A TECHNIQUE

FOR

LUMBAR

SPINAL

ANKYLOSING J.

the Edinburgh

McMASTER

Scoliosis

Unit.

Edinburgh

Fourteen patients with ankylosing spondylitis had an extension osteotomy of the spine. The Smith-Petersen technique was modified by using a compression finely controlled closure neurological complications. fusion

at nine

months,

of

the osteotomy, All the patients

having

and provides rigid internal were able to see straight ahead good

maintained

the normal lumbar thoracic kyphosis

lordosis, with the

and an increasing head and neck thrust

This

paper

reports

used

and

angular

designed closure

device of the

internal

fixation.

disabling but is also Smith-Petersen,

psychologically Larsen and

From

ognised

of

plight

devised the operation spine is hyperextended patient to see straight few surgeons

have

these

disturbing. Aufranc (1945)

unfortunate

rec-

patients

and

of spinal osteotomy. by which the in the lumbar region, enabling the ahead. Since their paper relatively attempted

the operation

1946; Adams 1952: Herbert 1962; Goel 1968; McMaster all of these have reported complications. The reported

(La

Chapelle

1959; Law 1959; McMaster and Coventry 1973). Nearly a high incidence of major mortality rate has varied

from 8% to 10% and neurological complications, up to and including paraplegia, have occurred in as many as 30% of the patients. Other complications have included rupture of the aorta, acute dilatation of the stomach, superior

mesenteric

turbances. patients.

Only reported

tions this

thrombosis Simmons no deaths

thus allowing state.

M. J. McMaster. MD. Edinburgh Scoliosis Hospital. Fairmilehead. 1985

030l-620X

204

psychological

(1977), in a or neurological

British

He

$2.00

Society

attributed under local

monitoring

of Bone

and

Joint

of the

Surgeon Orthopaedic

Surgery

_________________

were no serious and all had solid

the

results

of a prospective

study

correction

was

CLINICAL Margaret patients

June

obtained

with

a specially-

which allowed slow and finely controlled osteotomy, as well as providing rigid

1980

to

MATERIAL August

1982,

at

the

Princess

Rose Orthopaedic Hospital, Edinburgh, with ankylosing spondylitis each had an

sion osteotomy flexion deformity.

of the lumbar spine All the operations

14 exten-

to correct a severe were performed by

the author using a special method of intra-operative correction and internal fixation. There were I 1 men and three women whose mean age at operation was 42 years (range 31 to 66 years). Their mean duration of symptoms was 21 years (range 6 to 44 years) and all had been treated

conservatively

without

Two patients because of vertebral respectively, which had any neurological healed satisfactorily.

success.

had become much more stooped compression fractures of L I and L2 they had sustained in falls. Neither abnormalities Two other

and patients

the fractures developed in-

creasing pain in the back and noticed that their flexion deformity was getting worse. Both had developed a spontaneous pseudarthrosis in their ankylosed spine, one between T12 In seven

and LI, and the other between of the patients the hips also

and five of these had months to 10 years

FRCS. Consultant Orthopaedic Unit. Princess Margaret Rose Edinburgh EHIO 7ED, Scotland.

Editorial

852053

continuous

dis-

study of 19 complica-

following lumbar spinal osteotomy. success to performing the operation

anaesthesia, neurological

(

and

fixation. There after operation,

of methods designed to reduce the incidence of neurological complications during and after lumbar spinal osteotomy. A modification of the usual technique was

forwards. Occasionally there is increasing flexion at the cervicothoracic junction. Eventually the whole spine undergoes bony ankylosis in this deformed position, and the patient is bent forward and forced to look down at the ground. This ugly posture is not only functionally

the

for severe fiexion deformity device which allows a slow,

correction.

