# it classification

8/6/2019 # It Classification

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Franck Mabesoone

Department of Orthopaedics and Traumatology,Hpital Piti-Salptrire- F-75013 Paris, France

INTRODUCTION Over the past 50 years, much has been published on the different methods for the fixation of trochanteric fractures. In order to appreciate the results, one needs to understand the fracture patterns

involved. Many classification systems have been devised; however, since each has had a differentobject, none has been unanimously adopted by the orthopaedic community. Some of the systemsproposed have confined themselves to a simple anatomical description of the patterns observed (Evans;Ramadier; Decoulx and Lavarde). Other, more recent, systems were designed to provide prognosticinformation on the prospect of achieving and maintaining reduction of the different types of fractures(Tronzo; Ender; Jensen's modification of the Evans grading; Mller et al.) . In present-day surgical practice, it is important to know whether a fracture is stable or unstable: Theanswer to this question will guide the reduction technique, the type of fixation to be used, and thepostoperative management. A good classification must provide information on the fracture's potential of being anatomically reduced, with good apposition of the fragments. Also, it should be possible to tell, inthe light of the classification, whether a particular fracture is likely to become secondarily displaced afterfixation; this information must be available before the patient is allowed to weight -bear. This newapproach has made it possible to develop fixation hardware whose design takes account of thebiomechanical properties of fractures, in order to arrive at more dynamic modes of fixation. Finally, anyclassification system that aspires to universal adoption must be easy to use and reproducible; only if these criteria are met can it facilitate communication among surgeons. After the first papers showing the superiority of the surgical treatment of trochanteric fractures overother management modalities, attempts were made to classify the different fracture types in the light of the various authors' first experience with internal fixation. A review of the literature shows manyproposed classification systems (see Table above). Some of these will discussed in greater detail in thisreview article, either because they are widely used, or because they provide important anatomical orbiomechanical information. THE EVANS CLASSIFICATION(Fig. 1)


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Figure 1 Evans' classification Type I: Undisplaced 2-fragment fractureType II: Displaced 2-fragment fractureType III: 3-fragment fracture without posterolateral support, owing todisplacement of greater trochanter fragmentType IV: 3-fragment fracture without medial support, owing to displacedlesser trochanter or femoral arch fragmentType V: 4-fragment fracture without posterolateral and medial support(combination of Type III and Type IV)

R: Reversed obliquity fracture As early as 1949, EM Evans devised a classification system that had the twin merits of reproducibility and ease of use. It ha s beenwidely used in the English-speaking countries. In this system, fractures of the trochanteric region are subdivided into five types. Thefirst two types are two-fragment fractures, with a fracture line running parallel to the intertrochanteric line, without separation of thetrochanters. The fractures may be undisplaced (Type I) or displaced (Type II) . Type III is a three-fragment fracture, without

posterolateral support owing to displacement of the greater trochanter. Type IV also has three fragments; however, in this type,there is no medial support, because of displacement of the lesser trochanter or fracture of the medial arc h. In the four-fragmentfracture (Type V) , there is neither medial nor posterolateral support, since the comminution involves the greater and the lesser trochanter.Evans also described a fracture with a subtrochanteric fracture line that runs obliquely upwards and inwards; he called this pattern areversed obliquity fracture. The mechanical properties of this pattern are worth noting: Reversed obliquity fractures are inh erentlyunstable. The femoral shaft tends to displace medially by the downward and outward sliding of the greater trochanter; fixation,especially by sliding screws, is incapable of controlling this displacement.The modified grading proposed by Jensen and Michaelson in 1975 was intended to improve the predictive value of the Evanssystem, to indicate which fractures could be reduced anatomically and which were at risk for secondary displacement after fixation.An analysis, published in 1980, of the reduction of fractures in 234 patients managed with sliding screw -plate internal fixation madeit possible for the number of patterns to be reduced to three, the criterion being reducibility. Class I includes two-fragment fractures,which are considered stable. A study of this pattern shows that such fractures may readily be reduced in the coronal and the sagittal

plane. Class II contains Evans Type III and Type IV fractures, which are difficult to reduce in either the coronal or the sagittal plane; while Class III (Evans Type V) consists of very unstable fractures, which are difficult to reduce in both planes. In the light of a comparison with four other grading systems, the authors showed that this modified Evans system had the best predictive valu eregarding the reduction potential, and would, therefore, also indicate the likely risk of secondary displacement of the differentfractures.THE RAMADIER CLASSIFICATION(Fig. 2)


