THE DIAGNOSIS OF MENISCUS INJURIES

SOME NEW CLINICAL METHODS

BY A. GRAHAM APLEY, F.R.C.S., PORTSMOUTH, ENGLAND

INTRODUCTION

In the year 1803, William Hey of Leeds wrote of a condition which he termed internalderangement of the knee. This was not a clear-cut entity, but it did include the first,somewhat vague, description of locking ; and Hey suggested that locking might be due toa meniscus lesion. However, as he treated his patients by manipulation alone, direct con-firmation was not obtainable. The literature records hardly any progress in diagnosis foralmost one imundred years, but the succeeding twenty or so years contain a galaxy ofgreat names.

First. Sir Robert Jones and later DArcy Power, Martin, and Morison recorded theresults of numerous meniscectomies, and focused attention on the longitudinal split as theprimary lesion. Thmen, in 1924, Bristow1 opened a discussion on internal derangement ofthe knee at a meeting of The British Orthopaedic Association; and since that time Bristow2,Platt5, McMurray, and others have described large series of cases of knee injury, withcareful analyses of timeir findings. Despite the meticulous work in all these series, onefeature stands out,-namely, the high proportion of cases in which no meniscus split wasseen at operation. Sir Robert Jones quotes a figure of 10 per cent., while Bristow foundthat in 30 per cent. of hmis cases there was no split, this proportion including many normaland hypermobile menisci.

Many attempts at an explanation have been made, but as recently as 1930 Platt wasdriven to conclude that this group remained an enigma. However, by this time the rotationsprain of the knee, in which the attachments of the medial meniscus to the tibia, capsule,or tibial collateral ligament were damaged, had also been described ; and various authorshad already emphasized time difficulty in distinguishing a rotation sprain from a splitmeniscus.

With all these advances, two notable gaps remain: first, the absence of any constantand reliable pathognomonic sign for a split meniscus ; and, second, the difficulty of differ-entiating a split meniscus from a rotation sprain. The purpose of this paper is to describesome methods which aim at filling these gaps.

THE CAUSAL FORCE IN MENISCUS DAMAGE

The causal force in meniscus damage is clearly recognized. With the knee flexed andbearing weight, a twist occurs. Since the meniscus is fixed between the tibial and femoralcondyles, if excessive rotation takes place, something must give way. Sometimes thisgrinding force splits the substance of the meniscus, and from this primary tear secondaryextensions may occur, producing the different varieties of torn meniscus. Precisely thesame force may, instead, wrench the meniscus away from some of its peripheral attach-ments, thus producing the so-called rotation sprain. It is quite true that weight-bearing(and therefore a grinding force) is essential in the production of a split in the meniscus,

whereas it need not be present for a rotation sprain to occur. The important point, how-ever, is that the selfsame force may, on occasion, produce either type of injury; andtherefore time history may not help in differentiation.

* Read at the Spring Meeting of The British Orthopaedic Association, Newcastie-upon-Tyne,May 1946.

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FIG. 1 FIG. 2Distraction of time knee. Compression of time knee.

TIlE PRESENT METHODS OF EXAMINATION FOR MENISCUS INJURY

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VOL. 29, NO. 1, JANUARY 1947

Time roost iimmportant feature in time present-day nmetimod of exanmination for a immeniscusinjury is iotation of the tibia, while time knee is held in varying degrees of flexion, as, forexaimmphe, in McMurrays test. Timis imianoeuvre is calculated to displace a nmeniscal frag-nment anti to produce time well-known click, which is palpable, constant in position, andiecognizeti by time patient.. Togethmer withm time hmistory (whicim, although of time hmiglmest im-l)oltance, is Imot ticalt withm in thmis paper) ,a (iiagnosis can usually he immade. All too often,imowever, signs aic absent, anti there seem to be three disadvantages in thmis nmetimod ofcxanminatioim:

1. A chick is not a truly reliable sign. Its cause may lie in a different knee injui-y orin a diffeieimt joint entirely. Many surgeons fail to find it at all, altimougim McMui-raytieclares that time diagnostic click is reliably constant in hmis personal cases.

2. Time ioutine method of testing by rotation nmust necessarily pull on thmose tissuestianmage(I in ti Iotatiolm sprain, so producing extraneous pain. Timus, in time very process oftestilmg fot- a nielmiscus injury, time surgeon immy actively confuse time picture.

3. Time timir(i tiisadvantage, as Platt imas eimmphmasized, is that time present immethmotl isbased u0im unstable imiechanics. With time patient lying on his back anti the sui-geoimexaimminiimg imis knee, thmeie are two fixed points,-time pelvis, whichm rests on time bed, armd timeaimkle, imeki in time surgeons hmand. Between these two, the long connecting levers ()f timet.hmigii anti time leg are unstable, and are not aticquately steadied by the surgeons imand.