Ankylosing spondylitis may sometimes cause one of the most disabling deformities seen by the orthopaedic surgeon. The characteristic spinal deformities are flattening of smooth

IN

SPONDYLITIS

MICHAEL

From

OSTEOTOMY

had bilateral before spinal

LI were

and L2. affected

total hip replacement osteotomy. These

3 hip

replacements were needed to correct fixed flexion and to relieve pain. Assessment of the deformity. The main indication for the operative correction of a severely flexed posture in a patient with ankylosing spondylitis is the patient’s inability to see ahead for more than a few feet. It is, THE

JOURNAL

OF

BONE

AND

JOINT

SURGERY

LUMBAR

however. levels

important of the

to

spine

assess

and

SPINAL

the

of the

OSTEOTOMY

contribution

hips

to the

IN

of

flexed

ANKYLOSING

205

SPONDYLITIS

all

posture

before attempting correction. Severe flexion contracture of the hips can often be corrected by soft-tissue release and total hip replacement (Bisla, Ranawat and Inglis 1976;

Williams

itself

ci a!. 1977)

to allow A spinal

the patient osteotomy

and

this

may

be sufficient

to see straight ahead. is indicated only if the

by

hips

are

not significantly deformed or if, after hip operations, the patient is still unable to see ahead (Case I 1, see Figs 12, 14 and 16). The thoracic spine is usually the most flexed region but osteotomy at that level does not help because the ankylosed thoracic cage spine. A thoracic deformity creation a lumbar

of a compensatory osteotomy (Figs

perform the osteotomy first lumbar vertebra

spacious vertebral which is less easily

Ideally

the

lumbar

the osteotomy, In a few

spine

straight should

canal injured should

ahead. then

helping patients

the cervicothoracic ity by a lumbar

lumbar I and

extension overcome

of by

the the

lordosis by means 2). The safest level

of to

is in the lumbar spine distal to the because at this level there is a

relatively equina,

patient can see the upper body

prevents is best

be

extended

Endotracheal necessary

the

during

Correction could possibly

possibly

deformity fibre-optic tomy

OF

anaesthesia intubation

ankylosed

until

spine.

of of

is at

straight ahead an extension 1977).

fourth.

care injury

stiffness

very difficult and is often necessary

is to and

is to be avoided. table with and possupported

firm foam blocks which leave the abdomen free. This position reduces intra-abdominal combined with hypotensive anaesthesia and

infiltration of the operation site with a 1 : 400 000 of adrenaline, it greatly reduces bleeding during tion and makes (Malcolm-Smith

it easier to identify the and McMaster 1983).

neural

solution operastructures

The incision muscles

lumbar spine is exposed extending from T12 to are stripped subperiosteally

through L5. The from

a midline paraspinal the bone

laterally

to the tips

processes

at the level

ofthe

transverse

of the osteotomy. The anatomical details are usually obscured by ossification of the interspinous ligaments, the ligamentum flavum and the interfacetal joints. The technique of the osteotomy is basically that described VOL.

67-B.

by Smith-Petersen No.

2. MARCH

1985

c/

al. (1945),

and

2

Fig.

3

Fig.

4

spine can be Figures 3 and junction. an may unbalance

modified

(1952) and Law (1959) (Figs 5 and 6). It was necessary to perform an anterior spinal as a separate stage as described by Herbert La Chapelle (1946). The preferred site for the spinal osteotomy lumbar vertebrae

These

sites

are

is either between the second or between the third and

distal

to the

far enough from the sacrum to allow internal fixation device. Identification

the use of a if tracheos-

The patient is turned on to the operating care to avoid injury to the ankylosed neck, itioned face down, with the chest and pelvis on special hanging pressure;

by Adams not found osteotomy (1959) and posterior and third

Neck

Fig.

the

OPERATION

cervical

I

of this deformunbalance the

is essential. Great to avoid accidental

make intubation laryngoscope

cauda cord.

correction. flexion deformity

patient and still not enable him to see (Figs 3 and 4). These patients require osteotomy of the cervical spine (Simmons TECHNIQUE

the spinal

The centre of gravity lie just behind the site

to maintain the major

junction. osteotomy

containing than the

Fig.

Figures 1 and 2-Flexion deformity in the thoracolumbar overcome by creating a compensatory lumbar lordosis. 4-If the major fiexion deformity is at the cervicothoracic attempt at correction by a lumbar extension osteotomy the patient.

by noting vertebrae The fixation

spinal

cord

application ofthe level

and

are

of the is made

the position of the last rib or by counting the up from the sacrum. bony sites for the application of the internal device

must

be

prepared

before

cutting

the

osteotomy. With an osteotome, notches are carefully cut in the ossified ligamentum flavum on either side of the spinous processes of the vertebrae above and below the site of the osteotomy. Initially these notches are made only in the outer cortex of the bone and are completed by hammering a sharp Harrington hook (No. 1251) on an introducer

until

the hook

lies firmly

within

the bone.

