19: Tendon Transfers for Ulnar Nerve Palsy

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Procedure 19 Tendon Transfers for Ulnar Nerve Palsy

Sandeep J. Sebastin, Kevin C. Chung

See Video 15: Tendon Transfers for High Median and Ulnar Nerve Palsy

Indications

Delayed presentation (>1 year) of an ulnar nerve laceration

Failed motor recovery after repair/reconstruction of the ulnar nerve

Failed motor recovery after release of ulnar nerve compression at Guyon canal or cubital tunnel

Persistent motor weakness after completion of drug therapy in Hansen disease (leprosy)

Neurologic disorders (for example, Charcot-Marie-Tooth disease, syringomyelia)

Examination/Imaging

Clinical Examination

Functional deficit: The loss of function in ulnar nerve palsy results from the claw deformity, which causes an abnormal pattern of finger flexion, weak thumb key pinch, small finger abduction deformity, and loss of ring and small finger distal interphalangeal (DIP) joint flexion (Fig. 19-1). However, these problems may not be functionally disabling in all patients, and some may require correction of only one aspect. It is important to determine this and then to set a sequence for the appropriate corrective procedures. It is better to correct the lack of DIP joint flexion first, followed by transfers for restoring thumb key pinch, and finally correction of the claw deformity because it is difficult to establish appropriate intrinsic plus posture of the hand.

• Claw deformity (Duchenne sign): This is the characteristic resting posture of the ring and small fingers with hyperextension of the metacarpophalangeal (MCP) joints and flexion of the interphalangeal (IP) joint. It results from the unopposed action of the radial nerve–innervated long extensors at the MCP joint (hyperextension) and median nerve–innervated flexor digitorum superficialis at the proximal interphalangeal (PIP) joint (flexion) in the presence of paralyzed ulnar nerve–innervated interosseous muscles and the third and fourth lumbricals that normally flex the MCP joint and extend the PIP joint. The MCP joint hyperextension deformity may not appear immediately after an ulnar nerve injury and depends on the laxity of the MCP joint volar plate. The deformity is more pronounced in patients with a lax volar plate and develops over time in patients with a taut volar plate.

♦ In a high ulnar palsy, the deformity appears less severe because the flexor digitorum profundus to the ring and small fingers (innervated by the ulnar nerve) is paralyzed and the patient has no claw at the DIP joint (ulnar nerve paradox). Therefore, the increase in severity of a claw deformity after repair of a high ulnar nerve injury is a good prognostic sign and indicates reinnervation of the ring and small finger flexor digitorum profundus (FDP) (Fig. 19-2).

♦ A claw deformity results in an abnormal pattern of finger flexion because the IP joint flexes before the MCP joint. In a normal hand trying to grasp an object, the MCP joint flexes first (intrinsic action), followed by the long flexors (IP joint) to wrap the hand around the object. In ulnar nerve paralysis, the IP joint flexes before the MCP joint, which pushes the object out of the hand (Fig. 19-3).

♦ In an ulnar nerve palsy, the claw deformity usually involves only the ring and small fingers because the median nerve–innervated first and second lumbricals retain their function. In Hansen disease (leprosy) and lacerated wounds involving both nerves, the patient may have clawing of all four fingers.

• Weak thumb key pinch: This results from paralysis of the ulnar nerve–innervated adductor pollicis and first dorsal interosseous. In addition to the obvious muscle wasting in the first web space, a positive Froment sign demonstrates the muscle deficit. The patient is asked to pinch sheets of paper between the thumb and index finger of both hands. A positive Froment sign is indicated by marked thumb IP joint flexion in the affected hand as a result of the patient using the median nerve–innervated flexor pollicis longus to hold the sheet of paper, rather than using the adductor pollicis (Fig. 19-4).

• Small finger abduction deformity (Wartenberg sign): The small finger is abducted at rest, and putting the hand into a pocket can become difficult. This deformity results from unopposed action of the radial nerve–innervated extensor digitorum minimi (EDM) in the presence of the paralyzed ulnar nerve–innervated third palmar interosseous muscle that normally adducts the small finger. EDM causes abduction of the small finger in addition to extension because it has an insertion on the ulnar aspect of the base of the proximal phalanx (Fig. 19-5).

