Dr. A.A.Rawoot Tygerberg Hospital 18 March 2009



          Zone 1: FDS insertion to FDP insertion Zone 2: Zone 1 to proximal part of Al pulley

          Zone 3: Zone 2 to distal edge of flexor retinaculu Zone 4: Within carpal tunnel

Flexor tendon zones in the hand
Zone 5: Proximal to carpal tunnel Thumb Tl: FPL insertion to A2 pulley

          Thumb T2: Zone 1 to distal part Al pulley

          Thumb T3: Zone 2 to carpal tunnel


5 Annular, 3 Cruciform

Fibrous annular pulleys prevent bowstringing

A2 and A4 most important

         Cruciate pulleys are thin and provide flexibility

         Tendon repairs through C l and C2

Flexor tendon nutrition in the finger
Tendon Nutrition

Extra-synovial : forearm - palm

- paratenon

Synovial : Carpel Tunnel & digital flexor sheath

-   vincular arterial system

-   diffusion from synovial fluid

-   additional supply from distal oseous attachments


Watershed areas (Lundborg) :

          FDS under the A2 pulley

FDP under the A2 pulley and A4 pulley


Intrinsic repair response

Lundborg and Rank (1978) - intra-synovial flexor tendons initiate intrinsic repair response after tendon transection

          Gelberman et al (1980s) - studied effect of early digital mobilization following flexor tendon repair in zone 2

- immobilized: j linear tendon excursion

formation of peritendinous adhesions (extrinsic tendon repair) - mobilized: | linear tendon excursion (intrinsic repair response) Early restoration of gliding surface by day 10



Inflammatory phase (0-14 days) Reparative phase (2-6 weeks): Remodeling phase (> 6 weeks):

Inflammatory phase (0 - 14 days): Fibrin clot forms at repair site Macrophage and leukocyte migration Phagocytosis

Growth factors ( bFGF) peak

Cells from epitenon proliferate and migrate to repair site Gliding surface restored

Strength of repair is related to strength of suture


Reparative phase (2-6 weeks):

Intense collagen production - mostly type 1

Gradually orient themselves along the axis of tensile forces

Epitenon cellular ingrowth fills repair site gap


Strength increases at 2 weeks post-op

Repair site strength still principally related to the suture strength & material


Remodeling phase (> 6 weeks): Collagen fibers smooth and uniform

Collagen fibers are remodeling to be oriented parallel to the longitudinal axis Increased repair site strength


Extrinsic repair response

Dominated in the immobilization group

By 10 days after repair, the in-growth of peripheral adhesions dominated the repair site


Surgical principles

Operating room, loupe magnification GA or regional anaesthesia Tomiquet

         Meticulous tissue handling (Bunnell)

         Bruner type (zigzag) or midlateral incision, incorporate original lacerations

         Identify & protect neurovascular bundles

         Avoid devascularization of skin flaps

         Locating tendon ends:

-   haemorrhage within tendon sheath

-   'milking' proximal to distal

-   grasping exposed interior substance of tendon stump with fine toothed forceps

-   pre-op ultrasound

Avoid blind passage of instruments into tendon sheath - promote intrasynovial adhesions

If proximal tendon is retracted & inaccessible, retrieve by distal - proximal passage of small feeding catheter

20G needle placed l-2cm prox + distal to transected ends to stabilize ends for repair

          Protect annular pulleys, especially A2 and A4 Do repairs through C1 and C2 Reconstruct sheath where possible


Surgical technique


No man's land

          Attributed to Bunnell 1934 Zone 2

Discouraged primary repair in this zone

          The preferred treatment was free tendon grafting

          Kleinert reported excellent results with primary suturing in 1967

          Then it was believed that only FDP should be repaired in zone 2.

