Graft Options for ACL Reconstruction
Anterior cruciate ligament (ACL) reconstruction is one of the most commonly performed sports surgeries. In this surgery, torn native ACL is replaced by a tendon (called a ‘graft’) from patient’s own body or from a cadaveric tissue bank.
One of the most important decisions during ACL reconstruction is choosing the right graft to replace the torn ACL.
Although it is majorly your orthopaedic sports surgeon’s decision but knowing some facts helps the patients with basic awareness and helps them give an informed consent.
There is no single graft that is ideal for every patient. The decision depends on several factors, including age, activity level, type of sport, previous surgery, knee anatomy, associated injuries, occupation and the patient's expectations regarding return to sports.
Common graft options for ACL reconstruction in India include hamstring, bone-patellar tendon-bone (BPTB), quadriceps, peroneus longus and allograft. Lets have a look at all these options one by one.
Bone-Patellar Tendon-Bone (BTB) Graft
The BTB graft is one of the oldest grafts and uses the central portion of the patellar tendon along with small bone plugs from the patella and tibia.
It has traditionally been considered the gold-standard graft for ACL reconstruction, particularly in high-level athletes.
Advantages
Excellent fixation: Bone plugs allow strong fixation within the femoral and tibial tunnels.
Bone-to-bone healing: Bone-to-bone incorporation is generally faster and more predictable than tendon-to-bone healing.
Excellent stability: BTB grafts have a long track record of providing reliable anterior and rotational stability.
Strong option for high-demand athletes: It is commonly considered for athletes participating in pivoting and contact sports.
Large body of evidence: The graft has been studied extensively over several decades.
Useful in revision surgery: BPTB can be particularly valuable in selected revision ACL reconstructions depending on previous graft choice and tunnel anatomy.
Disadvantages
Anterior knee pain: This is one of the major disadvantages of BTB grafts.
Kneeling discomfort: Patients who frequently kneel down may find this graft uncomfortable.
Patellar fracture: Although uncommon, harvesting a bone plug creates a potential risk of patellar fracture.
Non-Cosmetic scar: The harvest incision is generally larger than that required for some soft-tissue grafts.
Extensor mechanism morbidity: Some patients experience persistent weakness of extensor mechanism of the knee.
Hamstring Tendon Graft
The hamstring tendon autograft, commonly using the semitendinosus with or without the gracilis tendon, has been one of the most widely used grafts for ACL reconstruction.
Advantages
Good strength and stiffness: A 4-fold hamstring graft provides adequate strength for ACL reconstruction.
Small incision: Harvesting is performed through a relatively much smaller incision.
Less anterior knee pain: Compared to the BPTB, hamstring graft causes less anterior knee pain and kneeling discomfort.
No bone harvest: There is no bone plug, making it particularly attractive for patients where avoiding patellar harvest is desirable.
Good cosmetic result: The graft can be harvested through a relatively small incision.
Useful in young athletes: Hamstring autografts remain an excellent option for appropriately selected athletes.
Disadvantages
Hamstring weakness: Harvesting the tendons can temporarily hamper hamstring strength.
Variable graft diameter: The size of the harvested tendons varies between individuals. A smaller graft may be associated with a higher risk of failure, particularly in young athletes.
Slower biological incorporation: Unlike BTB graft, the tendon is incorporated into the bone tunnel through a slightly slower tendon-to-bone healing process.
Possible sensory changes: Temporary numbness around the harvest site can occur.
Potential for tendon regeneration variability: Although hamstring regeneration can occur, the extent and functional significance can vary.
Quadriceps Tendon Graft
The quadriceps tendon has become increasingly popular as an ACL graft option. It can be harvested with or without a small bone plug from patella and provides a relatively thicker and robust graft.
Advantages
Large graft diameter: The quadriceps tendon can provide a thick graft, which can be particularly useful in young or high-risk patients.
Excellent strength: It provides strong mechanical properties suitable for ACL reconstruction.
Less anterior knee morbidity than BPTB: Patients generally experience less kneeling pain and anterior knee discomfort compared with BPTB grafts.
Useful in revision surgery: It is an important alternative when the patellar tendon or hamstrings have already been used.
Versatile: It can be harvested with or without a bone plug depending on the surgical needs.
Disadvantages
Quadriceps weakness: Temporary quadriceps weakness can occur following graft harvest.
Rehabilitation considerations: Restoring quadriceps strength can be challenging after quadriceps tendon harvest.
Harvest-site discomfort: Some patients may experience pain or tenderness at the harvest site.
Less long-term historical data: Although evidence is rapidly increasing, quadriceps tendon grafts have a shorter history of widespread use compared with BPTB and hamstring grafts.
Peroneus Longus Tendon Graft
It is a relatively newer autograft option for ACL reconstruction and getting increasingly popular.
