:

.,

#{149} .. The .

.

Calcaneus: Normal and AbnormaP Rajendra

Kumar,

MD

#{149} Kenneth

Matasar,

MD

Susan Stansberry, MD #{149} Ali Sbirkhoda, Ruppert David, MD #{149} John E. Madewell, LeonardE. Swiscbuck, MD

MD MD

The

congenital

calcaneus

disorders

is the affect

self,

whereas

sues

extend

mary

and

into

bone and

features.

This calcaneal

disorders

the

soft-tissue

the

important

of many

knowledge

should

disorders

the

disorders

facilitate

encountered

arise

adja-

calcaneal

disor-

calcaneus

are

a wide

salient

dis-

spec-

radiographic

radiographic in clinical

pri-

neoplas-

describes their

tis-

the

that

of the

article

it-

soft

majority,

neoplasms

This

calcaneus

Among

secondary

illustrates

acquired

hematologic,

constitute

and

and

in the

indirectly.

constitute

diagnostic.

and

neighboring

infectious,

disorders

disorders

arise in the

calcaneus

traumatic,

thus

Many

arising

arthritides

of calcaneal

various U

affect

features

ease-specific

bone.

Primary

miscellaneous

Radiographic

trum

tarsal

disorders

and

various to the

ders.

bone.

congenital,

other

whereas cent

the secondary

lesions,

tic,

largest

diagnosis

of

practice.

INTRODUCTION

The calcaneus is the largest of the tarsal bones and bears body weight in the upnight position. The bone is affected by a broad spectrum of congenital and acquired disorders. Many of these lesions arise in the calcaneus itself and constitute the primary disorders. Secondary disorders arise in the soft tissues adjacent to the calcaneus and involve the bone by direct extension. In this article, we describe the clinical and radiographic features of various calcaneal disorders. ANATOMIC CONSIDERATIONS calcaneus is roughly cuboidal in shape and has six surfaces: (a) the superior surface, with anterior, middle, and posterior facets for articulation with the talus; (b) the plantar surface, with a tubenosity along its posterior aspect; (c) the lateral surface, with a bony prominence for attachment of the calcaneofibular ligament; (d ) the medial surface, which extends anteriorly as the sustentaculum tall; U

The

Index 4642.35

terms: #{149} Bones,

Calcaneus,

Bone neopiasms. 4642.30 #{149} Bone neoplasms, metastases, diseases, 4642.70 #{149} Bones, infection, 4642.20 #{149} Bones,

fractures,

RadloGraphlcs

4642.41 1991;

#{149} Foot,

Departments (R.K., 5.5.,

lake,

Ohio

(RD.);

1989 1991

RSNA scientific assembly. ; accepted March 7. Address

CRSNA,

4642.30,

4642.33,

fibrous

4642.35

#{149} Bone

neoplasms,

dysplasia, #{149} Foot,

secondary,

4642.85

fractures,

#{149} Calcaneus

4642.41

1 1:415-440

I From the 775502774

and

neoplasms,

4642.33

of Radiology, the University L.E.S.); William Beaumont Penn

State

University Received reprint

of Texas Hospital,

Milton August 17, requests

S. Hershey

Medical Branch, 2 10 McCollough Royal Oak, Michigan (KM., AS.); Medical

1990; revision to R.K.

Center, requested

Hershey, October

Bldg. StJohn

Pennsylvania 22

and

received

Galveston, Hospital, O.E.M.). March

TX West. From 5,

1991

415

p .., (_

I’

‘,.,,*,

.

I,. ‘

.

#{149}4%

.

I

.

,b&’#{149}

b.

(e)

with

the anterior the cuboid;

where

face,

(Fig

which

surface,

(1)

and

articulates

the posterior tendon inserts

the Achilles

U sur-

calcaneus

has synovial

develops

articulations

with the talus to form the anterior, and posterior talocalcaneal joints the cuboid to form the calcaneocuboid

middle, and with joint.

Between the middle and posterior talocalcaneal joints lies the sinus tarsi, which conthe intenosseous talocalcaneal ligament. Several tendons and ligaments are attached to the calcaneus. The plantan aponeunosis inserts along its plantar aspect. The Achilles tains

tendon,

the common

cnemius and soleus, gest in the body and part of the posterior

Between the upper face of the calcaneus

tendon

of the gastro-

is the thickest and stronattaches to the middle surface of the calcaneus. part of the posterior sun-

and

lies the deltoid

netnocalcaneal and fibular

tached

to the calcaneus

the Achilles

bunsa. ligaments

(1).

Portions are also

VARIANTS

calcaneus

and

talus

ossify

month of intrauterine life tarsi to do so. Occasionally,

1).

The

NORMAL

The

from

healthy

and

infants

Hurler

two

ossification

as well

syndromes.

on radiographs.

centers

as those

with

An apophysis

ops along the posteroinfenior calcaneus in early childhood. sify at age 4-7 years in girls years in boys, at which time

nized

by the

3rd

and are the first the calcaneus

It fuses

in Down

devel-

aspect of the It begins to osand age 7-10 it can be necog-

with

the calca-

neus by age 1 2- 1 5 years in both sexes, a!though occasionally the apophysis may not close until age 1 6 years in girls and 22 years inboys (2). Occasionally, radiography of the hindfoot reveals some atypical appearances of the calcaneus that are not associated with a disease process. These normal variants include pseu-

tendon

dofractune

of the at-

nutrient plantar

of the apophysis, foramen, bone spur.

