,~s who ~

veraged~ed to’spiral:;olute

was

s;

~ about

:nerat

lers.the forty~.

"am. Th

-’ classiiie IV

that the~

ders.entsit allRanchoing themptom,s~ when

sier for

;rogressive)peared-’y becam:hese

.:~: . .i

or poslop,, :.:’:)"!:~{, ’

dder con,. . ,:,~~ram and:asingchanism,.~perativ¢and h>

Non-Ischemic Contractures of the::.:: . _ Intrinsic Muscles of the: Hand**

BY RICHARD 3". SMITH, M.D.S, NEW YORK~ N.Y.

trrom the Department of Orthopaedics, Hospital for Joint Diseases and the Mount Sinai:’the Mount Sinai School of Medicine, City University of New York, New York

mobility, strength, and versatility of the fingers depend on the integratedof the intrinsic muscles with the long flexors and extensors of the fingers z.8. ~

intrinsic mechanism becomes contracted or adherent, the digits maydeform, or dislocate .~

tschemic contracture of the interossei was first described by Finochietto in 1920..bietto and later Parkes a~, Bunnell, Doherty, and Curtis ~,~0, and others de-

b;ed the intrinsic-plus deformities consisting of metacarpophalangeal joint flexion[i0terphalangeal joint extension which are typically seen in patients with ischemic

of the intrinsic muscles of the hand. The intrinsic tightness test~limitedof the proximal interphalangeal joint as the metacarp0phalangeal joint is ex-

noted in these injured hands and was also described by these authors.There are, however, many causes for contracture of the intrinsic mechanism

¯ than ischemia-~*, aa, a~, ~.~ and in this paper these causes will be surveyed, with:i~,xamples given of each, together with a plan for their diagnosis and treatment. The

lion and nature of the resulting deformity wilt depend on the cause of the con-its duration, and the integrity of the joints in the affected fingers a. Theof these contractures will differ depending on t,hese variables.

Types of Intrinsic Contractureof ~he Lateral Band

:. The lateral bands of the dorsal apparatus (Fig. I) lie adjacent to the proximal

A B

.: K J

C D = F

Fro, 1¯ ::"::)iZommfinis.

[c an of the intrinsic apparatus of the finger: ,4, extensor digitorum’ band of extensor digitorum communis; C, transverse fibers of dorsal

slip; E, central slip; F, terminal tendon; G, oblique retinacular ligament;band; 1, oblique (spiral) fibers of dorsal apparatus; j, fibrous flexor sheath; K, lure-

. ~; , ¯ on; L, interosseus muscle.

?::i ’ 0-’ ....

ea5t- at the Annua Meeting of the American Society for Surgery of the Hand, San Fran-

. .~eu, Cahtornia, March 5, 1971. ,.he Uppe, ~ .... SUpported by The Orthopaechc Research Fund, Hospital for Joint Diseases, New York,

reatment, ;;: :/: 2 East Eighty-eighth Street, New York, N. Y. 10028.916.

¯ ’. 53-A, NO. 7, OCTOBER 1971

13’13- "

1314 R.J. SMrfn

phalanx 16. Any projection of bone or soft tissue deep to the lateral band raaplace it dorsally or laterally. The extensor apparatus distal to the projectionor soft tissue will tighten. Flexion at the proximal interphalangeal joim will beited when the metacarpophalangeal joint is held in extension. Displ~tcementtightening of the lateral band has been caused by fractures of the proximal phal,,tophaceous gout, and deep soft-tissue tumors of the proximal phalanx. To rehcontracture the mass is removed. If the intrinsic tightness test remains positivesurgery, after the tumor has been removed, the lateral band nmst be resectedside of the tumor.

CASE 1. A thirty-three-year-old police officer sustained a closed oblique fractureproximal phalanx of his right ring finger. The finger was splinted for three weeks andwith a small bone projection radially. The patient complained of limited flexion at theinterphalangeal joint. The intrinsic: tightness test was positive. Exploration revealed thelateral band to be displaced dorsal to the bone spike. The projection was removed and fulltion was restored (Fig. 2).

Fro. 2The lateral band of the dorsal apparatus is displaced by projection of bone or soft tissue,the lateral side of the proximal phalanx. The dorsal apparatus distal to the mass is tightene~l

limiting passive proximal interphalangeal joint flexion.

The Lumbrical-Plus Finger ’¢~i

The flexor digitorum profundus and the lumbrical form an integrated unit strutture which bifurcates in the distal part of the palm zz, z~,,24,,2L The entire unit is pulledproximally as the profundus muscle contracts. Normally when the finger flexes tilelumbrical muscle relaxes and elongates as the profundus contracts. The radial lat~band is thereby relaxed, permitting full flexion of the interphalangeal joints. When lfinger extends, contraction of the lumbrical tightens the lateral band and simulta.

neously pulls the profundus tendon distally z,.~s, 48. Thus, the unique origin of the tubrical on its own antagonist places it in a superb mechanical position to serve as th~

"work horse of the extensor apparatus" 44. As Parkes noted ~7, various types ofjury to the profundus tendon or to the lumbrical muscle can upset this balance, re-sulting in limited flexion at the proximal interphalangeal joint.

Lurnbrical Retraction

The tendon of the flexor digitorum profundus will retract proximally if the dis-tal phalanx is amputated or if the tendon is avulsed or lacerated within the hand. Ifthe laceration or avulsion of the profundus tendon occurs within the finger and there-fore distal to the origin of the lu~abrical, the lumbrical muscle will be pulled proximal-

ly by the retracted profundus tendon (Fig. 3,A). Retraction of the profundus may somewhat limited by the vinculae which tether its tendon to the proximal and middlephalanges. Nonetheless, retractiion of the lumbrical will increase the tension on theradial lateral band e~. The intrinsic tightness test will be positive. If the integrity ofthe profundus is restored promptly by suture, advancement, or graft of the tendon,the lumbrical origin will be drawn distally, allowing it to relax in normal fashion, anddigital balance will be regained. Frequently, after many weeks or months followinginjury, the radial lateral band may become adherent to adjacent tissues and thus itwill not loosen even after appropriate gurgery to the profundus tendon. In these cases,

THE JOURNAL OF BONE AND JOINT SURGERY

tl~e lateral ba~dto the pr~,icc~ion

mlangeaI ,,~i~.t willension, l-,~:,ptace

of the Prrigin of theposition to serve ~t~at, various types of

upset this balall¢¢,

t proximallyted within thein the finger and.’ill be pulledthe profunduse proximalase the tensionire. If the integril~r graft, of then normals or months:nt tissues andendon.