It provides a strong, relatively large-diameter soft-tissue graft and has the advantage of preserving the hamstring and patellar tendon. It can be particularly useful in selected young, active patients and in revision ACL reconstruction when conventional graft options are unavailable or have already been used.
Advantages
Good graft strength: The peroneus longus tendon provides a strong graft with favorable biomechanical properties.
Good graft diameter: It can provide an adequate graft size, which is important in reducing the risk of graft failure.
Preserves hamstrings and quadriceps: Harvesting does not compromise the hamstring or quadriceps tendons, which may be advantageous for running or sprinting athletes.
Useful in revision surgery: It provides an additional autograft option when hamstring or patellar tendon grafts have already been used.
Relatively low donor-site morbidity: Most patients maintain satisfactory ankle and foot function after appropriate harvest.
Potentially useful in young athletes: Preserving the hamstrings may be advantageous in patients involved in sports requiring high levels of running and sprinting.
Disadvantages
Possible ankle weakness: Some patients may rarely experience weakness of foot eversion or plantar flexion following harvest.
Ankle hematoma: There is a risk of hematoma formation at the harvest site
Potential sensory symptoms: Temporary numbness or altered sensation around the ankle may occur due to injury to aural nerve
Effect on ankle biomechanics: Although not clinically proven, harvesting the peroneus longus can theoretically affect ankle and foot biomechanics.
Less long-term evidence: Compared with hamstring and BPTB grafts, there is less long-term evidence regarding outcomes and donor-site effects.
Not suitable for every patient: Pre-existing ankle instability may make this graft less appropriate.
Allograft
An allograft is tissue obtained from a donor rather than from the patient's own body. These grafts are harvested from cadavers and stored well in a tissue bank.
Due to the risk of graft rejection, infection and higher cost, allografts remain the last preference in India.
Commonly used allografts include Achilles tendon, tibialis anterior tendon or other suitable donor tissues.
Advantages
No graft-harvest morbidity: The patient's own tendons are not harvested.
Shorter operative time: The surgeon does not need to obtain the graft from another part of the patient's body, so saves the surgical time.
Useful in selected revision cases: Allograft can be useful when suitable autograft tissue is unavailable.
Multiple graft choices: Different donor tendons can provide different sizes and shapes.
Disadvantages
Higher failure risk in young active patients: Allograft is generally not the preferred option for young athletes undergoing primary ACL reconstruction.
Slower biological incorporation: The graft has to undergo a process of incorporation and remodeling.
Disease transmission: Modern tissue screening makes this extremely uncommon, but it remains a theoretical risk.
Immune response: Although processed allografts generally have low immunogenicity, biological incorporation differs from that of an autograft.
Sterilisation and processing can affect graft properties: The preparation method can influence the biological and mechanical characteristics of the graft.
Selection of the ACL Graft
For most of the Indian patients, an autograft is always preferred because of its favourable biological incorporation and lower risk of graft failure compared with allograft in high-risk populations.
The decision between different autografts should then be individualised.
To summerise:
BPTB: Excellent stability and bone-to-bone healing, but more anterior knee morbidity.
Hamstring: Less anterior knee pain, but potential hamstring weakness and variable graft size.
Quadriceps tendon: Large and strong graft with relatively low anterior knee morbidity, but quadriceps rehabilitation is important.
Perseus Longus: Good back-up option but with theoretical risk of ankle weakness
So which ACL graft is the best?
There is no single best graft. The ideal graft depends on the individual patient.
Important factors include:
Age
Sport and level of activity
Risk of re-injury
Previous ACL surgery
Associated meniscus or cartilage injuries
Pre-existing ligamentous laxity
Occupation
Need for frequent kneeling
In general, following are the preferences based on patient’s sport involvement:
- BTB: Professional athletes, high pivot sports, contact sports (football, rugby)
- Hamstring: Recreational athletes, low-impact sports (cycling, swimming), agility sports (tennis, badminton, runners), kneeling sports (wrestling), skeletally immature
- Quadriceps: Competitive athletes who need kneeling down
- Allograft: Affording patient undergoing a revision or multi-ligament surgery
To Conclude..
Choosing the graft is one of the most important decisions in ACL reconstruction.
All the autografts are reliable options, while allografts have a more selective role.
The graft is selected by the surgeon according to the patient's age, sport, anatomy, previous surgery, risk factors and long-term goals.
Outcomes of ACL reconstruction depend on choosing the right graft, anatomical tunnel placement, robust fixation and a well-structured rehabilitation program.
The ultimate goal is not simply to reconstruct the ligament, but to help the patient return safely to an active lifestyle or sporting career.
If you have suffered an ACL injury, consult Dr.Ajinkya Achalare for the expert advice and treatment. Dr. Achalare is a fellowship-trained dedicated arthroscopy and sports surgeon with rich experience of treating various types of ligament and sports injuries. He can help help you choose the right treatment best suited for your age, activity and goals.
Comments