Pseudofractune

Seven

disease,

and

transient

pseudocyst,

of the apophysis

is a com-

mon normal variant. Frequently, a normal, partially ossified calcanea! apophysis ap-

416

U

RadioGrapbks

U

Kumar

et al

Volume

11

Number

3

2-5. Normal calcaneal variants. (2) Pseudofracture of calcaneal apophysis in a child. Lateral radiograph shows a fragmented apophysis (a). (3) Sever disease. Lateral radiograph shows sclerotic apophysis of the calcaneus in a child. (4) Sever disease resolved. Lateral radiograph of the calcaneus shows norma! fused apophysis in an adult. Note uniform opacity of fused apophysis. (5) Oblique radiograph of calcaneus shows a nutrient foramen (arrow). Figures

pears fragmented (Fig 2). So-called Sever observed in young

and

mimics

a fracture

disease children

is a normal variant and should not be misinterpreted as an abnormality (3) In infants, the radiopacity of the calcaneal apophysis is similar to that of the nest of the bone. However, in some infants, as they begin walking, the apophysis becomes sclenotic (Fig 3). This change in increased radiopacity of the apophysis does not occur in chi!.

dren

who

(4,5). fuses sumes

As the child ages and the apophysis with the calcaneus, it gradually asthe same appearance as the rest of the

do not

bear

body

bone (Fig 4). Infrequently,

a nutrient

observed

medial

May

on the

1991

weight

foramen plantan

normally

may surface

calcaneus on a radiograph of an internally notated foot. The foramen transmits blood yessels (Fig 5). Occasionally, a triangular area of narefaction due to lack of normal spongy bone is seen in the midportion of the calcaneus on a lateral radiograph (Fig 6). This so-called pseudocyst lacks well-defined bonders, and its base lies infeniorly (3). A small ringlike area of opacity may at times be present within this area of rarefaction and is believed to represent a nutrient canal.

A transient bone

spur

plantar usually

bone seen

spur

on the

is a small plantar

surface

be of the

Kumar

et al

U

RadioGrapbks

U

417

6. 7Figures 6, 7. Normal calcaneal variants. (6) Pseudocyst of the calcaneus. defined area of rarefaction (arrows). (7) Lateral radiograph shows transient child. Bone spur may be directed anteriorly, posteriorly, or straight down. chen, MD, Ignatius Hospital, Breda, The Netherlands.)

Lateral radiograph shows an illplantar bone spur (arrow) in a (Courtesy of PetenJ. van Wie-

a.

b. CoalitIon. (a) Lateral radiograph shows a bone bar (arrow) across the calcaneus and navicular, a finding indicative of calcaneonavicular coalition. (b) CT scan of both feet in another patient shows bilatera! talocalcaneal coalitions (black arrows) and calcaneonavicular coalition in the left foot (white arrow). C = calcaneus, n navicular, t talus. Figure

8.

of the graphs

calcaneus (Fig 7)

These

spurs

.

tend

nc and may point infenionly (6,7). U

PRIMARY

Primary calcaneus,

.

It

of infants disappears

on

to be bilateral anteriorly,

lateral radioby 1 year of age.

and symmetposteriorly,

on

1

MOdified Calcaneal

Essex-Loprestie Fractures

Extraarticular Calcaneal Beak

LESIONS

lesions are intrinsic as they directly

Congenital

Table

disorders arise in the

of the bone.

Disorders

U

Ra4ioGrapbks

U

Kumar

et al

fractures

type

joint

involvement

Undisplaced Displaced Comminuted Calcaneocuboid Source-Adapted

418

fractures tuberosity

Vertical Horizontal Medial avulsion Intnaarticular fractures Subtalar

Tarsal coalition is the most important congenital problem of the calcaneus clinically. In about 20% of the cases of congenital tarsal

of

Classification

joint from

involvement

reference

Volume

10.

11

Number

3

Table 2 Schmidt-Weiner

Classification

of Calcaneal

Type

Fractures

and

Their

Prevalence

Description

iA.t iB’

Fracture of calcaneal apophysis Sustentaculum tali fracture

iC’

Anterior

1D

Inferolateral

iE

Avulsion

2At

Beak

2B*

Achilles

3 4S 5A 5B 611

Linear extraarticular fracture Linear intraarticular fracture Tongue-type fracture Joint depression or comminuted

(%)

Prevalence 6 3

(intraa.rticular)

process

fracture

(intraarticular)

15

fracturel

(intraarticular)

1

4

fracture tendon

Posterior

avulsion

calcaneal

and Achilles Source-Reference #{149} Caused by avulsion t Occurs in children.

J

fracture

$

Caused § Usually

by direct trauma. occurs following

II Usually

seen

injury

with

40-60

including

tuberosity

extensive

soft-tissue

and usually

a fall from

in victims

5 fracture

fracture

tendon

1 1. or twisting

19 10-25

has a benign