INTRODUCTIONRadial nerve palsy is a serious functionalimpairment, causing loss of wrist, finger andthumb extension. The loss of wrist extensioncauses wrist instability and forces the fingers toflex at a mechanical disadvantage due to thefinger flexors commencing action in a short-ened position. This greatly reduces the strengthin power grip. The loss of finger and thumbextension deprives the hand of the ability tograsp large objects. In leprosy, radial nervepalsy is often associated with median and/orulnar palsy, which greatly compounds theimpairment and limits the number of tendonsavailable for transfer. The usual combinationseen is a high radial palsy, a high ulnar palsyand a low median palsy. Many combinations oftransfers have been developed for the treat-ment of radial nerve palsy.2,3,8,9,18,21,26,31 Theactions that need to be restored are wrist exten-sion, finger extension, and thumb extension-abduction. In triple nerve palsy thumb abduc-tion and primary finger metacarpophalangealflexion must be restored. The standard trans-fers that will be described in this chapter areshown in Table 8-2. While the standard trans-fers are very successful when performed cor-rectly, Riordan correctly points out that "thereis usually only one chance to obtain goodrestoration of function in such a paralyzedhand."28 If the first procedure is not performedwell, with excellent follow-up care, the chanceof making a good functional hand is small.

The surgeon must have a good understand-ing of the three-dimensional anatomy of the

forearm and should review this prior tosurgery. The principles of tendon transfersurgery as outlined in Chapter 1 must be fol-lowed carefully.

The issues involving nerve repair, in case oftrauma, will not be addressed here. The readeris referred to Green's discussion of this ifdesired.15 While some advocate early transferas a splint to prevent contracture. I would sug-gest that the therapy team should be able toprevent such problems during the time ofpotential nerve recovery.7,22

8Radial Nerve Palsy

l R. SCHWARZJ. JOSHUA

G. WARREN

TABLE 8-1: List of abbreviations used in thischapter.

ECRB Extensor carpi radialis brevisECRL Extensor carpi radialis longusECU Extensor carpi ulnarisEDM Extensor digiti minimiEPL Extensor pollicis longusFCR Flexor carpi radialisFCU Flexor carpi ulnarisFDS Flexor digitorum superficialisPL Palmaris longusPT Pronator teres

TABLE 8-2: Tendon transfer program fortriple nerve palsy.

First StagePT to ECRB yoked to re-routed ERCLFCR to EDC (and possible EPL)PL to re-routed EPL

Second StageFDS (long) to lateral bandsFDS (ring) opponensplasty

Pre-Operative TreatmentIt is essential that the therapy team obtains andmaintains joint mobility prior to tendon trans-fer and also to 'stretch' the long flexors out tofull length. Thumb webspace contracture, ifpresent, must also be corrected. Splinting isrequired, both to prevent contractures and toprovide the mechanical advantage that wristextension gives. Burkhalter notes that a simplecockup wrist splint can increase grip strengthby three to five times.23 More complex splintscan be designed that provide dynamic exten-sion of the thumb and fingers using outriggerswith rubber bands that allow full flexion.12

However these are very conspicuous andwould probably only be used by those whowill need to continue doing fine manual workprior to definitive surgery. Brand recommendsthat if only a cockup wrist splint is used then atnight a splint that keeps the fingers also inextension should be used to prevent long flex-or contractures.4

RECONSTRUCTION OF WRISTEXTENSIONThere have been many modifications of thebasic Pronator Teres (PT) to Extensor CarpiRadialis Brevis (ECRB) transfer since Jones firstdescribed the procedure in 1916.18 A fewauthors have advocated wrist arthrodesis.11,18

However the advantages of active wrist exten-sion are so strong and the results of an activetendon transfer are generally so good that thereis little reason to do a wrist arthrodesis as a pri-mary procedure unless there are inadequatemuscle-tendon units available for transfer.Brand has extensively studied the momentarms for the muscle tendon groups of the handand has devised a procedure which is a modi-fication of Jones' original procedure.4 We rec-ommend this procedure as the most sound andmost likely to function without complications.