A THEORETICAL SOLUTION

Flonm time foiegoing paragraphms it is evhient timat, in the examination of time knee, weare (healing with a confused problenm of mechanics. To solve timis problenm, it must beresolved into its tiistinct components. First, stabilization of time levers can be accoimm-phisimeti by haying time patient on his face and fixing his femur in a way wimicim will betiescribeti later. Second, to effect a diagnostic separation between meniscus and soft tissues,time application of a longitudinal stress is required. This stress simoulti, alternately, be aseparating (or distracting) force, and a compressing force; and timese two types of longi-tutiinal stress simould be capable of easy application.

FIG. 3

Rot at iorm of i o timknees--i miehi rimmary rmmanoeu vre.

11G. 4 FIG. 5Rotatioim alone. Time (list ra-tiomm test.

80 A. G. APLEY

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(Time various illustrations epito-immize bothm time theoretical argumentsand time I)ractiCal tests. These testsare easy to tiemonstrate in time pa-tient, but less so in print..)

Figure 1 shmows time timeoreticalresult of applying separation or dis-traction to time knee. Clearly , timesoft tissues are being stretcimed,wimile time immeniscus renmains uimdis-turbed. (For snmml)hicitv. Ofll timetibial collateral higammment is simown intime (hagranm, iMit time coronary fibersand time capsule must un(ieig() sinmi-har stretciming. 1 A test based oim thmisfact is, thmerefore, a test of time soft

tissues (higanmentous, fibrous, andcapsular I an(i of timese alone. 4uchmtt test would be positive in a rotation

sprain.Figure 2 illustrates time basis for

a compression test. Here time soft

tissues are clearly relaxed, but timenmeniscus itself is beiimg ci-ushmeti. In this position, in addition to time conmpression ah-eadv

produceti, rotatiolm can be addeti. Timis combination of conmpression and rotation consti-tutes a grinding force wimicim is an accurate reprotluction of time original (iestructive lot-ce

THE DIAt;NOSIS OF MENISCUS INJURIES 81

VOL. 29. NO. 1, JANUARY 1947

in nieniscus daimmage, so timat a positive grinding test 1)oiflts unequivocally to immeniscus injury.Expressed in timese siiimpie ternms, time two manoeuvres of coimmpression and distraction

forimm the basis of time proposed tests to fulfill time requireimments previously put forward.It renmains to translate timese theoretical considerations into practice; and, to do timis, a

posterior Immetimo(i of examination is employed.

THE POSTERIOR EXAMINATION OF THE KNEE

For timis exanmination time patient lies on imis face. He simould be on a coucim imot immorethman two feet. Imigim, or time tests beconme difficult, and he nmust l)e well over to time edge oftime coucim nearest time surgeon. Tostart time exaimmination, time surgeongras)s one foot in eacim imand, exter-nally rotates as fat- as l)ossibie, andtimen flexes i)Otim knees togetimer totimeir linmit t Fig. 3 . \Vimen timis iiimmitimas been i-eacimed, lie cimanges imisgras), iotttes time feet inward, antieXtelmds time knees togetimer again.Fimis l)rehilmminaly imianoeuvie tieimion-strates hiimmited iotation, I)ainful ro-tation, an(1 time exact angles of flex-ion at wimicim these occur ; time estiimma-tioim of timese angles i)rves usefullater in time exaimmination.

Time surgeon timen applies his leftknee to time back of time patientstimigim ( Fig. 4 ) . It is ilmmi)oltant to 01)-serve timat in timis position imis weighmtfixes Ofl( of time levers ai)solUtClv.Time foot is grasped in botim imantis,time ktmee is bent to a right angle, and

i)o\\erful external rotation is apphie(i. FI(m. 6Timis test deternmines wimetimer siimml)le Time grinding test.I( )t Itt ioim l)Ioduces l)ain.

Next, WithOUt chmalmgilmg time position of time hands, time i)atielmts leg is strongly l)uhiedUl)\itI(I, vhmile time surgeons weigimt preents time femur froimm rising off time couch t Fig. 5in timis position of (histraction, time peiful external rotation is repeated. Two timings cani)t (ietellmmine(i : I ) vimetimer ot not time immanoeuvre produces pain and 2 ) , stiil ]1t0Ft iimm-i)ortant., vimethmei time pain is greatel timan in rotation alone without time distractiotm. If timel)itiim is gieatei, the tiisti-action test is positive, anti a rotation sprain nmay l)e tiiagnosed.

