Fractures

in the

Immature Foot

Kaye E. Wilkins, M.D. Clinical Professor Orthopaedics & Pediatrics

University of Texas Health Science Center at San Antonio San Antonio, Texas

(210) 692-1613 e-mail: drkwilkins@aol.com

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FRACTURES IN THE IMMATURE FOOT

INCIDENCE

Fractures of the foot in children are rare. The foot and ligamentous structures

are very flexible - thus, the forces are often transmitted proximally to the tibia and

femur (FIGURE 1). When they do occur, fractures in the pediatric foot are usually

simple and require very little active treatment. Some fractures do require active

intervention such as fractures of the: talus, calcaneus, navicular, tarsal metatarsal

fracture dislocations, 5th metatarsal base and shaft, metatarsal neck fractures, and great

toe avulsions.

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FRACTURES OF THE TALUS

Fractures of the Neck

These are rare in children. The adult to children ration is 10:1.

The mechanism is usually a forced dorsiflexion of the neck of the talus against

the anterior lip of the distal tibia. The head and neck remain pronated but are dorsally

displaced and abducted (FIGURE 2). The diagnosis is usually made with the

radiographic technique of Canale and Kelly which delineates the anterior-posterior

outline of the neck of the talus.4 This view is taken with the foot pronated 15 and the

x-ray tube angled 75 to the table-top. This view separates the talar neck from the

underlying calcaneus.

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In treating these fractures, if they are nondisplaced, cast immobilization and non-

weightbearing until they are healed is usually sufficient. Displaced fractures usually

require a manipulative closed reduction which involves reversing the deformity by

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plantar flexing and supinating the forefoot (FIGURE 3). The acceptable limits of

reduction are

less than 5mm

displacement

and less than 5 of malalgulation. If one is unable to achieve satisfactory closed

reduction, the fracture must be reduced surgically. In the anterior approach the safe

interval is between the extensor hallicus longus and tibialis anterior. The surgical

dissection should be kept to a minimum. Internal fixation has no proven effect on

preventing avascular necrosis but is felt to hasten union.

The complications include avascular necrosis which can occur as high as 30%

even in undisplaced fractures. Weightbearing probably has no effect upon the

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development of avascular necrosis. Weight bearing should be allowed when the

fracture is healed or when the technicium scan has become nonreactive. Fortunately, a

crushed, deformed talar dome may produce a reasonable function in the child.

Fractures of the Lateral Process

This is a fracture of the area of the talus which involves both the fibular-talar and

subtalar joint. It often is misdiagnosed as an ankle sprain. Treatment usually consists

of open reduction and internal fixation if the fragment is large enough or excision if it is

small.

Transchondral Fractures (Dome)

Early radiographs may be negative and thus require bone scan or MRI for the

diagnosis.1 There are two types which include: posteromedial lesions produced by

inversion and plantar flexion of the foot with external rotation of the tibia. The

anterolateral lesions are caused by inversion and dorsiflexion and may have an

associated rupture of the fibular collateral ligament system.2

Canale and Belding doubted that the medial lesions were traumatic in origin.3 It

is felt that surgical excision gives better results if the lesions are symptomatic. The

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anterolateral lesions can be removed directly. The posteromedial lesions may need to

have an osteotomy performed of the medial malleolus to reach the posterior location on

the dome. Recently, Greenspoon and Rosman described a technique of bone-grafting

the medial lesions by approaching the talus through the non-articular medial surface.8

FRACTURES OF THE CALCANEUS

Incidence

The incidence is very rare in children occurring only 1/20th that of adults.19 It is

greater in males in adolescence. The female incidence is equal through all age

groups.18 It may be a cause of an occult limp in toddlers.20

Mechanism

In children, it is less from falls but more from direct injury, that is, lawn mowers

with open fractures. The child=s calcaneus is more flexible and thus less likely to crush.

A fall from a height is more common in children with joint depressions (FIGURE 4).