Pronator Teres to Extensor Carpi RadialisBrevis TransferThe ECRB has a strong moment arm for wristextension but it also has a moment arm forradial deviation. Therefore a simple PT toECRB transfer may lead to the development ofradial deviation of the wrist, which wastes thePT movement in a non-useful direction ofmovement. FCU (if present) can resist this butthis will weaken wrist extension. Three of four-teen patients undergoing PT to ECRB surgeryin our series developed radial deviationadversely affecting function21, and 5 of 40patients in Chotigavanich's series developedradial deviation.9 Some have also advocatedyoking ECRB to ECRL.18 ECRL has a greatermoment arm for radial deviation then wristextension, thereby further aggravating theproblem. Brand has shown well, when twotendons are yoked together, the one with thesmaller moment arm will be preferentially acti-vated by the transfer (Fig. 8-1).4 As ECRL has ashorter moment arm than ECRB for radialabduction, it will be the prime wrist mover,thereby pulling the hand into radial deviationfollowing surgery. Brand tried yoking ECRB toECU, but found that ECU had a small momentarm for wrist extension, and none when thewrist was pronated. He recommends yokingECRB to ECRL, detaching ECRL from its inser-tion in the base of the second metacarpal andreinserting it into the base of the fourthmetacarpal.4 This insertion has the samemoment arm for extension as the ECRB , andwill therefore give balanced extension. Tubianadescribes a similar procedure using the samerationale.31 This transfer is the key to success ofa rehabilitation program for someone withcombined nerve palsies. Good wrist extensionis necessary for effective finger flexion and willoptimize the function of tendon grafts forintrinsic and opponens transfers. Interestingly,the muscle fibre excursion for the PT (25 mm)is only half that of the wrist extensors (59 mm).The fact that many patients undergoing PT

84 Surgical Reconstruction & Rehabilitation in Leprosy

transfers for wrist extension eventually achievea full range of motion implies that the excur-sion of the pronator muscle actually increasesfollowing surgery.29 Brand suggests that sar-comeres are added or removed in response to achange in the tension of a muscle at rest, butthat this process is slow.5

Technique: The PT to ECRB transfer is usuallycombined with the FCR- to-EDC (Flexor CarpiRadialis to Extensor Digitorum Communis)transfer. Only the incisions for the wrist exten-sion part of the procedure will be describedhere (Fig.8-2). An 8-10 cm curved incision (1) ismade over the convex part of the middle of theradial border of the forearm to expose theinsertion of the PT and the tendons of ECRBand ECRL. At this level the ECRB tendon isusually surrounded by muscle but the tendonis easily found inside.

The insertion of PT is identified by follow-ing the muscle down to its fanlike insertion

onto the radius. The end is grasped and cut offthe radius, taking care to include a 1-2 cm stripof periosteum with it to use for the anastamo-

Radial Nerve Palsy 85

FIGURE 8-1 a. Two pulley wheels fixed to a common axle. b. For a given amount of rotation, the largerrope releases a longer length of rope (tendon) c. Both ropes are fixed together, similar to a double tendoninsertion. d. Pulling on common rope (tendon) causes the rope on the wheel with the larger moment armto become slack. Only the smaller wheel is functional (from Brand4, used with permission).

FIGURE 8-2 Incisions for PT to ECRB transfer(dark lines) and FCR to EDC transfer/ PL to EPLtransfer (light lines). a. Volar aspect b. Dorsalaspect. Incisions are numbered as in text.

(a)

(c) (d)

(b)

1

2

3

4

5

68 7

sis. It is easy to miss some of the upper attach-ments of PT to the radius. The PT is thenbrought around, superficial to the brachioradi-alis, to avoid adhesions to the radius (Fig. 8-3a).The wrist is put in a 45° extension splint. Asmall transverse incision (2) is then made overthe insertion of ECRL, making sure it is not theextensor pollicus longus. The ECRL is detachedand brought out through the proximal incisionand then passed down superficial to deep fas-cia to a small incision (3) over the base of thefourth metacarpal (Fig. 8-3b). Attachments of

the ECRL to radius are freed to allow it to lie onthe ulnar side of the ECRB. Here a distallybased flap of periosteum is elevated and theend of the ECRL is fixed to periosteum withbraided nylon suture. If finger and thumbextension transfers are being done in the sameoperation they are completed at this point.

