This document summarizes a seminar on flexor and extensor tendon injuries of the hand. The seminar was chaired by Prof. Dr. Kiran Kalaiah and presented by Dr. Yashavardhan.T.M. It provided an overview of tendon anatomy, classification of tendon injuries by zone, surgical techniques for repair, and postoperative rehabilitation protocols. Key points included the pulley system that guides tendon movement, zones of injury from I to V, and techniques like the six strand repair that aim to minimize complications like adhesion formation.

1. Department of Orthopaedics
Seminar on: Flexors & extensor tendon
injuries of hand.
Chairperson and moderator: Prof. & HOD: Dr. Kiran Kalaiah
Presenter : Dr. Yashavardhan.T.M

2. Introduction.
 Tendon injuries are the second most common injuries of the hand and
therefore an important topic in trauma and orthopaedic patients.
 “A glistening structure between muscle & bone which transmit force from
muscle to the bone’”
 Paratenon: Loose areolar tissue encasing tendon in low mechanical stress
area
 Tendon sheath: a dense fibrous tissue tunnel enclosing tendon in high
mechanical stress area
 70% collagen (Type I)
 Extracellular components
 • Elastin
 • Muco-polysaccharides (enhance water-binding capability)
 Endotenon – around collagen bundles
 Epitenon – covers surface of tendon
 Paratenon – visceral/parietal adventitia surrounding tendons in hand

3.  Most injuries are open injuries to the flexor or extensor
tendons, but less frequent injuries, e.g., damage to the
functional system tendon sheath and pulley or dull
avulsions, also need to be considered.
 After clinical examination, ultrasound and magnetic
resonance imaging have proved to be important
diagnostic tools. Tendon injuries mostly require surgical
repair, dull avulsions of the distal phalanges extensor
tendon can receive conservative therapy.

4.  Injuries of the flexor tendon sheath or single pulley
injuries are treated conservatively and multiple pulley
injuries receive surgical repair. In the postoperative
course of flexor tendon injuries, the principle of early
passive movement is important to trigger an "intrinsic"
tendon healing to guarantee a good outcome.
 Many substances were evaluated to see if they
improved tendon healing; however, little evidence was
found. Nevertheless, hyaluronic acid may improve
intrinsic tendon healing

5. Anatomical position
 Flexors muscles: FDP and FDS tendons have fibrous sheaths on the palmar
aspect of the digits
 Fibrous arches and cruciate (cross-shaped) ligaments, which are attached posteriorly
to the margins of the phalanges and to the palmar ligaments hold the tendons to
the bony plane and prevent the tendons from bowing when the digits are flexed.
The tendons are surrounded by a synovial sheath.
 Flexor tendon system consists of intrinsic and extrinsic components
 Extrinsics:
 FDP: flexing the DIP joint
 FDS: Flexing the PIP Joint
 FPL: Flexing the IP joint of the thumb
 Intrinsics:
 Lumbricals: Flex the MCP joints and Extend the IP joints
 FDP inserts on base of distal phalanx
 FDS inserts on sides of middle phalanx
 FPL inserts on proximal portion of the distal phalanx

6. INTEROSSEIUS, BLOOD SUPPLY & NERVE
SUPPLY

7. Pulleys of flexour
 Synovial sheath is reinforced by a system of fibrous pulleys
 5 annular pulleys (A) and
 3 Cruciform pulleys (C)
 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
 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.
 Function: increase the mechanical efficiency by preventing bowstringing

8. ZONES OF FLEXOR TENDON INJURY
 Zone I: Between insertion of FDP and FDS
 Zone II: From insertion of FDS to A1 Pulley
 Zone III: Between A1 pulley and distal limit of carpal
tunnel
 Zone IV: Within the carpal tunnel
 Zone V: Between the entrance of Carpal tunnel and
musculo-tendinous junction.
 FDS decussation at A1 pulley FDS slips rotate 180°
around FDP
 Slips rejoin at PIP – Camper’s Chiasma Insert on P2

9. Tendon nutrition
 Parietal paratenon
 Passive nutrition by diffusion
 Vincula and bony attachments
 Direct nutrition
 Segmental nutrition
 Vincula may prevent retraction
 Vascularity dominance is deep surface of tendon
 Consider with suture placement
 Biomechanically superior to place suture deep

10. TENDON HEALING
 Tendons are capable of actively participating in the
repair process through Intrinsic Healing
 Tendon healing occurs in three phases:
 1. Inflammation 2. Active repair 3. Remodelling
• Early tendon motion has significant role in
modifying the repair response
• Mobilized tendons showed progressively greater
ultimate load compared with immobilized tendons
• Studies confirm “Wolff’s law” which states that the
strength of a healing tendon is proportional to the
controlled stress applied to it

