Tendon Transfers Flashcards
1
Q
What should the patient’s joints be assessed for prior to considering a tendon transfer?
A
- mobility
- contracture
2
Q
What is a prerequisite for successful outcome of tendon transfers?
A
Flexibility of the joint to be moved by transferred tendons.
3
Q
So what are the goals of preoperative therapy?
A
Maintain passive mobility
Prevent joint contractures.
4
Q
What factors need to be considered when selecting a donor muscle for tendon transfer
A
- adequate strength
- tendon excursion
- straight line of pull
- synergism of action between the donor and recipient muscles 5. expendable donor
- tissue equilibrium
5
Q
What geometric feature correlates with the strength of a muscle?
A
Cross-sectional area of the muscle.
6
Q
What does the work capacity of a muscle correlate with?
A
Muscle volume.
7
Q
What does muscle excursion correlate with?
A
Muscle fiber length.
8
Q
How much tendon excursion can be found in wrist flexors and extensors?
A
30 mm.
9
Q
What is the amplitude of tendon excursion for finger extensors and flexors respectively?
A
- 50 mm
- 70 mm
Thus, when wrist tendons are used to restore finger function, there is usually incomplete correction.
10
Q
How can the effective amplitude of tendon excursion be increased?
A
- Increasing the number of joints the muscle tendon unit crosses.
- Dissection of the muscle from its surrounding fascial attachments.
11
Q
What is the most significant limb dysfunction after radial nerve palsy?
A
Inability to extend the wrist and stabilization for all other hand activities.
12
Q
What is the effect of restoring active wrist extension on grip strength?
A
Grip strength will increase 3- to 5-fold.
13
Q
What is the advantage of maintaining active wrist motion?
A
Tenodesis effect.
14
Q
What is the tenodesis effect?
A
Finger extension with wrist flexion. Try this on yourself.
15
Q
What are the indications for tendon transfer?
A
Insufficient recovery of function after nerve injury that has been observed for an appropriate length of time.
16
Q
What is often considered as an early tendon transfer within weeks after nerve injury?
A
Single tendon for wrist extension (eg, pronator teres to ECRB) as an internal splint,
17
Q
What is the advantage of the early tendon transfer?
A
Facilitates power grip by wrist extension, and finger extension through tenodesis effect
18
Q
What is the preferred timing for the delayed tendon transfers?
A
6 to 18 months.
19
Q
In general what are the available donor muscles for tendon transfers in radial nerve palsy?
A
All extrinsic median and ulnar nerve innervated muscles.
20
Q
What muscle tendon transfers are included in the Brand transfer for radial nerve palsy?
A
- PT to ECRB
- FCR to EDC
- PL to EPL
Thus, wrist, finger, and thumb extension, the critical deficits in radial nerve palsy, are restored.
21
Q
What is the Boyes tendon transfer?
A
A tendon transfer for radial nerve palsy including: 1. PT to ECRB
2. FDS III to EDC
3. FDS IV to EIP and EPL
4. FCR to APL and EPB
22
Q
What is the advantage of the Boyes transfer?
A
It can be used in patients who do not have a palmaris longus.
23
Q
What is the disadvantage of the FDS III and IV tendon transfer?
A
Bowing of the donor digits
24
Q
What tendon transfers are included in the FCU transfer for radial nerve palsy?
A
- PT to ECRB
- FCU to EDC 3. PL to EPL
25
What is the preferred tendon transfer to restore active wrist extension in a radial nerve palsy?
PT to ECRB
26
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
27
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
28
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.
29
What is the primary choice for restoration of finger extension?
FCR to EDC transfer.
30
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.
31
What are the two functions of the functioning EPL?
1. thumb IP extension
2. thumb adduction
32
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.
33
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.
34
What is the position of immobilization after tendon transfers for wrist extension, finger extension, and thumb extension?
1. 90◦ elbow flexion
2. neutral forearm rotation
3. 45◦ wrist extension
4. full extension of MPJ
5. thumb abduction and full extension of IP and MPJ
35
When should dynamic splinting be initiated?
After 3 weeks of initial immobilization.
36
What does the dynamic splint after tendon transfer for radial nerve palsy entail?
1. dynamic extension outrigger
2. 30◦ wrist extension
3. MP flexion block at 30◦ increased at weekly intervals
4. active ROM initiated at 5 weeks postoperation
37
How is extensor lag at the MPJ postoperatively addressed?
1. delay of passive ROM and dynamic splinting
2. extension splinting
38
What is the major deficit associated with low median nerve palsy?
