Distal Tibia

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Distal Tibia

Contents

Anatomy and Growth .. . . ..274

Classification ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...276

Epidemiology .. . . ..276

Literature.Review.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .276

Olmsted.County.Study. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .277

Type.1... . . ..278

Type.2... . . ..278

Type.3... . . ..278

Type.4... . . ..278

Type.5... . . ..278

Type.6... . . ..279

Evaluation . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .279

Type.1... . . ..279

Type.2... . . ..282

Type.3... . . .288

Type.4... . . ..293

Type.5... . . .294

Type.6... . . .294

Management ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...295

Type.1... . . ..295

Type.2... . . .296

Type.3... . . .298

Type.4... . . .298

Type.5... . . .299

Type.6... . . .299

Follow-up ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...303

Complications . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .303

Complete.Closure.... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...303

Partial.Closure... . . ..303

Irreducibility.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .303

Compartment.Syndrome.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .305

Malunion. ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. . .305

Nonunion. .. . . ..307

Ischemic.Necrosis.... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...307

Ankle.Stiffness. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .307

Osteoarthritis.... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...307

Synostosis... . . ..307

Author’s Perspective. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .307

A. Medial Malleolus. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .311

Anatomy . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .311

Classification ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .311

Epidemiology . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .311

Evaluation . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .312

Management ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...319

Complications . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .324

Physeal.Arrest. .. . . ..324

Irreducible.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .327

Nonunion. .. . . ..329

Malunion. ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...329

Overgrowth. .. . . ..329

Degenerative.Arthrosis.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .330

Osteomyelitis. ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...330

B. Lateral Plafond. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .338

Anatomy . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .338

Classification ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...339

Epidemiology . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .339

Evaluation . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .340

Management ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...343

Type.4.Fractures... . . ..343

Complications . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .349

C. Triplane Fractures .. . . ..353

History ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...353

Anatomy ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...355

Classification ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...357

Epidemiology .. . . ..362

Evaluation . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .362

Management ... .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. ...371

Undisplaced.Fracture.. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .371

Minimal.Displacement... . . ..371

Displaced.Fracture. . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .371

Comminuted.Fracture. .. . . ..375

Extra-articular.Fracture . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .377

Summary.of.Management. .. . . ..379

Complications . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .380

References . .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .. .384

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274 Chapter 11 Distal Tibia

The distal tibia is the only physis in which fractures in females exceed those in males. This is noted primarily in recent literature and may reflect the increasing popularity of women’s competitive sports, particularly softball, soccer, basketball, hockey, and skiing.

The distal tibial physis has the highest propensity for complication of any site (Tables 8.1, 8.5) [10, 76, 94].

Anatomy and Growth

Developmental cartilaginous and bone changes in the distal tibia follow a pattern distinct from other physes. This is well documented both roentgenographically [3, 25, 60, 63] and by MR imaging [13].

At birth the distal tibial epiphysis is entirely cartilaginous. The secondary center of ossification appears roentgenographically centrally, beginning around age 5 months (range in girls 0–12 months, in boys 2–

12 months [25]), and expands centrifugally. The lateral portion of the ossification center is more narrow (wedge shaped) than the medial [50, 63]. Ossification gradually extends into the medial malleolus, so that by age 8–11 years the malleolus is well defined roentgenographically. The lateral portion of the distal tibial articular cartilage extends proximally nearly the entire longitudinal length of the epiphysis to form an articulation with the distal fibula (the distal tibiofibu- lar joint) [63].

In the neonate the physis is flat, and the epiphyseal cartilage has many vascular canals [50, 63]. By age 2–3 years the physis develops undulations, most prominently anteromedially. By age 8–11 years these multiple undulations, sometimes called papillae or mammary processes, are evident roentgenographically (Fig. 2.10). By age 12 years or so the growth of this anteromedial area lags slightly behind the remaining physis producing a mild curve, apex proximally (Fig. 11.1). This has been called Poland’s hump [50, 72] or Kump’s bump [43]. This dome shape of this portion of the physis makes it roentgenographically indistinct. This should not be misinterpreted as an injury or premature physeal arrest secondary to trauma [50, 63]. The physis in this “hump” area is the first to close. During this phase of partial union, this me- dio-central zone of the physis is converted to a point of strength [43], thereby affecting all subsequent fracture patterns.

At birth the physis is at an angle of 80 degrees varus with the longitudinal axis of the tibia in the coronal plane. This angle gradually increases to 90 degrees (perpendicular) by age 12 years and is the same for

boys and girls [3]. It is generally accepted that the physis and the articular surfaces of the ankle joint are normally parallel with the floor (Fig. 11.1), although this fact, as well as the normal degrees of varus and valgus variation, have not been documented in children. This becomes important in determining accept- able parameters of both the angle of the tibia to the ankle joint, and of the ankle joint to the floor, following distal tibial physeal injury. The degree of altera- tion of these angles (Figs. 11.9g, 11A.14j) which pre- disposes to degenerative arthrosis in adulthood is unknown.

At birth the tibia is 20% of its total length. The distal tibial physis provides approximately 50% of growth of the tibia initially, until the tibia has reached 50%

of its adult length at about age 9 years in girls and 10 years in boys. Then the proximal tibia gradually assumes the major role [3]. The relative contribution of the distal tibial physis to the growth of the tibia di- minishes gradually with increasing total growth (Fig. 11.2), indicating an absence of growth spurt in the distal tibia [34]. At maturity the distal tibial physis has accounted for 40% of growth of the tibia (Fig. 11.3) and 17% of the lower extremity. The distal tibial physis provides 3–4 mm of growth annually, until age 12 years in girls and 14 years in boys, after which there is minimal longitudinal growth.

Fig. 11.1

Distal.tibia,.normal,.standing,.of.a.14.year.0.month.old.

boy . The. proximal. projection. of. the. tibial. physis. (ar- row).is.Poland’s.hump .The.ankle.joint.is.parallel.with.

the.floor.(0°)

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Prior to 1 year of age, the distal fibular physis is 0.4 cm more distal than the distal tibial physis. This difference gradually increases to exceed 1.0 cm by age 12 years [3]. Thus the distal tibial growth plate con- tributes a lesser percentage of distal leg growth than the distal fibular physis.

Since ligaments about the ankle are biomechani- cally stronger than the tibial or fibular physes, liga- mentous ankle injuries are uncommon in children. In contrast, chondro-osseous fractures involving the developing physes are common [55, 63, 75].