NE AND JOINT

NON-ISCHEMIC CONTRACTUREs OF THE INTRINSIC MUSCLES I 3 1 5

in which the profundus tendon is not repaired, flexion of the proximal in-joint may be restored by dividing the radial lateral band and the

fibers of the dorsal apparatus at the level of the distal half of the proximal

2. A thirty-year-old man lacerated the flexor digitorum profundus of the long fingerof the middle phalanx. He complained of inability to flex the distal interphalangeal

!lhe finger and of stiffness when he attempted to flex the proximal interphalangeal joint

tenodesis of the profundus stump was performed at the distal joint. In addition, theband was divided at the distal hall: of the proximal phalanx to restore full passiveto the proximal interphalangeal joint ( Figs. 4-A and 4-g).

FIG, 3radial lateral band caused by lumbrical :~etraction can occur following: a, flexorlaceration, b, loose tendon grafts, or c, tight imbrication of the lumbrical muscle

~ palmar tendon suture.

3. A thirty-one-year-old man had had lacerations of the tendons of the flexor digi-proflmdus and superficialis of the little finger ten days previously. There was limitation

flexion at the proximal interphalangeal joint when the metacarpopbalangeal jointextended. At surgery, full passive motion was restored to the proximal interphalangeal

~ lacerated flexor profundus tendon was pulled distally (Figs. 5-A and 5-B).4. Several months following amputation at the neck of the middle phalanx of thea twenty-one-year-old student complained of limited flexion of the proximal inter-

The joint flexed 45 degrees passiw~ly when the metacarpopbalangeal joint wasand 100 degrees when it was flexed. At surgery, the radial lateral band was divided,

pull of the retracted iumbrical muscle on the proximal interphalangeal joint. Fullwas restored (Figs. 6-A and 6-B).

Plus after a Loosely Inserted Tendon Graft

flexor tendon graft is inserted too lo, osely, the profundus-lumbrical unit isat. When the patient attempts to flex the interphalangeal joints of the in-

contraction of the profundus muscle belly will be transmitted to theband rather than to the graft (Fig. 3,*0. The metacarpophalangeal joint

flex; the interphalangeal joints wil!l exl:end. Either the tendon graft mustor the radial lateral band resected.

NO. 7, OCTOBER 1971

1 3 1 6R.J. SMITH :

FtG. 4--AFtc,. a- BFig. 4-A: Following laceration of the flexor profundus tendon in the finger, there s

of passive proximal interphalangeal joint flexion when the metacarpophalangeal joint isextended. ¯

Fig. 4-B: The radial lateral band is transected at the neck of the proximal Phalanxfull passive proximal interphalangealjoint flexion.

Comracture of the Lumbr~cal Jbllowing its Imbrication abou~ a PaltnarSuture Line with Tendon Grafts

In performing a tendon graft, the lumbrical muscle is often imbricatedthe palmar tendon suture line: so as to prevent adhesions of the graft to the skin

adjacent tendons as. However. if the lumbrical muscle belly is sutured too tightly.fibers may become fibrotic ancl contracted. If care is not taken to advance the luredcal distally at the time of its imbrication, there will be increased tension on thelateral band (Fig. 3,C). In either case, the radial lateral band may be resected store proximal interphalangeal joint flexion.

Intrinsic Contracmre following Tendon Transfer and Tenodesis

Many methods of tenodesis and tendon transfer have been recomn|endedthe treatmem of the paralytic claw hand 4~ The transferred tendon is passedto the deep transverse metacarpal ligament and sutured to a lateral band in eachthe clawed fingers. With each of these procedures, there is a potential risk of

correcting the deformity and creating an intrinsic-plus hand.

FIG.Laceration of flexor digitoram profundus and superficialis. Proximal traction on ti~e

profundus, as would occur with acti~ e attempts at inter ha " ¯cal proximally and limits nassiw .... ;~, ; ....... p , !a.ng.e~al jgmt flexion, pulis the

~ , ~ r.F~.,~,~a~ mt~qonalangeal JOlllt Ilexlon.

THE JOURNAL. OF BONE AND JOI N’r

"! NON-ISCHEMIC CONTRACTURES OF THE INTRINSIC MUSCLES 1 3 1 7

FIG. 4-Bn the finger, there is:arpophalangeal joint is

the proximal phalanx allowii

~ FIG. 5-B)n about a Palmar "[>n&ut ~:::.i !i ’~ ’ ,Wl~en the profundus tendon is pulled distally, relaxing the lumbrical, passive proximal inter-~[;~i:~’ ~2 i-i! :~,llmgeal joint flexion is increased.is often imbricated about:):;?~,:~.~!! ~

)f the graft to the skin and.~..~i,i~i:¢.,,y is sutured too tightly,~en to advance the lumbri~:.’ased tension on the radi~i~nd may be resccted to re.

,desis

e been recommendeded tendon is passed, a lateral band in eachs a potential risk of or{t. F~G. 6-A

,:,After an amputation through the neck of the middle phalanx of the index finger there is,limited proximal interphalangeal-joint flexion when the metacarpophalangeal joint is held ex-~nded.

)ximal traction on the cutint flexion, pulls the lumbri-

BONE AND JOINT SURGERY

Fto. 6-BWhen the metacarpophalangeal joint is flexed, relaxing the retracted lumbrical, there is full

I~rOximal interphalangeal-joint flexion.

~OL. 53-A. NO. 7. OCTOBER i971

1318 R. J. SMITH

FIG. 7-AA fifteen-year-old boy with Chm;cot-Marie-Tooth disease had clawing of the index finger du,

to intrinsic-muscle weakness.

FIG. 7-BSix months after transfer of flexor superficialis to the lateral band the patient is unable tn flex

the proximal interphalangeal joint. The clawed finger has been overcorrected.

The incidence of overcorrection and swan-neck deformity is probably greatestfollowing the Bunnell superficialis tendon transfer, particularly in patients withmarked laxity of the proximal interphalangeal joints. Overcorrection often may beavoided by transferring one superficialis tendon to several fingers. Hmvever, it" hfpcr-

extension of the proximal interphalangeal joint does develop after tenodcsis ortendon transfer for a claw hand. the intrinsic contracture may be corrected by tran-sccting the lateral band just distal to the site of tendon suture and proximal to theproximal i nterphalangeal joint. The transferred tendon will then act through the trans-verse fibers of the dorsal apparatus (Fig. I.C) to flex the metacarpophalangeal jointand thus prevent metacarpophalangeal-joint hyperextension. The transferred tendonwill serve as an active metacarpophalangeal joint knuckle bender. With hypercxten-sion of the metacarpophalangeal joint prevented, the central slip of the common ex-tensor tendon (Fig. I,E) will be able to extend the proximal interphalangeal joint z.