More often, children have other associated injuries with the fracture of the calcaneus.

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Diagnosis

Often, these findings are subtle on x-ray.7,21 It requires a minimum of 4 views

(lateral, axillary, dorsoplantar, oblique dorsoplantar) to visualize adequately the fracture

on plain x-rays.18 In infants with normal radiographs, radio nucleotide scan imaging or

MRI may be helpful. This may be another type of the so-called Atoddler@ fractures.20

To adequately evaluate the articular surface of the subtalar joint, CT scans are very

helpful.6,16 In those patients sustaining a fall from a significant height, the physician

should always check the lumbar spine for an associated compression fracture.

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Classification

Schmidt and Weiner describe three groups.19 First there is the extra-articular

which involves mainly the body of the calcaneus and the nonarticulating surface. This

is more common in the younger child. Secondly, there is the intra-articular which

usually is due to a fall from heights and is more common in older children and

adolescents. In this one, the articular surface is depressed. Finally, there is the loss of

bone with the loss of the achilles tendon insertion which is usually associated with some

type of open laceration, i.e., lawn mower injuries.

With the event of CT scans, Cosby and Fitzgibbons described three groups of

diaplacement of the articular surface.6 This classification is useful in determining

outcomes of non-operative treatment. In Type I, these are small fractures and are not

displaced less than 2mm. These usually do well with nonoperative treatment. In the

Type II, the articular surface is displaced greater than 2mm and can be treated

nonoperatively but may have poorer results than Type I. In Type III, these fractures

are comminuted with multiple small fragments and do poorly even with operative

treatment.

Management

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In the younger individuals remodeling may correct with minor joint incongruities.

Thus, the patient is treated non-weightbearing until the fracture is healed. In the older

child with joint depression, the fracture must be treated with open reduction and

internal fixation using a lag screw via lateral approach.

FRACTURES OF THE NAVICULAR

Fractures of the navicular in children are rare and often may be missed. They

may even be recognized only on a CT scan. If there is much incongruity of the joint

surface, surgical reduction may be required.

FRACTURES OF THE CUBOID

These are often overlooked. They are often called a Anutcracker@ fracture

because they are due to compressive forces of the cuboid between the calcaneus and

the two lateral metatarsals.9 If a cuboid fracture is present one must always check for

associated tarsal metatarsal disruptions. If the lateral cortex is incongruent, this can

disrupt the function of peroneus longus as it courses through its adjacent sheath.17 This

fracture also has been described as occurring as a stress fracture in infants who toe-

out.15

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TARSAL-METATARSAL FRACTURE DISLOCATIONS

Anatomical Factors

In this area, the ligaments are stronger on the plantar aspect. The second

metatarsal is recessed in its articular surface which makes it more stable.

Mechanisms

There are two mechanisms that account for this fracture pattern. The first is due

to flexion-abduction forces which produces a fracture in the base of the second

metatarsal and crush fracture of the cuboid. The second involves violent plantar flexion

in which the foot is loaded in a tiptoe position resulting in rupture of the weaker dorsal

ligamentous structures.

Treatment

The undisplaced fractures (less than 2mm) can usually be treated conservatively

with elevation and a compression dressing. The displaced fractures may require a

closed reduction in which Chinese finger-trap traction is applied to the toes. These may

require medial and lateral pins to stabilize the fractures. Some, if they are markedly

displaced, may require open reduction with pin fixation.

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METATARSAL FRACTURES

Fifth Metatarsal

Fractures of the base of the fifth metatarsal (metaphyseal) are seen in the

younger age group. One must differentiate this fracture from the apophysis. The

apophyseal line is usually is parallel to the metaphyseal shaft whereas the metaphyseal

fracture line is perpendicular to the metatarsal shaft. This is not a true avulsion fracture

by the peroneus brevis. The fracture occurs because of greater integrity of the

ligamentous insertion between the metatarsal and cuboid than the metaphyseal bone.