The ECRB is then sutured side to side to theECRL while applying equal tension on bothtendons. The PT is passed through the joinedECRB/ECRL tendon as far distally as possibleand sutured with braided nylon with moderate(1 cm) tension. The end is buried in the muscleand the anastamosis is covered with 6-0monofilament nylon. The skin incisions arethen closed. The wrist is immobilized in 45degrees of extension for four weeks beforemobilization is commenced (see Chapter 21 forspecific therapy techniques).

RECONSTRUCTION OF FINGER/THUMB EXTENSION

Thumb extensionBrand advocates the use of the palmaris longus(PL), when available, as the active tendon, toreplace the extensor pollicis longus (EPL).4 Inthe absence of the PL, the FCR is the tendon ofhis choice. The replacement of the abductorpollicis longus (APL) is also stressed by Brand,as it acts as an extensor of the metacarpal of thethumb, providing for a “circle” pinch. Toachieve this, the preferred active muscle is theFCR. However in these instances, Brand is con-sidering the radial paralysis alone with nor-mally functioning intrinsic muscles.

However in cases of leprosy, we normallyencounter a triple nerve paralysis, where theadductor pollicis and other intrinsic muscles ofthe hand are paralysed and consequently, themuscle imbalance is different. Moreover thenumber of active muscles available for thetransfer is limited.

86 Surgical Reconstruction & Rehabilitation in Leprosy

FIGURE 8-3 a. The PT is elevated with a strip ofperiosteum and transferred above the brachioradialis.b. ECRL is transferred to base of the ring metacarpal,ECRL is attached to ECRB and the PT is attached toECRB (from Warren33, used with permission).

MC2

PT moves

Prona

torter

es

ECRB

ECRL

ECRL

ECRL

ECRL

ECRB

Belly

ofpro

nator

teres

ECRB

Barch

ioradia

lis

ECRB

ECRL

Finger ExtensionMany active muscles have been used in thereplacement of finger extensors. Jones advocat-ed the use of the FCU18, while Brand has usedthe FCR for four-finger extension.3,4 Clezy,11

and later Fritschi,13 have advocated the use ofthe FCR for the restoration of four-finger andthumb extension. Goldner and Kelly14 and laterBoyes2 and Chuinard,8 have recommended theuse of the FDS muscles of the ring and/or mid-dle fingers for finger extension. However thisis acceptable only if the radial nerve is the onlyparalysed nerve. If there is associated ulnarand median nerve palsy (triple nerve palsy), asis usually the case in leprosy, these tendons areneeded for intrinsic muscle replacements.

Advantages and disadvantages of variousproceduresThe PL, if present, is an ideal muscle to use forthumb extension. The EPL tendon may be re-routed more radially to be attached to the PL toimprove the direction of action.

The FCU as the extensor of the fingers hasthe advantage of being strong and well able toprovide the necessary action. However, it lacksthe excursion required to provide a completerange of motion. (Its ulnar side fibres are only 4cms long). It is also too bulky and causes anunsightly bulge as it crosses over on the ulnarborder of the wrist from the flexor to the exten-sor aspect. It is an important muscle in its ownright, causing essential ulnar deviation in activ-ities like hammering and cutting vegetables.Use of this muscle for the transfer deprives thewrist and hand of these effective actions.

The FCR has the advantage of havinggreater excursion than the FCU and thereforecan cross more than one joint. It is also lessbulky and therefore is not as unsightly ontransfer. It has the disadvantage of having thescar of all tendon junctions at the region of theextensor retinaculum. This can cause problemswith mobilization in the post-operative perioddue to adhesions.

