Tendon Transfers

PRINCIPLES image


image    What should the patient’s joints be assessed for prior to considering a tendon transfer?


1.  Mobility


2.  Contracture


image    What is a prerequisite for successful outcome of tendon transfers?


Flexibility of the joint to be moved by transferred tendons.


image    What are the goals of preoperative therapy?


Maintain passive mobility.


Prevent joint contractures.


image    What factors need to be considered when selecting a donor muscle for tendon transfer?


1.  Adequate strength


2.  Tendon excursion


3.  Straight line of pull


4.  Synergism of action between the donor and recipient muscles


5.  Expendable donor


6.  Tissue equilibrium


image    What geometric feature correlates with the strength of a muscle?


Cross-sectional area of the muscle.


image    What does the work capacity of a muscle correlate with?


Muscle volume.


image    What does muscle excursion correlate with?


Muscle-fiber length.


image    How much tendon excursion can be found in wrist flexors and extensors?


30 mm.


image    What is the amplitude of tendon excursion for finger extensors and flexors, respectively?


1.  50 mm


2.  70 mm


Thus, when wrist tendons are used to restore finger function, there is usually incomplete correction.


image    How can the effective amplitude of tendon excursion be increased?


1.  Increasing the number of joints the muscle tendon unit crosses.


2.  Dissection of the muscle from its surrounding fascial attachments.


image RADIAL NERVE image


image    What is the most significant limb dysfunction after radial nerve palsy?


Inability to extend the wrist and stabilization for all other hand activities.


image    What is the effect of restoring active wrist extension on grip strength?


Grip strength will increase three to fivefold.


image    What is the advantage of maintaining active wrist motion?


Tenodesis effect.


image    What is the tenodesis effect?


Finger extension with wrist flexion. Try this on yourself.


image    What are the indications for tendon transfer?


Insufficient recovery of function after nerve injury that has been observed for an appropriate length of time.


image    What is often considered as an early tendon transfer within weeks after nerve injury?


Single tendon for wrist extension (e.g., pronator teres to ECRB) as an internal splint.


image    What is the advantage of the early tendon transfer?


Facilitates power grip by wrist extension, and finger extension through tenodesis effect.


image    What is the preferred timing for the delayed tendon transfers?


6 to 18 months.


image    In general what are the available donor muscles for tendon transfers in radial nerve palsy?


All extrinsic median and ulnar nerve innervated muscles.


image    What muscle tendon transfers are included in the Brand transfer for radial nerve palsy?


1.  PT to ECRB


2.  FCR to EDC


3.  PL to EPL


Thus, wrist, finger, and thumb extension, the critical deficits in radial nerve palsy, are restored.


image    What is the Boyes tendon transfer?


A tendon transfer for radial nerve palsy includes:


1.  PT to ECRB


2.  FDS III to EDC


3.  FDS IV to EIP and EPL


4.  FCR to APL and EPB


image    What is the advantage of the Boyes transfer?


It can be used in patients who do not have a palmaris longus.


image    What is the disadvantage of the FDS III and IV tendon transfer?


Bowing of the donor digits.


image    What tendon transfers are included in the FCU transfer for radial nerve palsy?


1.  PT to ECRB


2.  FCU to EDC


3.  PL to EPL


image    What is the preferred tendon transfer to restore active wrist extension in a radial nerve palsy?


PT to ECRB.


image    What muscle tendon transfers can be used for restoration of MPJ extension?


1.  FCR to EDC


2.  FCU to EDC


3.  FDS III to EDC


image    What is the theoretical advantage of the FDS III to EDC transfer in restoration for MPJ extension?


1.  Straight line of pull


2.  Expendable donor


3.  Sufficient strength


4.  Sufficient excursion


5.  Synergism


image    What are potential disadvantages of the FCU to ECRB transfer?


Weakness of wrist flexion with wrist radial deviation deformity and unnecessary strength of wrist extension.


image    What is the primary choice for restoration of finger extension?


FCR to EDC transfer.


image    Why does the FDS III transfer not interfere with the flexor power of the other three FDS muscles?


Because the FDS III has a separate muscle belly.


image    What are the two functions of the functioning EPL?


1.  Thumb IP extension


2.  Thumb adduction


image    How can the PL to EPL transfer restore thumb abduction in addition to thumb extension?


Rerouting the EPL from the third dorsal compartment and allowing it to lie along the first dorsal compartment will convert its adduction moment into an abduction moment.


image    Which anatomic route is used for the FDS III to EDC tendon transfer?


FDS III tendon is rerouted through a large window in the interosseous membrane of the forearm.


image    What is the position of immobilization after tendon transfers for wrist extension, finger extension, and thumb extension?


1.  90-degree elbow flexion


2.  Neutral forearm rotation


3.  45-degree wrist extension


4.  Full extension of MPJ


5.  Thumb abduction and full extension of IP and MPJ


image    When should dynamic splinting be initiated?

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Aug 28, 2016 | Posted by in Reconstructive surgery | Comments Off on Tendon Transfers
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