CASE 5. A fifteen-year-old boy with Charcot-Marie-Tooth disease had severe weakness ofthe intrinsic muscles of the index finger. The metacarpophalangeal join! hyperextended: theproximal interphalangeal joint had limited active extension. At surgery the superficialis tendonof the index finger was transferred to the radial lateral band after the method of Bunnell. Over-correction resulted, and he was unable to flex the proximal interphalangeal joint postoperatively.Six months later, under local anesthesia, the lateral band was transected just distal to the site oftendon transfer, restoring flexion of the interphalangeal joint IFigs. 7-A through 7-Dl.

THE JOURNAD OF BONE AND JOINT SURGERY

NON-ISCHEMIC CONTRACTURES OF THE INTRINSIC MUSCLES 1 3 1 9

lawing of the index finger due

the patient is nnable to~)rrected.

nity is probablymlarly in patients withcorrection often may ~ egets. However, if hypcr.elop after tenodesisay be corrected by’ tra~b~~re and proximal to theen act through the trans~

tacarpophalangeat join!The transferred tendon

’rider. With hyperexten.slip of the common c>nterphalangeal ioint e,

~se had severe weakness ofjoint hyperex~cndcd; the

ry the superficialis tendo~ ?method of Bunncll. Over"~

~geal joint postoperatively,ed just distal to the site ofthrough 7-D).

7)NE AND JOINT SURGERY

FIG. 7-C~[’lle radial lateral band is transected just distal to the site of tendon transfer. Twenty degrees

extension has been lost.

FIG. 7-]D

Flexion now is possible to 80 degrees.

Transfer of the tendon of the first dorsal interosseus muscle to the radial sidethe tong finger has been recommended to increase the power of pinch following

mtputation of the index ray 4~. If the transferred tendon is inserted to the base oftfie proximal phalanx, radial abduction of the long finger is strengthened. However,ff the tendon is sutured to the radial lateral band of the long finger, flexion of the

proximal interphalangeal joint may be I mited Its m "tletach~n~: the tra sferro,4 ,__.a - ,. , . otto.ns may be restored either by

: . ~ 7 n ...... u tcnuon or Oy (llVIO ng the radial lateral band distal to the:~evel or the tendon suture.

,h,trinsic Contracture Following Edema of th,. Hand

Intrinsic Contracture without Swan-.Neck Deformity Following Edema

.... Edema tbllowing fractures or blunt trauma about the hand and wrist is among

more common causes of contracture of the intrinsic muscles of the hand. Someon of motion of the interphalangeal joints is expected during the early post-

: traUmatic period, due to edema within the joints and para-articular tissues. As thesubsides, the patient may continue to notice the restriction. The true nature ofihe intrinsic contracture may be overlooked and the finger stiffness may be misdiag-

7, OCTOBER 1971

1320 R. J. SMITH

nosed as residual synovitis. The nature of the intrinsic contracture may Vary, butis usually the result of fibrosis or adhesions about the interosseus muscles or

tendons, if the extensor apparatus is not adherent to the proximal phalanx, thetrinsic tightness test is positive. The lateral bands and oblique fibers to each sid~the involved fingers are excised (Fig. I,H and 1) and passive motion is enco~

immediately postoperatively. In these cases it is unnecessary and probably unwisetransect the transverse fibers of the dorsal apparatus (Fig. l,C)which serve the metacarpophalangeal joint :/,~

CASe 6. A fifty-four-year-old beautician noted continued stiffness of the proximalphalangeal joints of all fingers eight months after treatment for a Colles fracture. The intri~tightness test was positive. The lateral bands and oblique fibers of the four fingers were resecl(Fig. 8). Full motion was restored.

Fro. 8Eight months after closed reduction for Colles’ fracture, a fifty-four-year-old woman noted ~continued stiffness of the proximal interphalangeal joints of the fingers. At surgery, ~he lateral

.bands and their oblique fibers were excised at both sides of each finger. (As shown herc, just therelewradial side has been operated on). Two ~nonths after operation there was excellent joint motion,

i lange

Intrinsic. Contracture with Swan-Neck Deformity Following Edema

At the metacarpophalangeal joints of the fingers, the collateral ligaments

(metacarpophalangeal ligaments) are dorsal to the axes of joint motion. The collater-al ligaments are thus stretched witlq flexion of the joints, and relaxed with extension.

THE JOURNAL ~)F’t}~NE AND JOINT SURGERY

ontracture lllay vary,aterosseus nm~sclcs or

proximal phalanx, the~lique fibers to each side~sive motion is encour~ry and probably unwg. 1,C)’which serve to

tiffness of the proximalColles fracture. Thethe four fingers were

NON-ISCHEMIC CONTRACTURE,S OF THE INTRINSIC MUSCLES 132 I

~he structure of the proximal interphalangeal joints, however, does not followpattern ’~6. The shape of the ihead of the proximal phalanx is such that theligaments are stretched to a maximum with mild flexion of the proximal

:eal joint. With long-standing contracture of the intrinsic muscles, thephalanx gradually assumes a position of hyperextension. In this position the

dorsal fibers of the collateral ligaments adapt to their shortened posit’ion andThe volar plate is stretched 4,~0. The intrinsic tightness test frequently can-

evaluated accurately because secondary contracture of the collateral ligaments~not permit flexion of the proximail interphalangeal joint. In these cases, release

tteral bands alone will not correct the deformity. After release of the intrinsicthe middle phalanx will snap from hyperextension to acute flexion as it is

y and volarly over the head of the proximal phalanx 4. In addition toof the insertion of the intrinsic muscle, the collateral ligaments of the proxi-

phalangeal joint must be excised t5

mr-year-old woman~’rs. At surgery,I-. (As shown hcic, just~s excellent.ioi~t

ing E’cte**ta

e collateral ligamcn~,~’,t motion. Theelaxed with

}NE AND JOINT

Ft(;. an intrinsic tenodesis, the lateral band, with its oblique fibers, is separated from

slip and triangular ligament and is freed distally. It is then transferred beneath

and sutured to the fibrous sheath opposite the middle of the proximal

’,To prevent recurrent hyperextension deformity after capsulectomy and intrinsicand to stabilize both the lateral and the, volar sides of the proximal interpha-

Littler has recommended tenodes.is of the lateral band volar to the axisof the proximal interphalangeal joint. The lateral band is transected at

third of the proximal phalanx (Fig. I,C) and is separated medially fromslip and triangular ligaments to the distal end of the middle phalanx. It is

volar to the axis of motion of the proximal interphalangeal joint volarligament ~4,3,) (Fig. 9). The tendort is then sutured to the fibrous flexor-

7, OCTOBER 1971

1322 R. J. SMITH

Fro. 10This patient with rheumatoid disease of ooth hands is attempting to flex all fingers. All

fingers of the right hand and the index finger of the left hand are dislocated at the metac;pha[angeal joints. The dislocation relaxes the interosseus tendons, allowing proximaiphalangeal-joint flexion The ulnar three fingers of the left hand are not dislocated at thecarpophalangeal joints. The intrinsic mechanism remains tighl and she is unable toproximal interphalangeal joints.

tendon sheath opposite the base of the proximal phalanx so as to hold theinterphalangeal joint in abou,E 30 degrees of flexion. The transferred and tenlateral band thus has a course and function similar to the oblique ret~nacular(Fig. 1,G). Flexion exercises are begun immediately postoperatively. Fullinterphalangeal joint extension is prevented by the use of a dorsal splint fk)r foursix weeks.