The FDS muscles to the ring and middle fin-gers have the advantages of good length so thatthe tendon sutures lie well distal to the retinac-ulum reducing the risk of adhesions. The FDShas adequate excursion to allow full range andindependent movement of the wrist and fin-gers. The relative disadvantage is that the FDSare antagonists to the movement they arerequired to produce making re-education moredifficult.

This transfer is usually done in combinationwith the previously described procedure forextension of the wrist; that is, in the same sit-ting it will follow Pronator Teres transfer to theECRB.

Palmaris Longus to Extensor Pollicis Longusand Flexor Carpi Radialis to ExtensorDigitorum Communis Transfer

Indication: Radial nerve paralysis in isolationor in combination with a high ulnar and lowmedian paralysis.

Technique: Following the PT to ECRB transfer, asmall incision (4) (Fig. 8-2) is made over thewrist crease over the visible PL tendon. Thetendon is identified, isolated and withdrawn inthe forearm via incision 5, about 10 cms proxi-mally. Through a longitudinal incision (7) justproximal to Lister’s tubercle over the level ofthe extensor retinaculum, the EPL is identifiedand isolated. It is divided at its musculo-tendi-nous junction. This tendon is withdrawn distal-ly, just proximal to the metacarpophalangealjoint of the thumb. It is tunneled subcutaneous-ly to lie over the tendon of the APL. The PL ten-don is then tunneled subcutaneously to meetthe EPL at this point, incision 6. It will lie basi-cally in line with the first metacarpal. The twotendons are sutured here with a short interlace,under high tension, with the thumb positionedin extension in the same plane as the palm (Fig.8-4).

Radial Nerve Palsy 87

Through the same incision over the wristcrease, just proximal to the insertion of theFCR, the tendon is isolated and detached fromits insertion and recovered in the forearmthrough a transverse incision (8) about 7 cmproximally. A longitudinal incision (7) is madeon the midpoint of the dorsum of the wrist andthe extensor retinaculum is cut along the sameline to expose the EDC. The FCR is tunneledsubcutaneously into this incision, finding thepath of least resistance using a blunt instru-ment.4 Setting the tension correctly is difficult,especially in triple nerve palsy. With the wristin about 45 degrees extension, and the fingersextended fully at the metacarpophalangealjoints, the FCR tendon is passed through the

individual slips of the extensor digitorum asdistally as possible after taking up the slack. Itis sutured in such a manner as to incorporateall the tendons in the stitch (Fig. 8-5). Anothermethod is to insert the FCR into the extensortendons of the ring and middle fingers andthen to attach the tendon of the index to that ofthe middle and the tendon of the little finger tothat of the ring finger. Most authors do notinclude the EDM for fear of creating too muchextension/abduction in the little finger.1 Greensuggests pulling on the EDC to assess the ade-quacy of little finger extension.15 If there is anextensor lag of the little finger, the EDM is alsoincluded in the transfer.

The transfer should then be tested passively.Wrist flexion should produce MCP joint exten-sion but not hyperextension. With the wristextended it should be possible to achieve full

88 Surgical Reconstruction & Rehabilitation in Leprosy

FIGURE 8-4 Route of PL to EPL transfer. Movingthe EPL tendon to the radial side of the wrist willproduce both abduction and extension.

FIGURE 8-5 FCR to EDC transfer. A single weaveis carried out obliquely, and the unsatisfied end isburied in one of the extensor tendons. A similar joinis carried out for an FDS transfer but comes eitherthrough he interosseous membrane around theulnar border.

EPL

EPL

EPL

PL

EPI EDQ

Extensorretinaculum

EDC, EDQand EPI

EPL

FCR

finger flexion. The tourniquet is now released,haemostasis achieved and the wounds closed.

In case the PL is absent, Brand advises theuse of one of the FDS tendons for extension ofthe thumb.3 This however can be done only ifthe paralysis is confined to the radial nerve, asthe FDS tendons will be needed for intrinsicreplacement procedures in a triple nerve palsy.Fritschi,14 and McEvitt and Schwarz21 however,advocate the use of the FCR divided in twoslips, one for thumb extension and the otherfor four-finger extension even when the pal-maris longus is present. The EPL can be takenout of the dorsal retinaculum as shown in Fig.8-5 to give more abduction. They advise leav-ing the palmaris longus in situ as a flexor of thewrist.