Treatment. Usually these are immobilized only for comfort. Warn the parents

beforehand that this fracture may be slow to heal completely or that the fracture will

also have some late displacement. Neither condition of which is of any functional or

cosmetic significance.

Diaphyseal fractures are usually seen in older teenagers. This is the true

AJones@ fracture in which there is very slow healing. This usually requires stabilization

with a screw placed axially up the intramedullary canal.

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Stress Fractures

These manifest by the classical signs of increased pain with activity, decreased

pain with rest. X-ray changes may not occur for 3 - 4 weeks. It needs to be

remembered that stress fractures can occur in young children as well.5 If it is a

diaphyseal fracture, union may be delayed even with stress fractures.

Osteochondral Fractures of the Metatarsal Head

These are often missed. They interfere with extensor tendon function and may

be painful. Excision is usually the treatment of choice.

Fractures of Metatarsal Shafts

These are usually the result of a direct blow to the foot. Thus, soft tissue injury

often is a major factor. Fasciotomies may be necessary.

Metatarsal Neck

This is the result of bending forces distally on the metatarsal area. Closed

reduction is usually accomplished by finger-trap traction followed by application of a

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well-moulded cast. It must be remembered that bayonet apposition is acceptable as

long as there is not significant dorsal or plantar angulation. Open reduction is done via

a dorsal approach in which the pins are inserted distally, then retrograded proximally

into the shaft. The most common complication is growth arrest which can occur if the

distal physis is involved.

PHALANGEAL FRACTURES

These are usually simple fractures treated by closed reduction with buddy taping.

The one exception in which operative management is required is an avulsion of the

proximal phalanx of the great toe by the collateral ligament. If there is significant

displacement of the collateral fragment, open reduction may be required.

COMPARTMENT SYNDROMES

Unfortunately, this is often unrecognized early. This entity must be suspected in

those injuries that have a significant crushing mechanism. The clinical findings12

include sensory loss of 50%. Pain on passive dorsiflexion of the toes is the most

reliable clinical sign .

Compartment pressure measurement will help make the diagnosis.

Measurements greater than 30 mm Hg. indicate abnormal compartment pressures. It

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must be remembered that intra-articular calcaneal fractures can increase the pressure

in the central plantar muscle compartment. Unrecognized compartment syndromes in

the foot can lead to claw toe deformities.11,13 Fasciotomy is the treatment of choice and

must include both dorsal interosseous and plantar compartment

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REFERENCES

1. Anderson, I.F.; Crichton, K.J.; Gratlan-Smith, T., et. al.: Osteochondral Fractures of the

Dome of the Talus. J. Bone Joint Surg., 71A:1147-1162, 1989.

2. Berndt, A.L. and Harty, M.: Transchondral Fractures (Osteochondritis Dessicans) of the

Talus. J. Bone Joint Surg., 41A:988-1020, 1959.

The most complete review of the types, mechanisms of injury and

treatment of this injury in the orthopedic literature. Differentiates

medial from lateral injuries. Found conservative management gave

as poor results in children as in adults. Describes four states in

these injuries.

3. Canale, S.T. and Belding, R.H.: Osteochondral Lesions of the Talus. J. Bone Joint Surg.,

62A:97-102, 1980.

Reviewed 29 patients and found lateral lesions associated with

trauma and more likely to be symptomatic. Medial lesions often

were less symptomatic. Gives treatment recommendations using

Berndt and Harty classifications.

4. Canale, S.T. and Keely, F.B.: Fractures of the Neck of the Talus. Long term Evaluation of

71 Cases. J. Bone Joint Surg., 60A: 143-156, 1978.

One of the most extensive reviews of talar fractures. Twelve of

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their cases were 16 years or younger. Described radiographic

techniques of evaluation. Gave guidelines for acceptable reduction.

5. Childress, H.M.: March Foot in a Seven Year Old Child. J. Bone & Joint Surg., 28A:877,

1946.

