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Date issued:  September 2019

For review: September 2021

Ref: A-263/JA/Physio/Anterior Cruciate Ligament v2

PDF:  Anterior Cruciate ligament [pdf] 1MB

Anterior Cruciate Ligament

The Knee joint is a complex weight bearing joint that relies on the interplay of ligaments and muscles to provide stability. The Anterior Cruciate Ligament (ACL) is one of the most important and commonly injured ligaments within the knee.  Extremely strong the ACL restricts the tibia (lower leg long bone) moving forward on the femur (thigh bone) and in conjunction with the Posterior Cruciate Ligament restricts internal rotation of the tibia towards the opposite leg.

An ACL rupture (completely torn ligament) is likely to cause instability as the restraining mechanism to movement will have been significantly damaged.  This can cause problems with even the most basic activities of daily living (washing, dressing, stairs, walking).

ACL injuries may not occur in isolation with other structures in the knee also being damaged commonly the Tibial or Medial collateral ligament (MCL), Medial Meniscus (Cartilage), Posterior Cruciate Ligament and the articular surfaces (Condyles).

You’ve suffered an ACL injury

The ACL is designed to withstand large forces, forces far greater than those that we impart on it on a daily basis.  When we have an accident or play sport we significantly increase the forces we put through the knee which in certain circumstances overloads the ACL causing full or partial rupture.

Commonly injured through awkward landing from a jump or planting the foot to take a shot or change direction in cutting or pivoting sports for example football & netball.   Injury can also be the result of a collision tackle (rugby) or a sudden twist either sporting (skiing, basketball) or accidentally in everyday life. ACL injuries can also occur due to non-impact injuries and twists alone, though less common.

Patients often report a “pop” sensation, sudden onset of pain with an immediate swelling of the knee preventing any further participation in recreational activity. The knee may “give way” or “buckle” particularly noticed on turning activities.

Associated ‘soft tissues’ (ligaments, muscles, tendons, joint capsule etc) surrounding the knee may also be damaged which causes inflammation or swelling.  This is the bodies natural response to injury, completely normal and the first phase of the healing process.  Referred to as the ‘inflammatory phase’ it should last for 3-5 days however if poorly managed can last longer causing pain, restriction of movement and loss of mobility.  Implementing the principles of POLICE (outlined below) as close to injury as achievable will help reduce inflammation and prevent further pain and movement dysfunction.

Further assessment and treatment cannot be achieved until inflammation is successfully managed.

 

Immediate treatment following ACL injury & reconstruction surgery

Following acute injury the aim of any treatment is to:

• Reduce swelling.
• Regain range of knee movement.
• Regain normal basic functional activity over several weeks.

It is important to reduce swelling as soon as possible for pain relief, restoration of knee range of movement and to allow muscular control at the knee to re-establish. 

The mnemonic POLICE (Protect Optimal Loading Ice Compression Elevation) is helpful in remembering the important elements of inflammation management.

Protection, you may be assessed for elbow crutches and encouraged to weight bear through the injured leg as pain allows.  Where greater damage to the stability of the knee has occurred (muscles, ligaments, cartilage) a brace may be applied.  Protecting the knee prevents further injury occurring therefore allowing the healing process to begin.

Optimal Load, Putting as much weight through the knee as comfortable/pain allows.  This means not pushing into or through the pain.  Walk as normally as possible using elbow crutches if required to maintain correct muscle recruitment patterns.  This will stimulate the healing process and gauged correctly can help reduce swelling through muscle contraction.  Optimal load will also prevent further joint and muscle stiffness as well as any deficits to control/balance (proprioception).

It is important to find a balance between resting your knee and loading/exercising.  Too much exercise and movement can prolong the inflammatory phase whereas not enough can result in a stiff weak knee.  Rest with your injured leg elevated on a bed with pillows under the calf and foot.  Do not place a pillow under the injured knee as this may slow the recovery of knee extension. Exercises and knee movement should be maintained in a pain-free range repeated little and often. 

You will benefit from being signed off work for two weeks.