Blood is supplied to the distal tibial epiphysis by multiple vessels entering circumferentially. Thus, no matter the fracture type, each fragment usually has adequate vascularity, and ischemic necrosis is unusual [39].

Physeal closure begins centromedially in the area of Poland’s hump and progresses first anteromedially, then posterolaterally [13, 53], and occurs progressively over a period of 18 months. Most other physes close beginning centrally, progressing centrifugally, and over a shorter time. This eccentric pattern of closure mimics nonphysiologic bone bridging [13]. The long closure time has an effect on fracture patterns, particularly medial malleolar, lateral plafond and triplane fractures (Sections A, B, and C, respectively) [43, 50, 63]. The anterolateral portion of the physis is the last to close. Complete closure of the distal tibial physis varies widely, from age 12 to 17 years (median, 14 years 10 months) in girls and from age 15 to 20 years (median 16 years 10 months) in boys [25, 63]. Distal tibial and fibular physeal closure occur at approximately the same time in both girls and boys [34].

Fig. 11.2

The. contribution. of. the. proximal. and. distal. physes. to. the.

growth.of.the.tibia .The.vertical axis.shows.the.relative.activity.

of.the.growth.plates .The.contribution. of. the. proximal. physis. is. shown. above. the.solid line,.and.the.distal.physis.is.be- low. the. line . (Adapted. from.

Pritchett.[73,.74],.with.permission)

Fig. 11.3

The.percentage.of.growth.of.the.proximal.and.distal.

tibial.physis.at.birth,.mid-childhood,.and.at.maturity . (Adapted.from.Pritchett.[73],.with.permission)

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Classification

A bewildering array of classifications has evolved to describe pediatric distal tibial fractures; more classifications than for any other physis. These classifications are based on several criteria; mechanism of injury, anatomy (roentgenographic), clinical orientation [84], outcome, and combinations thereof.

Classification based on the mechanism of injury has been particularly popular [5, 10, 14, 16, 17, 19, 22, 28, 31–33, 35–37, 44, 46, 53, 61, 80, 83, 97, 99] and is best described by Cummings [15] and by Gross [24].

The mechanism is expressed as a motion or position (supination, pronation, inversion, eversion, internal rotation, external rotation, adduction, abduction, dorsiflexion, plantarflexion, varus, valgus, etc., or as a combination of these). Few authors use these terms similarly, and rarely can results of case accumulations be compared using this mechanism of injury classification system. The type of associated fibular fracture is said to be indicative of the mechanism of injury. For example, a high oblique or transverse fibular fracture is said to indicate a pronation-eversion-external rotation injury.

Since a child can rarely describe the mechanism of injury, the type of fracture is deduced from the position and orientation of the fragments on the initial roentgenograph. In some cases this will be inaccurate due to change of position of the fragments between the time of fracture and the roentgenograph. The in- terobserver reproducibility of the mechanism of injury classification is low, also reducing its value [38].

Vahvanen and Aalto [83] noted that this classification system was, in children, largely unsuccessful. Poland [72] who presented the first general anatomic classification of physeal fractures in 1898, stated that a mechanism of injury classification of the distal tibia was “impossible” [3].

The anatomic classifications of Aitken [1] (Fig. 3.2) and Johnson and Fahl [30] (Fig. 11C.1) were specific for the distal tibia and were advances for their day, but are incomplete with present knowledge. The anatomic classification applicable at all physeal sites presented in Fig. 3.6 best fits the physician’s needs for evaluation, communication, treatment, and prognosis, and will be used here. The type 5 fracture is particularly common in the distal tibia and most can be placed into one of three groups [67]: medial malleolus, lateral plafond, and triplane fracture. Because these type 5 fractures are so common and because they often result in significant morbidity they will be discussed separately (Sections A, B, and C, respectively).

A pilon fracture is a comminuted fracture of the inferior articular surface of the tibia and malleolus caused by high-energy trauma resulting in axial compression of the ankle joint [47]. Pilon fractures that extend proximally into the diaphysis are rare in children.

Epidemiology Literature Review

Unfortunately, several large case series report distal tibial and fibular fractures together [5, 10, 12, 44, 75, 80], in a manner making data on each site difficult to decipher. The distal tibia was consistently the third most frequent site of physeal fracture throughout the twentieth century (Tables 4.5, 4.6, 4.11), accounting for approximately 11% of all physeal fractures. It is the most commonly injured physis in the lower extremity.

Fractures of the distal tibial physis are unique in that the incidence in females is higher than in males (Ta- bles 11.3, 11B.1, 11C.1) [66, 83].

Evaluation of distal tibial physeal fractures by type is fragmented. Many authors used a variety of mechanism of injury classifications which cannot be compared with each other. Of the anatomic classifications, some data are available using the Aitken classification (Table 11.1). Most of the available data used the Salter- Harris (S-H) classification (Table 11.2) [76].

Salter-Harris (S-H) type 1 fractures account for almost 9% of distal tibial fractures (Table 11.2) and occur at a slightly younger age. The average age was 10 years 6 months in one series [80] and 11 years 1 month in another [70]. It is of interest to note that when this fracture occurred in infancy during force- ful clubfoot manipulation no growth arrest occurred [20], while arrest has occurred in toddlers with clubfoot manipulation. This reflects the appearance of the secondary center of ossification in the epiphysis, and possibly that more force is used in toddlers.

Type 2 fracture is by far the most common type accounting for 46% of distal tibial fractures (Table 11.2).

The average age in 41 patients reported by Phan et al.

Table 11.1. Distal.tibial.physeal.fracture.by.type.(Aitken.classification,.Fig .3 2)

Year Author 1 2 3 Total

1936 Aitken.[1] 16 . 3 2 . 21

1979 Boissevain.[6] 32 . 7 1 . 40

ToTal 48 10 3 . 61

Percent 78 7 16 4 4 9 100

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[71] was 12 years 0 months and in 91 cases reported by Spiegel et al. [80] was 12 years 7 months. Com- pound type 2 fractures are rare (Fig. 3B.5a).

Salter-Harris type 3 fractures account for 23.5%

(Table 11.2) and, although they are less common than type 2, the distal tibia is a common site of type 3 fractures (Peterson type 4, Table 3D.2). The average age noted in 2 series was 10 years [41] and 11 years 10 months [80].