• Loss of small and ring finger DIP joint flexion (Pollock sign): This is seen in high ulnar nerve palsy with loss of innervation to the FDP of the ring and small fingers. The flexor digitorum superficialis (FDS) and the FDP of the index and long fingers are innervated by the median nerve (Fig. 19-6).

Sensation: It is important to document the level of sensation in the thumb and the fingers preoperatively. Loss of sensation on the dorsoulnar aspect of the hand, which is innervated by the dorsal branch of ulnar nerve, can help differentiate a high ulnar nerve lesion (e.g., cubital tunnel compression) from a low ulnar nerve lesion (e.g., Guyon canal compression), which should have preserved sensation over the dorsal-ulnar hand (Fig. 19-7).

Joints: To achieve a good result from the tendon transfer, patients must have good passive range of motion at the IP and the MCP joints. The most important aspect of assessment of an ulnar nerve palsy is determining whether the patient can extend the PIP joint with the examiner correcting the MCP joint hyperextension (Bouvier maneuver) (Fig. 19-8).

• Full active PIP joint extension: This indicates that the extensor mechanism is competent (Fig. 19-8A). This patient only needs correction of the MCP joint hyperextension and can use the intact extensor mechanism to obtain PIP joint extension. A static or a dynamic procedure will suffice for this patient. A static procedure is preferred because it is simpler.

• Incomplete active PIP joint extension with full passive extension: This indicates that the PIP joint is competent but that the extensor mechanism is incompetent (Fig. 19-8B and C). This patient will need a dynamic transfer, which is described later, to extend the PIP joint through the lateral band.

• Incomplete active and passive PIP joint extension: This indicates that there is a flexion contracture of the PIP joint (e.g., palmar skin shortage, stiff PIP joint) that needs to be addressed before any tendon transfers are considered (Fig. 19-8D).

Selection of motor: We use a static procedure (MCP joint volar plate advancement) for correction of the claw deformity in patients who are able to achieve full active extension of the PIP joint. In patients unable to achieve full PIP joint extension, we use a dynamic transfer and prefer the long or ring finger FDS as a motor. We prefer to use the ring finger FDS in low ulnar nerve palsy because the FDS is important for chuck grip, which is predominantly a function of the thumb and index and long fingers. In patients with high ulnar nerve palsy with a weak or absent FDP to the ring finger, the FDS remains the only flexor of the ring finger, and it is prudent to use the long finger FDS. Other motors that have been described include the extensor indicis proprius (EIP) and EDM (both have insufficient length, resulting in excessive tension of the extensor apparatus), wrist flexors (flexor carpi radialis [FCR], palmaris longus [PL]), and wrist extensors (extensor carpi radialis longus [ECRL], extensor carpi radialis brevis [ECRB]). (All need a tendon graft.) We use the ECRB lengthened with a PL tendon graft as the motor for restoring thumb pinch. Other motors that have been described include the brachioradialis, ECRL, extensor carpi ulnaris (ECU), EIP, and FDS.

FIGURE 19-1

FIGURE 19-2

FIGURE 19-3

FIGURE 19-4

FIGURE 19-5

FIGURE 19-6

FIGURE 19-7

FIGURE 19-8

Imaging

X-ray of the hand to examine the MCP and PIP joints

X-ray of the elbow (Fig. 19-9)

Nerve conduction studies

FIGURE 19-9

Surgical Anatomy

The muscles affected after low ulnar nerve palsy are the four hypothenar muscles (abductor digitorum minimus [ADM], flexor digitorum minimus [FDM], opponens digitorum minimus [ODM], and palmaris brevis [PB]), seven interossei muscles (four dorsal and three palmar), third and fourth lumbricals, and two thenar muscles (adductor pollicis [AP] and the deep head of the flexor pollicis brevis [FPB]). All these muscles are innervated by the deep motor branch of the ulnar nerve (Fig. 19-10).

In high ulnar nerve palsy, the flexor carpi ulnaris (FCU) and the ulnar half of the FDP (ring and small fingers) are affected in addition to the muscles listed earlier.

FIGURE 19-10

Positioning

The procedure is performed under tourniquet control.

The patient is positioned supine with the affected extremity on a hand table.

Procedure 1—Static Correction of Claw Deformity with an MCP Joint Volar Plate Advancement

Procedure

Step 1

The A1 pulley of each finger is completely divided and the flexor tendons retracted to expose the volar plate of the MCP joint (Fig. 19-13).

FIGURE 19-13

Step 1 Pitfalls

Take care not to extend the pulley division to the A2 pulley.

