CYSTS

OF

THE

ARTHROSCOPIC

C.

A.

From

MEDIAL

DIAGNOSIS

MILLS,

I. J.

the Mercy

P.

MENISCUS AND

MANAGEMENT

HENDERSON

Private

Hospital,

Melbourne,

Australia

We report the clinical and arthroscopic findings in 20 cases ofmedialmeniscal cyst with a mean follow-up of2O months. These were studied prospectively from a series of7435 knee arthroscopies in which there were 1246 stable non-arthritic

Cysts of the medial not been reported

knees

with medial meniscal tears. The diagnosis on referral was incorrect in seven, and incomplete in seven. There was coexistent meniscal injury in 17 (85%), but in the other three no tear was visible at

cysts.

arthroscopy. Ten knees had additional intra-articular abnormalities. Treatment of the cyst was by open resection in 12 and arthroscopic evacuation at meniscectomy in seven. In one case the cyst resolved after arthroscopic partial meniscectomy alone. Meniscal tears were treated

(King 1936 ; Brantigan and Voshell 1943 ; Bonnin 1953; Gillies and Seligson 1979 ; Cross and Watson 1981) and Kerlan and Glousman (1988) have suggested that bursitis of the tibial collateral ligament is relatively frequent. In our series the ratio of medial meniscal cysts to medial

by arthroscopic partial Medial meniscal

meniscal

diagnosed cause to arthroscopically pathology. meniscus

medial meniscectomy. cysts are an important

of knee

and

pain

diagnosable

Treatment and the cyst,

should which

but

are frequently and treatable

be directed may require

under-

scopic

series.

findings,

Received

Surg[Br] 28 May

1992;

1993;

17 August

diagnosis

have

relied

of a review

ofcoexistent

on operative

of lateral

meniscal

meniscal

pathology

has

tears

1246or

in stable

non-arthritic

knees

was

20 to

1.6%.

related

meniscal

towards both open surgery.

the

PATIENTS

AND

We made

a retrospective

study,

clinically

consecutive

patients

with

of2O

METHODS and arthroscopa cyst

ofthe

medial

meniscus seen by one surgeon (IJPH) in a total series of 7435 knee arthroscopies. Comprehensive records were kept of examination and arthroscopic findings and treatment. The diagnosis was made when a cystic process

75-B:293-8.

Accepted

accounts

as part

rare and have in any arthro-

also depended on open meniscectomy or on arthrography, and more recently on CT and MRI. Clinically, the condition is frequently misdiagnosed

ically, JBoneJoint

Previous

often The

meniscus are relatively in significant numbers

1992

involving the meniscocapsular

medial meniscus extended boundary. Menisci with

meniscalchanges that were not

were not recorded. intimately associated

beyond the entirely intra-

Extra-articular with the

cysts meniscus

were also excluded. Eighteen of the 20 patients were available for medium-term follow-up ; the other two had been The

followed average

for

two

follow-up

and was

six

months

postoperatively.

20 months

(2 to 120).

RESULTS The C.

A. Mills, FRACS, AOA I. J. P. Henderson, FRACS, Henderson Clinic, Mercy Melbourne, Victoria 3002, Correspondence ©1993 British 0301-620X/93/2530

should

Fellow Consultant Orthopaedic Private Hospital, 141

Australia.

be sent

Editorial Society $2.00

VOL. 75-B, No. 2, MARCH

Surgeon Grey Street,

1993

to Mr

ofBone

East

ages

developed I. J. P. Henderson. and

Joint

Surgery

of the

20 patients

ranged

from

20 to 62 years

(mean 35 SD 13). There were 6 women and 9 right-sided and 1 1 left-sided cysts. identical

symptoms

and

eral left knee, but this knee has not Details of each case are summarised Symptoms.

Only

two

patients

were

signs

14 men, with One patient

in the contralat-

yet needed in Table I. unable

surgery.

to recall

a

293

294

C. A. MILLS,

Table

I.