Multiple Flexor Digitorum Superficialis toExtensor Pollicis Longus and ExtensorDigitorum Communis Transfer

Indication: Isolated radial nerve paralysis

Technique: The FDS of the ring finger and/ormiddle finger are detached from their inser-tions through incisions in the respective fingersand recovered in the mid forearm. Here theyare tunneled through a window in theinterosseous membrane passing on either sideof the flexor tendon mass. The tendons arereceived in the dorsum and then tunneled sub-cutaneously to the dorsum of the wrist. Theextensor retinaculum is opened. The EDC ten-dons and the EPL are identified. The middlefinger superficialis is attached to the EDC andthat of the ring finger is attached to the EPL.The postoperative immobilization regime is thesame as that described for the FCR and PLtransfers (see below), although specific therapytechniques will obviously differ.

When the PL is available for the thumb, theFDS of the middle finger alone can be used forthe four fingers.

Post-operatively: Place the arm in a full plasterfrom the fingertips to the upper arm, with theforearm fully pronated and the elbow at 90°.The wrist is kept at 45° of extension with thefingers kept fully extended. The plaster isbivalved at three weeks and cut off below theelbow. Gentle range of motion and transferactivation exercises are commenced. By sevenweeks post-op a full unrestricted range ofmotion should be achieved (see Chapter 21).Physiotherapy should be continued until ade-quate wrist extension is achieved. Schreuderset al demonstrated continued improvement inactive range of movement following a PT toECRB transfer up to one year following thesurgery.24 This is probably because therapy notonly trains the patient to effectively use thetransfer, but also trains the muscle to increaseits excursion as noted above. It appears to takesome time for a muscle to increase its excur-sion.

Wrist Arthrodesis: Arthrodesis of the wristshould be reserved as a last option, as loss ofmovement of the wrist adversely affects thefunctioning of the hand. Even with a triplepalsy with a high median nerve involvement, amore functional hand can be obtained with the'hinge hand' operation (see below) than withan arthrodesis. Weiss et al33 report that efficien-cy of hand function decreases by only about20% following wrist fusion, but it should benoted that these were patients with normalneurologic status. Patients with multiple nerveparalysis would be expected to have a greaternegative impact on hand function from wristarthrodesis.

Indications:1. Wrist instability, subluxation or neuropathic

degeneration.2. Failed PT to ECRB transfer without hope of

successful revision.3. Triple nerve palsy with high median

involvement (relative).

Radial Nerve Palsy 89

There are now several methods of internalfixation available, which can be used if theequipment is obtainable. ArbeitsgemeinschaftOsteosynthesefragen (AO) techniques of plat-ing have reported non-union rates of 0-2%.17,33

The following method requires only K-wire fix-ation, is easy to perform and has a very highsuccess rate.13 If tendon transfers are plannedin the same hand, the arthrodesis should becarried out before the transfer to avoid disuseand further adhesions of the transfer. The idealposition of wrist fusion has not been deter-mined. In one study common activities of dailyliving were found to use an arc between 10degrees of flexion and 35 degrees of extension.6Most authors recommend a position of about10 degrees of extension.16 Pryce25 reported thatpower grip was greatest in slight extension andulnar deviation, and Kraft and Detels19 foundthat grip strength was similar from 0-30degrees of extension but was weakened in flex-ion. It would seem that a position of between 0and 10 degrees would be ideal.

