A

A

nterior

nterior

C

C

ruciate

ruciate

L

L

igament

igament

(ACL) Tears

(ACL) Tears

Objectives

Objectives

• By the end of this presentation,

you will be able to identify

the four ligaments that hold the knee joint together.

• By the end of this presentation,

you will be able list the most

common mechanism of injury for an ACL tear.

• By the end of this presentation,

you will be able to recognize

at least four of the signs and symptoms of an ACL tear.

• By the end of this presentation,

you will understand the

surgical process that is done to fix and ACL.

• By the end of this presentation,

you will be able to list the

main muscles that are strengthened during the rehabilitation
process.

• By the end of this presentation,

you will be able to create

your own effective prevention program.

The knee joint is formed by the femur, tibia, and

The knee joint is formed by the femur, tibia, and

patella. The ACL is one of the four main ligaments

patella. The ACL is one of the four main ligaments

in the knee that connect the femur to the tibia. The

in the knee that connect the femur to the tibia. The

knee is a hinge joint that is held together by the

knee is a hinge joint that is held together by the

MCL, LCL, ACL and PCL.

MCL, LCL, ACL and PCL.

The ACL runs diagonal through the knee, crossing the PCL

The ACL runs diagonal through the knee, crossing the PCL

while both of these connect the shinbone to the thigh bone.

while both of these connect the shinbone to the thigh bone.

Here is a completely

torn ACL.

When the ACL is injured, the shinbone can slide
forward on the thigh bone causing the knee to “give
way”.

Mechanism of Injury

Mechanism of Injury

• When the knee is forced into an unusual position,

the ligaments in the knee can partially or fully tear.

• Stopping and changing directions suddenly can

cause the ligaments to do this.

• Cutting, pivoting and jumping in sports such as

basketball, volleyball, skiing and soccer are all

causes of ACL tears.

This diagram
shows the
twisting
motion that
causes the
ACL to tear.

Mechanism of Injury

Mechanism of Injury

• Children can tear their ACL when they stumble or fall.

• It is much harder to fix a child’s tear because of the

need to avoid the growth plate.

• Teenage girls are two to eight times more likely to tear

their ACL then boys of the same age.

In the picture to below, you can see the athletes left knee
turned inward where she is in the process of tearing her
ACL. This typically happens when landing, cutting or
changing direction quickly.

Severity

Severity

• Grade I

A mild injury that causes only

microscopic tears in the ACL. Although

these tiny tears may stretch the ligament

out of shape, they do not affect the

overall ability of the knee joint to support

your weight.

• Grade II

A moderate injury in which the

ACL is partially torn. The knee can be

somewhat unstable and can "give away"

periodically when you stand or walk.

• Grade III

A severe injury in which the

ACL is completely torn through and the

knee feels very unstable.

Most ACL injuries are severe Grade III
10% - 28% being either Grade I or Grade II.

Lachman Test

Lachman Test

To verify the ACL tears we can perform a Lachman test.
The test is performed as follows: the patient is positioned lying supine with the
hip flexed to 45° and the knee to 90°. The examiner positions himself by
sitting on the examination table in front of the involved knee and grasping the
tibia just below the joint line of the knee. The thumbs are placed along the
joint line on either side of the patellar tendon. The index fingers are used to
palpate the hamstring tendons to ensure that they are relaxed; the hamstring
muscle group must be relaxed to ensure a proper test. The tibia is then drawn
forward anteriorly. An increased amount of anterior tibial translation compared
with the opposite limb or lack of a firm end-point indicates either a sprain of
the bundle of the ACL or a complete tear of the ACL.

How can you recognize an ACL tear?

How can you recognize an ACL tear?

A person with an ACL tear will experience:

o Swelling
o Loss of range of motion
o Pain or tenderness along the joint line
o Discomfort and unstable walking
- A person will report that the knee was forced

beyond its normal range

- A person may report having felt a pop, tear, or

snapping sound

What should you do if you

What should you do if you

suspect an ACL tear?

suspect an ACL tear?

• The first thing you should do is apply ice

and compression. A person should see a

doctor immediately where they can

determine if it is actually an ACL tear.

• If you need to move a person and they are

unstable, have them use crutches.

• A doctor should ask the person to describe

what happened. A lot of people who

experience an ACL tear will hear a pop,

tear, or snap.

Treatment for ACL

Treatment for ACL

tears

tears

There are both surgical and non-surgical options

for treating an ACL tears.

Surgical

* When doctors do ACL reconstructive surgery, they usually

replace the ligament by a substitute graft made of
tendon. This is because ACL tears that used suture to
sew it back together showed to fail over time. Some of
the grafts that doctors may use are Patellar, Hamstring,
Quadriceps, Auto graft (taken from a cadaver).

* In repair surgery, the doctors sews together the torn

ligament. This type of surgery has been shown to fail,
therefore more often the doctors will do reconstructive
surgery.