Ice: Effective at reducing inflammation ice should be applied as soon after injury as possible and continued for twenty minutes every two hours whilst you are awake.  At least five times a day and continued until inflammation settles usually 12 – 72 hours post injury.  Protect your skin from ice burn by wrapping a damp towel around the bag of ice before placing on the injured knee

Compression: Apply continuous compression (Compression stocking, Tubigrip or elasticated bandage) from thigh to ankle following ice therapy.  Compression helps to control inflammation formation and can be utilised whilst inflammation exists.

Elevation: Immediately as is practical and for at least the first 24 hours following injury try to keep the injured leg elevated ideally lying down so your knee is higher than your heart.  Do not sit for long periods with your foot lower than your body as this will cause increased swelling in your knee, lower leg and ankle.

Discuss utilising non-steroidal anti-inflammatory medication with your GP or Pharmacist alongside ice therapy to help control pain and swelling.

As pain and swelling decrease 7-10 days after injury you can start to spend more time up on your feet using elbow crutches.  Once muscular control of the knee has been regained, you can walk normally carrying all your weight and you are safe you will be weaned off the elbow crutches.

Diagnosing an ACL injury

The diagnosis of an ACL injury can often be suspected based upon the history or event.  The clinician will be interested in the direction of impact to the knee, the direction the knee moved, what position the leg finished in and any noises that occurred.  Whether you have any pain and if so how much, where and has it changed since the injury.  Rapid swelling (inflammation) within minutes or slower onset over hours can help determine the diagnosis.

A clinical examination will involve specific ligament stress tests which indicate the extent of laxity or damage the ACL has suffered.  Both knees will be assessed to gain comparisons.  A stiff and inflamed knee will be difficult to assess accurately and PRICE guidelines above should be followed.

X-ray or MRI scans are sometimes useful though not essential. These may be employed to confirm diagnosis and assess if other structures have been damaged.

Do I need to have surgery to repair / reconstruct my ACL?

The ACL cannot heal or be stitched back together therefore you have two options one, to have ACL Reconstruction (surgical repair) in which your own muscle tendons are used to form a new ACL or option two, not to have a ACL Reconstruction and manage without.

It is not uncommon to manage without a functioning ACL especially if you are happy to modify/reduce certain activities and have no desire to play sports that involve twisting or turning (football, netball, skiing etc).  Guided appropriate rehabilitation over several months will aid development of muscle tone and knee control which compensates the loss of the ACL.  A home exercise programme will need to be continued indefinitely to maintain good knee control and stability.

If you intend to continue with rotational or contact sports or feel that you may like the option to in the future then it is likely that you will need to have your ACL reconstructed.  Your age is not the determining factor for having an ACL reconstruction but the level of physical activity you aspire to regain is.

There is no evidence to suggest that having an ACL reconstruction will reduce the risk of developing osteoarthritis in later life.

Whichever option you decide a course of expert guided rehabilitation or prehabilitation (rehabilitation before surgery) by a Chartered Physiotherapist is advisable.

When should I have my ACL reconstructed?

It is advisable that you have recovered from the acute injury before surgery is undertaken.  Physiotherapy rehabilitation can aid this process.

Prehabilitation

Prehabilitation following initial injury and prior to reconstructive surgery is very important to aid your recovery back to health.

The goals/aims are to:

• increase range of motion (ROM) and restore full knee extension
• Achieve good muscle tone, control, strength, flexibility and proprioception (balance)
• Achieve an increased level of cardio-vascular fitness
• Achieve an increased awareness of your knee

 

The rehabilitation required will provide a seamless progression into exercise following surgery and be less of a shock to the system!

 

ROM and Flexibility

(Here are some ideas of exercises to be undertaken daily throughout the day)

• Extension hangs in sitting or prone lying
• Heel slides
• Bike pendulums: high seat half circles forwards/backwards leading to full revolutions on lower seat
• Seated calf stretch with towel – knee bent (Soleus) knee straight (Gastrocnemius)
• Seated hamstring stretch (back straight)

Heel Slides

Sitting with your back supported. Slide your heel towards your bottom, use a belt or towel under your foot to assist you.