Step 2

The neck of the metacarpal (immediately proximal to the volar plate) is cleared of soft tissue, including periosteum.

Step 3

A distally based flap of the volar plate is created by making two parallel longitudinal incisions and releasing the proximal attachment over the head of the metacarpal (Fig. 19-14A and B).

FIGURE 19-14

Step 5

The bone anchor sutures are passed through the proximal end of the flap and tied down.

Step 5 Pearls

It is better to pass the sutures for all the fingers through the volar plate and tie them at the end instead of completing one finger and then proceeding to the next (Fig. 19-16). Passing the suture through the volar plate requires significant retraction, and an adjacent flexed finger will hinder this.

The suture must hold a good bite of the thick portion of the volar plate.

FIGURE 19-16

Step 6

The wrist is maintained in a neutral position, and the ring finger capsular flap is sutured down to the neck of the metacarpal using the bone anchor sutures such that the MCP joint is flexed to about 45 to 50 degrees. The ring finger MCP joint should have slightly greater flexion compared with the long finger (Fig. 19-17).

The small finger flap is sutured next to obtain 50 to 55 degrees of MCP joint flexion and should be slightly more in comparison to the ring finger.

FIGURE 19-17

Step 6 Pearls

The amount of MCP joint flexion required to produce full PIP joint extension preoperatively can guide the surgeon regarding the degree of MCP joint flexion required intraoperatively.

Some authors recommend excising a 1.5-cm ellipse of skin (dermodesis) to prevent stretching the volar plate and overcorrecting the deformity.

Postoperative Care and Expected Outcomes

The hand is splinted with the wrist in neutral and the MCP joint in 50 to 60 degrees of flexion. The IP joints are left free to move.

Ten days after surgery, the wound is inspected, sutures are removed, and the position is maintained using a removable splint that the patient will wear for another 4 weeks, provided that the patient is reliable in keeping the splint on at all times, except in the daily cleaning of the hand. Thereafter, the patient is encouraged to move the MCP joint, and a knuckle-bender splint is provided. One should avoid passive stretching of the MCP joint. A protective removable splint is also provided for night wear and general protection for the next 4 weeks. The knuckle-bender and protective splints are discontinued 2 months after surgery, and the patient is allowed unrestricted activity.

Volar plate advancement is a simple procedure that gives good results in patients who can fully extend the PIP joint when the MCP joint is held in flexion. A bone anchor fixation of the volar plate reduces the incidence of loss of correction over time as a result of stretching. This procedure is not recommended for patients engaged in heavy manual labor who will certainly stretch the volar plate. A dynamic transfer may be more appropriate.

Procedure 2—Dynamic Correction of Claw Deformity with Transfer of Ring Finger FDS

Exposures

A Bruner-type incision centered over the PIP joint is made over the ring finger. Both neurovascular bundles are identified and retracted laterally to expose the flexor tendon sheath. Subsequently, the radial neurovascular bundle is retracted ulnarly, and a tissue plane is developed deep to it to expose the radial lateral band, which will receive the tendon transfer.

A second 3-cm longitudinal zigzag incision is made in the midpalm proximal to the proximal palmar crease. The skin and subcutaneous fat are dissected, and the common digital neurovascular bundles and the superficial arch are identified and protected. The flexor tendons are exposed.

A third 2-cm longitudinal incision is made on the radial aspect of the small finger proximal phalanx. The soft tissue is dissected to expose the radial lateral band (Fig. 19-18).

FIGURE 19-18

Pearls

Additional lateral incisions can be made on the ulnar aspect of the index finger and radial aspect of the long finger if a claw correction of all four fingers is required.

The ulnar lateral band of the index and the radial lateral bands of the long, ring, and small fingers are chosen so that the tendon transfer can produce some adduction of these digits in addition to flexion at the MCP joint and extension at the PIP joint.

The long finger FDS should be used in patients with a high ulnar nerve palsy.

Step 3

The origin of the lumbrical muscle from the FDP is identified. A mosquito forceps or a tendon passer is passed from the palmar incision along the lumbrical through the lumbrical canal (remaining superficial/palmar to the deep transverse metacarpal ligament) to exit on the incision made on the radial side of the small finger (Fig. 19-21).