Salter-Harris type 4 fractures account for 14% of distal tibial fractures (Table 11.2). Of these type 4 fractures 40% are triplane, and the remainder are of the medial malleolus or the lateral plafond [88]. The average age in the 18 cases reported by Spiegel et al.

[80] was 11 years 6 months.

Less than 1% of distal tibial physeal fractures were classified S-H type 5 (Table 11.2). None of those illustrated in the table references had normal initial roentgenographs, a prerequisite for this type, according to Salter and Harris [76]. It is interesting to speculate on the 100 (6%) unclassified fractures in Table 11.2. None were illustrated. Some may have been Peterson type 1.

The most severe type 5 fracture (fortunately the least common) is the adolescent pilon fracture [47]. These intraarticular fractures extend proximally well into

the metaphysis, and even the diaphysis, and are associated with variable articular disruption, comminution, talar injury, and fibular involvement. They are caused by axial compression of the ankle joint and are usually the result of high energy trauma.

Distal tibial physeal fractures are frequently associated with sporting activities. Football is frequently at the top of the list [22]. Birth fractures of the distal tibia physis are rare. Two cases have been recorded [79].

Olmsted County Study

Of the 951 physeal fractures in the Olmsted County study [68], 104 (11%) were in the distal tibia, making it the third most common site (Table 4.12). There were 51 boys and 53 girls (Table 11.3). The annual incidence was 30.5 physeal fractures per 100,000 males, while the female incidence was 31.1 fractures per 100,000.

The male age of maximal incidence was 15 years (155.4 fractures per 100,000 males), while the female age of maximal incidence was 11 years (215.9 fractures per 100,000 females). Fractures were noted in the male from age 0 years through age 16 years, and in the female from age 0 years through 15 years. When the fractures are grouped by age and type there is a

Table 11.2. Distal.tibial.physeal.fracture.by.type.(Salter-Harris.classification,.Fig .3 4)

Year Author^a 1 2 3 4 5 Unclassified Total

1974 Oh.[65] 0 19 13 12 0 0 44

1978 Goldberg.[22] 9 28 7 5 4^b 0 53

1978 Nolan.[61] 9 52 14 11 4^b 0 90

1978 Spiegel.[80] 36 91 55 18^c 2^d 10 212

1980 Vahvanen.[83] 12 44 38 18 0 42 154

1982 Karrholm.[111] 7 76 37 3 0 43 166

1982 MacNealy.[53] 11 90 49 39 0 5 194

1983 Cass.[88] 9 54 19 32^c 0 0 114

1987 Mizuta.[58] 2 12 8 11 0 0 33

1990 Mann.[55] 34 184 106 43 0 0 367

1991 Caterini.[12] 2 26 10 14 0 0 52

1996 Petit.[69] 0 15 4 10^c 0 0 29

2000 de.Sanctis.[16] 7 39 11 10 5^e 0 72

ToTal 138 730 371 226 15 100 1580

Percent . . 8 7 . 46 2 . 23 5 . 14 3 . . 0 9 . . 6 3 . . 99 9

a.Most.articles.have.more.than.one.author;.see.References

b.Cases.not.discussed.or.illustrated

c.Includes.triplane.fractures;.other.articles.did.not.specify

d.Both.cases.had.fractures.of.the.metaphysis,.and.therefore.were.not.type.5

e. .One.case.was.illustrated:.a.5-year-old.boy.with.bulging.of.the.metaphysis .Since.the.roentgenograph.was.not.normal.it.was.

not.a.type.5 .The.illustration.was.not.good.quality;.it.could.have.been.a.Peterson.type.1

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progressive increase in age of maximal incidence from type 1 through type 5 (Table 11.4).

Type 1

Type 1 fractures of the distal tibia occur sporadically throughout the age groups and have the highest incidence below 1 year (18.4 fractures per 100,000 children). They accounted for 8% of distal tibial physeal fractures (Table 11.4), and for 5% of all type 1 fractures (Table 3A.2).

Type 2

Type 2 fractures accounted for 43% (Table 11.4) and occurred from age 2 years through age 16 years with the maximal incidence at age 11 years (96.8 fractures per 100,000 children). The distal tibial physis accounted for 9% of type 2 fractures at all sites (Ta- ble 3B.2).

Type 3

Type 3 fractures accounted for 6% (Table 11.4) and occurred only at ages 11 through 15 years with maximal incidence at age 12 years (28.7 fractures per 100,000 children). Of all 126 type 3 fractures in the Olmsted study, only 6 (5%) were in the distal tibia (Table 3C.2). The relative paucity of type 3 fractures

among the top four most frequently fractured sites (Table 4.12) is unusual, but mirrored the low percentage of S-H type 1 fractures in the literature (Ta- ble 11.2). The stability provided by Poland’s hump (Fig. 11.1) may influence these percentages.

Type 4

Type 4 fractures accounted for 25% (Table 11.4) and occurred from age 8 years through 16 years with a maximal incidence at age 14 years (38.9 fractures per 100,000 children per year). The distal tibia was also the site of 25% of all type 4 fractures (Table 3D.2).

Type 5

Type 5 fractures accounted for 18% of all distal tibial fractures (Table 11.4). This is less than the 28% we found in a previous study [88], which included referral patients. This supports the need for population- based studies of unselected patients from the general community. The distal tibia accounted for 31% of all type 5 fractures (Table 3E.2). They occurred from age 9 years through 15 years, with a nearly equal maximal incidence of 28 fractures per 100,000 children for each of the ages 12, 13, 14, and 15 years. They are known to occur in children younger than reported in the Olmsted County study [80], and were more common in our referral practice.