The

upper two hooks should lie over the top of the lamina of the vertebra at the level above the osteotomy site, and the lower two hooks around the bottom of the lamina at the level below the osteotomy site. Once each bony site is prepared for later use the sharp hook is removed. Hammering the hooks after the osteotomy has been cut could displace the vertebrae and cause neural damage. The

osteotomy

removes

a posteriorly

based

wedge

of bone which includes the adjacent spinous processes and the ossified interspinous ligament; it exposes the interlaminar space. The ossified ligamentum flavum in the

midline

is nibbled

away

with

rongeurs

until

a small

area of dura is exposed. The dura is frequently adherent to the undersurface of the ossified structures; it can easily be torn unless it is separated carefully with a fine blunt dissector. Once separated, the dura is widely

206

M.

J.

McMASTER

compression were therefore

rod. Blunt modified

Harrington hooks in the Bio-Engineering

(No.

1253) Labora-

tories at the Princess Margaret Rose Hospital. A slot was cut in the top of the hook so that it was able to accept a compression rod after the hook had been placed in the bone. Similar hooks are now available commercially but

Fig.

these are too slim and tend to cut through the relatively soft bone found in these patients. The Harrington No. 1253 hook has a broader shoe and is therefore less

5

likely

to cut through bone when compression is applied. Four of these modified hooks are inserted into the prepared fixation sites above and below the osteotomy. A Harrington compression rod is pressed down into the hooks on each side of the spine. These rods are held in

LkzJ

place

by

special

bushes

which

are

advanced

rods and into the base of each hook enclosed by the hook but cannot pass osteotomy is closed by slowly tightening

of three stages of the operation technique for extension osteotomy

to show the of the lumbar

in the interlaminar to remove bone.

the same carefully an angle

level are identified and the removal of bone extended from the midline across thesejoints of 45 on each side (Figs 5 and 6). Bone

removed through

on each side to leave a slot extending anteriorly the fused facet joint into the intervetebral

The

space, fused

recommended spine.

exposed rongeurs

using laminectomy interfacetal joints

at is at is

and overlying and rongeurs.

bone is It is very

removed important

with fine to ensure

that the transverse axis of eventual closure, about which correction will occur, lies anterior to the cauda equina. This means that the osteotomy must extend anteriorly so that its apex lies at the anterior margin of the intervertebral canal, and laterally to give good exposure of the nerve roots (Figs 5 and 6). If the osteotomy is cut correctly, the cauda equina will be relaxed as the spinal column is extended and the osteotomy closes; an incorrect cut will allow hinging on the

bony

structures

behind

the

neural

elements,

the osteotomy closes, the dura, which is well exposed in the midline, is seen to wrinkle, confirming that the neural elements are being relaxed. If the dura does not wrinkle, the no

osteotomy premature

neural

foramen. The thickness of the bone removed is often between I and 2 cm. The bony sides of the osteotomy defect should be parallel and up to 8 mm apart, depending on the angle of correction required. During the preparation neural structures are protected with a blunt dissector osteotomes

and

osteotomy

has wedge

been completed, no attempt until the internal fixation

device has been applied. It was found to be very difficult to insert the Harrington hooks into the prepared fixation sites when they were already mounted on a

placed

‘V’

there is to the

shape

of

stable and prevents any rods prevent distraction is closed

a wake-up

the rotaand

test

is

of the lower limbs is deficit the fixation can chips removed during the

posteriorly

and

also

on both

sides

between the transverse processes of the vertebrae above and below the osteotomy. These transverse processes are nearer to each other once the osteotomy has been closed (Fig. 5). Postoperative care. Gastric dilatation is a serious complication which may occur in the few days after lumbar spinal osteotomy. Extension of the spine may cause the third part of the duodenum to be pinched between the superior spine which resolves

aspiration thoracic

Once the osteotomy is made to close the

are

to make sure bone posterior

interlocking

performed and the neurology checked. If there is a neurological be released. If all is well, bone

vomit

are

The

makes it very compression

maintain correction. Once the osteotomy

intervertebral not pinched

roots

should be inspected impingement of

structures.

osteotomy tion. The

result in serious neurological complications from stretching of the cauda equina. It is also important to remove enough bone from the pedicles above and below the foramina to ensure that the nerve as the osteotomy is closed.