CASE 7. A fifty-one-year-old man twisted his right hand in the steering wheel of a earyear previously. There were neither fractures nor dislocations but the hand became quite swolle.and swan-neck deformities gradually developed in the long and ring fingers. All fingers hadited proximal interphalangeal joint flexion when the metacarpophalangeal joints were heldtended tpositive intrinsic tightness test:. There was full metacarpophalangeal-joint motion.lateral bands and oblique fibers (Fig. 1.H and 1~ at each side of the index and little finge~

FIG. 1 1-A Fro. 1 1-BFig. 1 I-A: There are swan-neck deformities at the proximal interphalan~eal joints of each

the fingers in this sixty-two-year-o d woman with rheumatoid arthritis. ~Fig. 1 I-B: Flexion occurs only at the metacarpophalangeal and distal interphalangeal joints.

There are fixed extension contractures at the proximal interphalangeal joints,

THE JOURNAL OF BONE AND JOINT ~uRGER¥,

tie INTRINSIC MUSCLESI 323 ’

~ flex all fingers.ocated at the me~allowingt d~slocated at th

~he is unab!c

s to hold the proxi~

sferred and tenod{*e retinacular

atively. Full proxim~rsal splint for fou

:ering wheel of a carnd became quite;ers. All fingers fiad;eal joints were field~ngeal-joint motion:index and little

ngeal joints of each

interphalangea[ jointsts.

AND

F~G. 1 1-Crams of both hands reveal the deformities at the proximal interphalangeal joints.

°; no metacarpophalangeal-joint subluxation or gross destruction of the joint surfaces.

In the long and ring fingers, the collateral ligaments of the proximal interpha-and the ulnar lateral bands were resected. The radial lateral bands were transferred

Cleland’s ligament and tenodesed to the fibrous flexor sheath. Full flexion was restored.

tee flexion contracture of the proximal interghalangeal joints of the tenodesed long~ersisted.

Spasticity

Cerebral palsy, cerebrovascular accidems, Parkinson’s disease, encephalitis, and

upper motor neuron lesions all may cause spasticity of the interosseustotal management of these patients is complex. Complete neurological

evaluation of the patient, analysis of his needs, of the sensibility of hisand of the status of the extrinsic muscles all must be thoroughly considered

any surgery. In properly selected cases, however, correction of the deform-

improved function may be achieved by tenotomy of the lateral bands, ten-

lateral bands, or tenodesis of the superficialis tendon ,49 across the prox-

geal joint. If there is detbrmity at both the proximal interphalangeal

pophalangeal joints, surgical release must be performed proximal to the

p@halangeal joint. Interosseus tenotomy at the metacarpal neck or ulnary may lead to overcorrection and postoperative clawing by completely elim-

mterosseus muscle function. Stripping the interosseus nmscles t?om theirorigin and allowing them to slide distally was proposed by Bunnell 9, ~0

~seus muscles damaged by ischemia but still thnctioning. This procedure

found useful in some cases of interosseus muscle spasticity. By recessingins of the interosseus muscles distally, the fbrce of these muscles on both the

and proximal interphalangeal joints is lessened but not elimi-The deformity may thus be corrected without total loss of interosseus muscle

Cas~ 8. A fifty-four-year-old housewife had undergone surgery for a cerebral aneurysmyears previously. She remained with a left spastic hemiplegia. Sensation to the left hand was

fingers were held flexed at the metacarpophalangeal joints and hyperextended at theinterphalangeal joints. Function was most awkward in that she was unable to sufficient-

NO. 7, OCTOBER 1971

1324R. d. SMITH

Fro. I 1-DThrough an ulnar digital incision the lateral bands are seen to be dislocated dorsal

FtG. I l-EThe ulnar lateral band is separated from the central slip and trmngular ligament, transferredvolarward Eo Cleland’s ligament, and sutured to the fibrous sheath.

ly open the hand at the metacarpophalangeal "oints.

dfffic.ulty m curhng her fingers at th inter ,ge.r.objects w~thin her palm. She~ ~arev~ palm. The hand was virtually useless T2rnig2~ "’ J~,.nts for grasp, once an objectiul ar n inte block at the wr;~* ..... ,,~.~ . . " .~ ¯ . , ¯ c t~g/~tness test was negative. An.... ~ -~u,tcu m SEgnmcant out temporary improvement of the deform-~ty. At surgery, the interosseus muscles were dissected from the metacarpal shafts subperiostialty.

The hand was splinted in a clawed position for two weeks Postoperatively both the functionand appearance of the hand were improved. ,

R/wumatoid Intrinsic Contractures

Intrinsic muscle tightness has long been noted in many rheumatoid hands a. Thecauses are unclear ta, tg, zt.4~. Bywaters noted perivascular infiltration within the in-terossei which suggested inflammatory spasm of these muscles. Kestler noted fibrosisand increased collagenization in the interosseus muscle fibers. Brewerton stated that

in those rheumatoid patients with intrinsic-plus deformities, spasm accounts for the

interosseus shortening in the: first three years of the disease, and thereafter thesemuscles become fibrotic~

Although Amick and others aa, a

~ to be dislocated dorsally.

riangular ligament,

NON-ISCHEMIC CONTRACTI2IRES OF THE INTRINSIC MUSCLES 1325

FIG. 1 I-FI"1~¢ radial lateral band is transected along with its oblique fibers. The transverse fibers ofulnar lateral band are also sectioned. The finger immediately adopts a more natural position

~l’l~}t.h t, he me,ta.c.arpo.pha, langeal and, !nterphalangeal joints. The flexion deformity at the distal.Ifitelptlalangem jo mrs is also correctea Dy the lateral band tenodesis

¯ objects within her palm. She~ints for grasp, once an objeclightness test was negative. Any improvement of the deform-:tacarpal shafts subperiostially.operatively, both the function

~y rheumatoid hands a. The=- infiltration within the~cles. Kestler noted fibrosis~ers. Brewerton stated thates, spasm accounts for theease, and thereafter these

to find electrombographic

)F BONE AND JOINT SURGERY

FIG. 1 I-GFlexion compared in the right hand (operated on) and the left hand I not operated on). Both

~nds were symmetrically involved preoperatively.