Table 11.3. Distal.tibial.physeal.fractures.by.age.(years).and.gender.in.Olmsted.County,.Minnesota,.1979–1988.[68]

Age 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Total Percent

Male 1 1 0 0 0 0 1 0 0 2 1 2 6 6 12 14 5 0 0 0 0 0 . 51 . 49

Female 2 1 0 1 2 0 0 0 1 3 5 16 14 6 1 1 0 0 0 0 0 0 . 53 . 51

ToTal 3 2 0 1 2 0 1 0 1 5 6 18 20 12 13 15 5 0 0 0 0 0 104 100 0

Table 11.4. Distal.tibial.physeal.fractures.by.age.(years).and.type.in.Olmsted.County,.Minnesota,.1979–1988.[68].(Peterson.

classification)

Age 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Total Percent

Type.1 3 1 0 0 1 0 1 0 0 0 1 0 0 0 1 0 0 0 0 0 0 0 . . 8 . . 7 7

Type.2 0 1 0 1 1 0 0 0 0 2 3 15 7 5 2 4 4 0 0 0 0 0 . 45 . 43 3

Type.3 0 0 0 0 0 0 0 0 0 0 0 1 4 0 0 1 0 0 0 0 0 0 . . 6 . . 5 8

Type.4 0 0 0 0 0 0 0 0 1 2 2 1 5 3 6 5 1 0 0 0 0 0 . 26 . 25 0

Type.5 0 0 0 0 0 0 0 0 0 1 0 1 4 4 4 5 0 0 0 0 0 0 . 19 . 18 3

Type.6 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 . . 0 . . 0

ToTal 3 2 0 1 2 0 1 0 1 5 6 18 20 12 13 15 5 0 0 0 0 0 104 100 1

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Type 6

No type 6 fracture of the distal tibia occurred in the Olmsted County study, probably due to omission of documentation since this type was unknown at the time of data collection. They were likely documented by anatomic description or mechanism of injury (lawn mower, etc.). They were, however, common in our referral practice. These occur mainly from lawn mower injuries (Fig. 3F.2), but also from farm machinery (Figs. 3F.6, 11.14), motor vehicle accidents, snowmobiles (Fig. 3F.7), gun accidents (Fig. 3F.5), and boat propellers.

Evaluation

Tenderness directly over the physis is a more reliable sign than swelling or loss of motion, both of which may occur with isolated ligament or capsular damage.

Accompanying fracture of the distal fibular physis or diaphysis is common.

Three roentgenographic views should be obtained routinely in the evaluation of pediatric ankle injuries:

AP, lateral, and mortise views [22, 82]. Some lateral plafond fractures may be missed if only two views are

taken [38]. Physeal widening of more than 2 mm may indicate, but does not prove, rotational malalignment [71]. Oblique views are indicated prior to stress pic- tures [26]. Stress views are helpful to confirm undisplaced type 3 fractures, but must be done gently to avoid further damage to the physis.

Computed tomography is a useful diagnostic aid, especially for the evaluation of intraarticular fractures [28]. It is most advantageous in evaluating the triplane fracture, particularly 3 and 4 part fractures (Section C).

Magnetic resonance imaging of acute fractures of the distal tibia is best utilized for complex fractures (type 4 and 5, particularly when comminuted), when soft tissue or cartilaginous fragments prevent reduction, and when classification of the fracture by routine roentgenographs is uncertain [69].

Type 1

Type 1 are easy to recognize if the concept (transmetaphyseal fracture with extension to the physis) is known and accepted (Chapter 3A) (Figs. 11.4, 31.15).

Recognition is accomplished by routine AP, lateral, and 3/4 view roentgenograms. Tomograms, CT scans, and MRI are usually not necessary.

Fig. 11.4

Distal.tibia.type.1.fracture .This.4.year.2.month.old.girl.fell.3.feet.out.of.a.tree.injuring.her.left.ankle .a.AP,.lateral,.and.

oblique.views.show.transmetaphyseal.fractures.of.the.distal.tibia.and.fibula .The.physis.is.normal.and.there.is.no.displacement.of.the.epiphysis.on.the.metaphysis .The.large arrow.on.the.AP.view.identifies.site.of.possible.fracture.extension.distally.in.the.metaphysis .Widening.of.the.cortical.surfaces.of.the.metaphysis.on.the.lateral.view.(arrows).are.not.

possible.without.longitudinal.fracture.components .The.epiphysis.is.not.displaced.on.the.metaphysis .The.fracture.was.

reduced.manually.using.fentanyl.and.versed.anesthesia .(Continuation see next page)

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Fig. 11.4 (continued)

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b.AP.and.lateral.views.show.satisfactory.reduction,.widening.of.the.metaphyseal.cortical.surfaces,.and.on.the.lateral.a.

longitudinal.fracture.anteriorly.extending.distally.to.the.physis.(arrow),.confirming.a.type.1.fracture .c.CT.scans.(AP.and.

lateral).confirm.widening.of.the.metaphysis.and.multiple.longitudinal.fractures.extending.to.the.physis .d.MR.images.

(AP.and.lateral).also.confirm.fracture.extensions.to.the.physis.(arrows).which.is.otherwise.normal .e.Transverse.CT.images .Left.There.are.multiple.cortical.fractures.proximally.in.the.metaphysis .Right.Immediately.proximal.to.the.physis.

fragment. displacement. is. less. (note. multiple. mammillary. processes. medially) . A. long. leg. plaster. splint. was. worn.

2.weeks.followed.by.a.short.leg.walking.cast.3.weeks .f.Five.weeks.post.injury .Typical.fracture.healing.with.transmetaphyseal.sclerosis.and.normal.physis .The.child.was.allowed.to.ambulate.without.further.protection ..(Continuation see next page)

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Type 2

The metaphyseal fragment in type 2 fracture is most commonly lateral or posterolateral (Fig. 11.5), but may be medial or even anterior (Fig. 11.6). Fracture of

the fibular diaphysis is common when the metaphyseal fragment is lateral, or when the epiphysis is mark- edly displaced (Fig. 11.6). Occasionally, a type 2 fracture may appear to be a triplane fracture, and is differentiated most easily by a CT scan (Fig. 11.7).

g.Eight.months.post.injury.(age.4.years.10.months) .The.patient.is.normally.active.and.asymptomatic .The.fracture.is.

healed. and. the. physis. on. the. left. tibia. has. grown. slightly. more. than. on. the. left. (compare. Harris. . arrest.lines) .Note:.The.CT.scans.and.MRI.images.were.performed.for.investigational.purposes.and.are.not.necessary.in.

routine.cases

Fig. 11.5 Ñ

Distal.tibia.type.2.fracture.with.posterolateral.metaphyseal.fragment .This.15.year.5.month.old.boy.injured.his.right.

ankle.in.a.four-wheel.all-terrain.vehicle.accident .a.AP.and.lateral.show.type.2.fracture.with.posterolateral.displacement.of.the.epiphysis .b.Closed.reduction.was.performed.under.spinal.anesthesia .After.reduction,.a.bulky.compression.dressing.(Robert.Jones).was.applied .Three.days.later.a.long.leg.nonweightbearing.cast.was.applied.with.the.knee.

flexed.90°.and.worn.4.weeks .Active.motion.and.progressive.weightbearing.was.begun .Four.months.later.(age.15.years.