Details

of 20 patients

who

presented

I. J. P. HENDERSON

with

medial

meniscal

cysts Meniscus

Case

Age/sex

Side

Duration symptoms

of

Sport or cause

Cyst

site

te ar

Types

5ft

Cyst

resection

1

21

F

L

13 to 26 wk

Netball

Posterior

Radial

Posterior

Arthroscopic

2

37

M

L

1 yr

Squash

Posterior

HC

Posterior

Open

3

39

F

R

2.1 to 3 yr

None

Posterior

BH

Posterior

Arthroscopic

4

38

M

L

3 to 5 yr

Hurdling

Anterior

BH

Posterior

None

5

24

M

L

7 to 12 wk

Soccer

Posterior

Rim

Posterior

Open

6

20

M

R

2.1 to 3 yr

Aust

Posterior

Intact

7

58

M

L

Not

None

Middle

HC

Middle

8

33

M

Lt

5 to 9 yr

Basketball

Posterior

HC

Posterior

Arthroscopic

9

35

M

L

3 to 5 yr

Snow

skiing

Posterior

HC

Posterior

Open

10

26

M

R

3 yr

Aust

football

Middle

HC

Middle

Open

11

47

M

Rt

3 to 5 yr

RTA

Posterior

Degenerate

Posterior

Open

12

62

M

R

3 to 6 wk

None

Posterior

HC

Posterior

Open

13

27

F

L

1 3 to 26 wk

Fall on steps

Posterior

Degenerate

Posterior

Arthroscopic

14

25

F

R

3 wk

Netball

Middle

Intact

15

35

M

Rt

3 to 6 wk

Aust

football

Posterior

HC

16

20

M

L

3 to 6 wk

Aust

football

Middle

Intact

17

31

M

L

7 to 12 wk

Snow

skiing

Posterior

BH

Posterior

Open

18

26

F

Lt

7 to 12 wk

Step

aerobics

Posterior

HC

Posterior

Arthroscopic

19

38

F

R

Not

None

Posterior

IS

Posterior

Open

20

51

M

R

3 to 6 wk

Tennis

Posterior

HC

Posterior

Arthroscopic

.

t

known

known

HC = horizontal cleavage ; BH = bucket previous partial meniscectomy road-traffic accident

Table

II.

Incidence

Pain

of pain

Number

and

football

handle

other

; IS

inferior

=

symptoms

Other

surface

in 20 patients

symptoms

tear

Open

Open

Open Posterior

Arthroscopic Open

split

with

Number

medial

meniscal Duration symptoms

cysts of Number

None

2

None

6

0 to 3 wk

None

Dullache

2

Locking

3

3to6wk

5

Sporadic/minor

1

Giving

2

7 to 12 wk

3

7

General

swelling

7

13 to 26 wk

2

8

Stiffness

after

3

27 to 52 wk

None

I

1 to 2 yr

1

4

2 to 3 yr

3

10

3 to 5 yr

3

1

5 to 9 yr

1

Not

2

On exertion

only

Continuous Pain

on crossing

Pain

on squatting

Night

*

pain

non-steroidal

legs

14

anti-inflammatory

way

exercise

Reliefwith

NSAID

Relief

local

with

steroids

known

drugs

THE

JOURNAL

OF BONE

AND

JOINT

SURGERY

CYSTS

definite

start

symptom

to

was

their

symptoms.

discomfort

or

The aching

OF

THE

MEDIAL

characteristic exacerbated

by

exertion. Only two denied having pain ; they presented with mechanical symptoms. Even when pain was continuous, exertion increased the discomfort. Night

MENISCUS

arthroscopy. and the cysts

Twelve cysts by arthroscopic

The

seven

breakdown tomy were 12 requiring

(Table

indicated of definite

by 16 patients. patients were often relating

trauma

to the

Four had had a prior young and enjoyed their knee symptoms

frequently one known medial compartment

Table

III.

a cyst

of the

knee

meniscectomy. sport (see to a specific

to stress the medial of the joint.

Types

of meniscal

medial

was

tear

given

Most Table I), activity,

structures

and

The relation between is given in Table IV.

seven

pain was frequent, being reported by 14 patients. Nonsteroidal anti-inflammatory drugs had produced symptomatic relief in ten patients, partial benefit in two, and no benefit in three. One patient had not tried antiinflammatory drugs and two could not recall their use. Mechanical and other symptoms were common II). A history

295

cysts

which

time

open

The

other

reasons

relationship

cleavage,

Bucket-handle,

posterior

posterior

Horizontal

cleavage,

Degenerate

complex,

Rim

posterior

horn

horn

mid-meniscus posterior

horn

horn

Inferior

surface,

Radial,

posterior

amenable

to arthroscopic

removal

that

capsular

or

was

were

to the medial

considered

large

collateral

cyst

size,

ligament

ligament

repair

One patient had an anterior cyst, diameter, apparently fixed to the joint scopy this patient had a bucket-handle posterior

halfofthe

medial

or

which might

be

meniscus,

Table IV. Relation tears and cysts

with

less than 2 cm in line. On arthrotear of the and

arthroscopically.

a cyst

The

between

sites

of

that

meniscal

was

tear

meniscal

Cyst site

Number

Horizontal

tears

required.

meniscus

Tear

of the

by open resection and One was not removed.

were

that

not decompressible

associated

treated evacuation.

sites

and evacuation after prior partial meniscecanalogous to the more usual lateral cyst. The open removal were mostly seen early in the

series ; at preferable. close

were

the

7

Meniscal

3

tear

Anterior

Middle

Posterior

Posterior

I

2

12

2

Mid-part

0

2

0

2

Intact

0

1

2

1

posterior

horn

I

horn

Table

1

None

V.

Other

lesions

in

20

knees

with

cyst

of

medial

meniscus

3 Number

The practitioner the most

presumptive diagnosis was medial meniscal common being medial

of the four who had had meniscectomy

were

prior available.

Examination. medial joint

Preoperative line tenderness.