Hold for 10 seconds, repeat 10 times 3-4 times a day

Extension hangs in sitting or prone lying

Sit with your knee unsupported and foot on a raise or on a stool. Allow the weight of your leg to straighten your knee.

Hold for 10 minutes, repeat 2 times a day

Bike pendulums

High seat half circles forwards/backwards leading to full revolutions on a lower seat. 2-3 minutes, repeat 3 times a day

Seated calf stretch (Soleus muscle)

With your knee flexed/bent  30° and using a towel, belt or scarf, slowly pull your toes up toward your shin. Feel the stretch in your lower calf Hold for 30 seconds, repeat 3 times 3-4 times a day

Seated calf stretch (Gastrocnemius muscle)

With your knee straight and using a towel, belt or scarf, slowly pull your toesup toward your shin. Feel the stretch in your upper calf Hold for 30 seconds, repeat 3 times 3-4 times a day

Seated hamstring stretch

Sitting, maintain a straight body position, with your operated leg out in front of you, reach forward and attempt to grasp your ankle or your toes. Feel a stretch at the back of your leg

Hold for 30 seconds, repeat 3 times 2 times a day

 

Muscle strength and endurance

• Static Quads
• Bridging
• Sit to stand
• Static Lunge forwards and to the side
• 30° Squats
• Side lying abduction/adduction
• Gluteal squeezes supine or standing
• Prone hip extension
• Standing hip flexion/extension, abduction/adduction
• Ankle pumping
• Standing calf raises with/without support

Static Quads

Sitting with leg supported, tighten your thigh muscle until your leg is straight and your knee cap moves towards your hip. Hold 10 seconds

 

15 repetitions, 3-4 times a day

 

Bridging

Lie on back with both knees bent. Tighten your quads and hamstrings, squeeze your buttocks together and lift your bottom off the floor. Progress exercise by lifting both hands in the air.

10-15 reps, 2-3 times a day

Sit to stand

Stand up from sitting and sit down again without using your arms.

15-20 reps, 2-3 times a day

Lateral lunge

Stand with feet wide apart and toes pointing forward.  Step out to the left, keeping your toes pointing straight ahead and your feet flat.  Squat by bending the left knee.  Keep your right leg straight and the weight on the left foot.  Squat as low as possible, keep your right leg straight and hold this position for 2 seconds.  Return to the starting position and repeat.

Then alternate with your opposite leg.

10-15 reps, 2-3 times a day

Static lunge

Stand with erect posture and your legs hip width apart.  Take a step forward with the operated leg and squat down. Return to the starting position and repeat.

Then alternate with your opposite leg.

10-15 reps, 2-3 times a day

30° squat

Stand with feet hip width apart. Slowly bend knees to about 30 degrees, keeping knees lined up over feet and then straighten up to standing position, and repeat.

10 reps, 3-4 times a day

Standing Hip extension

Stand next to a bench and lean over it. Bend the operated knee to 90 degrees and then lift the whole leg behind you a little and lower it again. Keep your buttock tight throughout!  

10-15 reps, 2-3 times a day

Proprioception (Balance)

Single leg standing 30 – 60 seconds, 1-2 times a day

Wobble boards

Wobble cushion and Trampette

Single leg standing

Standing on the operated leg, lift the other leg off the floor and try to balance.

3 minutes practicing, 2-3 times a day

Variations -    Hold wall with one hand

Fold arms across chest

Close 1 or 2 eyes

Wobble Boards (two legs)

Stand on the wobble board. Practice balancing and do not let the sides of the board touch the floor

3-5 minutes, 1-2 times a day

Wobble Cushion

Standing on the operated leg, lift the other leg off the floor and try to balance.

3-5 minutes, 1-2 times a day

Gait (walking)

Weight shifting side-to-side and forward/backward

Progress from two crutches to one maintaining a normal walking pattern

 

Surgical Techniques

The Orthopaedic Knee Surgeons at Plymouth Hospitals NHS Trust commonly use one of the patients own hamstring tendons to form the ligament graft.