9.months).the.patient.was.normally.active.and.asymptomatic .Scanograms.showed.the.fracture.healed.and.the.right.

tibia.3.mm.longer.than.the.left .c.Three.years.8.months.post.injury.(age.19.years.1.month),.the.ankle.was.clinically.and.

roentgenographically.normal

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Fig. 11.5

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Fig. 11.6

Distal.tibia.type.2.fracture.with.anterior.Holland.sign .Several.sheets.of.

4×8-foot.sheetrock.weighing.over.100.pounds.each.fell.on.this.12.year.

2.month.old.boy’s.left.ankle .a.There.is.complete.anterior.displacement.

of.the.distal.tibial.epiphysis.which.has.metaphyseal.bone.attached.anteriorly.and.a.distal.fibular.fracture .The.skin,.ankle.joint.motion,.and.distal.

fibular.physis.are.intact .b.ORIF.of.both.fractures.utilized.Kirschner.wires . c.Six.months.post.injury.left.ankle.motion.was.80%.on.the.right.and.the.

gait.was.normal .Scanogram.showed.a.growth.arrest.line.on.the.right.

1/4.inch.from.the.physis,.no.growth.arrest.line.on.the.left,.and.the.left.

tibia.6.mm.shorter.than.the.right .(Continuation see next page)

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d.MRI.shows.a.narrow,.irregular.

physis.with.suggestion.of.a.tiny.

bar. at. the. site. of. pin. penetra- tion. (arrows. denote. pin. tract) . . e. MRI. rendering. technique.

confirms.a.small.bar.on.the.lateral.projection .f.On.the.transverse.reconstruction.MRI.view.

the.bar.comprised.4 5%.of.the.

entire.physis .Management.by.

observation. was. chosen . The.

bar. did. not. spontaneously.

break. loose. and. the. physis.

gradually. closed . The. ankle.

was. clinically. normal. and. the.

patient.participated.in.basketball. and. baseball . By. age.

14.years.2.months.the.left.tibia.

was. 15.mm. shorter. than. the.

right. and. the. distal. left. tibial.

physis.was.closed .Surgical.arrest.was.performed.on.the.left.

distal.fibula.and.the.right.proximal. tibia. and. fibula,. since. at.

this. age. the. proximal. tibia. is.

growing.at.a.greater.rate.than.

the. distal. end. (Fig .11 2) . This.

combination. was. chosen. because.arrest.of.the.right.distal.

tibial. physis. would. have. only.

prevented. the. discrepancy.

from. increasing . (Continuation see next page)

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g. Three. years. 10.months. post.

injury.(age.16.years.0.months) . The. patient. is. normally. active.

and. asymptomatic . Examina- tion.of.the.lower.extremities.is.

normal.except.for.the.surgical.

scars . Scanograms. show. the.

left. tibia. to. be. 14.mm. shorter.

than. the. right. and. all. physes.

closed

Fig. 11.7

Distal. tibia. type.2. fracture. with. large. posteromedial.

fragment .This.12.year.5.month.old.boy.injured.his.left.

ankle. while. wrestling .a. A. large. posteromedial. fragment.of.metaphysis.(Holland.sign).is.attached.to.the.

epiphysis . There. is. suspicion. of. a. sagittal. fracture.

through. the. centro-lateral. epiphysis. (a. triplane. fracture) .The.lateral.shows.mild.posterior.displacement.of.

the.epiphysis .b.A.coronal.CT.scans.show.the.epiphysis.

intact .(Continuation see next page)

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c.Transverse.CT.cuts.through.the.metaphysis.(left).showed.two.large.fragments,.while.that.through.the.epiphysis.(right).

was.normal,.negating.a.triplane.fracture .d.Open.exposure.under.general.anesthesia.recorded.a.10-mm.fracture.gap.

which.was.reduced.and.held.with.a.single.metaphyseal.screw .A.compression.bandage.was.followed.in.2.days.by.a.

short.leg.nonweightbearing.cast.for.3.weeks .The.screw.was.removed.6.months.post.fracture .(Continuation see next page)

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Type 3

Type 3 fractures occur primarily during rapid growth, for example just prior to beginning physeal matura- tion (Fig. 11.8). Type 3 fractures that are undisplaced or reduce spontaneously prior to roentgenographic analysis may be difficult to diagnose. A few clinical features help suspect the diagnosis: 1) absolute refusal to bear weight, 2) maximal tenderness over the physeal line, 3) passive longitudinal distraction and compression of the ankle are equally painful (unlike ligament or capsular injury), and 4) these fractures all occur prior to the beginning of closure of the physis and thus at an earlier age than the lateral plafond or triplane fractures. Comparison roentgenographs of the contralateral distal tibial will often show subtle differences in the width of the physis anteriorly, pos-

teriorly, medially, or laterally. If not, the diagnosis is confirmed by a stress roentgenograph. Fractures that are not confirmed on routine roentgenographs have been called “concealed epiphyseolysis” [71].

Type 3 fractures with rotational deformity (Figs.

3C.3, 11.9) are best visualized by comparing radio- graphs of the entire tibia with those of the contralateral normal tibia. The rotational deformity is always lateral [71] and may exist without fibular fracture or disruption of the interosseous ligament [8, 27, 42, 51, 54, 60, 71]. Lateral displacement of the tibial epiphysis, as may be seen with an eversion/abduction injury, will strike the fibular metaphysis (Fig. 3C.4). If the force is sufficient it may cause rupture of the distal tibio-fibular ligaments and detachment of the distal portion of the interosseous ligament, rather than fibular fracture. In this case, if the displacement has

e.Two.years.5.months.later.(age.14.years.10.months).the.patient.was.normally.active.and.asymptomatic .Both.tibiae.

measured.41 4.cm.on.scanogram .The.ankle.physes.are.closed .Note:.Since.the.ankle.joint.mortise.is.intact.this.patient.

may.have.done.equally.well.with.nonoperative.treatment .(From.Peterson.[66],.with.permission)

Fig. 11.8 Ñ

Distal.tibia.type.3.fracture .Twelve.year.2.month.old.girl.fell.ice.skating.twisting.the.right.ankle .There.was.no.clinical.

malrotation.of.the.foot.on.the.tibia .a.There.is.distal.tibial.physeal.widening.with.mild.anterolateral.displacement . There.is.suggestion.of.a.metaphyseal.fragment.(arrow),.but.this.is.overlap.of.an.oblique.fracture.of.the.fibula .b.Mortise.