11. ETIOLOGY
 sharp object direct laceration (broken glass,
kitchen knives or table saws)
 crush injury
 avulsions
 burns
 animal or human bites
 suicide attempts
 motor vehicle accidents

14. ZONE 1: ZONE OF FDP AVULSION
INJURIES
 Region b/w middle aspects of middle phalanx to finger
tips
 Contains only one tendon-fdp
 Tendon laceration occurs close to its insertion
 Tendon to bone repair is required than tendon repair
 Leddy classification of zone I flexor tendon injuries
 Type I: tendon retracted into palm (fullness in palm)
 Type II: tendon trapped in the sheath at PIP (unable to flex
PIP)
 Type III: tendon trapped in A4 pully

15. ZONE II-NO MANS LAND
 From metacarpal head to middle phalanx
 Called so because initial attempts for tendon repair here
produced poor results
 FDS and FDP within one sheath
 Adhesion formation risk is amplified at campers chiasma
 In each finger, the FDS tendon enters the A1 pulley and divides
into two equal halves that rotate laterally and then dorsally.
 The two slips rejoin deep to the FDP tendon over the distal
aspect of the proximal phalanx and the palmar plate of the PIP
joint at Camper's chiasma
 Insert as two separate slips on the volar aspect of the middle
phalanx.

16. ZONE III-DISTAL PALMAR CREASE
 B/w transverse carpal ligament and proximal
margin of tendon sheath formation
 Lumbricals origin here prevents profundus
tendons from over acting
 Delayed tendon repairs are succesfull even after
several weeks of injury

17. ZONE IV-TRANSVERSE CARPAL LIGAMENT
 Lies deep to deep transverse ligament. Tendon
injuries are rare.
 FPL and FDM enters its continuous sheath which
becomes the radial and ulnar bursae.
 The FDS and the FDP also enter a large sheath and
lie in the carpal tunnell

18. ZONE V LIES PROXIMAL TO TRANSVERSE
CARPAL LIGAMENT
 The Flexor tendons start in the distal third of the
forearm at the musculotendinous junction
 The superficialis group lies palmar to the conjoined
profundus tendon group covered by loose
subcutaneous tissue and skin.

19. SIGNS & SYMPTOMS
 Unable to bend one or more finger joints
 Pain when bending finger/s
 Open injury to hand (e.g., cut on palm side of
hand, particularly in area where skin folds as fingers
bend)
 Mild swelling over joint closest to fingertip
 Tenderness along effected finger/s on palm side of
hand
 Lies deep to deep transverse ligament Tendon
injuries are rare

20. EXAMINATION:
 INSPECTION
 There is a normal arcade to hand with index finger
showing least and little finger showing max flexion
If affected finger shows more extension than other
digits, chance of tendon injuries are high

21. Goals of reconstruction
 Coaptation of tendons
 anatomical repair
 multiple strand repair to permit active range of
motion rehabilitation
 Pully reconstruction to minimize bow-stringing
 atraumatic surgical technique to minimize
adhesions
 strict adherence to rehabilitation protocol.

22. Timing of flexor tendon repair:
 Primary: repair within 24 hours (contraindicated in case of
high grade contamination i.e. human bites, infection)
 Delayed Primary: 1-10 days when the wound can be still
pulled open without incision
 Early Secondary: 2-4 weeks.
 Late Secondary : after 4 weeks
 No repair if less than <25% laceration,
 only epitenon repair in 25-50% lacerations,
 core suture plus epitenon repair when >50% laceration
 Dorsal blocking splint for 6-8 weeks as conservative measure

23. Ideal tendon repair:
 Easy placement of sutures in the tendon
 Secure suture knots
 Smooth junction of tendon ends without gapping
 Minimal interference with vascularity strength

24. TECHNIQUES
 Retrieve the tendon ends through the sheath in an
atraumatic manner
 Maintain the integrity of the pulley system (especially
A2 and A4)
 Create “retinacular window” described by Lister for
preserving the flexor sheath
 Extend the original laceration for better exposure
 Zigzag
 Mid-lateral
 Avoid linear scars that cross flexion crease

25.  Milk the forearm with the wrist and MCP in flexion
 Do not attempt blind retrieval more than twice
 Make a separate incision if necessary
 Use a pediatric feeding tube to retrieve tendon
stump

26. CORE SUTURE

27. Six Strand Technique

28. Tendon Sheath Repair?
 Role of diffusion of nutrients from synovial fluid
 Tendon within the sheath have an intrinsic capacity
for healing
 Gelberman and woo in 1990 study on dogs
 Reconstruction of the sheath did not significantly
improve repaired tendons treated with early
motion rehabilitation.