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Figure 2 Ramadier's classification a: Cervico-trochanteric fracturesb: Simple pertrochanteric fracturesc: Complex pertrochanteric fracturesd: Pertrochanteric fractures with valgus displacemente: Pertrochanteric fractures with an intertrochanteric fracture linef: Trochantero-diaphyseal fracturesg: Subtrochanteric fractures D ecoulx and Lavarde's classification (1969)

Cervico-trochanteric fractures (a)Pertrochanteric fractures (b,c,d)Subtrochanteric fractures (e)Subtrochantero-diaphyseal fractures (f)

In 1956, Ramadier established a grading system that came to be widely used in France. He described four basic patterns, under four main headings, as a function of the fracture line. He recognized cervico-trochanteric fractures (a) , with a fracture line at the base of the femoral neck. According to Ramadier and Bombard, these fractures account for 27% of all the fractures in the trochantericregion. The fractures are usually impacted, and the displacement of the fragments produces a coxa vara deformity and internalrotation. Simple pertrochanteric fractures (b) account for 24% of trochanteric fractures; they have a fracture line that runs parallel tothe intertrochanteric line; frequently, the lesser trochanter is broken off. The greater trochanter is not, or only marginally, involved.Complex pertrochanteric fractures (c) , which account for 31% of all fractures in the region, have an additional fracture line thatseparates most of the greater trochanter from the femoral shaft; the lesser trochanter is often fractured. There will be a greater or

lesser amount of displacement. Ramadier described two infrequently encountered patterns: Pertrochanteric fractures impacted in avalgus displacement (d) , with a fracture line that begins on the greater trochanter and finishes below the lesser trochanter; and low

pertrochanteric fractures (e) . Trochantero-diaphyseal fractures (f) , which make up 10% of all fractures in the region, have a fractureline that follows a spiral line through the greater trochanter and into the proximal shaft. Often, the pattern contains a third fragment;there may be major displacement. Subtrochanteric fractures (g) have a more or less horizontal fracture line that runs below the twotrochanters. Displacement may be substantial: The proximal fragment is put into flexion by the action of the iliopsoas, and the shaftfragment tends to drop backwards.Decoulx and Lavarde (1969) enhanced the above system by the addition of a further pattern that had previously been described byEhalt - a trochanteric fracture with a more distal fracture line, which is slightly concave proximally and which crosses theintertrochanteric line just above the lesser trochanter. They called this pattern an intertrochanteric fracture, and made it part of afive-grade classification: cervico-trochanteric fractures; pertrochanteric fractures; intertrochanteric fractures; subtrochantero-diaphyseal fractures; and subtrochanteric fractures (Fig. 2) .THE BRIOT CLASSIFICATION(Fig. 3)

Figure 3 Briot'sgrading of diaphyseo-trochantericfractures A Evans' reversedobliquity fractureB "Basque roof"fracturesC Boyd's "steeple"


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fractureD Fractures with anadditional fracture lineascending to theintertrochanteric lineE Fractures withadditional fracturelines radiatingthrough the greater

