ACL is composed of multiple collagen
surrounded by an endotendineum which is
grouped into fibers measuring around
38mm in length (range 25 to 41 mm) and
10 mm in width (range 7 to 12 mm)
Microspocially composed of interlacing fibrils
(150 to 250 Nanometer in diamter)
synovial membrane envelope the ACL
- From the posteromedial corner of medial
lateral femoral condyle in the intercondylar
- Fossa in front of & lateral to anterior spine
ACL is composed of two principal parts
1. Small Anteromedial band
2. Larger bulky posterolateral portion
- Anteromedial bundle is tight in flexion and
posterolateral bundle is tight in extension
- In extension both bundles are parallel
- In flexion both bundles are crossed
These attachments allow the ACL to resist
anterior translation and medial rotation of the
tibia, in relation to the femur.
- Tibal nerve( Infiltrates the capsule
- Golgi tendon receptors
- Major blood supply is from
MIDDLE GENICULAR ARTERY
Bony attachments do not provide a significant
source of blood to distal or proximal ligaments
ACL vascularization arises from the middle
genicular artery and vessels of the infrapatella
fat pad and adjacent synovium
The artery gives rise to periligamentous
vessels which form a web-like network within
the synovial membrane
These periligamentous vessels give rise to
penetrating branches which transversely cross
the ACL and anastomose with a network of
longitudinally oriented endoligamentous
Terminal branches of the inferior medial and
lateral genicular arteries supply the distal
portion of the ACL directly.
The extremities of the ACL seem to be better
vascularized than the middle part, and the
proximal portion seems to have a greater
vascular density than the distal portion
CAUSE OF ACL INJURY
The anterior cruciate
ligament can be injured
Slowing down while
Landing from a jump
Direct contact or
collision, such as a
Several studies have shown
that female athletes have a
higher incidence of ACL injury
than male athletes because of
- Physical conditioning
- Muscular strength
- Neuromuscular control
- pelvis and lower extremity
- the effects of estrogen on
ACL injuries occur in combination with
-Articular cartilage or
Secondary damage may occur in patients who
repeated episodes of instability due to ACL
With chronic instability, up to 90 percent of
patients will have meniscus damage when
reassessed 10 or more years after the initial
Similarly, the prevalence of articular cartilage
lesions increases up to 70 percent in patients
who have a 10-year-old ACL deficiency
Partial tears of the anterior cruciate ligament
Most ACL injuries are complete or near
Injured ligaments are considered "sprains" and
are graded on a severity scale.
Grade 1 Sprains.
The ligament is mildly damaged . It has been
slightly stretched, but is still able to keep the knee
Grade 2 Sprains.
The ligament is stretched to the point where it
becomes loose. This is often referred to as a
partial tear of the ligament.
Grade 3 Sprains.
This type of sprain is most commonly referred to
as a complete tear of the ligament. The ligament
has been split into two pieces, and the knee joint
When ACL is injured , pt might hear a
Other typical symptoms include:
-Pain with swelling.
-Loss of full range of motion
-Tenderness along the joint line
-Discomfort while walking
ANTERIOR DRAWER TEST
PIVOT SHIFT TEST
KT-2000 ARTHROMETER TEST
ANTERIOR DRAWER TEST
To perform anterior drawer test, examiner
grasps pt's tibia & pulls it forward when the
affected leg is flexed at 90 degree while noting
degree of anterior tibial displacement
This is a variant of the anterior drawer test
The examination is carried out with the knee in 15 deg
flexion, and external rotation (relaxes IT band)
For a right knee, the examiner's right hand grips the
aspect of the calf and the left hand grasps outer aspect
the distal thigh
Attempt to quantify the displacement in mm is done by
comparing this displacement to the normal side
End point should be graded as hard or soft
- End point is said to be hard when the
abruptly halts the forward motion of the tibia
- End point is soft when there is no ACL &
restraints are more elastic secondary
PIVOT SHIFT TEST
During this test,
pt is kept in supine & examiner holds pt's leg with
abduct the pt’s hip (to relax the ITB and allow the
tibia to rotate)
Holding the heel in one hand and applying a valgus
stress in the other hand, the
knee is slowly flexed
The tibia, as well as the valgus, subluxes
easily if anterior force is applied.
