at MCP
joints and the IP joints in full extension

54. Zone V Repair
• In zone V, multiple tendons, nerves, and vessels frequently are injured so its important to identify
the tendons accurately
• Properly match the tendon ends by careful attention to their location and level in the wound,
their relation to neighboring structures
• Blood clots within the tenosynovium usually serve as clues in locating severed tendons
• Repairs done in the distal forearm do not absolutely require an intratendinous repair, double
right-angled or mattress suture may be used
• Immobilize the wrist in about 45 degrees of flexion, with fingers in 50 to 60 degrees of flexion at
MCP joints and the IP joints in full extension

55. Postoperative Rehabilitation

56. Immobilization
Indication for immobilization after flexor tendon surgery is usually not required,
exceptions
• Children or adults unable to cooperate with hand therapy
• Unstable bone repair
• Concerns about the effect of tension on microneurovascular repairs.
• Unwilling to adhere to strict early mobilisation protocols

57. Passive Motion Protocol
• Modified Kleinert: Active extension, passive flexion by rubber bands.
• Duran: Controlled Passive Motion Methods

58. Modified kleinert

59. Duran Protocol

60. Flexor Tendons Reconstruction
When FDS and FDP tendons have been divided in the critical area of the pulleys,
flexor tendon grafting may be indicated if
• Injuries resulting in segmental tendon loss
• Neglected >3 to 6 weeks with tendon degeneration and scar within the tendon
sheath i.e. chronic flexor tendon injuries
• If a gap cannot be closed because of myocontracture
• Large section of tendon has been damaged in Zone II injury
• Delayed presentation of FDP avulsion injuries associated with significant tendon
retraction

61. Requirements before tendon graft
• Skin is pliable;
• Any wounds are well healed
• Tissues through which tendon is expected to glide must be relatively free
of scar
• Edema has subsided
• Joints allow a full passive range of motion
• Sensation in the finger is normal or at least one digital nerve is intact

62. Boyes preoperative classification helps to identify the severity of injury, with
higher grades portending worse outcomes

63. Single-Stage Tendon Graft
• Considered when the flexor tendon sheath is relatively intact and unscarred and
the pulley system is competent
• Attempt can be made to dilate collapsed pulleys with urethral dilators
• However, if unsuccessful, a two-stage procedure with pulley reconstruction
should be undertaken
Age is a strong prognostic factor. Results are best in patients 10 to 30 years old, and
worst results in very young and in patients older than 50 years
Bora FW Jr: Profundus tendon grafting with unimpaired sublimis function in children. Clin Orthop Relat Res
1970;71 (71):118-123.

64. Two-Stage Tendon Graft
Indications
• Crushing injuries associated with fracture or skin damage
• Damaged pulley system
• Excessive scarring of the tendon bed
• Failure of previous operations
• Stiff joints

65. First stage
Excision of tendon and scar from the flexor tendon bed
Preserving or reconstructing the flexor pulley system
• Dacron-impregnated silicone rod is inserted to maintain the tunnel in the area of
excised tendons until passive motion and sensitivity have been restored to the digit
Second stage
• Done when the finger is soft, supple, and well healed with mobile joints
• Earliest time for the second stage is about 8 weeks, but usually 3 months is
required, depending on the patient’s needs and the surgeon’s judgment
• Consists of
Rod removal
Tendon graft insertion

67. Pulley Reconstruction
Goal
• To enable maximum excursion and
strength with controlled gliding of flexor
tendons
• To minimize friction
Two main techniques are
• Weaving the pulley graft through
remaining pulley rim
• Creating a new pulley loop around bone

68. Graft Choices
• Palmaris longus tendon
• Plantaris tendon
• Extensor Digitorum longus to 2nd 3rd or 4th toes
• Flexor digitorum longus to 2nd toe
• Flexor digitorum superficialis
Intrasynovial grafts (FDS and toe flexors) have better
morphologic and functional characteristics than that of
extrasynovial grafts. Extrasynovial grafts have been
thought to lead to more adhesions
Flexor tendon grafting to the hand: An assessment of the intrasynovial
donor tendon. A preliminary single-cohort study. J Hand Surg Am 2000;
25(4):721-730.

69. Complications
Short term:
• Infection
• Injury to neurovascular structures or pulley system
• Abnormal scarring
Long term:
• Adhesion
• Rupture
• Joint contracture
• Triggering
Rarer complications
• Lumbrical plus finger
• Quadrigia effect

70. Adhesions
• Most common complication despite early motion protocols
• Higher risk with Zone II injuries
• Treatment
Physical therapy
Tenolysis when patients progressive gain in digital motion has plateaued,
usually 3- 6 months after repair
Adhesion formation with restriction of tendon excursion and the need for
tenolysis has reported rates from 12% to 47%
LaSalle WB, Strickland JW: An evaluation of the two-stage flexor tendon reconstruction technique. J
Hand Surg Am 1983;8(3):263-267.

71. Tendon rupture
• Noted by the patient as “popping” in the hand
• 7-10 days postop when tensile strength is weakest
• MRI may help in diagnosis
• 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 graft

72. References
• Campbells Operative Orthopaedics,13th edition
• Green Operative Hand Surgery, 7th edition
• Apleys system of Orthopedics,9th edition
• Articles