(left).and.oblique.(right).views.show.widening.of.the.physis,.incongruity.of.the.epiphysis.to.the.metaphysis,.and.slight.

lateral.shift.of.the.epiphysis.on.the.metaphysis .A.long.leg.cast.was.applied.without.anesthesia.or.reduction .c.Four.

months.later.(age.12.years.7.months).the.patient.was.normally.active .There.was.very.mild.right.heel.varus .The.AP.view.

shows.centromedial.physeal.closure.of.the.distal.tibia .The.distal.fibular.physis.is.open.and.growing.and.is.further.distal.

than.on.a .This.represents.normal.fibular.growth.(relative.overgrowth) .The.lateral.view.shows.anterior.physeal.closure.

with.approximately.2.mm.residual.posterior.displacement.of.the.epiphysis .(Continuation see next page)

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Fig. 11.8

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spontaneously reduced during patient transport, the initial roentgenograph may be normal, but 3 weeks later there may be subperiosteal ossification along the lateral border of the distal tibia (Fig. 11.9d) [9].

Lateral “slipping” of distal tibial epiphysis has been

known to occur in renal osteodystrophy [81] and my- elodysplasia. Partial or complete physeal closure occurs frequently following type 3 fractures (Figs. 3C.5, 11.8c, d).

É Fig. 11.8 (continued)

d.Tomograms.confirm.a.large.physeal.bar.of.the.distal.tibia .Phemister.physeal.arrests.were.performed.on.the.ipsilat- eral.fibula.and.posterolateral.aspect.of.the.tibia .e.Nine.months.post.injury.(age.13.years.0.months) .There.is.complete.

closure.of.the.right.tibial.and.fibular.physes.(left) .Comparison.view.of.the.left.ankle.is.on.the.right .There.is.persistent,.

but.no.increase.of.relative.overgrowth.of.the.right.fibula.(arrows) .The.patient.developed.an.incisional.neuroma.which.

was.excised.and.the.nerve.reanastomosed .The.neuroma.recurred.and.was.excised .f.Four.years.1.month.post.fracture,.

age.16.years.3.months,.persistent.mild.right.heel.varus.caused.no.symptoms.or.abnormal.shoewear.and.was.felt.to..

be.due.to.mild.relative.overgrowth.of.the.fibula .Note:.Would.initial.closed.reduction.have.avoid.the.premature.physeal.closure.and.subsequent.neuroma.complication?.Will.the.persistent.mild.ankle.varus.predispose.to.degenerative.

arthrosis?

Fig. 11.9

Distal. tibia. type.3. fracture. with. malrotation . This.

12.year.7.month.old.boy.injured.his.right.ankle.playing.

football .On.examination.the.right.foot.was.externally.

rotated. compared. with. the. left .a. AP. view. of. both. . ankles. show. widened. physis. on. the. right. (left). and. . significant. differences. in. the. contours. of. Poland’s.

hump .Type.2.fracture.of.the.distal.fibula.is.not.evident . b.Mortise.view.shows.widening.of.the.distal.tibial.phy- sis.and.fracture.of.the.distal.fibular.metaphysis.(arrow).

suggesting. a. type.2. fracture .(Continuation see next page)

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Type 4

Type 4 fractures traverse the articular cartilage, epiphysis, and physis, but not the metaphysis. They are occasionally seen with medial malleolar fractures

(Figs. 11.10, 11A.3) and are the rule with lateral plafond fractures (Section B). They are more common in older children whose physes may be partially closed, predisposing the remaining open physis to succumb to the trauma force (Fig. 3D.2).

c.Lateral.(left).and.oblique.(right).views.of.right.ankle.show.widening.of.the.tibial.physis.(horizontal arrow).and.fracture.

of.the.fibular.metaphysis.(oblique arrows) .The.foot.was.internally.rotated.and.a.short.leg.nonweightbearing.cast.was.

worn.3.weeks .d.At.cast.removal.4.weeks.later.there.is.new.subperiosteal.bone.formation.extending.proximally.up.the.

tibial.diaphysis.(arrows).suggesting.significantly.more.rotational.injury.and.possibly.epiphyseal.displacement.than.on.

the.initial.roentgenograph .The.patient.limped.for.several.weeks .e.Four.months.post.fracture,.age.12.years.11.months,.

the.patient.was.asymptomatic,.the.examination.and.gait.were.normal .Standing.roentgenograms.revealed.the.beginning.of.a.Poland’s.hump.on.the.normal.left.(right),.persistent.physeal.widening.and.lack.of.Poland’s.hump.on.the.right.

(left),.but.with.beginning.normal.growth .f.Sixteen.months.post.fracture,.age.14.years.0.months,.the.patient.was.nor- mally.active.and.asymptomatic,.but.there.was.mild.right.ankle.valgus.clinically .The.growth.arrest.line.(arrows).and.the.

physis.are.parallel.indicating.normal.growth.of.the.physis.which.is.open.throughout .g.Two.years.5.months.post.fracture,.age.15.years.1.month,.standing.roentgenograph.shows.all.physes.are.closing .There.is.residual.3°.valgus.on.the.

right,.compared.with.3°.varus.on.the.normal.left

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Type 5

Type 5 fractures (Chapter 3E) are frequent in the medial malleolus [1] (Section A) (Fig. 3E.5), with fewer occurring on the lateral plafond (Section B, Fig. 11B.8).

The metaphyseal portion of the fracture is often small, even tiny (Fig. 11.11a) and visualization may require multiple roentgenographic views in different planes of rotation. The triplane fracture (Section C) crosses the metaphysis, physis, epiphysis, and articular cartilage (usually) and therefore meets all the criteria of a type 5 fracture.

Type 6

Type 6 fractures (Chapter 3F) usually occur on either the medial (Figs. 3F.2, 11.14) or lateral (Fig. 3F.7) side.

Those that involve only the central portion of the physis (Fig. 3F.4) or the entire physis (Fig. 3F.6) are uncommon.

Fig. 11.10

Distal.tibia.type.4.fracture,.undisplaced .This.8.year.11.month.old.girl.fell.skiing .a.The.fracture.is.visible.on.the.AP.view.