The jaws of the mosquito forceps are used to hold another mosquito forceps, which is brought into the palmar wound by withdrawing the first forceps. The tip of the mosquito forceps holds the distal end of the ulnar slip of the FDS and brings it out of the radial aspect of the small finger. The mosquito forceps is not removed and continues to hold the tendon.

The same procedure is repeated to bring the radial slip of the FDS through the lumbrical canal on the radial aspect of the ring finger (Fig. 19-22).

FIGURE 19-21

FIGURE 19-22

Step 3 Pitfalls

The key step in this surgery is to remain volar to the axis of the MCP joint by passing the tendon through the lumbrical canal, remaining palmar to the deep transverse metacarpal ligament. This direction of pull will ensure MCP flexion after the tendon is attached to the lateral band.

Step 4

The tourniquet is released and hemostasis secured. The midpalmar incision and the distal half of the ring finger incision are closed.

Step 5

The forearm is pronated, and a rolled-up towel is placed in the palm so that the wrist is in neutral position and the MCP joints are flexed beyond the rolled towel.

The hemostat holding the FDS slip on the radial side of the ring finger is pulled to bring the MCP joint into about 60 degrees of flexion. (Aim to get slightly greater flexion than the adjacent long finger so that the normal cascade can be obtained.) The PIP joint is held in full extension by the assistant, and a single preliminary suture of the FDS to the lateral band is made.

The tension and the finger cascade are confirmed by taking the wrist through a gentle range of motion. If the tension is correct, two or three nonabsorbable horizontal mattress sutures are placed between the FDS and the lateral bands.

Step 5 Pearls

The MCP joint cascade can be corrected by tightening or loosening the FDS attachment to the lateral band.

The desired tension is to keep the MCP joint in about 60 to 70 degrees of flexion and the IP joint in full extension, with the wrist at about 20 degrees of extension. In most cases, the ideal tension cannot be established because of the large amount of excursion of the FDS, which reaches 70 mm. Therefore, getting close to this posture is acceptable because the FDS, which is considered a smart tendon because of its excursion, can modulate the tension to reach an acceptable posture (Fig. 19-23).

FIGURE 19-23

Step 6

The remainder of the skin incisions are closed with 5-0 nylon.

Postoperative Care and Expected Outcomes

The hand is splinted with the wrist in neutral position, the MCP joint in 60 to 70 degrees of flexion, and the IP joints in full extension.

Ten days after surgery, the wound is inspected, sutures are removed, and the position is maintained using a removable splint that the patient will wear for another 4 weeks, provided that the patient is reliable in keeping the splint on at all times, except in the daily cleaning of the hand. Thereafter, the patient is given a dorsal blocking splint that keeps the MCP joint flexed but allows full extension and flexion of the IP joint for another 4 weeks. The splint is discontinued 2 months after surgery, and the patient is allowed unrestricted activity.

The transfer of FDS reliably corrects MCP joint hyperextension but does not improve grip strength and may not fully correct the loss of PIP joint extension. This procedure gives good results in supple joints, although the patient may develop a swan neck deformity from loss of volar restraint provided by the FDS.

Procedure 3—Restoration of Thumb Adduction with an ECRB Tendon Transfer

Exposures

A 3-cm longitudinal incision is made starting at the base of the ulnar aspect of the long finger metacarpal and extending distally. The soft tissue is dissected, and the ECRB is exposed at its insertion onto the base of the long metacarpal. Distally, the dorsal interosseous fascia overlying the interspace between the long and ring metacarpals is divided, and interosseous muscles are exposed (Fig. 19-24).

Through this incision, the ECRB tendon is identified immediately proximal to the extensor retinaculum.

A 1-cm longitudinal incision is made on the ulnar aspect of the thumb MCP joint, and the soft tissue is dissected to expose the insertion of the adductor pollicis.

A 1-cm incision is made at the proximal wrist crease, and the tendon of the palmaris longus is identified and exposed.

FIGURE 19-24

Pearls

If the PL is determined to be absent preoperatively, half of the tendon of the ECRB can be used as a tendon graft. Approximately 10 cm of tendon graft will be required to bridge the gap between the distal end of the ECRB and the adductor tendon. Another option is to consider the plantaris tendon.

Pitfalls

One should look out for the branches of the superficial radial nerve in the dorsal incisions and the palmar cutaneous branch of the median nerve radial to the PL in the volar incision.

Step 1

The ECRB is divided at its insertion.