trochanter In 1980, Briot tried to simplify the Ramadier system and to introduce biomechanical concepts. He merged the cervico -trochantericand the pertrochanteric fractures. In his opinion, a fracture at the base of the neck, with a line running parallel to theintertrochanteric line and medial to the iliofemoral ligaments, was as difficult to fixate and reduce as were pertrochanteric fractureswith a line lateral to these ligaments. To the previous system, Briot added fractures with an oblique line running upwards andinwards; however, by definition, he excluded subtrochanteric fractures, because they do not affect the trochanters, and because themechanical problems involved in this pattern are totally different, even where these fractures are associated with undisplacedfractures of the greater trochanter or a detachment of the lesser trochanter. In this way, Briot established three well -defined patternsof trochanteric region fractures:(1) pertrochanteric fractures with a fracture line running parallel to the intertrochanteric line, which may detach a posterior c orticalfragment (this lesion will be discussed further below). Under the same heading, Briot consider s pertrochantero-diaphyseal fractureswith a downward and inward slanting line that continues distal to the lesser trochanter.(2) the intertrochanteric fractures described by Decoulx;(3) diaphyseo-trochanteric fractures (Fig. 3) with a fracture line running upwards and outwards that extends to, but not beyond, theintertrochanteric line. One pattern in this group would be Evans' reversed obliquity fracture; while the fracture line may al so turn

back and continue downwards along the intertrochanteric line, to produce the steeple-shaped pattern described by Boyd.

THE ENDER CLASSIFICATION(Fig. 4)


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Figure 4 Ender's classification T rochanteric eversion fractures -1 Simple fractures-2 Fractures with a posterior fragment-3 Fractures with lateral and proximal displacementT rochanteric inversion fractures -4 With a pointed proximal fragment spike-5 With a rounded proximal fragment beak-6 Intertrochanteric fracturesSubtrochanteric fractures

-7 and 7a Transverse or reversed obliquity fractures-8 and 8a Spiral fractures

Some authors have adopted a more pragmatic approach: Instead of merely describing the patterns of trochanteric fractures, theyhave analysed the potential for achieving reduction potential and for the maintenance of reduction following fixation.In 1970, HG Ender, in his description of a technique for condylocephalic nailing, gave a fracture grading system based upon thefracture mechanism. The first type is represented by eversion fractures, with an anterior opening of the fracture site (1) , sometimesinvolving the separation of a posterior fragment (2) . In this group, Ender described fractures with substantial lateral and posterior displacement of the distal fragment (3) , which shows that major soft tissue damage has occurred, resulting in severe instability.The second group consists of impaction (inversion and adduction) fractures ; typically, the distal medial beak of the neck fragmentis impacted in the metaphysis (4 and 5) .The last two groups are intertrochanteric fractures (6) and subtrochanteric fractures (7 and 8) .Ender felt that a knowledge of the fracture mechanism was useful when it came to performing external reduction manoeuvres bef ore

doing closed nailing using his hardware. As a result, the Ender grading system has been applied only in conjunction with Ender'scondylocephalic nailing system.THE AO CLASSIFICATION(Fig. 5)


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Figure 5 AO classification A1: Simple (2-fragment) pertrochanteric area fractures A1.1 Fractures along the intertrochanteric lineA1.2 Fractures through the greater trochanterA1.3 Fractures below the lesser trochanterA2: Multifragmentary pertrochanteric fractures A2.1 With one intermediate fragment (lesser trochanter detachment)A2.2 With 2 intermediate fragmentsA2.3 With more than 2 intermediate fragmentsA3: Intertrochanteric fractures

A3.1 Simple, obliqueA3.2 Simple, transverseA3.3 With a medial fragment

The AO classification, proposed by Mller et al. in 1980-1987, attempts to be descriptive and to provide prognostic information, inthe light of what can be done with present-day fixation techniques. Type A fractures are fractures of the trochanteric area. Thesefractures are divided into three groups.Group A1 contains the simple (two-fragment) pertrochanteric fractures whose fracture line runs from the greater trochanter to themedial cortex; this cortex is interrupted in only one place. There are three subgroups, reflecting the pattern of the medi al fractureline: A1.1 fractures run above the lesser trochanter; A1.2 fractures have calcar impaction in the metaphysis; while A1.3 frac tures aretrochantero-diaphyseal fractures that finish up distal to the lesser trochanter.The fractures in Group A2 have a fracture line pattern identical to that of Group A1 fractures; however, the medial cortex iscomminuted. They are subdivided into A2.1 fractures, with one intermediate fragment; A2.2 fractures, with two fragments; and

