Tendon Transfer Principles : Mnemonic

tendon transfer

Mnemonic: SEACOAST-1

a. Synergistic: act together to produce a single composite movement (facilitate each other). e.g.

  • Finger flexors ↔ Wrist extensors
  • Finger extensors ↔ Wrist flexors

b. Expendable: There must be atleast 1 muscle that can continue to perform function of transferred tendon. e.g., 2 out of ECRB, ECRL, ECU (wrist extensors) can be transferred

c. Adequate strength: The donor muscle should achieve at-least 85% of the physiological power of the recipient to be effective. Muscles usually lose 1 grade MRC muscle power following transfer. The relative strengths (working capacity) of muscle are:

  • BR, FCU: 2
  • FCR, PT, Wrist extensors (ECU, ECRB, ECRL), Finger flexors (FPL, FDS, FDP): 1
  • Finger extensors (EDC, EI, EDM): 0.5
  • Thumb extensors (APL, EPL, EPB), PL: 0.1

d. Contractures released: Joints should be supple. In hands, MCP joints must have full passive range of motion.

e. One tendon (donor), one function: Transfer of a single donor tendon to 2 recipients that perform opposing functions across a given joint will result in decreased transfer force, amplitude and efficiency.

f. Adequate excursion: Excursion of donor and recipient muscles should be matched. Boyes 3-5-7 rule provides a helpful mnemonic regarding excursion of wrist or finger extensors or flexors.

  • Wrist level tendons (ECRL, ECRB, ECU, FCR, FCU): 30 mm
  • Digital extensors (EDC, EIP, EDQ, EPL): 50 mm
  • Digital flexors (FDS): 70 mm

g. Straight line of pull: Tendon transfer should result in a linear vector of pull to maximize efficiency and minimize potential deforming forces. To achieve this, the muscle might have to be dissected free – till close to its origin (taking care not to injure the main nerves and vessels supplying it). The plane where it lies (above or below surrounding muscles) may also need to be changed.

h. Tissue equilibrium: The transferred tendons should lie in a healthy bed of tissue with no edema, inflammation, or scarring. If the bed is scarred, it should be excised and covered with flap earlier.

i. 1 joint/pulley

We can also use another mnemonic: 13 S

In a Sensible patient, I will transfer a:

  1. Strong, Sacrificeable, Synergistic tendon with Sufficient excursion
  2. Straight through a Scarless, Stable bed, Subcutaneously
  3. Across a Supple, Sensate joint
  4. To achieve a Single function by Securing distally

Operative technique

1. Repair technique: 3 Pulvertaft weaves

2. Tension: Set so as to allow for some slight postoperative stretch

3. Postoperative program: 3 weeks immobilization followed by active and passive mobilization

Common tendon transfers

a. Low radial nerve transfers:

  • Thumb extension: PL – EPL
  • Digital extension:
    • Brand: FCR – EDC
    • Jones: FCU – EDC
    • Modified Boyes: FDS ring – EDC

b. High radial nerve transfers:

  • Wrist extension: PT – ECRB

c. Low median nerve transfers (Transfer to Abductor pollicis brevis):

  • Riodran: FDS ring
  • Burkhlater: EIP
  • Camitz: PL
  • Huber: ADM

d. High median nerve transfers:

  • Thumb flexion: BR – FPL
  • Index/middle finger flexion: FDP (ring and small) – FDP (index and middle) side to side transfer

e. Low ulnar nerve transfers:

  • Power pinch:
    • ECRB with graft to adductor pollicis
    • FDS to adductor pollicis
  • Clawing:
  • Wartenberg deformity:
    • Ulnar slip of EDM to radial aspect of MP joint (and inserting into radial collateral ligament)

f. High ulnar nerve transfers:

  • Power pinch: ECRB with graft to FDP
  • Digital flexion: Side to side FDP transfer as in median nerve palsy

g. Musculocutaneous nerve transfers:

  • Clark: Pectoralis major transfer
  • Hovnanian: Latissimus dorsi transfer
  • Steindler flexorplasty: Transfer of common flexor origin onto the shaft of humerus proximal to the elbow

h. Axillary nerve transfers:

  • L’Episcipo procedure: Tendons of insertion on the latissimus dorsi and the teres major are transferred posterolaterally on the humerus, converting internal rotators to external rotators.

Write your Viewpoint 💬

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.