Loss of thumb opposition and sensation of palmar surfaces of thumb, index, long and radial half of ring finger.
39
What muscles facilitate thumb opposition?
1. abductor pollicis brevis
2. opponens pollicis
3. superficial head of flexor pollicis brevis
40
What are conditions leading to loss of thumb opposition?
1. median nerve laceration
2. chronic carpal tunnel syndrome
3. congenital deficiency of thenar musculature (thumb hypoplasia) 4. polyneuropathy
5. thenar trauma
41
What trapeziometacarpal joint motions constitute thumb opposition?
1. abduction
2. flexion
3. pronation-opposes the volar surfaces of the thumb and fingers
42
What explains maintained ability of thumb opposition after complete median nerve laceration at the wrist?
Variable ulnar nerve innervation of the superficial head of the flexor pollicis brevis.
43
What are four reliable options for opponensplasty?
1. EIP
2. ADM (Huber)
3. Palmaris longus (Camitz) 4. FDS of the ring finger
44
What are the landmarks of the vector line of pull for the most common tendon transfers to restore thumb opposition?
1. Os pisiforme 2. APB insertion
45
What is the most common tendon transfer used for low median nerve palsy?
EIP to APB transfer.
46
Where can the EIP tendon be located at the dorsum of the second MPJ?
Ulnar to the EDC tendon to the index.
47
How is proper tensioning of the opponensplasty assessed?
1. Full thumb adduction with passive wrist flexion.
2. Appropriate thumb opposition with passive wrist extension.
48
What is the Huber transfer?
Abductor digiti minimi transfer for thumb opposition.
49
What is the classic indication for the Huber transfer?
Congenital hypoplastic thumb.
50
What is the advantage of the Huber transfer?
Cosmesis—the muscle bulk restores the hypoplastic thenar eminence.
51
What is the disadvantage of the Huber transfer in thumb hypoplasia?
Insufficient tendon for thumb MCP reconstruction. The long or ring finger FDS transfer does not have this
limitation although it lacks bulk.
52
What is the position of immobilization after opponensplasty?
1. Thumb spica with opposition of thumb.
2. Slight wrist extension for EIP and ADM transfers.
3. Slight wrist flexion for FDS and PL transfers.
53
What additional deficits distinguish the high from the low median nerve palsy?
1. Inability to bend the thumb IP joint (FPL).
2. Inability to bend the index and long finger (FDS, FDP).
54
What progressive deformity may develop after chronic high median nerve palsy?
Swan neck deformity of the small and ring finger (absent FDS function).
55
How is the variability in loss of finger flexion particularly of the long finger explained?
Variable innervation of the FDP of the long finger by the ulnar nerve.
56
What is the preferred procedure to restore a normal finger flexion cascade in high median nerve palsy?
Side-to-side tenodesis of long and index finger FDP to the ring and small finger FDP.
57
What donor muscle is most commonly used for restoration of FPL function?
Brachioradialis.
58
How can the available excursion of the brachioradialis muscle be maximized?
1. Mobilization of the muscle.
2. Freeing it from its fascial envelope up to the proximal forearm.
3. Excursion up to 5 cm can be accomplished.
59
What is the appropriate tension of the BR to FPL transfer?
1. Full IP extension with 20 of wrist flexion.
2. Adequate IP flexion with wrist extension.
60
How can lack of active forearm rotation be addressed?
Rerouting of the biceps tendon insertion to the lateral aspect of the proximal radius.
61
What is the significance of sensory deficits?
1. Limit the usefulness of tendon transfers.
2. Every effort to restore sensation should be made prior to tendon transfer via: i. Nerve repair/grafting
ii. Nerve decompression
iii. Nerve transfers
iv. Neurovascular island flaps
62
What is low ulnar nerve palsy as opposed to high ulnar nerve palsy?
Lesion of ulnar nerve distal to innervation of FDP.
63
Which fingers will typically be clawing in low ulnar nerve palsy?
Small and ring fingers.
64
What is the reason for the claw deformity?
Absent intrinsic muscle function (remember that the ulnar innervated lumbricals extend the ring and small finger
PIP joints).
65
Why do index and long finger typically not develop clawing in isolated ulnar nerve palsy?
Persistent function of the radial two lumbrical muscles that are median innervated.
66
What does the claw deformity involve?
1. hyperextension of the MPJ
2. inability to fully extend the PIP and DIP
67
Which type of ulnar nerve palsy will demonstrate more significant clawing?