After the anterior subluxation of the tibia is
noticed, the knee is slowly flexed, and the tibia
will reduce with a snap at about 20° to 30°of
Immediately after injury
R.I.C.E (Rest Ice Compression Elevation ()
Non surgical treatment
Exercise (after swelling decreases and weight-bearing
Nonsurgical management is indicated in
- partial tears and no instability symptoms
- complete tears and no symptoms of knee
- Who do light manual work or live sedentary
- Whose growth plates are still open (children)
Modification of active lifestyle to avoid high
Muscle strengthening exercises for life
May require knee brace
Despite above precautions ,secondary
damage to knee cartilage & meniscus leading
to premature arthritis
Timing of Surgery
1) Swelling in the knee must go down to near-normal
2) Range-of-motion (bending and straightening)
of the injured knee must be nearly equal to the
3) Good Quadriceps muscle strength must be
Usually it takes a couple of weeks after injury
before ACL reconstruction can be performed.
The presence of any associated injuries to the
knee joint involving cartilage, meniscus, or other
ligaments may change the time-frame for surgery.
ACL tears are not usually repaired using
sew it back together, because repaired ACLs
generally been shown to fail over time
Therefore, the torn ACL is generally replaced
substitute graft made of tendon
The grafts commonly used to replace the ACL
gracilis, or posterior
Patients treated with surgical reconstruction of
ACL have long-term success rates of 82 %-
The goal of the ACL reconstruction surgery is
to prevent instability and restore the function of
the torn ligament, creating a stable knee.
Recurrent instability and graft failure are seen
Active adult patients involved in sports or jobs
require pivoting, turning or hard-cutting as well
heavy manual work are encouraged to
Activity, not age, should determine if surgical
intervention should be considered.
In young children or adolescents with ACL
early ACL reconstruction creates a possible
growth plate injury, leading to bone growth
problems. The surgeon can delay ACL surgery
the child is closer to skeletal maturity or the
may modify the ACL surgery technique to
A patient with a torn ACL and significant
instability has a high risk of developing
knee damage and should therefore consider
It is common to see ACL injuries combined
damage to the menisci (50 %), articular
1.PATELLAR TENDON AUTOGRAFT.
The middle third of the patellar tendon of the patient,
with a bone plug from the shin and the patella is used
patellar tendon autograft. Occasionally referred to by
surgeons as the "gold standard" for ACL
recommended for high-demand athletes and patients
jobs do not require a significant amount of kneeling.
In addition, most studies show equal or better
outcomes in terms of postoperative tests for
laxity (Lachman's, anterior drawer and
tests) when this graft is compared to others.
The Disadvantages of the patellar tendon
-Postoperative patello femoral pain
-Pain with kneeling
-increased risk of postoperative stiffness
-risk of patella fracture
-Persistent Tendon Defect
2.Hamstring tendon autograft.
The semitendinosus hamstring tendon on
side of the knee is used in creating the
tendon autograft for ACL reconstruction.
Some use an additional tendon, the gracilis,
is attached below the knee in the same area.
Hamstring graft proponents claim there are
problems associated with harvesting of the
compared to the patellar tendon autograft
- Fewer problems with anterior knee pain
- Less postoperative stiffness problems
- Smaller incision
The graft function may be limited by the strength
type of fixation in the bone tunnels, as the graft
not have bone plugs.
There have been conflicting results in research
as to whether hamstring grafts are slightly more
susceptible to graft elongation (stretching), which
lead to increased laxity during objective
There are some indications that patients who
intrinsic ligamentous laxity and knee
of 10 degrees or more may have increased risk
postoperative hamstring graft laxity on clinical
Therefore, some clinicians recommend the use
patellar tendon autografts in these hypermobile
residual medial collateral ligament laxity
(grade 2 or more) at the time of ACL
reconstruction may be a contra-indication
use of the patient's own semitendinosus
gracilis tendons as an ACL graft.