A2.3 fractures, with more than two intermediate fragments.Group A3 fractures are characterized by a line that passes from the lateral femoral cortex below the greater trochanter to th e proximal border of the lesser trochanter; often there is also an undisplaced fracture separating the greater trochanter. A3.1 fracturesare reverse intertrochanteric fractures (with an oblique fracture line); while A3.2 fractures are transverse (intertrochanter ic). A3.3fractures involve the detachment of the lesser trochanter, and are notoriously difficult to reduce and stabilize.SOURCES OF INSTABILITY The mechanical rle of the medial arch, and the implications of its failure in trochanteric fractures, have been stressed in a number of papers. In particular, Evans has drawn attention to medial arch compromise as a source of instability. His own Types IV an d Vare the most unstable patterns. If the calcar is involved, there will be instability in the coronal plane. There is less agreement on theextent to which stability is affected by lesser trochanter fractures.Some authors think that medial stability is usually preserved if only the lesser trochanter is fractured, since the structure described asa "massive cancellous apophysis behind the calcar" does not have a major weight-bearing function.


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In 1964, Ottolenghiin distinguished between intradigital fractures, whose fracture line is medial to the digital fossa of the greater trochanter, and extradigital fractures (Fig. 6) .

Figure 6 Extradigital fracture line (Ottolenghi)posterior openingFrom above

The latter, whose line is more lateral than in the usual patterns, will leave all the rotator insertions on the proximal fragment.Displacement of the neck and trochanter fragment in external rotation will open up the fracture at the back; reduction must b eachieved by external rotation of the shaft fragment.The detachment of the posterior portion of the greater trochanter may also pose major problems. It has been held responsible for difficult reduction in the sagittal plane. Boyd and Griffin (1949) were the first to consider the instability of trochanteric fractures inthe coronal as well as the sagittal plane. This concept was also embodied in the classification established by Tronzo in 1973 . AmongTronzo's patterns, there are three involving an explosion of the posterior wall (Fig. 7) :

Figure 7 Tronzo's classificationPosterior viewType 3 | Type 3 Variant | Type 4Fractures with posterior comminution

In the first, the neck spike is telescoped into the shaft fragment, and there is a large lesser trochanter fragment. In the s econd, thegreater trochanter is also totally broken off; while, in the third, the neck spike is not telescoped into the shaft, but is dis placed medialto the shaft. This grading system gives a good indication of the degree of instability of a given fracture, from lack of medial and/or

posterior support. However, the system may be somewhat too complex for wider use.Briot studied the way in which the posterior wall of the trochanteric region affects the stability of trochanteric fractures. Damage tothe posterior wall is a major source of sagittal instability, and, in particular, external rotation. From cadaver studies, Br iot found thatthe fracture may detach a posterior plate, situated between the lateral lip of the linea asper a and the spiral line, comprising theintertrochanteric crest and the lesser trochanter. This plate may be completely avulsed, sometimes with additional fractures lines;equally, it may be separated from the femur in its upper part (Fig. 8) .


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Figure 8 Briot's posterior plate fracturesBriot's posterior plate fractures a Boundaries of posterior plateb Maximum extent of platec Possible fracture lines

It is thought that this posterior comminution causes malunion in external rotation. Ender described this fracture, with detachment of a posterior fragment, among his Type 2 fractures in external rotation; however, he stressed the rle of the soft tissue lesio ns in hisType 3 fractures.CONCLUSION