¢ ~dence of spontaneous actlwty m the interossei of rheumatoid hands, electromyo-graphic and histological changes have been noted in these muscles by several~orkers. Boyes had suggested that intrinsic muscle changes in the rheumatoid handmay be secondary to the deformity of the metacarpophalangeal joints. Brewertonnoted intrinsic muscle contracture of the hand in 13 per cent of 300 ambulatorypatients with rheumatoid disease wholn he examined, and in 48 per cent of all those~vith ulnar deviation.

The location and severity of the intrinsic tightness in the rheumatoid hand ismost variable. It may be dependent on the age of the patient, the duration and

,~everity of the disease, the integrity or degree of destruction of the joint capsule and~trticular surfaces of the involved hand. or on the use of the hand. Atrophy of theinterossei, however, appears to bear no relationship to the deformities 4~

Several points regarding the metacarpophalangeal joints of the fingers in therheumatoid hand bear emphasis:

VOL. 53-A, NO. 7, OCTOBER 1971 ......

1326 R. 3. SMITH

1. If there is any imbalance of forces in the sagittal plane of the mctac~phalangeal joint the predominant force is directed volarward 42,4a.

2. The proximal phalanx will not dislocate or subluxate dorsally in the no:course of the disease :1;

3. Synovitis within the metacarpophalangeal joint may weaken the collarligaments and decrease their stabilizing effect on the proximal phalanx 4a, thus a:ivolar force at the joint would tend to cause subluxation of the proximaltoward the palm rather than flexion about an axis of rotation 4.2.

4. The interosseus 1nuscle to the ulnar side of each finger is usuallythan that to the radial side: of the finger.

Rheumatoid intrinsic contractures of the fingers may be classifiedfollows:

Limited Flexion of t,~e F’roximal lnterphalangeal Joint with Extension qf theMetacarpophalangeal Joint; No Def.ormity

This is the mildest type of rheumatoid intrinsic contracture and clinically apears similar to the early no,n-rheumatoid intrinsic contracture. The treatment,however, is somewhat different. The lateral band to the ulnar side of each finger isexcised along with the obl:ique and transverse fibers (Fig. I,H,I, and C. The trans-verse fibers are excised in order to decrease the probability of volar subluxation ofthe metacarpophalangeal joints later in the course of the disease. Riordan and Harrishave warned against excising ~!hese fibers in the non-rheumatoid hand for fear ofsubsequent hyperextension def3rmity at the metacarpophalangeal joints. This pre-caution appears unnecessary in the rheumatoid hand, since the resultant of forces atthis joint is directed volarward.

Hyperextension Contracture of the Proximal lnterpkalangeal Joint; No Meta-carpophalangeal-Joint Changes

In the rheumatoid hand, if stability at the metacarpophalangeal joint has beenweakened by synovitis and collateral ligament attenuation, the proximal phalanxwill respond to a volar-directed force by subluxating ~ rather than flexing about anaxis of motion. If the joint dislocates completely, the proximal phalanx will alsotend to migrate proximally. With proximal displacement of the finger, the interosseusmuscles are relaxed 5, and proximal interphalangeal joint motion is usually pre-served. If, however, the metacarpophalangeal joints remain stable and do not sub-luxate, the force of any intrinsic-muscle contraction will be transmitted to the proxi-mal interphalangeal joint, which may then gradually hyperextend into a swan-neckdeformity (Fig. 10).

In these cases, surgery at the proximal interphalangeal joint requires release ofboth lateral bands, capsulectomy, and tenodesis as in intrinsic contracture with swan-neck deformity following edema of the hand. At the metacarpophalangeal joints,the transverse fibers of the :intrinsic apparatus (Fig. I,C) should be sectioned ~.~ prevent volar subluxation as described in the section immediately previous (Figs. 11-A through 1 l-G).

Volar Subluxation of tke M,etacarpophalangeal Joint Without Ulnar Deviation

To rebalance the forces about the dislocated metacarpophalangeal joint in therheumatoid hand, a diminished volar-directed force at the base of the proximalphalanx is required. Generous resection of the metacarpal head in performingarthroplasty will usually relax the interossei and lumbricals by shortening the dis-tances from their origins to their insertions. However, if a prosthesis is insertedafter metacarpal-head resection, the width of the prosthesis between the bone endsmay sufficiently stretch the contracted intrinsic muscles to require their release.

THE JOURNAL OF BONE AND JOINT SURGERY

Ptt

f~ri

ittal plane of the~ward 42, 43.,luxate dorsally in the

may weaken the colproximal phalanx 4~on of the proximal phal

ationach finger is usually ti

~ers may be classified

Joint with Extension

,ntracture and clir~icallyontracture. The ~rcatment.:ulnar side of each finger

g. l,H,l, and C. The trans,,lity of volar subluxation nt3isease. Riordan and Harri,q,

~eumatoid hand for fear tff,ii~halangeal joints. This prece the resultant of forces at

’halangeal Joint; No Meta,

opbalangeal joint has be~{on, the proximal phalanxlther than flexing about an’roximal phalanx will als,f the finger, the interosseusnt motion is usually pre-tin stable and do not sub-e transmitted to the proxi--’rextend into a swan-neck

11 joint requires release ofsic contracture with swan-

tacarpophalangeal joints,should be sectioned ~’~ totiately previous (Figs. I I-

J/ithout Ulnar Deviation

pophalangeal joint in thehe base of the proximalpal head in performing

by shortening the dis-a prosthesis is inserted

between the bone ends~quire their release.

~ONE AND JOINT

NON-ISCHEMIC CONTRACTURES OF THE INTRINSIC MUSCLES 1327

lateral bands are resected, extension of the interphalangeal joints isthrough contraction of the extensor digitorum communis-~6 In the

ltoid hand, the tendon of the exte, nsor digitorum communis may often beor dislocated. Reconstruction of the rheumatoid hand may require eitherrelocation of the extensor tendon. Occasionally, the surgeon may tenodese

tensor tendon to the base of the proximal phalanx. Under these circumstances,ral band must be allowed to remain intact in order to provide inter-

)int extension. Since the ulnar interosseus is usually tighter than the:us to the radial side of the finger, the ulnar interosseus tendons are excised

ml to the metacarpophalangeal join’~. If the proximal interphalangeal joint isthe ulnar lateral band is tenodesed as in hyperextension contracture

previous section.