3.QUADRICEPS TENDON AUTOGRAFT.
The quadriceps tendon autograft is often used
patients who have already failed
Middle third of the patient's quadriceps tendon
a bone plug from the upper end of the patella
This yields a larger graft for taller and heavier
patients. Because there is a bone plug on one
only, the fixation is not as solid as for the
There is a high association with postoperative
anterior knee pain and a low risk of patella
fracture. Patients may find the incision is not
Allografts are grafts taken from cadavers and are
becoming increasingly popular.
These grafts are also used for patients who have
ACL reconstruction before and in surgery to repair
reconstruct more than one knee ligament.
Advantages of using allograft tissue include
- Elimination of pain caused by obtaining the
The PATELLAR TENDON ALLOGRAFT
allows for strong bony fixation in the tibial and
tunnels with screws.
However, allografts are associated with
- Risk of infection, including viral
transmission (HIV and Hepatitis C)
There have also been conflicting results in
research studies as to whether allografts are
slightly more susceptible to graft elongation
(stretching), which may lead to increased laxity
Recently published literature may point to a
higher failure rate with the use of allografts for
Failure rates ranging from 23% to 34.4% have
been reported in young, active patients
returning to high-demand sporting activities
after ACL reconstruction with allografts.
This is compared to autograft failure rates
ranging from 5% to 10%.
Meta-analysis of Patellar vs.
Hamstring tendons in ACL
•Controlled trials with minimum 2 year follow-up•
Evaluated; return to pre-injury level of
activity, KT testing, Lachmanscores, pivot shift
scores, ROM, complications, failures•4 studies
fulfilled inclusion criteria•B-T-B showed a
>20% chance return to pre-injury activity level
versus hamstring, (p value = 0.01)
Yunes, M. et al “Patellar Versus Hamstring
Tendons in ACL reconstruction; A Meta-analysis”
Arthroscopy Vol. 17, No. 3 (March)
The best scenario for the use of the synthetic
graft is when the
graft can be buried in soft tissue, such as in
This allows for collagen ingrowth and ensures
the long-term viability of the synthetic graft.
It will be sure to fail early if it is laid into a joint
bare, especially going around tunnel edges,
and is unprotected by soft tissue.
The main disadvantage is that all the long-term
studies have shown high failure rate. There is the
potential for reaction to the graft material with
synovitis, as seen with the use of the Gore-Tex graft.
With the Gore-Tex graft, there was also the increased
risk of late hematogenous joint infection.
The results that have been reported with the use of
graft suggest that it should not be used for ACL
Unacceptable failure rates have also been reported
with the use of the Stryker Dacron ligament and the
Ultimate load to failure of femoral fixation
Endo-button: tape 500N
BioScrew: Endo-pearl 700N
Bone mulch screw 900N
Cross pin 900N
Endo-button with closed loop tape 1300N
Interference Fit Screws
Quick, familiar, and easy to use.
Direct bone to tendon healing, with Sharpey’s fibers at the
Less tunnel enlargement.
The disadvantages are as follows:
Longer graft preparation time.
Bone quality dependent.
Damage to the graft with the screw.
Divergent screw has poor fixation.
Removal of metal screw makes revision difficult
The advantages are as follows:
Strongest tested fixation.
May individually tension all bundles of graft.
The disadvantages are as follows:
Pin may tilt in soft bone and lose fixation.
Steep learning curve of fiddle factor.
Special guides are required.
The EB is a small oval button that anchors the graft against
the outer femoral cortex.
The Endobutton (EB) is the most widely used femoral fixation
device worldwide that is designed specifically for soft tissue
Pioneered by Dr. Thomas Rosenberg and introduced around
1990, it was the first device specifically designed to hold soft
As originally designed, the surgeon would tie a Dacron tape
connecting the button to the tendon.
In the past 5 years, this technique has been largely
supplanted by use of the EB-CL (continuous loop), which
obviates the need to tie knots.
Due to the longevity of the device, there is a much greater
literature concerning it than any of the other newer, soft
The Endo-button with closed loop tape is strong,
The plastic button is cheap, available and easy to
Fixation site is distant with increase in laxity, with
the bungee cord effect.