Murray’s

gave

test

positive

patients (75%). A definite medial this was permanent

of the referring general cyst in only six patients, meniscus tear. The notes arthroscopic

examination Rotary signs

lines

swelling. Operation.

were

swelling was present in 1 1 and intermittent

The

tender type

in the

of meniscal

time of arthroscopy (Table carefully probed on its superior the meniscosynovial junction

group tear

medial

always testing

of meniscal

former group it was slowly increasing from 0.5 to 4 cm in diameter. Ten joint

partial

in 15

in 16 patients; in 5. In the

in size and ranged were tender. All five with was

intermittent recorded

III). Each meniscus and inferior surfaces, tested. Fifteen of the

at the was and torn

menisci had tears in the posterior third of the meniscus. In the three patients with intact menisci the cysts were removed separately by an open procedure after the VOL.

75-B, No. 2, MARCH

1993

meniscal

tear

3

Medial

synovial

shelf

2

Medial

femoral

condylar

degeneration

stage

2

1

Lateral

femoral

condylar

degeneration

stage

2

1

Fat-pad

showed and Mctear

Lateral

impingement

1

Anterior

cruciate

tear

2

Posterior

cruciate

tear

I

was

treated

the cyst weeks

by arthroscopic

left alone. The and had resolved

partial cyst had completely

patients had a repair of a capsular open excision and two also required collateral ligament.

meniscectomy reduced in size by six weeks.

defect repair

and by two Eight

at the time of of the medial

Of the 16 patients with a palpable swelling preoper15 had a cyst which was in direct communication with the meniscus. The other patient is described above. All four patients without preoperative swelling were found at arthroscopy to have cysts extending from the meniscus beyond the meniscal border that could be atively,

296

C. A. MILLS,

decompressed arthroscopically. were all left in situ and none Two with

patients,

one

a horizontal

The three intact has required further

with

a bucket-handle

cleavage

tear,

horn, have required further for mechanical symptoms. Other lesions. In ten of the diagnosed chronic

at arthroscopy effusion associated

one patient had lateral meniscal

lateral

were

arthroscopic

The

treated

other

V). One a reactive

pathological

Table

series

Summary

of reported

which

a compensation Six patients

and

athletic

one

lesions

activity.

The

were had a and

term

and

and

either

and

Barrie

(1979)

found

that

meniscal

Number

of

has

and

made

used

studied

for

several

entities,

of reports

in Table

making

difficult,

but

an

VI.

surgically

7. 1% of

macroscopic

been

clinical

evaluation

has been

1 571

removed

menisci

or microscopic.

cysts were less entirely within

medial

cyst’

pathological

comparison

synovial the

‘meniscal

different

attempt

chondroplasty. arthroscopically.

include

that running ability is limited. aching, but only after maximal

DISCUSSION

patients with arthroscopic

resection

case, finds reported some

posterior

patient synovitis,

medial

by arthroscopic by arthroscopic was resected

the

menisci surgery.

meniscectomy

20 knees (Table with

femoral condylar changes The fat-pad impingement

VI.

of

varus knee deformity. The tears were treated by partial

meniscectomy.

shelves

tear

both

I. J. P. HENDERSON

menisci

contained

cysts,

In all, 124 of the 215

than 1 mm in diameter and 159 the body of the meniscus. Burk

were et al

cysts Recommended

treatmentt

medial cysts

Meniscal tear(%)

Lat:med ratio

M:F ratio

2:8

2:2

Meniscus

Cyst

Comment

-

-

-

Plus

2:6

1 :6

-

-

-

-

2:8

3*

TOM

OC

-

2

-

-

-

APM

ADC

-

Radiological

9

100

-

0: 2

-

-

Excluding

Arthroscopic

3

100

7:3

1 :4

APM

ADC

-

Radiological

I

-

5

-

-

-

-

Arthroscopic

1

14

-

-

APM

ADC

-

85

5 :5

2 :3

APM

ADC/OC

-

Author

Type

Wroblewski(l973)

Clinicalandopen

Barrie

(1979)

Pathological

13

100

1:3

Schuldt

and

Radiological

8

100

Opensurgery

8

Arthroscopic

et al(l988) (1990)

Wolfe

(1980)

CrossandWatson(l98l) Spence Burk

and

Parisien Peetrons, (1990)

Robertson

Allaer

(1986)

and

Jeanmart

Keatingetal(l99l)

Current S

including

t

TOM

series

(1992)

lateral

l29

Arthroscopic

5O

20

open cysts

meniscectomy

; APM

= arthroscopic

partial

meniscectomy

Instability of the knee was determined both at the preoperative visit and at examination under anaesthesia. Sixteen knees were without instability. One had a grade 2 medial laxity, two others had grade 2 medial laxity in combination, in one with grade 2 ACL deficiency and in the other in combination with grade 2 PCL laxity, and one knee had grade 3 ACL deficiency. Histology. showed locular

with

Histological mild

19 small

cysts

10mm