Now, in experienced hands, it is believed best to repair both FDS and FDP (FDS first)


Suturing material

Braided polyester fiber 3/0 or 4/0 most popular

          Flexibility & ease of handling

          Minimal mechanical trauma to tendon

          Allow early digital mobilization


Repair methods

Core sutures: greatest tensile strength - multiple sites of tendon interaction

-   Kessler/ modified Kessler, Bunnell

-   newer - Tajima, Strickland At least 4 strand core suture

Dorsal placement of core suture

Locking better than grasping

Knot placement does not have an effect on tensile strength but placement away from the repair J, tendon glide


Multistrand positives:

-   Less gap formation

-   Less tendon ruptures

Multistrand negatives:

-   Technically more difficult

-   Tendon thicker

-   Increased gliding resistance


Epitendinous sutures

| repair site bulk

1 tensile strength

Bite of 25% of diameter of tendon

Obliquely lacerated tendons

Change from modified Kessler (grasping) repair to locking Kessler repair Lengthen the longitudinal strands


Partial tendon lacerations

General consensus that lacerations of less than 60% of the tendon substance should not be repaired

Potential complications:

-  triggering

-  entrapment

-  late rupture

Beveled edge can be trimmed


Annular pulley injuries

A2 and A4 pulleys should be repaired or reconstructed if they are deficient Reconstruction can be done by using a free tendon graft or part of the extensor retinaculum




Surgical technique and quality of repair likely attributes to only 50% of end result success

Different rehab protocols - no method guarantees successful outcome in all pts


Early moblization following tendon repair:

-   stimulates tendon healing

-   minimises adhesions

Controlled motion of healing tendon

-   improves tensile strength

-   improves gliding

          Tendon excursion of 3 - 5 mm required to prevent firm adhesions ( Duran & Houser)

          Rehabilitation should be individualized: 1. Type of injury

2 Quality of repair

3.       Compliance of patient

4.       Patient's insight


Rehabilitation - Methods

          Early Passive Motion Fingers splinted in flexion - rubber band traction

          Pt instructed to extend fingers actively for 5sec

          Repeated 10 X / hour

Bands left unattached at night & during alternating periods - prevents flexion contractures of IPJ's

Warn pts against passive extension of wrist & fingers


Dorsal splint:

-   wrist: approximately 20 degrees flexion

-   MCPJ's: approximately 40 - 70 degrees flexion

-   IPJ's: full extension



-Significant loss of PIP J extension

-Poor mobiliser of the DIP joint if used without distal palmar bar


Early Active motion

Dependant on - strong repair

-   early referral to OT

-   pt comprehension & compliance Wait 3-5 days - avoid fresh bleed & adhesions Dorsal blocking splint

         Initial passive flexion & extension - overcome stiffness

'place & hold' exercises: finger placed in flexion & held for 5sec Gentle active flexion +/- 14 days post op


Rehab - wk 5-6

Splint removed for hand wash, lotion or hand cream, scar tissue massage Active movement with minimal resistance Splint remoulded - more wrist ext Paraffin wax or U/S - reduce joint stiffness

         Tendon gliding exercises Rehab - wk 7 - 12

         Dorsal splint worn at night

         Activities against resistance introduced Return to light duty

         Return to normal duty by wk 12 No contact sport for another 4 wks


Complications of Flexor tendon repair

         Gap formation - due to:

-   breakage of suture material

-   inadequate suture method

-   poor immobilization

-   excessive prox muscle pull

(Lindsay & Thompson)

         > 3 mm: No significant repair-site tensile strength increase between 3-6 weeks > 3 mm: Gap filled with fibrosis

         > 3 mm: Gap progressively increased in size till tendon eventually ruptured Less gap formation with multistrand, multigrasp suture methods - 4 strands being optimal

         Tendon rupture

50% because of pt non-compliance

         May present like infection

         Prompt re-exploration and repair




Flexion contractures

Prompt recognition

         NB: Extend PIP's and DIP's fully and regularly during exercises Addition of palmer bar to dorsal splint






Extensor Tendon Rehab

Dynamic Splinting with early passive motion

-   D5 post-op - dorsal dynamic extension splint

( wrist 40-45 ext, MCPJ rests at 0 ) + palmar block

-   allows controlled flex of MCPJ 0-30

-   achieve gliding of repaired tendon

-   passive flex of IPJ's through FROM within splint

- 3 - 4 wks post-op palmar block removed - T MCPJ flexion & tendon excursion allowed

-   initially fingers ext with short lever arm (IPJ's flexed)

-   wrist in slight flex ( wrist flex synergistic with finger ext)


Passive splinting with early active motion

-   D3 - 5 post-op, hand placed in volar splint ( wrist 40-45 ext, MCPJ 20-30 flex )

-   'place & hold' exercises in the splint

-   progress to active ext of MCPJ from 30-0

-   splint worn for 4 wks then shortened

         Either treatment regime may still lead to ext tendon adhesions over MC

         Early oedema control, digital scar massage, early motion prevent adhesions