Increased in tunnel widening.
Plastic button has low pullout strength, dependent
on the sutures
In the largest meta-analysis of anterior cruciate
ligament reconstruction (ACLR) autografts, the
EB-hamstring combination was found to have
the highest stability rates of any graft-fixation
construct when paired with modern tibial
fixation.Morbidity has been minimal.
Milagro (Beta-Tricalcium Phosphate,
Polylactide Co-Glycolide Biocomposite)
The Milagro screw can be used for femoral or
tibial fixation for soft tissue or bone–tendon–
bone (BTB) autografts or allografts. It is
available in various diameters from 7 to 12mm
and in 23-, 30-, and 35-mm lengths. The
Milagro screw is made from a polymer
composite, Biocryl Rapide.
EZLoc Femoral Fixation of a Soft Tissue Graft
The EZLoc (Arthrotek, Warsaw, IN) is a cortical
femoral fixation device for a soft tissue anterior
cruciate ligament (ACL) reconstruction that combines
superior fixation properties (high resistance to
slippage, infinite stiffness, and 1427N strength) with a
simple surgical technique.
The EZLoc consists of a deployable lever arm
connected to an axle in a slotted body through which
the ACL graft is looped.
The EZLoc comes sterilely package with a sharp-tip
passing pin that is secured in the slotted body with a
suture tied under tension. The passing pin is passed
through the tunnels, the gold lever arm is positioned
lateral, and the soft tissue graft is looped through the
slot in the EZLoc.
Tibial Fixing Devices
Ultimate load to failure of tibial fixation devices.
Single staple 100N
Double staple 500N
Screw post 600N
BioScrew and button 600N
Screw and washer 800N
Washer Loc 900N
What is an “Anatomic” ACL reconstruction?
Every person is different; some people are short,
others are tall. Similarly, each person has a
different size and shape of the ACL. In order to
properly reconstruct the ACL it is important to
reproduce each persons individual anatomy.
The goals of anatomic ACL reconstruction are to:
Restore 60 – 80% of normal ACL anatomy
Regain stability and return to pre-injury activity
Maintain long term knee health
What is anatomic Double-Bundle ACL
In a “double-bundle” ACL reconstruction, the
ACL is restored using two bundles. Just like
the normal ACL, there will be an AM and a PL
In a “single-bundle” reconstruction, the ACL is
restored using one bundle. There are some
benefits of a “double-bundle” reconstruction,
when compared to a “single-bundle”
Anatomic double-bundle reconstruction better
restores knee stability compared to single-bundle
Because anatomic double-bundle
reconstruction uses two bundles to restore the
ACL, it allows for a replacement of a larger
Pre requisite for single-bundle/
An ACL insertion site greater than 18 mm
allows for double-bundle reconstruction.
If the insertion site is less than 14 mm, there is
only space available for a single-bundle
Between 14 – 18 mm, we can perform either
double- or single-bundle reconstruction.
Indications for single bundle
The patient is still growing and his or her
growth plate is not closed.
The patient has severe arthritis of the knee.
The patient has multiple knee ligament injuries
or a knee dislocation and multiple other
ligaments need to be reconstructed at the
The patient has bone that is severely bruised.
The patient has a small Intercondylar“notch”.
A prospective comparative cohort study was carried
out with 72 consecutive patients with chronic ACL
deficiency to compare three ACL reconstruction
procedures using hamstring tendon grafts.
The first 24 patients underwent a single-bundle
procedure using a six-strand hamstring tendon graft.
The next 24 patients underwent a nonanatomical
double-bundle procedure using four-strand and two-strand
hamstring tendon grafts.
The final 24 patients underwent the anatomical
double-bundle procedure using the same four-strand
and two-strand hamstring tendon grafts. All 72
patients underwent postoperative management with
the same rehabilitation protocol.There were no
significant differences among the background factors.