29. Partial Tendon Laceration
 Rupture, entrapment, triggering
 Partial laceration involving 60% or less are best
treated by early mobilization WITHOUT
tenorrhaphy

30. 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

31. 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
 Distal digital exposure to confirm diagnosis
 In Type I, a second distal palm incision will be needed
 Tendon is reinserted into the base of distal phalanx
 Distally based periosteal flap is raised distal to volar
plate
 Tendon is sutured through drill holes in the distal
phalanx and button tied over the nail plate

32. 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 longum
subsequently ruptures

33. Type III
 Attached bone fragment that fractures off the volar
base of distal phalanx
 A4 pulley prevents proximal retraction
 Both Vinculae are preserved
 Type III attention is turned to ORIF

34. Complications
 Short term:
 Infection
 Injury to neurovascular structures or pulley system
 Abnormal scarring
 Long term:
 Adhesion
 Rupture
 Joint contracture
 triggering
 Adhesion
 Most common complication despite early motion protocols
 Tenolysis when patients progressive gain in digital motion has
plateaued, usually 3-6 months after repair

35. Quadriga effect
 Tendon advancement shortens the FDP &
completes the grip before the normal fingers, if the
tension on tendon graft is set too high, and limit
their flexion and thus week grip

36. Two stage technique
 Create a supple pseudosynovial sheath by
implanting a silicone rod
 Soft tissue coverage or pulley reconstruction is
performed at the first stage
 8 weeks later, when psuedosynovial sheath is
formed, the rod is replaced by a tendon graft
 1. Palmaris longus and plantaris
 2. Tendon grafts that include synovial sheath

37. Tendon Juncture
 Pulvertaft weave, with two or more passes through
the proximal motor tendon

38.  Distal end may be secured in multiple ways

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

40. PULLEY RECONSTRUCTION
 Must be done during the first stage
 Well-healed pulley reconstruction facilitates early
mobilization and gliding of tendon graft
 Reconstruction during the second stage increases
the likelihood of pulley rupture and adhesion
formation
 Material used
 Autogenous grafts: PL, Plantaris, to extensors, EIP,
Extensor retinaculum, fascia lata

41. Flexor compartment of thumb.

42. Kleinert Protocol
 Combines dorsal extension block with rubber-
band traction proximal to wrist
 Originally, included a nylon loop placed through
the nail, and around the nail is placed a rubber
band
 This passively flexes fingers, & the patient
actively extends within the limits of the splint

43. Duran protocol
 At surgery, a dorsal extension-block splint is
applied with the wrist at 20-30° of flexion, the MCP
joints at 50-60° of flexion, and the IP joints straight

44. Extensor Tendons
 1. Extrinsic System radial N innervated
 2. Intrinsic System ulnar and median N
innervated
 Extrinsic Extensors
 Wrist Extensors: ECRL, ECRB, ECU
 Finger Extensors: EDC, EIP, EDQM
 Thumb Extensors: APL, EPL, EPB
 EDC has a common muscle belly with multiple tendons
 EIP & EDM lie on the ulnar side of the respective EDC
tendon

45. Thumb Extensors
 APL inserts on the metacarpal and radially abducts it
 EPB inserts on proximal phalanx and extends MCP Joint
 EPL inserts on distal phalanx and extends IP Joint
 Testing the Extrinsics:
 APL:Palpate with thumb abduction
 EPB:MP extension with IP flexion, palpate tendon
 EPL:Palpate tendon with retropulsed thumb
 EDC:Test with wrist in neutral-extension

46. Vascularity & Innervation
 Volar and dorsal metacarpal vessels
 Median nerve supplies radial one or 2
lumbricals
 Ulnar nerve supplies ulnar 2 lumbricals

47. Extensor Apparatus
 EDC tendon trifurcates into central slip & 2 lateral
slips
 Intrinsic extensor tendons join the lateral slips to
form the lateral bands
 Winslow’s Rhombus
 The central slip inserting on the base of the
middle-phalanx
 and two lateral slips inserting to the distal-phalanx.

