ACL INJURY

Anatomy
• Originates from the medial wall of the lateral femoral
condyle.
• The ACL attaches in front of the intercondyloid
eminence (tibial plateau), being blended with the
anterior horn of the medial meniscus.
• There are two bundles of the ACL—the anteromedial
and the posterolateral, (named according to where the
bundles insert into the tibial plateau).
• These attachments allow it to resist anterior translation
and internal rotation of the tibia, in relation to the
femur.
• It is tense in extension, ‘lax’ in flexion.
 Basic Science and Biomechanics
• Primary restraint to anterior translation of the tibia
• Secondary restraint to tibial internal rotation and to
varus and valgus stress.
• An intact ACL resists forces up to 2500 N and strain
of about 20% before failing.
• The forces placed on an intact ACL :
 about 100 N during passive knee extension,
 about 400 N with walking and
 1700 N with cutting and acceleration- deceleration
activities.
 Causes of ACL Injury
• Occurs when an athlete rapidly decelerates,
followed by a sharp or sudden change in
direction (turning).
• ACL failure has been linked to heavy or stiff-
legged landing (jumping incorrectly)
• Twisting or turning the knee while landing,
especially when the knee is in the valgus (knock-
knee) position.
• Stopping suddenly.
• Direct contact or collision, such as a football
tackle.
 Risk factors
• Women are significantly more likely to have an
ACL tear than men participating in the same
sports.
• Women tend to have a strength imbalance, with
quadriceps being stronger than the hamstrings.
 Signs and symptoms
• Sudden loud "pop" sound
• Knee swelling that usually worsens for hours after the
injury.
• A feeling of instability or "giving way" with weight bearing
• Moderate to severe Pain
• Loss of full range of motion
• Tenderness along the joint line
• Discomfort while walking
• Inability to continue activity
• Continued athletic activity on a knee with an ACL injury can result in
massive cartilage damage, leading to an increased risk of developing
OA later in life.
 Diagnosis
• Thorough clinical examination in experienced
hands is highly accurate
• Commonly used tests are
• Lachman test
• Anterior drawer test,
• Pivot-shift test,

• The diagnosis is usually confirmed by MRI,

 Lachman's Test:
• Patient is supine with knee
passively flexed to
approximately 20 °.
• Examiner provides an anterior
force to the tibia while
applying posterior pressure to
the femur; repeats the process
2–3 times
• Positive Test: Increased
anterior tibial translation, pain:
indicating ACL tear (primarily
posterolateral bundle)
 Anterior Drawer Test
• Patient is in supine with hip
flexed 45° & knee flexed 90 °.
• Examiner draws the tibia
straight forward (no rotation)
• Positive Test: Increased
anterior tibial translation,
pain, indicates ACL tear
(mainly the anteromedial
bundle)
 Pivot Shift Maneuver
• The patient lies supine with the hip
flexed and abducted 30° and in slight
medial rotation (20°).
• The examiner holds the patient's foot
with one hand while the other hand is
placed at the knee, holding the leg in
slight medial rotation
• The examiner then applies valgus
stress to the knee while maintaining a
medial rotation torque on the tibia at
the ankle.
• The leg is then flexed, and at
approximately 30° to 40°, the tibia
reduces or "jogs" backward.
• The patient says that that is what the
"giving way" feels like, indicating a
positive test.
Management
 ACL Reconstruction
• The reconstructive surgery is usually done several
weeks after the injury in order to allow the
swelling and inflammation to go down.
• During surgery the ACL is not repaired, because
the ACL cannot heal independently, as there is no
blood supply to this ligament.
• It is reconstructed/replaced using other tendons
in the body
 Graft Material Properties
• The central third bone patellar tendon bone (BPTB)
graft has an initial failure strength of upto 2977 N,
• The strength of a quadrupled semitendinosis-gracilis
graft complex has been estimated as high as 4000 N.
• These strengths are greatly reduced after surgical
implantation
• Current thought is that the initial graft strength must
exceed that of the normal ACL to maintain sufficient
strength.
• BPTB autograft is currently considered the gold
standard.
 Contd…..
• For BPTB auto graft, the central/middle 1/3 of the patella tendon is
removed along with bone fragments on each end from the kneecap
and tibia. The graft is then threaded through holes drilled in the
tibia and femur, and finally screwed into place.
• Advantages :
• The patella tendon and ACL are relatively the same length
• It uses a bone to bone attachment which is much stronger
than other healing methods.
• Disadvantages:
• Anterior knee pain (removal of bone from the kneecap).
• Increased scar formation as compared to a hamstring.
• Risk of fracturing the patella.