FIG. 12-A FIG. 12-BFig. 12-A: With ulnar deviation and volar subluxation of the metacarpophalangeal joints in

lhe rheumatoid hand. the ulnar interossei are tighter than those to the radial side.Fig. 12-B: As a step in the reconstruction of these hands, each of the ulnar interossei is divided

and those of the index, long, and ring fingers are transferred to the radial side of the base of theproximal phalanx of the adjacent finger.

Volar Subluxation of the Metacar.t)ophalangeal Joint With Ulnar Deviation

Volar dislocation of the proximal phalanx in the rheumatoid hand is most fre-quently accompanied by ulnar deviation. The imbalance of forces about the joint~s in both the sagittal and frontal planes. It is unclear whether the intrinsic contrac-tures contribute to. or result from, these deformities. There is no doubt, however,that intrinsic-muscle contractures constitute but one abnormality about a joint whichmay also exhibit abnormalities of bone, synovium, ligaments, and extrinsictendons 47. As previously noted, the proximal interphalangeal joint may not be af-fected by the ~ntrinsic contracture when the proximal phalanx is dislocated and theinterosseous and lumbrical muscles thereby relaxed. With surgical relocation of theproximal phalanx, however, the intrinsic muscles are stretched and limited flexion atthe proximal interphalangea[ joint ensues.

[n an attempt to rebalance the forces about the ulnar-deviated and dislocatedmetacarpophalangeal joint, a radially directed force (or ulnar force in the infrequentevent of radial deviation) can be added by means of the crossed intrinsic trans-fer ~z,~s,~o. The tendons of the interossei to tl~e ulnar sides of the index, long, andring fingers are transected at the proximal phelanx and the proximal ends are trans-

VOL. 53,-A, NO. 7 OCTOBER 1971

1328 R, J. SMITH

FIG. 13-A Fro. 13-B

FIG. 1 3-CFig. 13-A: Preoperative photograph of a rheumatoid hand with ulnar deviation and volar

dislocation of the metacarpophalangealjoints and ulnar intrinsi z tightness.Figs. 13-B and 13-C: The crosse.d intrinsic transfer has been performed at the second and

third and fourth webs. Other reconstructive procedures were performed at the metacarpopha-langeal joints, including synovecto~ay, extensor-tendon relocation, and ulnar collateral-ligamentresection. The postoperative appearance and function of the hand were greatly improved.

ferred to the radial side of’ the adjacent finger. Flatt t8 advised that the transferredinterosseus tendon should be satured to the base of the proximal phalanx midwaybetween the volar and dorsal ;_aspects. The tendons of the flexor digiti qulnti andabductor digiti quinti are transected but not transferred (Figs. 12-A and 12-B~.

It is difficult to be certain that correction of the ulnar deviation in patientsundergoing crossed intrinsic transfer (usually with arthroplasty) is due to activclycontracung transferred interosseus muscles. In the reconstruction of these deformedhands, arthroplasty, relocation of the extensor tendons, and shortening of the meta-carpals may contribute to the correction of the deformity. Postoperatively, however,many patients exhibit strong active radial deviation at the metacarpophalangeal

THE JOURN’~tE OF BONE AND JOINT SURGERY

Fro. 13-B

th ulnar deviation and volat ::5:htness.oerformed at the second and’formed at the metacarpopha.and ulnar collateral-ligamentere greatly improved.

vised that the transferred

roximal phalanx midway .

e flexor digiti quinti and

gs. 12-A and 1 2-B ~.

nat deviation in patients

plasty) is due to actively

uction of these deformed

I shortening of the meta-

’ostoperatively, however,

he metacarpophalangeal

BONE AND JOINT SURGERY

NON-ISCHEMIC CONTRACTURES OF THE INTRINSIC MUSCLES

"IABLE I

NON-I$CHEMIC INTRINSIC MUSCLE CONTRACTURES OF THE HAND

1329

Intrinsic TightnessCause Test Joint Involved Treatment

Fractures or Positive Proximal interphalangeal Remove tumor or bonetumors at spike; resect obliqueproximal fibers and lateral bandphalanx on side of mass, if

necessary

Flexor profundus Positive Proximal interphalangeat Resect oblique fibers andlaceration lateral band on radial

side of proximal phalanxFlexor profundus Positive Proximal interphalangeal Resect oblique fibers and

contraction lateral band on radialtransmitted side of proximal phalanxthrough or tighten graftlumbrical

Lumbrical fibrosis Positive Proximal interphalangeal Resect oblique fibers andlateral band on radialside of proximal phalanx

Excessive Positive Proximal interphalangeal Resect lateral band distaltightness tendon (occasionally to tendon transfertransfer or metacarpophalangeal)tenodesis

brical

ndon

~l~lr stlbluxation,meRlCarpophalan-~Xat joint withulnar deviation

Fractures, blunt Positive Proximal interphalangeal Resect oblique fibers andtrauma or tight

lateral band radial anddressings ulnar sides of each fingerFractures, blunt Usually negative Proximal interphalangeal Resect oblique fibers and

trauma or tight because of lateral band one side ofdressings secondary joint the finger; lateral bandcontracture tenodesis opposite side

of finger; proximalinterphalangeal jointcapsulectomyUpper motor May be positive or Proximal interphalangeal Distal interosseus slideneuron lesions negative with or withoutproximal interphalangealjoint tenodesis

Rheumatoid Positive Proximal interphalangeal Resect lateral band,arthritis transverse and oblique

fibers both sides of finger

Rheumatoid Usually negative Proximal interphalangeal Resect lateral band,arthritis because or transverse and oblique

secondary joint fibers both sides of fingercontracture

Rheumatoid Positive; negative Metacarpophalangeal Resection arthroplasty orarthritis if swan-neck (proximal interphalangeal) prosthetic arthroplasty

deformity at metacarpophalangealproximal joint with resectioninterphalangeal ulnar lateral band atjoint metacarpophalangeal

joint (lateral bandtenodesis and proximalinterphalangealcapsulectomy withswan neck)

Rheumatoid Positive (negative Metacarpophalangeal Crossed intrinsic transferarthritis if swan-neck (proximal interphalan- (also ulnar lateral band

deformity at geal) tenodesis and proximalproximal interphalangealinterphalangeal capsulectomy withjoint) swan neck)

Iomts of fingers where a crossed intrinsic transfer has been performed. Active ulnardeviation of these fingers is lost (Figs. 13-A, 13-B, and 13-C).

Frequently, after crossed intrinsic transfer, there is weakness of extension ofthe proximal interphalangeal joint which may persist for several months, in no case,however, has the patient failed to regain active extension of the proximal inter-phalangeal joint.