The postoperative anterior laxity measured
was significantly less after the anatomical
double-bundle reconstruction than after the
single-bundle reconstruction. Concerning the
results of the pivot-shift test
Outcome of Arthroscopic Single-Bundle Versus
Double-Bundle Reconstruction of the Anterior
Cruciate Ligament: A Preliminary 2-Year
Se-Jin Park, M.D., Young-Bok Jung, M.D., Hwa-
Jae Jung, M.D., Ho-Joong Jung, M.D., Hun Kyu
Shin, M.D., Eugene Kim, M.D., Kwang-Sup Song,
M.D., Gwang-Sin Kim, M.D., Hye-Young Cheon,
P.A., Seonwoo Kim, Ph.D.Received: December
29, 2008; Accepted: September 9, 2009;
Published Online: February 22, 2010
ArthroscopyVolume 26, Issue 5, Pages 630–636,
113 were included in this study. They serially
obtained clinical and radiologic data
preoperatively and postoperatively. They
compared preoperative data and data at 2 years
postoperatively in patients who had undergone
single-bundle ACL reconstruction versus patients
who had undergone double-bundle ACL
There were 50 single-bundle reconstructions and
63 double-bundle reconstructions. Anteroposterior
stability was assessed objectively by anterior
stress radiographs with the telos device (telos,
Marburg, Germany) and the maximal manual test
Double-bundle reconstruction of the ACL by a
method using 2 femoral tunnel and 2 tibial
tunnels showed no differences in stability
results or any other clinical aspects or in terms
of patient satisfaction.
Skeletally immature patients
Anterior cruciate ligament injuries in skeletally
immature adolescents are being diagnosed
with increasing frequency.
Nonoperative management of midsubstance
ACL injuries in adolescent athletes frequently
results in a high incidence of giving-way
episodes, recurrent meniscal tears, and early
onset of osteoarthritis
The concern about ACL reconstruction in the
athlete with open growth plates is that there
premature fusion of the plate, growth arrest,
and potential for angular deformities.
Skeletally immature patients
Non surgical methods
Non surgical method
In some less active individuals with mild-to-moderate
instability, reduction of activity level
may be all that is necessary until they have
had an appropriate growth spurt and maturing
of the physes.
Muscle strengthening exercises
Away from sports activities
TRANSEPIPHYSEAL REPLACEMENT OF
ANTERIOR CRUCIATE LIGAMENT USING
QUADRUPLE HAMSTRING GRAFTS
The transepiphyseal replacement of anterior
cruciate ligament using quadruple hamstring
procedure described by Anderson is indicated in
patients in Tanner stage I, II, or III of development.
The procedure is contraindicated in patients in
Tanner stage IV of development, who can have
conventional anterior cruciate ligament
The tunnels are drilled centrally through the
epiphysis and fixed with a button on the periosteal
surface. There are no reported growth deformities
Anderson transepiphyseal replacement of
anterior cruciate ligament using quadruple
physeal-sparing, combined intraarticular
and extraarticular reconstruction of acl by Kocher,
Garg, and Micheli
Anterior Cruciate Ligament Reconstruction
in Skeletally Immature Patients With
Lauren H. Redler, M.D., Rebecca T. Brafman,
B.A., Natasha Trentacosta, M.D., Christopher S.
Ahmad, M.D.(Department of Orthopaedic Surgery,
Columbia University Medical Center, New York,
New York, U.S.A.)
Arthroscopy Volume 28, Issue 11, Pages 1710–
1717, November 2012
Moises Cohen, M.D., Ph.D., Mario Ferretti, M.D.,
Ph.D., Marcelo Quarteiro, M.D., Frank B.
Marcondes, M.D., João P.B. de Hollanda,
M.D., Joicemar T. Amaro, M.D., Rene J. Abdalla,
M.D., Ph.D.(Orthopedic Sports Medicine Division,
Department of Orthopaedic Surgery and
Traumatology, Universidade Federal de São
Paulo–Escola Paulista de Medicina, São Paulo,
ACL reconstruction by use of the transphyseal
technique in an immature skeleton with a
hamstring autograft, with careful attention
being paid to the technique, resulted in good
clinical outcomes and no growth abnormalities.