• Increased risk of tendinitis.
• Increased levels of pain.
Knees following ACL reconstruction
(BPTB graft)
 Semitendinosus-Gracilis Graft
• Two tendons are taken from Semitendinosus &
Gracilis and wrapped together to form the new ACL.
• Advantages :
• Less pain associated with post surgery healing as no bone is
removed,
• Incision is small.
• Disadvantage: the new ligament takes longer time to
heal since there is no bone to bone healing
• Tendon to bone connection takes relatively long to
become rigid
 Graft Fixation
• In the first 6 to 12 weeks of rehabilitation, the fixation of
the graft rather than the graft itself is the limiting factor
for strength in the graft complex
• For central third BPTB grafts, interference screw fixation of
the bone blocks in the femoral and tibial tunnels has been
shown to exceed 500 N for both metallic and bioabsorbable
screws. Graft slippage has not been a problem with this
construct.
• For hamstring grafts, the strongest fixation, with the least
amount of graft slippage, is with soft tissue washers, which
can provide a construct strength above 768 N.
 Graft Healing
• After implantation, ACL grafts undergo
sequential phases of avascular necrosis,
revascularization and remodeling.
• Implanted grafts begin to resemble a native ACL
structure as early as 6 months after
implantation, but the final maturation does not
occur until after 1 year.
 Complications after ACL
Reconstruction
• Loss of Motion
• Anterior Knee Pain
 Loss of Motion
• Most common complication after ACL reconstruction.
• Loss of extension is more common than loss of flexion
and is poorly tolerated
• Harner and colleagues (1992) use a loss of knee
extension of 10 degrees or knee flexion of less than
125 degrees to define loss of motion,
• The term "arthrofibrosis” is used synonymously with
loss of motion
• Loss of motion can result in anterior knee pain,
quadriceps weakness, gait abnormalities and early
articular degenerative changes.
 Factors responsible for loss of motion
• Arthrofibrosis, infrapatellar contracture
syndrome, patella infera.
• Inappropriate ACL graft placement or tensioning.
• "Cyclops" syndrome.
• Acute surgery on a swollen inflamed knee.
• Concomitant MCL repair.
• Poorly supervised or poorly designed
rehabilitation program.
• Prolonged immobilization.
• RSD.
 Preventive Measures
• The most important immediate goal is to obtain
and maintain full knee extension immediately
after surgery.
• Prone heel height side-to-side difference should
be less than 5 cm by 7 to 10 days after surgery
• Knee flexion to 90 degrees should be achieved by
7 to 10 days after surgery.
• Patellar mobility should show steady progression
after surgery with proper mobilization techniques.
 Contd…..
Methods:
• Continuous Passive Motion
• Weight-bearing
• Muscle Re-education
• Electrical Stimulation and Biofeedback
• Proprioception Training
• ACL Bracing
 Contd….
• To improve extension, prone hangs, manual
pressure extension against a theraband, and
backward walking can be used.
• To improve flexion, wall and heel slides, supine,
prone, or sitting leg hangs, and manual pressure
can be used.
 Anterior Knee Pain
• Anterior knee Pain along with Effusion is another common
problem after ACL reconstruction
• May be related to the choice of graft material.
• Decrease in anterior knee pain with the use of hamstring
autografts is noticed when compared with BPTB autografts.
• Early rehabilitation to regain ROM and promote quadriceps control
is important in the prevention
• Patellar mobilization techniques should be included to prevent
contracture of the retinacular structures surrounding the patella
• Patient who show signs of anterior knee pain, the rehabilitation
program should be modified to eliminate exercises that may place
undue stress on the patellofemoral joint
 Rehabilitation Protocol for ACL
Reconstruction
General Rehabilitation Approach
• Full passive extension immediately after surgery
• Immediate motion
• Closed-chain exercises
• Emphasis on proprioception return and neuromuscular control drills.
• Drop-lock brace locked in extension during ambulation
• 2 wk for athletes.
• 3 wk for general patients
• More gradual progression of flexion
• Week 1 :- 90 degrees.
• Week 2 :- 105 to 115 degrees
• Week 3 :- 115 to 125 degrees
• Week 4 :- >125 degrees.
 Contd…..
• CKC exercises that have been shown to produce
actual co-contraction are used early
• Vertical squats (0-45 degrees).
• Lateral lunges.
• Balance drills.
• Neuromuscular training and proprioception
must be incorporated into every phase of the
rehabilitation program.
Rehab Program
 Phase 1 (0-2 weeks)
The GOALS of this phase are to:
 Reduction of swelling
 Partial weight bearing to full weight bearing
exercises
 Regain normal range of motion
 Increase quadriceps & hamstring strength.