1. Low ulnar nerve palsy.
2. Persistent function of ulnar two FDP in low ulnar nerve palsy will produce deforming force on the PIP joints. These FDPs are not functional in high ulnar nerve palsy.
68
What eponym describes the clawing of ring and small fingers?
Duchenne sign.
69
What is the Bouvier maneuver?
Blocking of MP hyperextension that will allow the EDC to fully extend the PIP and DIP.
70
What is the Wartenberg sign?
Inability to adduct the extended small finger.
71
What is the deforming force for the Wartenberg sign?
Unopposed pull of the radially innervated EDQ (absent fourth dorsal IO muscle).
72
What is the Froment sign?
Hyperflexion of the thumb IP joint with key pinch to compensate for the deficient thumb adductor.
73
What is the Jeanne sign?
Hyperextension of the MPJ of the thumb with attempted key pinch.
74
What tendon transfers are available to restore thumb adduction?
1. ECRB to thumb adductor via intercalated tendon graft
2. FDS of long or ring to thumb adductor insertion
75
Which route is used for the ECRB transfer for thumb adduction?
1. subcutaneously extracompartmental
2. around the second or third metacarpal neck
3. volar to adductor pollicis
4. deep to flexor tendon and neurovascular structures
76
What additional function can be restored to improve the power of key pinch?
Index finger abduction.
77
What transfers are available for restoration of index finger abduction?
Accessory slip of abductor pollicis longus or EIP (EIP transfer may lead to unacceptable amount of abduction).
78
What are the general two types of tendon transfers that are performed for correction of claw deformity?
1. static transfer
2. dynamic transfer
79
What is involved in a static anti-claw transfer?
Tenodesis of the lateral bands with a tendon graft around the deep transverse metacarpal ligaments providing an internal splint that prevents hyperextension of the MPJ.
80
What does the Zancolli lasso procedure effectively treat?
Claw deformity.
81
What does the Zancolli Lasso procedure consist of?
1. FDS is looped back to itself around the A1 pulley. 2. Providing a dynamic flexion moment at the MPJ.
82
What tendon transfer to correct claw deformity originates from the dorsal side of the wrist?
The Bunnell-Stiles tendon transfer.
83
What are the steps of the Bunnell-Stiles tendon transfer?
1. ECRL transected distally and rerouted dorsally.
2. Two slips of palmaris longus or plantaris graft extension sewn into the ECRL.
3. Tendons rerouted through the lumbrical canal (volar to the deep transverse metacarpal ligament).
4. Graft tails attached to radial lateral bands of the ring and small fingers or alternatively to radial side of proximal phalanx (see next question).
84
What deformity can occur after the Bunnell-Stiles transfer to the radial lateral bands?
Swan neck deformity.
85
How can the development of swan neck deformity after the Bunnell-Stiles tendon transfer prevented?
Transfer of the tendon to the proximal phalanx rather than the lateral band.
86
What patient factors lead to a higher likelihood of swan neck deformity after the Bunnell-Stiles transfer into the lateral bands?
PIP joint hyperextensibility.
87
What additional function is lost in a high ulnar nerve palsy?
Absent small and ring finger FDP.
88
What tendon transfer reliably restores ring and small finger DIP joint flexion?
Side-to-side transfer of small and ring finger FDP to median innervated index and long finger FDP tendon.
89
What is the most common mechanism for combined nerve palsies?
Lacerations—particularly at the wrist.
90
What is the most common combined nerve palsy?
Low median-ulnar nerve palsy
91
What are the requirements for restoration of wrist and hand function in low median and ulnar nerve palsy?
1. Improve key pinch.
2. Thumb abduction (to improve opposition).
3. Tip pinch (increase index strength in pinch which has been compromised by first dorsal interosseous palsy). 4. Power finger flexion with coordinated MP and PIP motion.
5. Sensibility in the distribution involved in key pinch.
92
What is the preferred thumb opposition transfer in combined median-ulnar nerve palsy?
1. EIP transfer
2. second choice: PL, FDS
93
What muscles are preferred for restoration of thumb adduction?
1. ECRB
2. Long finger FDS
94
How can the last two transfers use the FDS if these are for combined ulnar-median nerve palsies?
Because they are for low (wrist level) combined palsies.
95
What procedures can help to improve thumb-index tip pinch?
1. Thumb IP fusion.
2. Transfer of APL with graft extension to first dorsal interosseous.
96
What type of procedure will help with integration of MP and IP joint motion?
Intrinsic transfers (eg, Bunnell-Stiles).