the

threaded rods, thus applying compression by the four hooks. The advantage of this technique is that it allows a slow and finely controlled closure of the osteotomy; there is no sudden snap or rapid closing of the wedge space. As

Fig. 6 Diagrams

along

where they are through it. The the nuts on the

stomach

after

mesenteric vessels lies behind it. a few

may become large quantities

days

but

pass over obstruction

if it is not

distended of fluid,

into the lungs. cage, these patients

easily develop To prevent

which The

aspiration pneumonia, this complication, a

THE

JOURNAL

OF

recognised

and the patient with the danger

Because cannot

passed before the patient wakes and is in place for 48 hours or there is no obstruction.

it and the usually the may of

of the ankylosed cough properly and which can nasogastric

be fatal. tube is

up from the anaesthetic until it is apparent that

BONE

AND

JOINT

SURGERY

LUMBAR

bed

After

the

with

a

operation, small

the

patient

pillow

under

to back coughing

to

side. and

OSTEOTOMY

is nursed

on a firm

the

Because of the rigid internal fixation, unnecessary, and the patient can from side encourage

SPINAL

osteotomy

site.

external support is be log-rolled safely

Physiotherapy the removal

of

is needed pulmonary

to

IN ANKYLOSING

case

while

nibbled

207

SPONDYLITIS

the

away

ossified from

ligamentum

the midline

flavum

before

the

was

being

osteotomy

was

extended. Dura was adherent to the ligamentum flavum and could not be separated until an initial small opening had been made in the ossified ligament. The small tears were repaired and gave no further problems.

secretions. The use of an absorbable subcuticular stitch allows the application of a well-moulded underarm plasterjacket five days after the operation. Thisjacket is

Soon after operation two patients had excessive volumes of bile-stained fluid aspirated through their nasogastric tubes. In both patients, bowel sounds were

applied

normal and there ileus. Obstruction

with

the

patient

lying

frame and no further patient is then allowed to hospital t#{149}wo weeks after light sedentary work is forbidden until the spine

face

down

on

a plaster

correction is attempted. The walk and is usually fit to leave operation. After a few weeks, allowed but heavy lifting is is solidly fused. The plaster

jacket is removed after nine months provided that radiographs show a solid fusion. A Jewett brace is worn for a further three months and after this there are no restrictions. Complications. There were no deaths or neurological complications in any of the 14 patients treated by this technique. tear

Table

The only complication in the dura in three

1. Details

of

during patients.

14 patients Before

with

operation was a small This occurred in each

ankylosing

spinal

spondylitis

who

underwent

surgery

suspected,

but

develop, days in gastric

gastric

and both tubes

was no other of the third part

evidence of paralytic of the duodenum was

distension

the gastric patients,

was

aspirations allowing

without

further

not

settled removal

allowed within of the

to a few naso-

complications.

RESULTS The

14 patients

three (Table lumbar and who had

have

years, with I). Osteotomy vertebrae

been

followed-up

from

in nine

patients

and

fourth lumbar vertebrae in three. had a spontaneous pseudarthrosis their osteotomy performed at

extension Correction

osteotomy

one

year

of the

lumbar

between

the

third

The two patients before operation the site of the

spine

of curve

Duration Duration of disease

(years)

Sex

(jeers)

Condition hips

43

F

26

Bilateral

Age Case I

of

THR

Level

Soon after operation

Final follow.up

of follow-up

Back

(years)

Before

After

Increase

Severe

None

Slight flexion cervicothoracic junction

pain

of osteotomy

Complications

(degrees)

(degrees)

13-14

Dural

44

44

12-13

-

40

38

2.5

Mild

None

Duodenal obstruction

30

30

2

Severe

Mild

tear

at 36 years 2

35

M

3

66

F

44

4

31

M

7

0

-

L3-L4

20

flexion

L2-L3

-

33

31

2.5

Severe

Mild

L2-L3

-

44

34

2.2

None

None

40

33

1.9

Mild

None

deformity

5

58

M

41

6

47

M

20

30 fiexion deformity

Bilateral

THR

L2-L3

7

40

M

19

Bilateral THR at 39 years

Tl2 -LI (pseudarthrosis)