The different classification systems devised to date for the grading of trochanteric fractures contain several points that ar e of importance in the analysis of radiographs of such fractures.Stable two-fragment fractures, with a pertrochanteric or a paratrochanteric (basicervical) line, may be considered as one category,since their grading, reduction, and stabilization are straightforward.Two factors must be considered in the assessment of stability: loss of medial support, as a result of a separation of the lesser trochanter in association with a fracture of the medial arch; and comminution of the posterior cortex, which is frequently as sociatedwith a separation of the greater trochanter. The fracture must be reduced in internal rotation, to close the an terior gap and to replacethe posterior cortical fragments.One fracture pattern warrants separate consideration - the reversed obliquity fracture described by Evans. This fracture is similar tosubtrochanteric fractures, in that it is difficult to reduce and causes major instability.This review does not attempt to draw up yet another classification. Such an attempt would not be very productive, since there is nosuch thing as a perfect system for the grading of trochanteric fractures. Any system to be use d in traumatology needs to be simple,

and precise enough to produce the same results when used by different observers, or by the same observers at different points intime . Equally, it must be go beyond a mere description, to provide predictive informatio n regarding the stability potential of thevarious fracture patterns.

Evans' classification (1949) Type I: Undisplaced 2-fragment fractureType II: Displaced 2-fragment fractureType III: 3-fragment fracture without posterolateral supportType IV: 3-fragment fracture without medial support,Type V: 4-fragment fracture without posterolateral and medialsupportReversed obliquity fracture

Boyd and Griffin's classification (1949) Linear intertrochanteric line fracturesIntertrochanteric line fractures with comminutionSubtrochanteric fracturesFractures of the trochanteric region and the proximal shaft

Ramadier's classification (1956) (a) Cervico-trochanteric fractures(b) Simple pertrochanteric fractures(c) Complex pertrochanteric fractures(d) Pertrochanteric fractures with valgus displacement


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(e) Pertrochanteric fractures with an intertrochanteric fractureline(f) Trochantero-diaphyseal fractures(g) Subtrochanteric fractures

D ecoulx & Lavarde's classification (1969) Cervico-trochanteric fracturesPertrochanteric fracturesIntertrochanteric fractures

Subtrochanteric fracturesSubtrochantero-diaphyseal fractures

Ender's classification (1970) Trochanteric eversion fractures Type 1: Simple fracturesType 2: Fractures with a posterior fragmentType 3: Fractures with lateral and proximal displacementTrochanteric inversion fractures Type 4: With a pointed proximal fragment spikeType 5: With a rounded proximal fragment beak

Intertrochanteric fractures :Type 6

Subtrochanteric fractures Types 7 and 7a: Transverse or reversed obliquity fracturesTypes 8 and 8a: Spiral fractures

T ronzo's classification (1973) Type 1: Incomplete fracturesType 2: Uncomminuted fractures, with or without displacement;both trochanters fracturedType 3: Comminuted fractures, large lesser trochanter fragment;posterior wall exploded; neck beak impacted in shaftType 3 Variant: As above, plus greater trochanter fractured off and separatedType 4: Posterior wall exploded, neck spike displaced outsideshaftType 5: reverse obliquity fracture, with or without greatertrochanter separation

Jensen's classification (1975) Displaced or undisplaced stable 2-fragment fracturesUnstable 3-fragment fractures with greater or lesser trochanterfracture4-fragment fractures

D eburge's classification (1976) Cervico-trochanteric fracturesPertrochanteric fracturesIntertrochanteric fracturesSubtrochanteric fracturesTrochantero-diaphyseal fractures

Briot's classification (1980) (1) Pertrochanteric fractures - simple- with posterior wall explosion- extending into the shaft


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(2) Intertrochanteric fractures (3) Diaphyseo-trochanteric fractures - Evans' reversed obliquity fracture- "Basque roof" fractures- Boyd's "steeple" fracture- fractures with an additional line ascending to theintertrochanteric line- Fractures with additional fracture lines radiating through thegreater trochanter

AO classification (1981) G roup A 1: Simple (2 -fragment ) pertrochanteric areafractures A1.1 Fractures along the intertrochanteric lineA1.2 Fractures through the greater trochanterA1.3 Fractures below the lesser trochanterG roup A 2: Multifragmentary pertrochanteric fractures A2.1 With one intermediate fragmentA2.2 With 2 intermediate fragmentsA2.3 With more than 2 intermediate fragmentsG roup A 3: Intertrochanteric fractures

A3.1 Simple, obliqueA3.2 Simple, transverseA3.3 With a medial fragment

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