Thmen the surgeon icalms \Vehl over time h)atient anti, witim imis wimole body weigimt, coimm-resses time tii)itt (iownwar(.i olmto time couchm (Fig. 6) . Again hme rotates l)owel-fuhhy, IIIm(iagain ime asks tWo questions: ( 1 ) Does it imurt.? (2) How immucim (toes it imurt? If timeadditiolm t)f coimmplessiolm imas i)ioduce(i an increase of l)ain, timis gI-in(ling test is l)ositive, alm(iimmeniscal (laimmage is (hiagnoseti.

Incidentally, this question of time aimmount of pain is not a matter of fine imait-hitme mhistinc-tioim; time patient immust be sure of a considerable difference, and indeeti he usually is.

THE USES OF THESE TESTS

1. So far, attention imas been focuseti on differentiating a nmeniscus injui-v frommm arotatiolm sprain. Thmis is time first, almd l)elimal)s time nmost iimmportant, use of timese tests. Fime-

82 A. G. APLEY

are also useful in other types of cases, however, in some of which it is necessary to intro-duce modifications.

2. In nmany patients the history lacks diagnostic precision and the common l)hysicalsigns of meniscus damage cannot be elicited ; the findings are vague, although the patientsmay be grossly disabled. Again, in many patients the diagnosis of a lesion of the posteriorimorn of time meniscus may be difficult. In both types of cases, surgeons are not unreasonablychary of operating in time absence of any single clear diagnostic feature in the history ortime physical examination. Not infrequently, therefore, the patient limps his way, formonths or years, with the aid of physiotherapy. There is, therefore, a second use for thetests ; for, if time grinding test is positive, then the doubt as to the diagnosis (and mci-dentally the meniscus) should be removed.

With a suspected tear of the posterior horn, the grinding test is modified ; instead ofholding time leg at a rigimt angle, the knee is flexed much more acutely. The importance isnow apparent of determining, in the preliminary manoeuvre (Fig. 3) , the angle of flexionat which pain is produced by rotation, for the test should always be repeated at preciselythis angie. In timis way it may be possible to obtain accurate localization of the meniseuslesion as well.

3. A third use of time tests is in the diagnosis of lesions of the lateral meniscus, whichmay also be difficult at times. For this purpose the tests are modified by rotating the footinward instead of outward ; in other words, a reverse grinding test is performed. The clueas to whether this is worth trying is again given by the preliminary manoeuvre, in whichboth rotations at all angles of flexion were performed.

LIMITATIONS OF THE TESTS

Any diagnostic test simould be judged by three fundamental criteria : (1 ) It simould befairly easy to do ; (2) it should be constantly positive for the precise lesion concerned;and (3) it should be negative for all other lesions.

The grinding test is not too difficult, but it does need a good deal of practice andcareful attention to detail. The use of a low couch, the application of considerable forcein compression and rotation, and carrying out the test at the suitable angle of knee flexionare all important points, the neglect of which may result in failure.

As to whether the grinding test is always positive with a meniscus lesion and thedistraction test with a soft-tissue lesion, it is perhaps too early. to say. This paper is beingpresented at a somewhat early stage in the hope that more widespread trials will follow.Since becoming accustomed to the tests, however, the author has been surprised by theirconstancy.

With regard to other lesions, the author has three times found the grinding test positivewimen timcre was a pedunculated loose body other than a split meniscus. This does notseem to be a serious drawback for, quite apart from the help afforded by roentgenograms,operation was no less indicated.

RESULTS

Time results by timcse methods are shown in Table I. The number of cases is smallbecause, in time great majority of cases, the orthodox methods established the diagnosissimply and firmly. These cases are therefore omitted, and only fifty cases remain. Broadlyspeaking, Groups A and B are those in which only the application of the new tests per-mitted a diagnosis to be made; whereas Groups C and D, especially Group D, are those inwimicim the tests resulted in the correction of wrong diagnoses.

Group A consists of ten cases. In none was there a history typical of meniscus injury,anti in none was a single positive physical sign found by orthodox methods. In all ten,imowever, the grinding test was clearly positive, and in each a split meniscus was removedat operation.

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THE DIAGNOSIS OF MENISCUS INJURIES 83

TABLE I. RESULTS

Findings by Orthodox Methods Findings by New Methods

No of Tynical . . . . Positive ActualGroup .. Positive Positive 1-v

ases rnsrory . . . . . iiis- . . lagnosis.. of Meniscus Meniscus Diagnosis Grmdmg traction Diagnosis

Injury Tests est Test --

---- 10 0 0 Nomeniscus 10 0 Split Split meni.scuslesion meniscus at operation

B 13 Variable 0 Probably 13 0 Split Split meniscusno meniscus meniscus found

lesion at operationC 15 Variable 0 ? Split 0 15 Rotation Rotation sprain

meniscus sprain (not proved)D 9 Fairly good 3 Probably a 0 9 Rotation Rotation sprain

split sprainmeniscus

E 3 Miscellaneous cases for discussion

--- 3 23 __

In time thirteen cases of Group B, orthodox physical examination was again negative;but time histories varied from complete vagueness to more or less definite hints of meniscusdamage. Again, however, the grinding test was constantly positive ; and in these cases, too,a split nmeniscus was removed at operation.

