What is a graft in ACL surgery?

An ACL graft is a substitute for the normal ACL in your knee. The ACL (anterior cruciate ligament) is one of the four major stabilising ligaments in the knee. It is commonly injured in sporting activities. The ACL does not heal very well, and an injury usually results in an unstable knee. This in turn can result in the development painful arthritis in later years. Surgery is usually recommended for an ACL tear, especially in younger people and those who are active (read: Do I need to have ACL surgery?).

Over the years, attempts have been made to try and repair the ACL once it has been torn. Unfortunately, the success rates for a repair are not good. The standard procedure performed by most surgeons, therefore, is to use a substitute tendon in your knee to replace the torn ACL. This substitute tendon is called the ACL graft.

The basic procedure of an ACL reconstruction is to remove parts or all the torn ACL and replace it with the ACL graft. Tunnels are created in the thigh bone (femur) and shin bone (tibia). The ACL graft is threaded into the middle of the joint and secured on the femur and tibia using fixatives such as metal buttons, screws, or staples.

Types of ACL graft

The most common grafts used in ACL surgery can be divided into three types, autograft, allograft, and synthetic grafts.

An autograft is a tendon which is taken from another location on your own body and used to make the new ACL. The site where the tendon is removed (harvested) is called the donor site. The term “donor site morbidity” is a term used to encompass any “negative factors” or possible complications associated with harvesting the tendon. This obviously includes the skin incision and resulting scar, but can also include infection, fracture and injury to blood vessels and nerves.

An allograft is the same type of tissue used in an autograft, but the difference is that it is obtained from another human donor.

A synthetic ACL graft is a manufactured cord or ribbon-like implant which is not made of human tissue.

I will briefly discuss the least common ACL graft choices first.

Synthetic ACL graft

The synthetic ACL graft appears to be attractive a first glance. This is because you do not have to remove any tissue from another area of the body. There are therefore no extra skin incisions, no risk of fracture, no graft harvest pain etc. (no donor site morbidity). They are extremely strong, and the marketing behind these products will have you believe that you may return to your sporting activity much quicker than with a tendon graft. This is especially attractive for professional and semi-professional athletes. Unfortunately, synthetic grafts have a high failure rate. If the graft fails, this means that you will have to have a revision procedure to restore stability to the knee.

Allograft

An allograft also appears to be an attractive option. The advantage of an allograft is that once again there is no donor site morbidity as the graft is not harvested from your own body. It is also possible to choose from a variety of tissues, including hamstring, patella, quadriceps and Achilles tendons.

The biggest problem with using an allograft relates to potential infection. Because of the high prevalence of HIV and other infectious diseases in South Africa, the graft must be treated before it can be used inside your body. This may include irradiation. This treatment can weaken the graft and result in high risk of failure. It is therefore not a great choice for an ACL graft in our country. They are, however, successfully used for other ligaments in the knee where failure rates are not as high. In countries where the risk of contracting an infectious disease from the graft is low, “fresh” allografts are used more frequently and successfully as they do not have to go undergo the same treatment before being used in your knee.

Autograft

The most common ACL graft choice in South Africa is therefore the autograft. This is a tendon which is taken from another area of your body. The three commonest harvest sites are the hamstring tendons, the quadriceps tendon, and the patellar tendon.

Hamstring ACL autograft

The hamstring tendons are the cord-like structures which you can feel on the back of your knee towards the inner side. To harvest them, a 2 or 3 cm incision must be made on the front of the upper end of the tibia. One or two of the hamstring tendons (semitendinosis and gracilis) are harvested from the leg which is undergoing the ACL reconstruction. These are then prepared to create the new ACL graft.

Patellar tendon (BTB) autograft

The patellar tendon is the strong tendon connecting the kneecap (patella) to the tibia in the front of your knee. A patellar tendon graft is also called a bone-patellar-tendon-bone graft or BTB graft. Harvesting of the graft involves an incision on the front of the knee, starting from the lower end of the patella.  A small bone plug is removed from the patella and the tibia along with a 1 cm strip of tendon in-between the two bone plugs for the ACL graft.