Step 1 Pearls

The ECRB may have a portion of its insertion on the base of the index metacarpal. Care should be taken to protect the ECRL insertion.

Step 2

The ECRB tendon is withdrawn proximal to the extensor retinaculum (Fig. 19-25).

FIGURE 19-25

Step 3

The exposed portion of the PL tendon is held with a hemostat, and the tendon is divided distal to the hemostat.

The hemostat is used to pull the tendon distally and free it from the surrounding antebrachial fascia.

The PL is harvested using three 1-cm transverse incisions in the forearm.

Step 3 Pitfalls

Confirm that it is the PL that you are dividing. There have been reports of inadvertent harvest of the median nerve.

Step 4

The PL tendon graft is sutured to the distal cut end of the ECRB using a Pulvertaft weave (Fig. 19-26).

FIGURE 19-26

Step 4 Pearls

This tendon juncture should be planned so that it does not lie at the middle and ring metacarpal interspace. The bulky weave may not glide well in this narrow interspace.

Step 5

A subcutaneous tunnel is made superficial to the extensor retinaculum to pass the tendon.

Step 6

A curved hemostat is used to make a subcutaneous tunnel from the ulnar aspect of the thumb MCP joint to the third to fourth intermetacarpal space. This tunnel is made superficial (palmar) to the adductor pollicis but deep (dorsal) to the flexor tendons (Fig. 19-27).

The hemostat then grabs the ECRB extended by the PL graft and brings it out to the thumb.

FIGURE 19-27

Step 7

The tendon is sutured to the tendon of the adductor pollicis with the wrist in neutral position. Tension is adjusted so that the thumb lies just palmar to the index finger.

Step 7 Pearls

Tension adjustment is checked by wrist tenodesis. When the wrist is extended, the thumb should fall into abduction, and with the wrist in flexion, the thumb should lie firmly against the palm (Fig. 19-28).

FIGURE 19-28

Step 8

The tourniquet is released, and all skin incisions are closed with 5-0 nylon.

Postoperative Care and Expected Outcomes

The hand is splinted with the wrist and thumb in neutral position.

Ten days after surgery, the wound is inspected, sutures are removed, and the position is maintained using a removable splint that the patient will wear for another 4 weeks, provided that the patient is reliable in keeping the splint on at all times, except in the daily cleaning of the hand. Thereafter, the patient is given a protective splint and encouraged to move the thumb and wrist.

The transfer of ECRB restores thumb pinch and improves the ability to perform activities of daily living. Patients recover about 50% of the pinch strength of the contralateral thumb. This transfer may restrict thumb opposition and palmar abduction.

Procedure 4—Correction of Abduction Deformity (Wartenberg Sign) of Small Finger

Exposures

A 3-cm chevron-shaped incision with the apex directed ulnarly is made over the dorsal aspect of the small finger MCP joint. The skin and soft tissue are dissected to expose the tendon of the EDM (Figs. 19-29 and 19-30).

The radial collateral ligament of the small finger MCP joint is exposed by making a longitudinal incision in the proximal portion of the extensor hood overlying the radial aspect of the small finger MCP joint.

FIGURE 19-29

FIGURE 19-30

Pitfalls

Care should be taken to protect branches from the dorsal branch of the ulnar nerve.

Step 1

The ulnar insertion of the EDM is detached from the extensor hood and dissected proximally from the remainder of the EDM for about 2 to 3 cm proximal to the MCP joint.

This tendon is now passed radially under the EDM and the extensor digitorum communis (EDC) to the small finger to reach the radial side of the small finger MCP joint.

Step 2

The tendon is sutured to the phalangeal attachment of the radial collateral ligament with the wrist in neutral position with the assistant holding the small finger adducted (Fig. 19-31).

FIGURE 19-31

Step 2 Pearls

The transfer of the ulnar half of the EDM tendon to the radial collateral ligament is useful in patients with low ulnar nerve palsy who have an abduction deformity but do not have clawing or have clawing that has been corrected by a previous transfer.

In patients who have clawing, an additional 2.5-cm oblique palmar incision is made between the distal palmar crease and the proximal digital crease of the small finger. The common digital neurovascular bundle is identified and retracted radially to expose the deep transverse metacarpal ligament. The EDM tendon is retrieved using a hemostat and passed from dorsum to palmar between the fourth and fifth metacarpals, remaining palmar to the deep transverse metacarpal ligament. It is passed through a slit made in the proximal half of the A2 pulley and sutured to itself with the assistant holding the wrist in neutral position, the MCP joint in 20 degrees of flexion, and the small finger adducted (see Fig. 19-31).