Technique: A lazy S incision is made from thebase of the third metacarpal to a point 7 cmproximal to the tip of the radial styloid in thecenter point of the dorsal forearm. The skin ismobilized at the level of the deep fascia, pre-serving as many of the veins as possible. Thedeep fascia and retinaculum are then raised asan ulnar- based flap along the full length of theincision. This can be difficult to keep as onepiece, especially over the distal radius. Theextensor tendons are now exposed. The exten-sor digitorum tendons are retracted ulnar-wards and the extensor pollicus longus tendonradially. The periosteum is then stripped off ofthe radius. A strip of bone graft is harvestedfrom the distal end of radius by cutting agroove 5 cm long, 5 mm deep and 6 mm wide,tapering distally. An oscillating or circular sawis best for this, although I (RS) usually use osteotomes. The joint spaces of the

radioscaphoid, radiolunate, capitolunate jointsare opened and the articular cartilage of eachjoint surface is removed with bone nibblers,saw or a gouge. Some also include the thirdCMC joint.

With the wrist held in 30° extension, thegroove in the radius is extended through thelunate and scaphoid using a gouge or fine nib-blers. This groove is then continued directlyinto the head of the capitate, gouging a holewith a gouge or a drill with the wrist in flexion(Fig. 8-6). This extends up into the base of thethird metacarpal and must be wide enough tofit the bone graft. The distal end of the bonegraft is then gently hammered into the hole,after which the wrist is slowly extended untilthe graft fits back into the groove. Cross K-wires are used to stabilize the wrist. Anyremaining cancellous bone is used as bonegraft. The periosteum is then sutured over thegraft and the fascial flap sutured over the ten-dons and skin closed.

A plaster extending from the PIP joints toabove the elbow is placed for 10 weeks total. Acheck X-ray must be taken prior to plasterremoval. The plaster can be trimmed to allowfinger movement at four weeks. If not buriedthe K-wires should be removed at one month.

The finger and thumb extension procedurescan be carried out when there are 3 weeksremaining until plaster removal.

90 Surgical Reconstruction & Rehabilitation in Leprosy

FIGURE 8-6 Wrist arthrodesis. The bone graft isharvested from the distal dorsal radius and placedin the carpus and inserted into the base of thethird metacarpal after creation of a groove throughthe lunate, scaphoid and capitate.

Daves

Complications: Infections and skin edge necro-sis are unusual. The most common, and seri-ous, complication is delayed or non-union. Therate of non-union has been reported at 5-18% using techniques not utilizing plates.10,16

AO plate methods of fusion however havereported non-fusion rates of 0-2%.16 Adhesionsof extensor tendons can occur. Carpal tunnelsyndrome has been reported in 4-10% ofarthrodeses using the AO plate fixation.16

COMBINED NERVE PALSIESAs mentioned, in leprosy radial nerve palsy isusually seen in combination with median and/or ulnar palsies. Combined nerve palsies maybe seen in other peripheral neuropathies aswell. A complete hand assessment is mandato-ry to determine which muscles are still avail-able for transfer. In the presence of a low medi-an/high ulnar palsy, the most usual presenta-tion, the usual plan is a two or three stagereconstruction to carry out the procedures out-lined in Table 8-2. In the first stage the wristand finger/thumb extension replacement pro-cedures are performed. There is concern thatremoving the PL would leave the wrist withouta dedicated flexor. Zachary has demonstratedthat the PL alone is not adequate to providewrist flexion in a hand with a simple radialnerve palsy.34 While it appears to be adequatein a triple nerve palsy hand, removing it willleave the wrist without an independent flexor.For this reason we usually use FCR to activateextension in both fingers and thumb. Howeverthe finger flexors will also stabilize the wrist inflexion. Therefore if independent thumb exten-sion is needed the PL could be used in this sit-uation. In the second stage a sublimus transfer(FDS to lateral bands, see Chapter 6) is carriedout for intrinsic replacement, and an opponensreplacement is performed using flexor digito-rum superficialis (Chapter 7). It is important to

avoid making the sublimus replacement sotight that the finger extensor transfer is unableto extend the metacarpophalangeal joints.l It isbest to do a Bunnell type transfer to the lateralbands as opposed to the flexor pulleys, as withthe latter the finger extensors have to extendthe interphalangeal joints on their own.Arthrodesis of the thumb metacarpopha-langeal joint or a half flexor pollicus longustransfer would be appropriate for stabilizingthe thumb (Chapter 6).