Quadriceps tendon autograft

The quadriceps tendon is the strong tendinous attachment of the quadriceps muscle. It attaches to the top part of the patella. Harvesting involves a skin incision on the front of the knee, starting from the upper end of the patella. A small bony plug from the top of the patella is removed along with a 1 cm strip of quadriceps tendon.

Hamstring, patellar and quadriceps tendons are usually harvested from the same leg which is undergoing the ACL reconstruction. They may also be harvested from the other leg if needed (e.g. in multi-ligament reconstructions and revision procedures).

A brief comparison of the autograft options

Of the three autograft options the hamstring tendon is the most popular graft choice in recent years in South Africa. It is a strong graft. Harvesting does not involve cutting into bone and therefore there is no risk of fracture.

The BTB or patellar tendon graft was the original ACL graft choice, and in some countries is still regarded as the gold standard. It is stiffer than the hamstring graft, but the strength of a hamstring graft is still stronger than your original ACL. The disadvantage of the patellar tendon graft is that it involves cutting into the bone and therefore fracture is a risk. There is also increased risk of developing anterior knee pain (pain in the front of the knee).

The quadriceps graft is probably the least widely used. There is also a risk of patella fracture in harvesting this graft although some surgeons use a quadriceps graft without a bone plug. There is said to be a lower risk of anterior knee pain.

So which ACL autograft is best?

Several studies have been performed to try and evaluate which graft is the best. As far as performance goes there is no clear winner with regard to long-term stability. There are no significant differences between the three autografts when comparing muscle strength, function, return to sports and patient satisfaction.

Which ACL graft should I choose?

The question remains, therefore, which ACL graft one should choose if having an ACL reconstruction? In my opinion the answer is that you should go with the graft that your surgeon recommends. Allow the surgeon to do what he or she does best. I would, however, be cautious if your surgeon recommends using an allograft or a synthetic graft in your knee for a primary (first time) ACL reconstruction. Many of the revision procedures that I have had to perform have resulted from previous use of a synthetic graft.

In conclusion…

A knee surgeon should be familiar with the harvesting and use of all the different types of ACL graft but many of us will have a preference and this includes myself. My preferred graft is the hamstring graft. I find it easy to harvest with a low rate of complications and good results. For a revision procedure my preference is to use the hamstring graft from the other leg although the option remains to use the quadriceps or patellar tendon graft from the same leg if the patient prefers this option.

Yours in good health,

Dr Warren Matthee

MB BCh (Wits), MRCS (England), MMed (Ortho Surg), FC Orth (SA)

Orthopaedic Surgeon

admin@drmatthee.com

(011) 304 6784

About the author…

I am an orthopaedic surgeon with a special interest in sports injuries and minimally invasive (arthroscopic) surgery of the knee and shoulder. I perform ACL reconstructions as well as general orthopaedic procedures at Waterfall Hospital in Waterfall/Midrand and Morningside Mediclinic in Sandton. Besides these, I also treat patients from other areas as well, including Rosebank, Sunninghill and Fourways.

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The post ACL graft options in ACL reconstruction – which one? appeared first on Dr Warren Matthee.

• How is an ACL reconstruction performed?
• Is ACL surgery major surgery?
• How long does an ACL reconstruction take?
• Is ACL surgery painful?..

1. How is an ACL reconstruction performed?

People who have an ACL tear and need to have ACL surgery (ACL reconstruction) often don’t fully understand what is involved in the procedure. Some people do not want to know all the details but it is important to have a basic understanding of what is being done.

The ACL or anterior cruciate ligament is one of four major stabilising ligaments in the knee. It is commonly injured after sporting activities. These includes rugby, soccer, netball and basketball but it may also be injured in a non-sports related injury. The ACL has poor healing potential. A tear usually results in instability. Surgery is usually recommended for young people and active individuals. For more information on whether or not you need to have an ACL reconstruction, please see this article: Do I need to have ACL surgery?