30

20

1.5

Severe

None

8

35

F

16

Bilateral THR at 25 years

L3-L4

37

32

1.5

Mild

None

9

35

M

II

35

35

1.8

Severe

None

10

47 31

M

30

37

25

1.4

Severe

None

M

6

None

None

II

L2-L3

Bilateral

L2L3

--

L2-L3

Dural

tear

48

44

1 .5

12-13

Dural

tear

45

45

1.6

Mild

None

26

20

I .6

5evere

None

38

30

1

Moder-

None

THR

at 31 years

12

46

M

23

3

37

M

IS

-

-

LI 12 (pseudarthrosis)

14

33

M

IS

12-13

Duodenal

obstruction THR.

total

VOL.

67-B.

hip replacement

No.

2. MARCH

1985

in deformity at

Hip flexion contractures Required bilateral THR at age of 33

Slight

flexion

at

cervicothoracic junction

at 38 years

-

to

a mean of one year eight months was between the second and third

ate

208

M.

pseudarthrosis. patient

This

was

between

and

LI

three

different

ways.

wedge of the

closed, vertebral

In I 0 patients

the ossified anterior longitudinal of the anterior disc space (Case Figs 12 to 17). In two patients ligament

avulsed

two vertebrae. longitudinal

a bone

was

fragment

from

the

compression

fracture

of the

bodies at the level 19). The immediate

posterior

lower

of

part

of the osteotomy postoperative

ciently for them 9; Case 1 1 Figs

of the

the anterior there was

One

patient

had

rod on the other loss of correction.

a broken

side

was After

Harrington

intact fusion

rod

and there of the

was oste-

otomy, there was vety little loss of correction in any patient. At final follow-up. the mean correction at the o3teotomy site was 33 (range 20 to 45) showing a mean loss since operation of 5 (range 0 to 12). The osteotomy had corrected all the patients suffi-

ligament with opening 2, Figs 7 to I 1 ; Case I 1, the anterior longitudinal

In the other two patients, ligament remained intact and

of the vertebral 4. Figs 18 and

occurred in one of a fracture

months.

but the minimal

showed

correction column there

nine

in one

and between LI and L2 in the other. Radiographs of the spine after operation

that. as the posterior in the anterior part

wedge

T12

J. McMASTER

.

to see straight I 2 and I 6).

posture was significantly with the result. During

a

of one

ahead (Case 2, Figs 7 and Both their height and their

improved the period

and all were of follow-up,

pleased satis-

factory correction was maintained at the osteotomy site, but three patients noticed a deterioration in their posture caused by increasing flexion deformity at other sites. Two of these patients had increasing flexion at the cervicothoracic junction. not yet severe enough to re-

(Case correc-

tion from

measured on the radiographs of the spine ranged 26 to 48 with a mean of 38 All patients had solid posterior fusion on radiographs taken when the plaster jacket was removed after

quire otomy

treatment, in the

though they may need cervical ostefuture. The third patient had increasing

;

r

I-,

Figs

7 and

8

Figs 9 and

10

Fig.

THE

JOURNAL

11

OF

BONE

AND

JOINT

SURGERY

LUMBAR

pain

and

restored

flexion by

contractures

bilateral

SPINAL

at the hips.

total

hip

His posture

replacements

after his spinal osteotomy. At final patients could still see straight ahead. had

OSTEOTOMY

IN

was

18 months

follow-up

all

with

spontaneous

pseudarthrosis,

described

their

pain pain.

as being very severe, while five had mild to moderate At final follow-up only two patients complained of

mild

backache. Before spinal

all

but

two

of

209

SPONDYLITIS

had

retired;

them

to work A further

more major

was

expressed

by all the patients,

the

Before their osteotomies, all but two of the patients had back pain. Seven ofthese 12 patients, including

the two

ANKYLOSING

all

three

felt

that

their

operation

easily in the home. advantage of the was

enabled

operation,

which

an improvement

self-esteem. Before the osteotomy many ofthese patients, especially the women, were reluctant to be seen outside their homes. The new appearance provided a marked psychological

improvement. DISCUSSION

osteotomy, the

deformity

I I men

operation, seven of these work after recovery periods to one year. Ofthe women,

from

-

Figs

12 and

working.

prevented After

This the

men were able to return to varying from three months two were housewives and one

--

:____

had

13

J

study

has

technique and spinal osteotomy spondylitis complications

shown the

possible, which

that

modification

of the

method of correction for severe deformity

operative

make lumbar in ankylosing

without the high incidence of major has been reported in other series.