6. Crosby, L.A. and Fitzgibbons, T.: Computerized Tomography Scanning of Acute

Intra-articular Fractures of the Calcaneus, A New Classification System. J. Bone & Joint

Surg., 72A:852-859, 1990.

7. DeBeer, J. D.; Maloon, S., and Hudson, D.A.: Calcaneal Fractures in Children.S. Af.

Med. J., 76:53-54, 1989.

8. Greenspoon, J. and Rosman, M.: Medial Osteochondritis of the Talus in Children:

Review and New Surgical Management. J. Pediatr. Orthop., 7:705-708, 1987.

9. Hermel, M.B., and Gershon-Cohen, J.: The Nutcracker Fracture of the Cuboid by Indirect

Violence. Radiology, 60:850-854, 1953.

10. Letts, R.M. and Gibeaut, D.: Fracture of the Neck of the Talus in Children. Foot and

Ankle, 1:74-77, 1980.

Report on 12 cases of fractures of the talar neck in children. Four

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cases were younger than 3 years of age. Noted avascular necrosis in

undisplaced fractures.

11. Manoli, A. and Weber, T.G.: Fasciotomy of the Foot: An Anatomical Study with Special

Reference to Release of Calcaneal Compartment. Foot & Ankle, 10:267-275, 1990.

12. Meyerson, M.D.: Management of Compartment Syndromes of the Foot. Clin. Orthop.,

271:239-248, 1991.

13. Mittlmeier, T.; Machler, G.; Lob, G., et al.: Compartment Syndrome after Intra-articular

Calcaneal Fracture. Clin. Orthop., 269:241-248, 1991.

Three recent articles emphasizing the need to recognize and treat

-aggressively compartment syndromes in the foot.

14. Mulfinger, G.L., and Tureta J.: The Blood Supply of the talus. J. Bone Joint Surg., 52B:

160-167, 1970.

Describes the blood supply of the talus as coming from three

sources. Points out the vulnerability of the neck to developing

avascular necrosis in fractures.

15. Nicostro, J. F. and Haupt, H.A.: Probable Stress Fracture of Cuboid in an Infant. J. Bone

& Joint Surg., 66A: 1106-1108, 1984.

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16. Pablot, S.M.; Daneman, A.; Stringer, D.A. and Carroll, N.: The Value of Computed

Tomography in the Early Assessment of Comminuted Fractures of the Calcaneus. A

Review of Three Patients. J. Pediatr. Orthop., 5:435-438, 1985.

17. Phillips, R.D.: Dysfunction of Peroneus Longus after Fracture of Cuboid. J. Foot Surg.,

24:99-102, 1985.

18. Rasmussen, F. and Schantz, K.: Radiologic Aspects of Calcaneal Fractures in Childhood

and Adolescence. Acta Radiologica. (Diag), 27:575-580, 1986.

19. Schmidt, T.L. and Weiner, D.S.: Calcaneal Fractures in Children. An Evaluation of the

Nature of the Injury in 56 Children. Clin. Orthop., 171:150-155, 1982.

Reviews patterns of these injuries in children. Less common injury

from fall than adults. Higher incidence of injury by lawn mower or

direct blows. Higher incidence of other associated fractures, fewer

intra-articular fractures.

20. Starshak, R.J.; Simons, G.W. and Sty, J.R.: Occult Fracture of Calcaneus - Another

Toddlers Fractures. Radiology, 14:37-40, 1984.

21. Wiley, J.J., and Profitt, A.: Fractures of the Os Calcis in Children. Clin. Orthop.,

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188:131-138, 1984.

22. Wylie, J.J.: Tarsometatarsal Joint Injuries in Children. Pediatr. Orthop., 1:255-260, 1981.

Describes three common mechanisms of injury. Found patterns of

injury similar to adult. Eighteen cases reviewed. All treated with

manipulative reduction, with or without percutaneous pin fixation.

Results were uniformly good.