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Knee Ligament Injury

NINE

Knee Ligament Injury

the International Knee Documentation

Committee (IKDC) recommendations

for minimum two-year follow-up together

with Lysholm and Tegner scores. In regard

to PCL injuries, serial assessments in

conservative care are important as most

of these injuries occurring in sports are

interstitial or partial. In 2011, we still

do not have an accepted international

management protocol for PCL injuries.

In all assessments, the patient is reassured

and given hard evidence of progress and

outcome. The arthrometer accuracy is

periodically confirmed by ‘accuracy’ and

‘linearity’ tests.

WHATAM I MEASURING

IN CRUCIATE LIGAMENT

INJURY?

In ACL injury, l measure Anterior Tibial

Translation (ATT) at 67N and 89N. The

difference is normally 1mm and the manual

maximum should be <12mm.The involved

(I) and non-involved (N) difference (I: N)

is critical.

In PCL injury, l measure passive Posterior

Tibial Translation (PTT) @ 89N and

compare this translation to that of the

non-involved knee at the Quadriceps

Neutral Angle (QNA).

WHEN CAN’T I USETHE

KT1000

TM

ARTHROMETER?

In an acute knee injury there is pain and

likely inhibition and it is unreasonable to

contemplate forced passive motion. There

may be motion deficit and partial locking.

The presence of joint effusion prevents the

patella engaging the trochlear groove and

the patella has to be ‘fixed’ for the exam

procedure. Therefore, patella pain and

apprehension may preclude exam. Small

adults and children have short tibiae and

the arthrometer may not fit comfortably.

One must beware a bucket-handle

meniscal tear blocking potential knee

motion.

CLINICAL EXAMPLES

VL was an 18-year-old female dancer with

knee giving way in active daily living. She

had no haemarthrosis and was noted to

be hypermobile with loose knees. She had

normal knee laxity profile on clinical exam.

Magnetic Resonance Tomography (MRT)

showed ACL oedema and arthrometry

confirmed her abnormal Compliance Index

(CI) but no significant

side:side

difference.

She was given a rehab programme and did

well on follow-up.

KG was a 24-year-old female netball player

who presented with chronic knee injury

eleven months post ski fall. She had been

treated for MCL sprain. On return to sport,

she had instability episodes. Her Lysholm

score was 77 fair and Tegner activity score

three with desired level seven. Clinically,

her knee showed ACL laxity and functional

exam revealed pathological hop test. MRT

confirmed proximal ACL disruption.

She was referred for ACL reconstruction

and at six months post op her graft

stability was confirmed and she soon

returned to sport with confidence.

TH was a 35-year-old male rugby fly-half

who had frontal contact knee injury with

haemarthrosis, intact ACL laxity profile, no

sag at 90° but posterior tibial translation

discomfort 15° suggestive of interstitial

posteromedial band PCL injury. MRT

confirmed interstitial PCL tear and bone

bruising.

At 14 weeks status post injury, his PTT

was 2.5mm v 1.5mm N @ 15° and 2mm

@ 90° v 1mm N. He was given a rehab

programme and returned to sport at 22

weeks with no sequelae.

CONCLUSIONS

The ideal

side:side

differences in tibial

translation have been established for many

years and it is the difference between

the bad and the good knee which should

determine definitive patient management,

and not just focus on the injured

knee. A 3.5mm difference in anterior

tibial translation has been deemed the

critical level. At the ESSKA Congress

in Oslo, a special ACL seminar findings

concluded that a difference of >4.5mm in

a symptomatic patient (knee instability)

was even more critical and that symptoms

beyond five months would result in knee

kinematics never returning to normal

whatever subsequent treatment is

undertaken, including late reconstruction.

Accurate measurement of knee laxity

in relation to ACL injury especially is

therefore essential. I have found the

KT1000

TM

arthrometer easy to use with

reproducible measurements on follow-up

exam. Patient selection and set up are

important and these measurements are

part of the IKDC recommendations for

cruciate ligament care. Knee scanning is

not necessary to determine whether an

ACL or PCL injury has occurred as the

exam and arthrometry does this. I use MRT

to ensure that there is no associated injury,

which either requires surgical attention or

may hamper an otherwise intended rehab

programme. A select few knee orthopaedic

surgeons ask me to assess their patients

pre and post op and for decisions

regarding whether surgery is deemed

necessary. All patients should have this

benefit and have defined scientific outcome

measures for their injury. I am in my 20th

year of using the arthrometer, unparalleled

in the UK, and have had excellent results

with sub-acute and chronic injuries and in

conservative and operative care.

KT1000

TM

Arthrometry

in Knee Ligament Injury

DISPLACEMENT PREDICTION

>3mm 1:N @ 89N ACL deficiency 94% chance

>5mm 1:N +

Recommend ACL

>200hrs/yr IKDC 1 reconstruction

>12mmATT man max Flexion rotation drawer +ve

>18mm man max

Functional disabillity in ADL

>18mm

Rehab failure

DISPLACEMENT PREDICTION

3-5mm @ 89N 20° flexion Interstitial PCL injury

1-3mm I:N 20’ - same 90° Interstitial or partial

PCL injury

5-7mm @ 89N ipsilateral

Consider surgery if

combined

>7mm @ 89N ipsilateral

Surgery even if isolated

VL KT1000

TM

67N 89N CI MAN AQD PTT

25°

MAX

Involved mm 8 11 3 13 4 2

Non-involved 8 10 2 12 3.5 2

mm

KGKT1000

TM

67N 89N CI MAN AQD PTT

25°

MAX

Involved mm 8 10 2 13 5 2

Non-involved 5 6.5 1.5 7.5 1.5 2

mm

KGKT1000

TM

67N 89N CI MAN AQD PTT

25° +6mm

MAX

Involved mm 6 7 1 9

2 2

Non-involved 5 6.5 1.5 7.5 1.5 2

mm