The actual technique used to perform the ACL surgery varies widely. The materials used to fix the new tendon (graft) in position in the knee also varies according to surgeon preference. Despite these factors no specific technique has been shown to be significantly superior to another. The results and outcomes of the various techniques are good, providing that basic (but important) surgical principles are adhered to.

Before surgery

I perform ACL surgery in the safe and controlled environment of an operating theatre. You are normally admitted to hospital on the day of surgery. It is possible to do an ACL reconstruction as a day-case procedure, but most patients stay overnight. This is for monitoring and pain control purposes.

When you are admitted to the hospital you will need to be starved. This means that you should have had nothing to eat or drink in the six hours before the surgery. It is okay to have small sips of clear fluid such as water or black tea and coffee for up to 2 hours before the surgery. If you are on any chronic medication you may take these as normal on the morning of surgery.

The exception is if you are a diabetic. You must not take any diabetic medication on the day of surgery. If you have diabetes your glucose is checked on admission to the ward. You may receive insulin to control your blood sugar levels. You should also not be any blood thinning agents. The stopping of these medications will have been discussed with you prior to the surgery.

Once admitted to the ward you will be prepared for the operating theatre. The orthotist will visit you and measure you for the appropriate size leg brace. You will also be measured for TED (thrombo-embolic deterrent) stockings. These are used to lower your risk of getting a blood clot (DVT). These are compressive, above-knee stockings that are applied to your legs at the end of the procedure. You will go to the operating theatre with the brace and stockings with you.

In the operating theatre

When it is time for your surgery a porter will fetch you and transfer you to the operating theatre. You will be lying flat on your back in a comfortable position on the operating table. A tourniquet will be applied to your thigh. This will be inflated during the procedure (and once you are asleep) to prevent bleeding and allow for good vision.

The anaesthetic

My preference for an ACL reconstruction is to perform the procedure under a general anaesthetic. With a general anaesthetic you are placed into a deep sleep and your breathing is controlled by the anaesthetist. In addition to the general anaesthetic, a local anaesthetic nerve block is often given. This is usually given after you are sleeping already so you will feel and remember nothing.

It is possible to do ACL surgery under a spinal anaesthetic. One disadvantage of doing it this way is that you may mobilise slower afterwards. You may also have increased risk of developing a blood clot.

The incisions

The incisions depend largely on what type of graft is being used to create your new ACL. The commonest graft is your own hamstring tendons. These are removed from your thigh through a small incision in the upper part of your shinbone (tibia). The incision usually measures 2 to 3 cm in length. If you have a patellar tendon or a quadriceps tendon graft then you will have a slightly longer incision. This will be on the front of your knee just below or just above the kneecap.

There will be three or four other incisions which are made for the arthroscopy. These are very small “stab” incisions, measuring about half a centimetre in size.

The graft

The three commonly-used grafts used to reconstruct the ACL are your own hamstring tendons, your patellar tendon or your quadriceps tendon. My preference is to use the hamstring tendons (further reading: ACL graft options in ACL reconstruction – which one?). These long cord-like tendons are located in the back of your thigh. They assist with bending of the hip and of the knee. One or both of the hamstring tendons on the inner aspect of the knee are removed (semitendinosis and gracilis). These tendons are combined and folded over to form a sturdy graft of suitable diameter and strength. The use of these tendons does not normally result in any significant functional impairment after the operation. There is some evidence to show that these tendons may re-grow to some extent.

An arthroscopy of the knee is performed. The knee is filled with fluid to expand the joint. A special high-definition camera is then inserted into the knee to make a thorough inspection. Any other injuries such as meniscal tears can be diagnosed and repaired at the time of the ACL surgery.

For the ACL reconstruction a tunnel is created in the thigh bone (femur). Another tunnel is created in the shinbone (tibia). These are carefully positioned to ensure optimal functioning of the new ACL graft.