DiscussionIncreased tension on the lateral bands of the fingers may affect the inter-

VOL. S3.-A, NO. 7, OCTOBER 1971 . ~. ~

1 330 R.J. SMITI4

phalangeal joints, the metacarpophalangeal joints, or both. The resulting stiff1or deformity of the fingers has been termed intrinsic contracture. Frequently,ever, with intrinsic contracture neither the lumbricals nor the interossei exhi itdence of pathological change. S~Jch imbalance of forces within the fingers may

displacement of the lateral band, injury to the tendon of the flexor digitorumfundus, spasticity of the interossei, or tendon transfers t0 the lateral bands. To

these cases examples of intrinsic contracture is thus a misnomer. The term isestablished, however, and is justified if it is assumed to describe a clinicalwhere the forces of the intrinsic mechanism of the finger overbalance thoseextrinsic muscles.

In the past, ischemia of the interosseus muscle has been noted as a causeintrinsic-muscle contractures. Many other causes of imbalance have been descrThe effects of the imbalance will depend on the integrity of the metacarpophalatand interphalangeal joints, the cause of the contracture, and its duration. Retion of function may involve resection of the ulnar or radial lateral bands, cxcisionithe oblique or transverse fibers of the dorsal apparatus, laleral band tenodcsis.

osseus tendon division or transfer, capsulectomy or arthroplasty.A plan for the diagnosis and the treatment of these deformities has been

sented (Table I).

ReferencesI. AMICK, L. D.: Mnscle Atrophy ir~ Rheumatoid Arthritis: An Electrodiagnostic Study.

Rheumat., 3: 54-63, 1960.2. BACKHOUSE, K. M., and CATTON, W. T.: An Experimental Study of the Functions of

Lumbrical Muscles in the Human Hand. J. Anat., 88: 133-141, 1954.3. BACKHOUSE, K. M.: Mechanical Factors Influencing Normal and Rheumatoid Metacarp~i.!i

phalangeal Joints. Ann. Rheumat. Dis., 28 (Supplement): 15-19, 1969.4. BATE, J. T.: An Operation fi)r the Correction of Locking of the Proximal lnte

Joint of Finger in Hyperextension. J. Bone and Joint Surg., 27:142-144, Jan. 15. BOYES, J. H.: Bunnell’s Surgery of the Hand. Ed. 5, pp. 316-324. Philadelphia, .I.B. Li

cott, 1970.6. BRAITHWAITE, F,; CHANNELL, G. D.; MOORE, F. T.; and WmLLtS, J.: The Applied Anat,

of the Lumbrical and Interosseous Muscles of the Hand. Guy’s Hosp. Rep., 97:1948.

7. BREWeR’rON, D. A.: Hand Deformities in Rheumatoid Disease. Ann. Rheumat.183-197, 1957.

8. BUNNELL, STERLING: Surgery of t~e Intrinsic Mnscles of the Hand Other Than Thoseducing Opposition of the Thumb. J. Bone and Joint Surg., 24: 1-31 Jan. 1942

9. BUNNELL, STERLING; DOHERT~C, E. W.; and CURTIS, R. M.: Ische~ic Contracture.the Hand. Plast. Reconstruct. Surg., 3: 424-433, 1948. Local.

10. BUNNEt,~, S~’ER~INC;: Ischaemic Contracture, Local, in the Hand. J. Bone and Joint3S-A: 88-I01, Jan. 1953.

11. BYWA’rERS, E. G, L.: Pathogenesis of Finger Joint 1,esions in Rheumatoid Arthritis.Rheumat. Dis., 28 (Supplemertt): 5-10, 1969.

12. CAMPBELL, R. D., JR.: Arguments about Indications for Intrinsic Transfer in the RhcunHand. American Society for Surgery of the Hand Correspondence Letters, December1969.

13. CLAWSON. B. J.; NOBt.E.J.F.; and LUFKIN, N. H.: Nodular Inflammatory andLesions of Mu?scles From Four Hundred and Fifty Autopsies. Arch. Pathol., 43:1947.

14. CI.ELAND, J.: On the Cutaneous Ligaments of the Phalanges. J. Anat. Physiol., 12: 526-522~1878.

15. CURTIS, R. M.: Capsulectomy of :he lnterphalangeal Joints of the Fingers. J. BoneJoint Surg., 36-A: 1219-1232, Dec. 1954.

16. EYLER, D. L., and MARKEE, J. E.: "[’he Anatomy and Function of the Intrinsic Musculatureof the Fingers. J. Bone and Jo at Sucg., 36-A: 1-9, 18-20, Jan. 1954.

17. F~NOCHIETTO, R.: Retraccion de Vc.lkmann de Los Musculos lntrinsicos de las Manos. B0~Trab. Soc. Cir. Buenos Aires, 4.: 31-37, 1920.

18. FLATT, A. E.: Crossed Intrinsic Transfers. American Society for Surgery of the Handrespondence Letters, March 16, 197,).

19. FLATT, A. E.: The Care of the Rheumatoid Hand. Ed. -) pp. 35-4") 61-64. St.C. V. Mosby Co., 1968. -’

20. GOLDNER, J. L.: Deformities of the Hand Incidental to Pathological Changes of theand Intrinsic Muscle Mechanisms. J. Bone and Joint Surg., 35-A: 115-131, Jan. 1953.

21. GOLDNER, J. L.: Intrinsic and Extensor Contracture of the Hand due to lschemia andConditions. In Hand Surgery, by J. E. Flynn, pp. 978-992. Baltimore, The WilliamsWilkins Co., 1966.

22. HAINES, R. W.: The Extensor Apparatus of the Finger. J. Anat., 85:251-259, 1951. ’

THE JOURNAl. OF BONE AND

The resul{ing Stil.’ture. Frequently,

.:" interossci exhibit1 the fingers may

-" flexor digitorum

~" lateral bands.whet. The term is

scribe a clinical

erbalance those of

.’n noted as a causec have been clescri:

: metacarpoits duration. Rest/i

oral bands, excision

band tenodcsis, intey.

wnlitics has been pr¢~(

odiagnostic Study. Art1,

of the Functions of

)-heumatoid Metacarlx~

"oximal Interphalan44, Jan. 1945.iladelphia, J. B. Lippir~:i

The Applied Anatom;~osp Rep. 97:

qn. Rheumat. Dis..

)ther Than Those Prn~m. 1942.Contracture, Local.

Bone and Joint Surg(,

matoid Arthritis.

sfer in the RheumatoidLetters, December ~

tory and Degenera,w¯ Pathol., 43: 579-589.

Physiol., 12: 526-52’L

Fingers. J. Bnne and

Intrinsic Musculatur~

’os de las Manos.

;cry of the Hand

61-64. St. l.ouis.