Taken from the same injured leg the surgeon harvests the hamstring through a small incision on the inner aspect of the leg just below the knee. The remainder of the operation is performed using an arthroscope (keyhole surgery) removing the damaged ACL, drilling tunnels and positioning the new hamstring graft. The hamstring graft is tensioned and fixed into place with a screw and end button.

The new graft does not immediately function in the same way as a natural ACL. The graft undergoes many changes during its recovery being most vulnerable to damage over the first three months. Expert guided rehabilitation by a Chartered Physiotherapist is vital to the ongoing recovery process and a successful outcome.

To successfully rehabilitate an ACL you must strike a balance between exercise and mobility.  The correct amount of exercise and mobility will develop knee control and prevent stiffness or soft tissue contracture.  Too much mobility or exercise may place undue stress or strain on the graft causing complications.  Your Chartered Physiotherapist will expertly guide you through each stage of your recovery

Post Operative Physiotherapy:

At all times rehabilitation should be governed by common sense. If exercises cause knee swelling (an effusion) then there may be something wrong; probably overdoing the exercises, and you should return to a lower level of exercise and seek advice from your Physiotherapist or Surgeon.

During the first six weeks the graft is going through a healing phase when hopefully it is binding to the bone. Thereafter we believe that it starts to develop a blood supply. It may be however that the graft is weakest at about six weeks post op (6-12 weeks). Butler et al (1989), and then progressively strengthens. The stimulation of rehabilitation is important at this time. From twelve weeks onward the knee can gradually be pushed harder, introducing running. Between four and six months post op, cutting and turning can be introduced with sport specific training starting at six to nine months, and a return to sport at nine to twelve months. Obviously, not everyone aspires to sport, and your rehab should be tailored to your requirements, but rehab is important for everyone!

 

During the first six weeks do your own regime daily. Your physiotherapist will advise you how much and how frequently you should exercise, but in general aim to work through an exercise schedule at least three times per day. From six weeks onward, your rehab protocol becomes more intensive (with limitations), and you should aim to work five days a week resting completely for two days.

Knee Bracing:

Knee braces or splints are not routinely prescribed following ACL reconstruction unless indicated.  You may find that a Tubigrip support or elasticated bandage (available at the chemist) gives you confidence, and there is nothing wrong with using this.  Make sure it is not too tight.

 

ACL REHABILITATION

Returning to work and sport

This is a guideline as to how soon you can return to particular activities. Your return will be guided by your surgeon and Physiotherapist.

 

Work

To be agreed with Surgeon

Work (Return)

• Light work: such as office job                         4 - 6 weeks
• Medium: physical job                                     2 months
• Heavy: manual job (roofs and Ladders)          3-4 months +
• Suggest phased return for any manual job.
• Driving                                                           4 – 6 weeks

DVLA guidelines state the patient must be safe and competent to return to driving. Are they able to do an emergency stop?

 

Physical activity

To be agreed with surgeon or physiotherapist

SPORT (RETURN)

• ACL class or supervised exercises                 6 weeks
• Swimming without flippers or aids                  2 months (No breast stroke)
• Light individual sports/non-competitive   
• Without rotation                                             3 to 4 months
• Start slow running                                          3 months
• Twisting/pivoting activities                              6 months
• Contact/high performance including impact
• and rotation (football, rugby, skiing)                9-12 months

These times are guidelines. The exact progression may vary depending on the individual. Rehabilitation will be monitored by your physiotherapist and surgeon. You are advised not to return to full activity too early. Over stressing the graft too early may increase the risk of graft failure.

Each phase of exercises will work on:

• Range of Movement/Stretching
• Strengthening                                                               
• Proprioception/Balance/coordination
• General mobility and Cardiovascular

 

The reference list below was used to develop this protocol.  If you are interested in learning more these resources may be a good place to begin.

References and Bibliography

 

Butler, DL, Kappa Delta Award paper. (1989) Anterior Cruciate Ligament: its normal response and replacement ;7:910-921

 

Beynnon, BD., Fleming, BB., (1998) Anterior cruciate ligament strain in-vivo: a review of previous work. Journal of Biomechanics. 31(6), 519-25.