The new ACL graft is then inserted into the knee joint and threaded through the tunnels in the femur and tibia. It is secured usually by a small metal button on the outside of the femur. In the tibia it is secured using either an absorbable interference screw or a metal button. Sometimes a secondary is fixation point used on the tibia as a backup. Another screw or staple is usually used for this. The knee is tested for full range of movement and stability and the fluid is drained from the joint.

Wound closure

Incisions are closed with dissolving stitches and waterproof dressings are applied. I use a TED compression stocking and apply a wool and crepe bandage to the knee after the operation is completed. When you wake up you will also have a brace on your leg.

After the surgery

You will spend a short period of time in the recovery room after having woken up from the general anaesthetic. After that you will then be transferred to the ward. As soon as you are comfortable and have had something to eat and drink and are not feeling nauseous you will be seen by the physiotherapist. They will begin assisting you with basic mobilisation. This includes getting out of bed, using crutches and going to the bathroom.

You will be discharged home the following day. You will be asked to return to the rooms for a follow-up appointment approximately 10 days after the operation. At this stage the dressings will be removed and the wound will be inspected.

2. Is ACL surgery major surgery?

A common question I get asked is whether or not an ACL reconstruction is major surgery. I usually described as a “big operation” but not “major surgery”. These are purely subjective terms, however. It is certainly not a five or 10 minute procedure like a ganglion removal or a carpal tunnel release. Is also not as big an operation as a total knee replacement. The blood loss is minimal, and because it is done arthroscopically it is “minimally invasive”.

An ACL reconstruction is a highly technical procedure. It is usually only performed by an orthopaedic surgeon who has the necessary training and experience to perform it correctly. Not all orthopaedic surgeons will therefore do this procedure.

3. How long does an ACL reconstruction take?

I was once told by one of my mentors that a good ACL reconstruction should never take the surgeon less than one hour to do. If one considers all the steps that are performed in the procedure it is easy to understand why. Nowadays the surgical technique is quite streamlined. It has been made easier to some extent by the newer fixation devices and graft preparation techniques. If there are no other structures in the knee which have to be repaired then it is possible to perform an ACL reconstruction safely in under an hour. Sometimes it can be done in 45 minutes or less. If there are other procedures which need to be performed (e.g. meniscal repair, extra-articular tenodesis) then it may take closer to 2 hours.

I always emphasise to my patients that it takes as long as it takes to do it right. My aim is always to work efficiently, effectively and expertly and, of course, safely. I do not to try and do the procedure as fast as possible. One must also bear in mind that it takes time to administer and wake up from the anaesthetic. There is also extra time involved in preparation before the actual surgery begins It is important to tell your loved ones that you may be in the operating theatre for two or three hours and this is completely normal.

4. Is ACL surgery painful?

The ACL reconstruction itself is done under a general or spinal anaesthetic and therefore no pain is felt during the procedure. If you have a general anaesthetic then you will obviously be asleep. Even if you have a spinal anaesthetic, sedation is usually administered as well to help you sleep during the procedure. You will therefore not be aware of anything that is going on during the operation.

I use local anaesthetic to numb all the areas of skin where incisions are made. At the end of the procedure I also use local anaesthetic to inject around the capsule of the knee joint. This helps with post-operative pain relief. If a local nerve block is used then this will also assist in controlling the pain after the procedure.

In my experience patients usually wake up and feel quite comfortable initially. When the local anaesthetic wears off they makes begin to experience some discomfort. Fortunately we can control this using a variety of pain medications. These may be given in your drip while in hospital, and orally in tablet form when you go home.

There are obviously limitations as to the amount of strong medication that can be taken to control pain. Most people still experience some discomfort after the operation. The good news is that this is never unbearable and is only rarely severe enough to disturb one’s sleep.