It should be noted that not all patients witha triple nerve palsy will be candidates for allprocedures. In our study 18 of 21 patientsundergoing reconstructive surgery for radialnerve palsy secondary to leprosy reactions hadinvolvement of all three nerves.21 Of these 18,only eight had intrinsic reconstruction and tenhad opponens reconstruction. Reasons for thiswere partial nerve palsy, refusal of furthersurgery, or unsuitability for further reconstruc-tion. Some patients presented with severe con-tractures or shortened digits and were not con-sidered candidates for reconstruction of allfunctions.

In combined low median and high radialnerve palsy with an intact ulnar nerve, an FCRto EDC transfer should be carried out. The FCUwill maintain wrist flexion. The PL should thenbe used with a re-routed EPL to provide thumbextension and abduction. This procedure mayprovide enough abduction that the patient maynot desire to proceed with an opponensplasty.Combined high median and radial nerve palsywith intact ulnar nerve is virtually never seenin leprosy. If it does present, Omer recom-mends wrist arthrodesis, or PT to ECRB trans-fer if available, for wrist extension with theFCU transferred to EDC and EPL forfinger/thumb extension.22,23 A tenodesis ofFDP tendons of the index and middle finger toFDP of ring and little fingers is carried out togive active finger flexion of all fingers. The

Radial Nerve Palsy 91

thumb is stabilized by thumb MCP arthrodesis,tenodesis of FPL across the IP joint and tenode-sis of the APL tendon to the radius.

If the median nerve is intact with a com-bined radial/ulnar palsy then a Bunnell typesublimus transfer is carried out as second stageprocedure. Again, arthrodesis of the thumbmetacarpophalangeal joint or a half flexor pol-licus longus transfer would be appropriate forstabilizing the thumb.

The hinge hand procedureIt is not uncommon to be requested to reacti-vate a hand in which there are very few mus-cles functioning. The patient desires appear-ance, social acceptability and as much functionas possible. There are many options aimed atproviding the maximum possible function andappearance. Transfers for tetraplegic patientsare described elsewhere.16 However there is arelatively simple procedure that often gives asatisfactory result in the severely motor defi-cient hand.

If there is only one muscle of reasonablestrength that can be used in isolation, it can beused to activate wrist extension to provide a“hinge hand”. The hand at rest should be in anormal posture and when the wrist is extendedthe fingers close for grasp. Patients do not havea lot of strength but there is usually enough sta-bility to hold large light objects especially ifthey have a stem for easy holding. If this mus-cle can be used to provide a good wrist exten-sion it is possible by tenodesis of the flexors toprovide a hand that grasps, albeit weakly.

A normal strength ECRB or ECRL is usuallyadequate although the wrist extension may bestabilised by yoking one tendon to the 4thmetacarpal base to give pure wrist extension.No other active transfer will be needed. Ifthere is no active wrist extensor it is necessaryto transfer some other muscle, yoked to givebetter wrist extension stability. Suitable mus-cles need to be relatively strong and they

include brachioradialis, pronator teres, flexorcarpi radialis and FDS.

It is desirable to tenodese any extensor ten-dons at the same time as the active transfer isinserted. This allows a uniform tension to beachieved across all extensors. The techniquedescribed is similar to that of Zancolli.35 Theflexor tendons are tenodesed 3 months orlonger before the extensors are dealt with sothat they can be put in more tightly than wouldbe possible if extensors were done first. A ten-odesis of thumb opposition can also be per-formed, usually at the time of the flexor ten-odesis. This will alter the ability to graspobjects of wide diameter but will improve theability to hold something like a drinking glasswith a narrow stem as the rim of the glass willbe supported all around. Alternately, theabductor and long flexor of the thumb can betenodesed.