Step 3

The tourniquet is released, hemostasis is secured, and the skin is closed with 5-0 nylon.

Postoperative Care and Expected Outcomes

A splint is applied that keeps the small and ring fingers MCP joints in 60 to 70 degrees of flexion and the wrist in neutral position. The IP joints are left free.

Ten days after surgery, the wound is inspected, sutures are removed, and the position is maintained using a removable splint that the patient will wear for another 4 weeks, provided that the patient is reliable in keeping the splint on at all times, except in the daily cleaning of the hand. Thereafter, the patient is encouraged to move the MCP joint, and a protective removable splint is also provided for night wear and general protection for the next 4 weeks. The protective splint is discontinued 2 months after surgery, and the patient is allowed unrestricted activity (Fig. 19-32).

This is a simple procedure to correct an annoying disability.

FIGURE 19-32

Procedure 5—Side-to-Side FDP Transfer for Restoration of Ring and Small Finger DIP Joint Flexion Strength (High Ulnar Palsy)

Exposures

A 4-cm longitudinal incision is made 2 cm proximal to the wrist crease ulnar and parallel to the tendon of the palmaris longus. The antebrachial fascia is divided, and the PL tendon is retracted radially. The median nerve is identified and retracted radially. Next, the FDS tendons to the ring and long finger are identified and retracted radially. Immediately below are the FDS tendons to the small and index fingers. The index FDS is retracted radially, and the small FDS is retracted ulnarly. This exposes the four FDP tendons.

Pitfalls

The palmar cutaneous branch of the median nerve runs on the radial aspect of the PL.

Postoperative Care and Expected Outcomes

A protective dorsal blocking splint is provided that keeps the MCP joint in 60 to 70 degrees of flexion and the wrist in neutral position. The patient is allowed to actively move the IP joints.

Ten days after surgery, the wound is inspected, sutures are removed, and the protective splint is maintained for another 4 weeks. Thereafter, the splint is removed, and the patient is allowed unrestricted activity.

This procedure should be performed before claw correction, and patients should be warned that the surgery will exaggerate the claw deformity.

Hastings H, McCollam SM. Flexor digitorum superficialis lasso tendon transfer in isolated ulnar nerve palsy: a functional evaluation. J Hand Surg [Am]. 1994;19:275-280.

This prospective outcome study demonstrated no significant improvement in grip strength after surgery for patients who returned for late follow-up an average of 40 months after Zancolli FDS lasso procedure. (Level II evidence)

Ozkan T, Ozer K, Gulgonen A. Three tendon transfer methods in reconstruction of ulnar nerve palsy. J Hand Surg [Am]. 2003;28:35-43.

This prospective clinical series compared the FDS four-tail procedure, the ECRL four-tail procedure, and the Zancolli lasso procedure. The ECRL four-tail procedure and the Zancolli lasso procedure were found to provide greater grip strength. The FDS four-tail procedure was found to result in greater improvements in correcting the claw deformity. (Level II evidence)

Smith RJ. Extensor carpi radialis brevis tendon transfer for thumb adduction: a study of power pinch. J Hand Surg [Am]. 1983;8:4-15.

Smith performed this operation on 15 patients with paralysis or loss of the adductor muscle. In 8 patients, he simultaneously performed a tendon transfer to the first dorsal interosseous tendon, using the extensor indicis proprius in 4 patients and an accessory slip of the abductor pollicis longus in the other 4. He reported one episode of synovitis at the index-long interspace, but 14 of his 15 patients reported significant improvement. Overall thumb pinch strength was doubled by the procedure, rising from 25% (preoperatively) to 50% (postoperatively) of the strength of the contralateral thumb. (Level IV evidence)

Trevett MC, Tuson C, de Jager LT, Juon JM. The functional results of ulnar nerve repair: defining the indications for tendon transfer. J Hand Surg [Br]. 1995;20:444-446.

This clinical series provided follow-up on patients with ulnar nerve palsies and reported patient functional impairment. Manual laborers with ulnar nerve palsy had difficulty coping at work, whereas sedentary workers tended to be able to cope. The authors suggest early tendon transfers in patients involved in manual labor to avoid an unnecessarily long waiting period. (Level IV evidence)

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