In summary…

ACL surgery (ACL reconstruction) is a common procedure which should only be performed by orthopaedic surgeons with suitable training and experience in the correct technique. I hope I have answered some of the more commonly-asked questions about the procedure in this article.

Yours in good health,

Dr Warren Matthee

MB BCh (Wits), MRCS (England), MMed (Ortho Surg), FC Orth (SA)

Orthopaedic Surgeon

admin@drmatthee.com

(011) 304 6784

About the author…

I am an orthopaedic surgeon with a special interest in sports injuries and minimally invasive (arthroscopic) surgery of the knee and shoulder. I treat patients at Waterfall Hospital in Waterfall/Midrand and Morningside Mediclinic in Sandton. Besides these, I also treat patients from other areas as well, including Rosebank, Sunninghill and Fourways.

Get in Touch

Please use the form below to get in touch with Dr Matthee’s rooms.

The post ACL reconstruction – four questions answered appeared first on Dr Warren Matthee.

• Do I need surgery to fix the ACL?

The answer depends on your age and levels of activity, the amount of instability that you have, and the general condition of your knee. ACL reconstruction is almost always recommended for a young person with an ACL tear. It may also be recommended for patients of any age who have otherwise healthy knees. This is true especially if they enjoy being active or if they have symptoms of instability. An ACL reconstruction is generally not recommended if there is significant arthritis in the knee.

• Why do I need ACL surgery?

The problem with the ACL is that once it is torn it does not heal. Sometimes the torn ligament can be re-attach to the bone but unfortunately it’s normal function is usually lost. The result is an unstable knee which “gives way”.

People with an ACL tear often complain of a sensation of the knee partially dislocating. This is noticed especially when you do twisting or pivoting movements. Having an unstable knee can result in damage to other structures in the knee such as the meniscus. The meniscus is a supporting cartilage in the knee which acts like a “shock absorber”. A meniscal tear or injury, especially in a healthy knee, can result in the development of painful arthritis (osteoarthritis). Having an unstable knee as a result of an ACL tear can put you at risk for developing a meniscal tear. This can cause arthritis in the knee in later years.

• Can the ACL be repaired, or must it be reconstructed?

Arthroscopic picture of ACL tear

The difference between ACL repair and ACL reconstruction is that in a repair we reattach the original torn ligament to the bony surface where it tore off. A reconstruction involves removing part or all of the original ligament and replacing it with a substitute, called a graft. The graft is usually a tendon borrowed from another place in your knee. The graft may also be obtained from other donors (allograft) and synthetic grafts are also available.

Through the years surgeons have tried new techniques to perfect the technique of repairing the ligament. Unfortunately this has not resulted in overwhelming success. A repair is therefore not the gold standard treatment. A reconstruction is therefore the tried and tested method to restore stability to your knee.

• In summary…

If you have an ACL tear it is recommended that you be see an ACL surgeon familiar with the intricacies of this procedure. This should be done as soon as possible to discuss the correct treatment. Delays of a few weeks can result in significant injury to the knee. This can have profound effects in years to come. I have had many years training in this particular procedure and it is an operation that I enjoy doing. The operation is done arthroscopically (“keyhole surgery”). The following article may also be useful: ACL reconstruction – four questions answered.

Yours in good health,

Dr Warren Matthee

MB BCh (Wits), MRCS (England), MMed (Ortho Surg), FC Orth (SA)

Orthopaedic Surgeon

admin@drmatthee.com

(011) 304 6784

About the author…

I am an orthopaedic surgeon with a special interest in sports injuries and minimally invasive (arthroscopic) surgery of the knee and shoulder. I treat patients at Waterfall Hospital in Waterfall/Midrand and Morningside Mediclinic in Sandton. Besides these, I also treat patients from other areas as well, including Rosebank, Sunninghill and Fourways.

Get in Touch

Please use the form below to get in touch with Dr Matthee’s rooms and we will respond to you shortly.

The post Do I need to have ACL surgery? appeared first on Dr Warren Matthee.