Arthroscopic Surgery

Arthroscopic Surgery

There are many benefits to this surgery and it is
becoming more popular.
This surgery:
-Uses smaller incisions
-Has fewer risks than open
surgery
-Rehabilitation is usually quicker
-Doctors can see and
work on the knee structures

The picture
above shows
an
arthroscopic
view of an
ACL after
using a
hamstring
auto graft.

The primary goal
of ACL surgery is to
restore normal
stability in the
knee and the level
of function you had
before the knee
injury, limit loss of
function in the
knee, and prevent
injury or
degeneration to
other knee
structures.

Non-Surgical

Non-Surgical

Rehabilitation

Rehabilitation

• The picture above shows two young girls focusing on

balancing and strengthening the muscles in their legs.

• If a child or young teen tears their ACL, doctors may

suggest only physical therapy.

• Physical therapy will work on the same exercises as post

surgery, but an athlete may have to modify their activity

style. For example, limit sports involving cutting, pivoting

and landing.

• A knee brace does not prevent knee injuries but can help to

stabilize the knee.

Rehabilitation

Rehabilitation

• Physical therapy is a crucial part of ACL surgery. Most

of the success of the surgery is dependent upon the
athletes determination to build strength within the
knee. This should begin immediately after surgery.

• The first 10-14 days after the surgery, the focus is on

the ability to fully straighten the knee and restore
quadriceps control. The knee should be iced regularly
to reduce swelling. Activities such as the ones below
are done by the physical therapist in rehabilitation.

Rehabilitation

Rehabilitation

• The entire rehabilitation process takes about 4-6 months to

make sure that person is completely ready to return to

health. The use of a functional brace is not required after a

successful surgery and rehabilitation, but a lot of people

feel a greater sense of security using one.

Sample Rehabilitation Program

Sample Rehabilitation Program

WEEKS 0-2:
•Non weight bearing
•Quadriceps and Hamstring isometrics
•Electrical muscle stimulation
•Ankle ROM and strengthening
•Heel slides
•Patellar mobilization
WEEK 4:
•Non weight bearing
•Quadriceps and Hamstring isometrics
•Straight leg raises
•Electrical muscle stimulation
•Pool exercises (hip and ankle)
•Stationary bike
•Stairmaster
WEEK 6:
•Non weight bearing
•Quadriceps and Hamstring isometrics
•Straight leg raises with weight
•Hamstring curls
•Hip resistance exercises
•Pool for ROM
•Cycling for ROM

StairMaster

Straight leg raises

•

Sample plan

WEEK 8:

• Begin weight bearing

• ROM should be 0 and 110 degrees

• Cycling

• Hamstring curls 

• Jump rope

• Swimming
3 MONTHS:

• ROM 0 and 125 degrees

• Treadmill walking

• Cycling

• Quarter squats

• Sport specific skills
4 - 6 MONTHS:

• ROM 0 and 140 degrees

• Treadmill walking

• Isotonic knee extensions

• Step-ups

Returning to competition

Returning to competition

• The patient may return to sports when there is no more

pain or swelling, when full knee range of motion has
been achieved, and when muscle strength, endurance
and full use of the leg have been fully restored.

• If patient has met criteria of full ROM, good stability,

and 90% or better strength compared to uninvolved
extremity they are considered to be eligible to return to
play.

• They should also have a positive psychological mind

set.

• The final decision should be made by the physical

therapist who has been through the entire
rehabilitation process.

Prevention

Prevention

• There has been much research into the prevention of ACL tears.
• Similar to preventing all other injuries, proper warm up and

stretching is vital.

• The newest prevention techniques for ACL tears has been in

specific jumping and landing training techniques. Programs that
are designed to enhance the dynamic function of the leg are ones
that have proven to work the best.

• Many preventive programs have these same common

denominators:

o *Improving balance on single legs specifically
o *focusing on avoiding the knock-kneed position when landing, stopping

and cutting

o *strengthening the core muscles around the pelvis including the

hamstring and back of thigh

o *plyometrics
o *teaching proper landing techniques
o *using verbal cues such as “light as a feather” or “recoil like a spring”

when teaching landing help athletes focus on the technique

Interesting Facts: ACL Tears in

Interesting Facts: ACL Tears in

Females

Females

• For about ten years now, it has been shown that

females have a higher rate of ACL tears especially
those in the key sports such as basketball,
volleyball, and soccer. We are not exactly sure
why females have a higher incidence rate but
there are some suspected reasons.

o * the relative strength and muscle pattern of the

hamstring relative to the quadriceps.

o *high levels of estrogen
o *lack of proper training at a young age
o *a narrower notch width of the femoral head

This diagram shows one of the possible theories on

This diagram shows one of the possible theories on

why females tear their ACL more often. Look at the

why females tear their ACL more often. Look at the

“reverse U shape” compared to the “A shape

“reverse U shape” compared to the “A shape

notch”.

notch”.

The End

The End