~anges of the IExtens0t31, Jan. 1953¯o Ischemia and othet¯ e, The Williams and

-259, 1951.

AND JOINT SURGER’r

... NON-ISCHEMIC CONTRACTURES OF THE INTRINSIC MUSCLES 1331

E. B.: Anatomy, Injuries and Treatment of the Extensor Apparatus of the Handits. Clin. Orthop., 13: 24-41, 1959.

E. B.: Guidelines to Deep Structures and Dynamics of Intrinsic Muscles of therod. Surg. Clin. North America, 48: 993-1002, 1968.

Kr:STtt’:R, O. C.: Histopathology of the Intrinsic Muscles of the Hand in RheumatoidArthritis: A Clinico-Pathological Study. Ann. Rheumat. Dis., 8: 42-58, 1949.

K.: The Proximal Interphalangeal Joint. Anatomy and Causes of Stiffness iners. J. Bone and Joint Surg., 50-B: 656-663, Ang. 1968.

~"~:, [.ANDSbIEER, J. M. F.: The Anatomy of the Dorsa Aooneura~i- ~" -*- .... ,-:.:~"" ils Functional Significance. Anat. Rec. 104.31-44 ~0a~ ..... ~ ut m~ r~uman elnger and

"i/~;t~mM~a~n~’F]r~ eMr~ ~(~t2n, at°.mi_ca.l.~a~d ,F~nctior~afl’£~,estigations on the Articulations of~:’ 7 ’ihe Hum g . ~nat., z,t CSupp~ement), 1 ?55.:’~, LIPSCOMB, P. R.: Surgery of the Arthritic Hand; Sterling Bunnell Memoria Lecture M

’ Clin. Proc.. 40: 132-164, 1965. ¯ ayo~ Lt-r’r~g, J. W.: R. esto~ration of the Ob ique Retinacular Ligament for Correctln Hyper-

extension Deformity ot the Proximal Internhalan-eal J-: ...... - ~- .’. gdede la Main P ’ . ~ ~, v, mt. L~ lVlaln Kneumatolae Grouped’Etu . ar~s, Expansmn Scientifique Fran~aise, 1969.

3f( MeAGUER, S. W.: Tengtomy of the Lateral Bands. American Society for Sur,er of: " Hand Correspondence getters November 28 107n g y the:~2 MILFORD, L. W" Retaining Eigaments of ti;e ]5~", ~ ¯"J" "" ~ gr:s oI me Hand; Gross and Microscopic

Anatomic Study, p. 31. Philadelphia g~.. B Saunder,. lOt~,~L Mom’rz, U Electromyograpbic s{udi£s" in Aduli" g"""

,~andinavica, 6(Supplement): 1-123 1963 Kneumatoid Arthritis. Acta Rheum.

ti~., MOBRISO~, L. R; SHORT, C. L.; LUDWIG, A. O.; and SCHWAB, R. S.: The Neuromuscular~S~,,stem in Rheumatoid Arthritis. Electromyographic and Histologic Observations Am JMed. Sci.. 214: 33-49, 1947. ¯ ¯ ¯

!t:~; Mt~EL~.e~ E. E., and MEAD, SEDGWmK: The Electromyogram in Rheumatoid Arthritis.’ Am.J. Phys. Med., 31: 67-73, 1952.~ Pt,~K~S, A. R.: Traumatic lschaemia of Peripheral Nerves With Some Observations on;’" Volkmann’s Ischaemic Contracture. British J S ~rg., .32:403-414, 1945.~, PARKES, A. R.: The "Lumbrical Plus’ Finger J Bone and Joint Surg., S3-B: 236-239, Ma

1971. " ’ y,~]~, PULVERTAFT, R. G.: The Treatment of Profundus Division by Free Tendon Graft. J. Bone

and Joint Surg., 42-A: 1363-1371 Dec. 1960}9. RIORDAN D C and HARRIS CRAMPTON, JR.: Intrinsic Contracture in the Hand and itsi Surgical Treatment. J. Bone and Joint Surg. 36-A: 10-20 Jan. 1954.

",{~ RIORDAN, D. C.: Surgery of the Paralytic ~and Instructional Course Lectures, The Ameri-¯ ~an Academy of Orthopaedic Surgeons, Vol. i.6, pp. 79-90. St. Louis, The C. V. Mosby

i : Co. 1959.gh SI.OCVM, D. B.: Amputations of the Fingers and the Hand. Clin. Orthop., 15: 35-59, 1959.~ SMITH. E. M.; JUVINALL, R. C.; BENDER, L. F.; and PEARSON, J. R.: Role of the Finger

: Flexors in Rheumatoid Deformities of the Metacarpophalangeal Joints. Arth. Rheumat., 7:ii ¯ 467-480, 1964.

,~ SMtTU. R. J., and KAPLAN, E. B.: Rheumatoid Deformities at the MetacarpophalangealJoints of the Fingers. A Correlative Study of Anatomy and Pathology J Bone and JointSurg., 49-A: 31-47 Jan. 1967

.t0~. STAcg, H G.: Muscle Function in the Fingers; J Bone and Joint Surg.Nov. 1962. , 44-B: 899-909,

~; STE~N8ERG, V. L., and WYNN PARRY, C. B.: Electromyographic Changes in Rheumatoid Arthri-tis. British Med. J., 1: 630-632, 1961.STRANDBERG, V.: The Frequency of Myopathy in Patients with Rheumatoid ArthritisTreated with Triamcinolone. Acta Rheum. Scandinavica, 8:31-44, 1962.

47, STRAUB L. R " The Rheumatoid Hand. Clin. Orthon., 15:127-13

" ’ "" : " ~ " " ’ " and

41l ~u~m~~r~c~a~uSs~e~s.e~mT.h~. ~i~.?~,.~flt~_2E0x~,e~l;~.Dlgltorum ~;lmgm59unis’ Interosseous

4~. SWaNsoN, A. B.: Surgery of the Hand in Cerebral Palsy and the Swan-Neck Deformity. J.Bone and Joint Surg. 42-A: 951-964, Sept. 1960.

~0, WOZNY. WOJCteCH, ~’nd LONG, C~Ag~ES, Ih Electromyographic Kinesiology of the Rheuma-toid Hand_ Arch. Phys. Med. Rehab., 47: 699-704, 1966.

.~I, EDUA~DO: Contractura Isquemica Local. Prensa M6d. Argentina, 4~: 2714-2718I959. ,52.ZANCoe~|. EDUAaOO: Structural and Dynamic Bases of Hand Surgery, pp. 136-154. Philadel-phia, J. B. L ippincott, 1968.

~"OL.53-A, NO. 7, OCTOBER 1971