 

Fitzgerald, GK,  Lephart,  SM, Hwang,  JH,  Wainer,  MR., (2001) Hop tests as predictors of dynamic knee stability. Journal of Orthopaedic Sports Physical Therapy. 31:588-597

 

Heijne, A., & Werner, S., (2007) Early versus late start open kinetic chain quadriceps exercises after ACL reconstruction with patellar tendon or hamstring grafts: a prospective randomized outcome study. Knee Surg Sports Traumatol Arthrosc. 15:402-414.

 

Hickey, KC., Quatman, CE., Myer, GD., Ford, KR., et al., (2009) Methodological report; Dynamic field tests used in an NFL combine setting to Identify lower extremity functional asymetries. Journal of strength and conditioning research.  23(9) 2500.

 

Herrington, L., Myer, G., & Horsley, I. (2013) Task Based rehabilitation protocol for elite athletes following Anterior Cruciate ligament reconstruction: a clinical commentary. Physical Therapy in Sport. 14, 188-198.

 

Hiemstra, LA., Webber, S., MacDonald, PB., Kriellaars, DJ., (2000) Knee strength deficits after Hamstring and patella tendon ACL reconstruction. Medicine and Science in Sports and Exercise. 32(8):1472-1479

 

Myer, G., Paterno, MV., Ford, KR., Quatman, CE., & Hewett TE., (2006) Rehabilitation after anterior cruciate ligament reconstruction: Criteria-based Progression through return-to-sport phase.  Journal of Orthopaedic & Sports Physical Therapy, 36(6), 385 – 402.

 

Myer, G., Ford, K., & Hewett, T., (2008) Tuck jump assessment for reducing anterior cruciate ligament injury risk. Athletic Therapy Today. 13, 39-44

 

Myer, G., Chu, DA., Brent, J., & Hewett, T., (2008) Trunk and hip control neuromuscular training for the prevention of knee joint injury. Clinical Sports Medicin. 27, 425-448

 

Myer, G., Paterno, MV., Ford, K., & Hewett, T., (2008) Neuromuscular training techniques to target deficits before return to sport after anterior cruciate ligament reconstruction. Journal of  Strength and Conditioning Research. 22, 987-1014.

 

Noyes, FR., Braber, SD., & Mangine, RE., (1991) Abnormal lower limb symmetry determined by functional tests after anterior cruciate ligament rupture, American Journal of sports medicine, 19 513-518.

 

Padua, DA., Marshall, SW., Boling, MC., Thigpen, CA., Garrett, WE Jr., Beutler, AI., (2009) The Landing Error Scoring System (LESS) is valid and reliable clinical assessment tool of jump landing biomechanics: The JUMP-ACL study. American Journal of Sports Medicine. 37, 1996-2002.

 

Perry,  MC., Morrissey, MC., King, JB., Morrissey, D., & Earnshaw, P., (2005) Effects of closed versus open kinetic chain knee extensor resistance training on knee laxity and leg function in patients during the 8- to 14-week post-operative period after anterior cruciate ligament reconstruction. Knee Surgery, Sports Traumatology, Arthroscopy. 13(5), 357-69.

 

Pauole KK, (1996) The physical performance T-Test as a measure of speed, Power, and agility in females. Long Beach, CA: California State University; 1996

 

Shiraissha M, Mizuta H, Kubota K, Otsuka Y, Nagamoto N., (1996) Stabilomatric assessment in the ACL-reconstructed knee. Clinical Journal of Sport and Medicine. 6(1):32-39

 

Tyler TF, McHugh MP, Gleim GW, Nicholas SJ., (1998) The effect of immediate weight bearing after ACL reconstruction. Clinical Orthopaedics and Related Research. Dec (357): 141-148

 

Whatman C, Hing W, Hume P. (2012) Physiotherapist agreement when visually rating movement quality during lower extremity functional screening tests.  Physical Therapy in Sport. May;13(2):87-96.