In a few of time cases in Group B, the history alone might possibly have led to opera-tion. This links up with Group C, for in the fifteen cases of this group, there was a similarvariability and vagueness in the history, coupled with absence of orthodox physical signs.To all appearances, therefore, Groups B and C are alike. In all the cases of Group C,however, time distraction test was positive, and a diagnosis of rotation sprain was thereforemade.

Group D carries the argument a stage further, for it consists of nine cases in whicimtime imistory definitely was suggestive of meniscus damage; moreover, in three of timem a

I)oSit.i\e McMurrays sign was probably obtained. Again the grinding test was negativeanti time distraction test positive, and a rotation sprain was therefore diagnosed. With thisdiagnosis, in Groups C and D operation into the joint was not indicated. In a few casesnegative au- artlmrogranms were obtained, but the results with this method are insufficientlyconstant to afford proof. Purely conservative methods, including manipulation in some,al)peal to have justified time diagnosis. It is not unlikely that, without these tests, at leasttime three cases nmentioned, and probably several more of this group, would have come tooperation, and that normal menisci would have been removed. Here, timen, are cases withan apparent diagnosis of meniscus damage, which were actually examples of rotationsprain. It is impossible to resist the speculation that this may provide the explanation forsome of timose enigmatic cases in which normal menisci are removed.

Group E consists of three miscellaneous cases. In one, the diagnosis of split meniscuswas made on time basis of the history, a positive physical examination by orthodox methods,and also a positive grinding test; nevertheless a normal meniscus was removed. Theremaining two cases had previously had meniscectomy ; in both, a fragment of time posteriorhorn remained, diagnosed by the positive grinding test. They also showed a positivedistraction test, however,-a curiosity explained by the presence of postoperative adimesionsminmicking rotation sprain. Thus an apparent contradiction proved, in fact, to be con-firmatory evidence of the validity of these tests.

One curious case was seen. The patient had a reasonably suggestive imistory and avery obvious McMurrays sign. When the grinding test was performed, and conmpression

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84 A. G. APLEY

and rotation were applied, there was a sudden click. Much to the patients surprise, andsomewhat to the authors, the knee was locked. To satisfy himself, the author locked andunlocked it three times in all. Fortunately this was not a very painful process ; and it doesseem to suggest that, in the grinding test, the correct type of force is being used.

SUMMARY

Some new tests for time diagnosis of meniscus injury, and its differentiation from rota-tion sprain, have been described. These tests aim at separating the individual componentsin knee-joint injury, and at reproducing the causal grinding force of meniseus damage.Witim wider experience, it is hoped timat they may help to reduce time percentage of errorsin the diagnosis of knee-joint injuries.

NOTE : In connection with the preparation of this paper, thanks are especially due to Mr. GeorgePerkins, Professor Piatt, and Mr. W. R. Bristow for valuable criticism and advice. The author is alsomost grateful to Brigadier D. Fettes, Colonel E. M. Townsend, and Colonel E. P. N. Creagh for theirgenerous cooperation ; and to hmis brother, Dr. J. Apley, for his invaluable assistance.

REFERENCES

1. BRISrow, W. R. : Internal Derangement of the Knee-Joint. J. Bone and Joint Surg., 7 : 413-450,Apr. 1925.

2. BRISTOW, W. R. : Internal Derangement of the Knee Joint. J. Bone and Joint Surg., 17 : 605-626,July 1935.

3. HEY, WILLIAM : Practical Observations in Surgery, Chap. 6. London, 1803.4. JONES, ROBERT: On Certain Derangements of the Knee. Clin. J., 28: 51-64, 1906.5. MCMURRAY, T. P.: Time Diagnosis of Internal Derangements of the Knee. In The Robert Jones

Birtimday Volume, pp. 301-306. London, Humphrey Miiford, 1928.6. MARTIN, A. M.: Discussion on the Diagnosis and Treatment of Injuries of the Knee-Joint Other

Thman Fractures and Dislocations. British Med. J., 2: 1070-1076, 1913.7. M0RIS0N, RUTHERFORD: Injuries to time Semilunar Cartiiages of the Knee-Joint. Chin. J., 42: 1-7,

1913.8. PLATT, HARRY: Lesions of the Semilunar Cartilages of time Knee Joint. Acta Chir. Scandinavica, 67:

654-665, 1930.9. PLATT, HARRY: Personal Communication.

10. POWER, DARCY: Resuits of the Surgical Treatment of Displaced Semilunar Cartilages of time Knee.Britisim Med. J., 1: 61-67, 1911.

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