___ Figs

14 and

15

Figs

16 and

17

Case I I . Figures 12 and I 3-This 3 1-year-old patient with a severely flexed posture caused by 50 flexion contractures of both hips and a lumbar kyphosis of24 . Figures 14 and 15-After bilateral hip replacements the flexion contractures were reduced to 9 but the patient still had difficulty in seeing ahead. Figures 16 and 17-Extension osteotomy was performed at L2-3 and the spine corrected by 48 to give a 24 lumbar lordosis. The patient stands upright and can see straight ahead.

VOL.

67-B.

No.

2. MARCH

1985

in

210

M. J. McMASTER

All these series used Petersen ci al. (1945), through the posterior pressure legs are

the technique described by Smithin which the spine is osteotomised elements and corrected by direct

on the osteotomy extended.

site

while

the upper

body

and

have

difficulty We had

nique,

and

in coughing no serious all

because complications

14 patients

were

see straight ahead. with maintenance

All had of good

though

be

it should

of their rigid chests. using this tech-

corrected

sufficiently

to

a solid fusion in nine months correction at the osteotomy,

noted

that

the

overall

posture

in

three of our patients deteriorated during follow-up because of increasing flexion at either the cervicothoracic junction or the hips. McMaster and Coventry (1973), reporting on 17 patients followed for a mean of 10 years after had

lumbar osteotomy, fused correction

tamed; spine

but active or the hips

and

detract

once the osteotomy region was main-

disease in the thoracic and cervical could allow increased local deformity

from

correction the disease deformity

found that the lumbar

in

the

initial

overall

correction.

was more lasting if osteotomy had “burnt out”. Unfortunately, is already crippling, it is not

The

was

done after if the spinal possible to wait

for the disease to become quiescent. However, correction lost at sites other than that of the lumbar osteotomy can often be improved by either hip replacement or cervical osteotomy. In conclusion, lumbar spinal osteotomy is a potentiFig. Case

4. The There

The by this

18

spine has been corrected 31 is a posterior wedge compression

ossified

anterior

pressure.

ally dangerous operation correction at operation

Fig.

This

by

vertebral often

extension osteotomy. fracture of L2.

column

occurs

with

of

I am grateful to Dr Mark Smith-Petersen technique working at the Mayo Clinic,

if the osteotomy has been incorrectly cut and the axis of angulation lies either in the same plane as the cauda equina or posterior to it. A third source ofproblems may

Adams

be

Bisla

nipping

of

nerve

roots

in

their

intervertebral

canals at the level of the osteotomy when too little bone has been removed. After the closure of the wedge osteotomy using the old technique, the spine becomes very unstable and needs to be controlled by the application of plaster shells, before the patient is removed from

this

and does

that not

the osteotomy occur,

more bone removed. obtained safely. The combination and and

the compression stable fixation,

safely in an also facilitates

has

compression Up

to

been can

45

cut be

correctly.

correction

‘V’ shape

of the

without care

external of these

MK. Vertebral of the spine.

be

The

operation

advantages

but

also

who first introduced spinal osteotomy Minnesota, USA.

me while

to

the

I was

and

safeguards

Inglis

osteotomy

AE. Total

hip replacement involvement of the

spondylitis with 1976:58-A:233-8.

EH. Osteotomy kyphosis in a case of Surg 1946:28:851-8.

in

for correction Surg [Am] on

of the ankylosing

lumbar spine spondylarthritis.

control bleeding during posterior Surg [Br] 1983:65-B:255-8.

McMaster litis.

PE. Osteotomy Surg

MJ, Coventry Proc

Mayo

fusion

for

MB. Spinal

Clinic

osteotomy

in MarieSurg [Am]

correction J Bone

Surg

for scoliosis.

of the spine for fixed 1962:44-A: 1207-16.

[Am]

deformity

for kyphosis, especially 50 cases. J Bone Joint

WA. Lumbar spinal osteotomy. J Bone Joint 41-B: 270-8. Malcolm-Smith NA, McMaster MJ. The use of induced

Joint

the

in patients hip. J Bone

of fixed flexion 1968:50-A:287-94.

Law

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