Tendon Transfer

Epidemiology

 

Nearly 2/3 cervical level injury survivors have C6 root level function

- biceps and wrist extension function

 

Requirements

 

1. Transfer / Triceps

 

2. Object manipulation

- grip 

- key grip / self catheterisation 

 

Timing

 

Consider > 18/12

 

Allows

- serial evaluation

- psychological adjustment

 

Delayed if evidence of neurological recovery

 

Principles

 

1. Start on side with most function / or dominant limb

 

2. If 2 point discrimination > 10mm

- operate on only one limb, as patient uses visual cues

 

3. Keep treatment simple

 

4. Restore elbow extension first if C6

- Moberg Deltoid - Triceps

- aids transfer

 

5. Perform only one operation at time

 

6. Don't transfer spastic muscles

-  ? dynamic EMG

 

7. Remember principles of tendon transfer

 

Classification

 

Neurologic level 

- lowest level with normal motor & sensory function bilaterally

- level of bony fracture doesn't exactly correspond with level of cord injury

 

Frankel Grade

 

A Complete neurological deficit

B Sensory only below injury level

C Motor < 3 below level

D Motor < 5 below level

E Normal

 

Transfer summary

 

C5

- Moberg deltoid to triceps transfer

 

C6

- Moberg deltoid to triceps transfer

- FPL tenodesis

 

C7

- BR to EDC / EPL for finger extension

- ECRL to FDP for finger flexion

 

C8

- Zancolli FDS tendodesis to prevent intrinsic plus

 

C5 Quadriplegia

 

Intact

- deltoid / supraspinatus / biceps

 

Require

- elbow extension / Moberg deltoid to triceps

- forearm pronation / Zancolli Biceps tendon re-routing

 

A.  Deltoid to Triceps transfer  - Moberg

 

Indications

- Triceps < Grade 3

 

Benefits

- helps stabilisation in wheelchair

- helps transfers

- improves control of self-help devices

 

Procedure

- posterior 1/3 of deltoid isolated

- dissect up till see AXN entering posterior deltoid & stop

- preserve as much of its tendinous insertion

- tendon grafts obtained / EDL or T anterior

- tendon grafts interlaced between distal deltoid belly & triceps aponeurosis

 

Post op

- elbow immobilised in extension for 6/52 with GHJ adducted

- then slowly flex 10° per week

- avoid transfer for 3/12 

 

B.  Zancolli Biceps Tendon Rerouting 

 

C5 level patients lack ability to place hand in working position

 

Procedure

 

1.  Obtain passive pronation first

- removal of interosseous membrane + DRUJ

 

2. Biceps tendon exposed

- Z Plasty

- distal 1/2 rerouted around neck of radius

- sutured to at tension to obtain full pronation & yet allow extension

 

C6 Quadriplegia

 

Intact

- wrist extension - BR, ECRL, ECRB 

- pronation

 

Require

- elbow extension / Moberg biceps to triceps transfer

- stronger wrist extension / BR to ECRB

- Key pinch / BR to FPL / Moberg FPL tenodesis 

 

A.  Moberg FPL Tenodesis

 

Indication

- strong wrist extensors with no finger flexors i.e. C6 lesion

- creates key pinch

 

Mechanism

- tenodesis of FPL to provide flexion with wrist extension

 

Procedure

 

Release of A1 pulley of thumb

- permits bowstringing

- increases mechanical advantage

 

FPL tenodesis to volar radius

- exposed in forearm

- divided 6 cm proximal to wrist

- tenodesed to volar radius by passing through hole in radius & sutured to itself 

 

Dorsal tenodesis of extensor hood of thumb MCPJ 

- stops MCPJ hyperflexion

- hood sutured to dorsum of MC through drillholes

 

Fusion of IPJ of Thumb

- at zero degrees

- via longitundinal K wire

 

Post op

- thumb spica for 4/52

 

B.  BR to FPL 

 

Indications

- strong ECRL or ECRB

 

C.  BR to ECRB

 

Indications

- strong BR with weak ECRB/ ERCL

 

Advantage

- allows wrist extension for tenodesis effect of finger flexors

- gives grasp

 

C7 Quadriplegia

 

Intact

- triceps

- EDC

 

Require

- finger & thumb flexion

 

Criteria

 

Many SCI patients can be helped with hand surgery - 75%

 

Suitable criteria

- 2 point discrimination < 10mm

- plateau of neurology 12-18/12

- grade 4 MRC power of transfer (lose minimum 1 grade)

- no uncontrolled spasticity

- no excessive pain in hand

- psychologically stable

 

Zancolli 2 Stage procedure

 

Stage I / Finger & thumb extensors

- BR to EPL / EDC

- use CMCJ thumb 

- thumb MCPJ volar plate capsuloplasty / suture plate to MC neck / stop hyperextension

- transfer BR to EPL & ED via long radial incision

- immobilize for 4/42

 

Stage II / Grasp

- 6/12 later

- ECRL to FDP

 

Options to power FPL

1. TT to ECR Tertius if present

2. Side to side suture to ECRB

3. Passive tenodesis (Moberg)

 

C8 Quadriplegia

 

Intact

- FDP/FDS

 

Require

- prevent MCPJ hyperextension

 

Zancolli FDS Lasso tenodesis

 

Technique

- divide FDS slips at A2 level

- pass proximal slips under A1 

- suture slips to FDS above A1 

- effectively suture FDS to A1