Technique-flexors: Initially the flexor side isoperated on. The FDS tendons are locatedabout 2-3 cm above the wrist on the radial sideof the forearm, and sutured together, side byside, when the fingers are straight. For attach-ment to the radius, use a small 2-3 mm diame-ter drill or burr and drill a series of 3 smallholes, the distal two being 0.5 cm apart and thethird one some 1 cm proximal. The bridge ofbone between these two distal holes isremoved so a cavity down to the marrow is dis-played (Fig. 8-7). The flexor tendons are identi-

92 Surgical Reconstruction & Rehabilitation in Leprosy

FIGURE 8-7 Tenodesis tech-nique. Three holes are drilled inthe distal radius. Then the bonebetween the distal two holes isnibbled to create a larger singlehole. A sub-cortical tunnel is thencreated between these two holesthrough which a single tendonwill then be passed.

0.5

1.0

R

fied and pulled tight with the fingers extended,and wrist straight or up to 10 degrees flexion.They are sutured together at the site of the dis-tal hole. The long finger tendon is then cut andpassed into the distal hole and out through theproximal hole. A strong Silk or braided nylon isused to pass this tendon into the distal cavityand out through the proximal hole so the ten-

don can be sutured back to itself, (Fig. 8-8).This means that only 3-4 weeks immobilisationis required for enough healing to start physio-therapy. If the tendon is inserted in bone via aBunnell suture so that the tendon just ends inthe bone a much longer immobilisation isrequired. This tenodesis ought to result in thefingers being flexed at the MCP and PIP jointswhen the wrist is extended (Fig. 8-9). Thedegree of flexion will depend on the position of

the wrist when the tendon length is cut beforesuturing.

The long extensor of the thumb can beattached similarly but it is often better to divideEPL and attach it to the insertion of FCR so thatthe thumb automatically pulls out straight andinto abduction when the wrist extends. Thisshould be done at the same time as the flexortendon tenodesis. McDowell and House rec-ommend stabilizing the thumb by car-pometacarpal joint fusion, combined with ahalf flexor pollicus longus to extensor pollicuslongus transfer to stabilize the interphalangealjoint.20 After this procedure the arm is plas-tered with the wrist flexed, the fingers straightand the thumb fully opposed and abducted.

Technique-extensor: The methodology fortransferring the basic active motor (PT or ifabsent brachioradialis) into ECRB is asdescribed above.

For the finger extensors it is necessary toopen the forearm for about 5 cm proximal tothe wrist with an incision that allows dissectiononto the ulna bone about 2-3 cm proximal tothe wrist joint, where the tendons will beattached. The attachment technique is the sameas for the FDS (Fig. 8-10). The tension for thissuture is fixed at neutral when the fingers arestraight and wrist extended about 10-15degrees. This should allow the fingers tostraighten when the wrist is allowed to drop

Radial Nerve Palsy 93

FIGURE 8-8 Tenodesis technique.A single flexor tendon is passedfrom the distal hole back throughthe proximal to be sutured backto itself and the remaining tendonends are buried in the distal hole.

FIGURE 8-9 Hinge handprocedure. Extension ofwrist produces flexion of thefingers (from Warren33, usedwith permission).

FIGURE 8-10 Hinge hand procedure. Attachmentof finger extensors to ulna (from Warren33, usedwith permission).

R

towards flexion (Fig. 8-11), but to flex at theMCP and IP joints when the wrist is extended.The exact tension that can be applied willdepend on what the tension is in the flexortendons. This can easily be tested on the tablebefore final suturing and closure.

The arm is plastered with wrist fullyextended and the fingers straight as is done forthe pronator teres splint. If the thumb has alsobeen operated on it will require to be held inabduction and opposition. The plaster ought tobe above elbow especially if ECRB or BR is theused motor.

Physiotherapy is relatively easy. The cast isleft on for 4 weeks and then the transferredwrist extensor is re-educated. The fingers willautomatically activate so that when the wristextends the fingers flex, and when the wristflexes the fingers extend and the thumb isabducted and extended.

SUMMARYWhile radial nerve palsy, and especially com-bined nerve palsies, are a serious disability,surgery for these conditions is usually veryrewarding. Careful attention to technique isessential to achieve correct balance, and skilledtherapy is necessary to achieve a good result.

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