(left,.arrow),.but.is.best.seen.on.the.mortise.view.(right) .A.short.leg.nonweightbearing.cast.was.worn.3.weeks,.followed.

by.a.short.leg.walking.cast.3.weeks .b.Eight.months.later.(age.9.years.7.months).she.was.normally.active.and.asymptomatic .The.physis.is.normal,.there.is.no.abnormality.of.the.metaphyseal.edge.(arrow).or.new.subperiosteal.bone.

suggestive.of.a.type.5.fracture,.and.the.physis.is.parallel.with.the.growth.arrest.line.confirming.normal.longitudinal.

growth .c.Five.years.7.months.post.injury.(age.14.years.6.months).the.patient.continues.to.be.normally.active.and..

asymptomatic .The.ankle.is.normal,.all.growth.plates.and.closed,.and.the.growth.arrest.lines.(arrows).persist,.but.are.

fading

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Management

In general, accurate reduction is the first priority of management and repeated manipulations should be avoided [30, 41]. Types 4 and 5 are the most likely to require open reduction and internal fixation [40, 41].

The percentage of physeal fractures that are treated by surgery is higher at the distal tibia than at other sites; 16.5% in the series by de Sanctis et al. [16].

Fibular fractures seen in conjunction with distal tibial fractures are routinely reduced along with the tibial fracture. These fibular fractures tend to be stable after reduction and usually require no internal fixation in the skeletally immature individual. Fixa- tion may be indicated for the older child nearing skel- etal maturity with a comminuted or displaced fracture of the tibia [38]. In this case a small diameter rush pin placed perpendicularly across the center of the physis into the intramedullary cavity of the fibula gives added stability to the tibia, and problems from growth arrest are rare.

Type 1

Most type 1 fractures usually require only aligning the epiphyseal-metaphyseal fragment with the diaphysis and immobilization (Fig. 11.4). If the child is not yet walking treatment for comfort is all that is necessary. In walking age children a long leg cast with the knee bent 45° will make direct weightbearing difficult. In older children, change to a walking cast for an additional 2–3 weeks provides further protection from reinjury.

If there is metaphyseal comminution, displacement, or angular deformity, closed reduction and ap- plication of a nonweightbearing cast would be appropriate. This is to protect the comminuted metaphysis from angulation. Weightbearing or nonweightbearing plays no part in physeal bar formation. If a physeal bar forms (Fig. 31.15), it is a product of damage to the germinal layer at the time of fracture, rather than from the pressure of weightbearing.

Fig. 11.11

Distal.tibia.type.5.fracture.with.physeal.bar.formation .Boy.age.3.years.7.months.fell.from.a.tree .a.Distal.tibial.type.5.

fracture.with.proximal.displacement.of.the.medial.malleolar.fragment .The.metaphyseal.fragment.is.tiny.and.difficult.

to.see .Treatment.was.cast.without.reduction .b.Twenty-one.months.later.(age.5.years.4.months).there.is.a.physeal.bar.

medially;.the.growth.arrest.line.is.perpendicular.to.the.longitudinal.axis.of.the.tibia;.asymmetric.growth.of.the.remaining.normal.physis,.producing.45°.varus.angulation.of.the.physis;.and.adaptive.contouring.of.the.lateral.tibial.articular.

surface,.allowing.the.ankle.varus.to.be.less.than.the.physeal.varus .The.medial.malleolus.is.present.but.not.yet.ossified . The. fibula. has. grown. normally. (not. overgrowth) . A. 10-year. follow-up. of. this. case. can. be. found. in. Reference. 100 . . (Reprinted.from.Peterson.et.al .[67],.with.permission)

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Type 2

Undisplaced type 2 fractures require only protection from displacement (Fig. 11.12). Fractures displaced more than 2 mm should be reduced closed (Fig. 11.5).

The metaphyseal fragment and intact periosteal hinge on the same side aid reduction, prevent over-reduction, and provide stability. The patient should be well sedated or anesthetized to obtain complete muscle re- laxation. Reduction must be gentle and attempted only once or twice. Repeated or forced reduction may damage the physis [6, 59, 66]. Failure of closed reduction is likely due to interposed soft tissue (see Compli- cations).

Incomplete reduction demands open reduction.

The incision should be positioned for the best visualization of the fracture site [66]. This is necessary to both extract any interposed bone or soft tissue, but also to insure optimal reduction. This often requires

additional small incisions to insert internal fixation devices. Not all open reductions require internal fixation. Some reduced fractures are quite stable. The sta- tus of the fibula is important. If the metaphyseal fragment is large and accessible, one or two cannulated lag screws parallel to the physis are optimal (Figs. 11.7d, 11.13). When the metaphyseal fragment is small or in- accessible the fracture should be treated like a type 3, preferably with anatomic reduction which may be stable and not require internal fixation. If unstable, the physis may be crossed with fixation (Fig. 11.6b);

the fewest and smallest diameter smooth wires to achieve stability should be used. These wires should be removed as soon as possible, preferably no later than three weeks.

Cast immobilization for four weeks is sufficient for type 2 fractures. Weightbearing has no deleterious effect on future growth of the tibia. Damage to the growth plate occurs at the time of injury [18].

Fig. 11.12

Distal.tibia.type.2.fracture .Twelve.year.2.month.old.girl.injured.her.left.ankle.sliding.into.third.base.(softball) .The.ankle.

was.swollen .a.AP.and.lateral.roentgenograms.show.type.2.fracture.with.large.posterior.metaphyseal.fragment.attached.to.the.epiphysis.(arrows).with.2.mm.or.less.posterior.displacement .A.Robert.Jones.compression.bandage.was.

applied.with.the.foot.in.neutral.dorsiflexion .Five.days.later.a.short.leg.nonweightbearing.cast.was.applied .Three.

weeks.later.the.cast.was.removed.and.the.patient.started.active.motion.and.progressive.weightbearing .(Continuation see next page)

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b.One.year.later.(age.13.years.2.months).the.growth.arrest.line.is.parallel.with.the.physis .The.distal.tibial.and.fibular.

physes.are.closing.and.the.tibial.physis.is.closed.anteriorly.(arrow) .c.Comparison.views.of.the.right.distal.tibia.are.important.here .The.uninjured.physis,.though.still.open,.is.so.narrow.as.to.have.minimal.growth.remaining .Therefore.no.

further.treatment.was.recommended .The.patient.was.followed.at.the.clinic.an.additional.21.years.with.no.ankle.symptoms.or.abnormal.findings

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The type 2 fracture was thought by Salter and Har- ris [76] to have a uniformly good prognosis [75]. Sub- sequent authors [64–67] have frequently found accompanying growth arrest, particularly if the fracture was displaced initially.