48. Lateral band:

49. Juncturae Tendinium
Functional roles:
 spacing of ED tendons force redistribution coordinate
extension MP stabilization
 Ring finger has least independent extension due to the
orientation of the juncturae
 The most common patterns single extensor indicis proprius
inserting to the ulnar side of the index extensor digitorum
communis a single extensor digitorum communis to the index
finger a single extensor digitorum communis to the long
finger, a double extensor digitorum communis to the ring
finger, an absent extensor digitorum communis to the small
finger, and a double extensor digiti quinti with double
insertions

50. SAGITTAL BANDS
 Stabilize the common extensor during digital flexion over MCPJ
 Limit the excursion of the common extensor tendon during digital
extension
 EDC allows extension of MP joint via insertion onto the sagittal
bands
 There is usually no tendinous insertion of EDC to the dorsal base
of the proximal phalanx
 No MP joint hyperextension: EDC extends MP, PIP, and DIP joints
even in the absence of intrinsic muscle function.
 INTRINSIC PARALYSIS: “slack” develops in EDC system distal to the
sagittal bands all producing a flexion posture at PIP and DIP
joints, the “claw” finger.

51. Transverse & oblique fibres of Interosseous
Hood
 Transverse & oblique fibres of Interosseous Hood
 1) EDC Tendon
 2) Central Slip
 3) Lateral Slip
 4) Intertendinous Connection
 5) Volar Interosseous Muscle
 6) Lumbrical Muscle

52. Triangular Ligament
 Connects both lateral bands over the middle
phalanx.
 • Limits the volar and lateral shifting of the
 lateral conjoined extensor tendon during
 digital flexion
 • In boutonniere deformity; elongated
 • In fixed swan neck deformity; retracted

53. Retinacular Ligament
 Lateral continuation of the triangular ligament
extending from the lateral margin of the lateral
conjoined extensor tendon to PIPJ articular volar
plat

55. Extensor Tendon Injury
Extensor apparatus Extrinsic muscles (ED, EI, EDM)
 Intrinsic Muscles ( Lumbricals and Interossei)
 Fixed fibrous structures.
 Zone 1
 • Mallet finger – persistent flexon of distal phalanx
 • Closed: splinting 6-8 weeks
 • Open: suture repair, Soft tissue reconstruction

56. Pullout Wire and K pin

57. Zone II injury- Middle Phalanx Level:
 • Repair by interrupted suture.
 • Immobilization for 5-6 weeks
 • DIP joint in extension
 • PIP joint left free

58. Zone III injury- PIP joint level
 Most complex anatomically and physiologically
 Causes two deformities
 Boutonniere disruption of central tendon
 Closed: splinting MCP and PIP in hyperextension
for 6 weeks
 Open: suture repair (figure of 8 suture)
 Swan Neck excessive traction of central tendon
 Closed: splinting DIP & Open: suture repair

59. Zone IV injury-
 shaft of proximal phalanx level
 Repair relatively easy
 Adhesion is the problem

60.  Zone V injury – MP joint level.
 Closed: splinting, 45 extension at wrist and 20
 flexion at MCP & Open: suture repair by 5.0 prolene
 Zone VI injury- Metacarpal level
 Better prognosis than in fingers
 All structures, even inter-tendinous band should be repaired.
 Core type suture possible. Delayed suture is possible.
 Zone VII- wrist level
 Extensor tendons are under dorsal retinaculum. Retinaculum
should be repaired or partially preserved. Adhesion is the
Grasping core suture should be used. Immobilization for 5-6
weeks.

61. IMMOBILIZATION
 Keep the tendon in a shortened position
through splinting or casting
 Tendons immobilized for 3 weeks
 In week 4, gentle active motion of the repaired
tendon is introduced
 Rehabilitation depends on zone of injury

62. IMMOBILIZATION
INJURIES IN ZONES PROXIMAL TO
MCPs
INJURIES IN ZONES DISTAL TO
MCPs
 May be immobilized for 3 weeks.
 Afterwards, finger may be placed in
removable volar splint between
exercise periods for 2 weeks
 Progressive ROM after 3 weeks
 If full flexion is not regained rapidly,
dynamic flexion may be started
after 6 weeks
 Require a longer period of
immobilization (usually 6
weeks)
 A progressive exercise
program is initiated
 Dynamic splinting during
day and static splinting at
night to maintain extension

63. EARLY PASSIVE MOTION
 Extensors are held in extension by dynamic, gentle
rubber band traction, and the patient is allowed to
actively flex the fingers—passively moving repaired
extensor tendons

64. EARLY ACTIVE MOTION
 Early active short arc program (developed by Evans)
allows tendon to actively move 3 days after surgery
 Therapist must take care to ensure stress applied by
early active motion does not overpower strength of
surgical repair
 Splinting program is complex and specific and requires
a skilled occupational therapist

65. Manchester Short Splint.
 Wrist
◦ Finishes at dorsal wrist crease
◦ Allows 45 degrees extension
 MCPJ
◦ 30 degrees flexion
 Exercises
◦ Commence 4th or 5th day
◦ Motion initiated at DIPJ

66. THANK YOU !!!