 Ex Programme
• Use of Cryo-cuff
• Isometric contraction of Quads
• Quad Sets - stand against wall, push extended
knee against rolled towel
• Progress to straight leg raised to 30°.
• Wall Slides- to increase knee flexion
• Assisted Knee Flexion
• VMO Strengthening Exercise
• Supported Bilateral Calf-Raises
• Walk without crutches
 Phase 2 (2-12 weeks)
The GOALS of this phase are to:
 Regain full knee extension
 Restore knee flexion to +130°
 Perform a full squat properly
 Regain good balance and control
 Re-establish proper gait.
 Ex Programme
• Mini squats - Progress to full squats → single-leg half squat
• Mini Lunges - Progress to full lunges
• Leg Press - Double-leg → single
• Step-ups - lateral & forward
• Bridges:
- Double-leg → single
- Floor → Swiss ball
• Hip Abduction, Extension ex with Theraband
• Wobble board - Assisted → un-assisted → eyes closed (assisted →
unassisted)
• Stork Stand - Assisted → un-assisted → eyes closed (assisted →
unassisted) → unstable surface
• Static Proprioceptive hold/ball throwing
• Functional Exercises that can be performed at this time include:
- Walking, Bike.
 Phase 3 (3 - 6 months)
The GOALS of this phase are to:
 Regain/Maintain full range of motion
 Regain full strength and power
 Increase agility
 Allows for adaption to direction change,
acceleration and deceleration
 Making able to perform restricted sports-
specific drills
 Ex Programme
• Continue exercises from Phase 2, progress as
necessary
• Jump & Land drills:
• Jump from block & stick landing
• Double-leg landing → single-leg
• Plyometric Drills:
• Jumping over blocks, sideways & forward
• Hopping up & down steps/stairs
 Phase 4 (6 - 12 months)
• The GOAL of this phase is a return to activity,
• It requires an ability to perform some functional performance tests such
as:
• Illinois Agility Test
• Zig Zag Agility Test
• Standing Vertical Jump: jump straight in the air from standing, start and
land on two feet as stable as possible.
• Heiden Hop Test: jump as far as possible with the uninjured leg and land
on the injured leg. Your ability to stick the landing is indicative of good
knee function.
• Isokinetic Testing: To evaluate muscle strength. The individual should
have at least 90% quadriceps strength of the uninjured leg. They should
also have equal hamstring strength to their uninjured leg .
Criteria for Return to Sports after ACL
Reconstruction
• Full ROM
• KT-l000 side-to-side difference < 3 mm
• Quadriceps strength 85% or more of contralateral side
• Hamstring strength 100% of contralateral side
• Hamstring-to-quadriceps strength ratio 70% or greater
• Functional testing battery 85% or greater compared with
contralateral side
• Single-leg hop
• Timed leg hop for 20 ft
• Vertical jump
• No effusion
• No pain or other symptoms
 The Illinois Agility Test
• The Illinois Agility Test (Getchell, 1979) is a commonly used test of agility in sports, and as such there are
many norms available.
• purpose: to test running agility
• equipment required: flat non-slip surface, marking cones, stopwatch, measuring tape,
• procedure:
• The length of the course is 10 meters and the width (distance between the start and finish points) is 5
meters.
• Four cones are used to mark the start, finish and the two turning points.
• Another four cones are placed down the center an equal distance apart. Each cone in the center is spaced
3.3 meters apart.
• Subjects should lie on their front (head to the start line) and hands by their shoulders.
• On the 'Go' command the stopwatch is started, and the athlete gets up as quickly as possible and runs
around the course in the direction indicated, without knocking the cones over, to the finish line, at which
the timing is stopped.
• Results: The table below gives some rating scores for the test
• Agility Run Ratings (seconds)
• Rating Males Females
• Excellent < 15.2 < 17.0
• Good 16.1-15.2 17.9-17.0
• Average 18.1-16.2 21.7-18.0
• Fair 18.3-18.2 23.0-21.8
• Poor > 18.3 > 23.0
 Zig-Zag Agility Test
• The objective of this test is to monitor the development of the athlete's speed
and agility.
• Required Resources
• 5 cones
• Flat non-slip surface
• Stopwatch
• Method:
• The athlete warms up for 10 minutes
• Mark a rectangle 10 by 16 feet with four cones and places a cone in
the centre
• Give the command "GO" and starts the stopwatch
• The athlete commences the test at the Start & Finish cone and follows
the grey route indicated in the diagram
• Stop the stopwatch and record the time when the athlete's torso
crosses the Start & Finish cone
THANK YOU