Type 3

Type 3 fractures are often only mildly displaced or tilted (Figs. 3C.5, 11.8). These are usually easily reduced and held with a cast. Rotational alignment must be assessed in all cases and corrected when necessary (Fig. 11.9). A long leg nonweightbearing cast with the knee bent is appropriate in older children and in all cases of initial rotational deformity. In the rare case that might require open reduction, internal fixation is frequently unnecessary. A long leg cast with the knee bent would prevent rotation of the foot on the tibia.

Type 4

Anatomic reduction of these fractures is essential in order to achieve joint surface congruity and the best chance to maintain growth. Undisplaced fractures may be treated by immobilization (Figs. 3D.2, 11.10, 11A.3). Displaced fractures are best treated with reduction. Internal fixation is used when the reduction is unstable or to avoid redisplacement (Fig. 11.A.6).

The 2-mm rule is often invoked here [2]. If the frag- ment is easily reduced by closed reduction, percutaneous fixation may be appropriate in some cases. When possible the fixation should be epiphyseal to epiphyseal, distal and parallel to the physis. Small diameter smooth pins are appropriate in small children and pins or cannulated screws in older children. In older children whose physis is already partially closed, cross- ing the remaining physis is inconsequential. Oblique pinning provides more secure fixation. Postoperative weightbearing should be avoided until the internal fixation is removed (three weeks), or in older children until the fracture is healed (Sections A and B).

Fig. 11.13

a.Distal.tibia,.type.2.fracture .b.ORIF.metaphysis.to.metaphysis .(Redrawn.from.Peterson.HA.[66],.with.permission)

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Type 5

Type 5 fractures traverse the articular cartilage, epiphysis, physis, and metaphysis. The triplane fracture also meets these criteria and is discussed in Section C. The metaphyseal fragment is usually on the medial side (Fig. 3E.5,) (Section A), infrequently on the anterior, posterior, or lateral (Section B) as- pects.

This fracture has the greatest potential to develop a physeal bar. If the fragment is left unreduced a physeal bar is unavoidable (Fig. 11.11). It needs anatomic reduction and maintenance of reduction until healed.

This invariably means open reduction and internal fixation (Fig. 11A.9). Even with anatomic reduction and internal fixation, physeal bar formation is a defi- nite possibility (Fig. 11A.4), and the parents must be informed.

The incision is positioned for the best view of the fracture. This is usually anterior [48, 66, 67]. Separate small incisions are needed for percutaneous insertion of the fixation pin or screw. Since these fractures are more unstable than type 4 fractures, cannulated screws are optimal, even in young children if possible.

The ideal is one screw metaphysis to metaphysis proximal to the physis, and one screw epiphysis to epiphysis, distal to the physis, and both parallel with the physis (Fig. 3E.5). If the metaphyseal fragment is too small to accept internal fixation, two screws in the

epiphysis will aid control of sagittal plane rotation of the malleolus. Excision of a tiny metaphyseal portion of the fracture may help to visualize the physis, thereby helping the reduction, but does not preclude the chance of bar formation.

Adolescent pilon fractures have been treated both operatively and nonoperatively. Open reduction and internal fixation promotes earlier mobilization and may reduce posttraumatic osteoarthrosis [47].

Type 5 fractures need postoperative protection without weightbearing for four to six weeks in larger children. This often means a long leg nonweightbearing cast with the knee flexed, followed progressively by a short leg nonweightbearing cast, short leg weightbearing cast, air cast, splint, etc.

Type 6

Type 6 fractures (Fig. 11.14) always need initial irriga- tion and debridement. The nature of accompanying soft tissue loss determines the ongoing treatment. An immediate or delayed soft tissue flap graft may be re- quired to obtain skin coverage and may delay or prevent the inevitable accompanying physeal closure [85]. External fixation devices are helpful in immobi- lizing limbs when soft tissue flap grafting is necessary [91]. Soft tissue flap grafts applied directly to the bone might prevent bar formation. Bar formation should be expected in all cases. If there is enough growth re-

Fig. 11.14

Distal.tibia.type.6.fracture .This.9.year.9.month.old.sustained.extensive.soft.tissue.loss.of.the.left.ankle.in.a.farm.auger.

injury .a.The.medial.malleolus.is.missing.and.the.remaining.epiphysis.is.displaced.anteriorly.on.the.metaphysis.(combined.type.6.and.3.fractures) ..(Continuation see next page)

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maining, a bar invariably occurs. The resulting deformity requires reconstructive surgery. Transfer of iliac crest bone to reconstruct an absent medial malleolus can be very helpful (Fig. 11.14). Prophylactic transfer

of the iliac crest apophyseal cartilage at the time of injury has been successful in reconstructing the medial malleolus and preventing a bar formation in one case [57].

b.Following.debridement.there.was.absence.of.the.anterior.metaphysis.and.instability.of.the.epiphysis .c.The.epiphysis.

was.stabilized.with.two.smooth.Steinmann.pins .d.The.open.wound.was.debrided.on.multiple.occasions.covered.with.

split.thickness.skin.grafts.on.the.16th.post.injury.day .e.Five.months.post.injury,.age.10.years.2.months,.a.bar.was.form- ing.at.the.exposed.medial.physis .Normal.fibular.physis.and.Harris.line .(Continuation see next page)

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f.Six.months.post.injury.the.bar.was.more.obvious.on.MRI .Scanogram.showed.the.left.tibia.1.cm.shorter.than.the.right . Surgical.physeal.arrest.of.the.left.distal.fibula.and.lateral.tibia,.and.of.the.normal.right.distal.tibia.and.fibula.were.performed.at.age.10.years.4.months .g.Thirteen.months.post.injury,.age.10.years.10.months,.left.ankle.varus.was.27° ..

h.Standing.photograph.shows.left.ankle.deformity.and.adequate.skin.coverage .(Continuation see next page)

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i.At.age.11.years.0.months,.open.wedge.osteotomy.[60].was.combined.with.reconstruction.of.the.medial.malleolus.

using.tricortical.iliac.crest.apophyseal.bone,.and.fibular.osteotomy .Normal.skin.and.subcutaneous.tissue.were.mobi- lized.from.posterior.to.anterior.to.the.medial.malleolus .j.At.age.16.years.10.months,.7.years.1.month.post.injury,.the.

patient.is.active.in.soccer.and.basketball .He.has.mild.intermittent.ankle.swelling.and.aching.with.weather.change . There.is.no.limp