ACL Reconstruction : What A Patient Needs To Know

ACL (anterior cruciate ligament) reconstruction is performed on approximately 100,000

people each year in the United States. It is one of the more common knee injuries

sustained in athletic competition requiring surgical treatment. What should a patient

know when they are forced to make decisions on such an injury?

Ligaments are the soft tissue structures which connect bones together and provide

mechanical restraint to excess motion in a joint. The ACL is the ligament which

connects the femur (thigh bone) to the tibia (shin bone) and prevents excessive anterior

translation thereof (tibia slipping out in front of the femur). This checkrein may be torn

during both contact and non-contact injuries, often with associated knee damage

(meniscus tears, medial collateral ligament injuries). Football, basketball, and soccer

are the most common team sports involved, but ACL tears are also seen in individual

sports such as tennis, snow and water skiing, BMX, and any other activity where rapid

changes in direction are demanded.

In an athletic individual who wishes to continue to participate in sports, surgical

reconstruction is generally appropriate. The reasons for this are twofold. First, a

patient with an ACL tear will most likely experience recurrent instability during

athletics, and often in lower level activities of daily living, without surgical

reconstruction. The symptoms of this (pain, swelling, giving way) impair function, and

are usually alleviated with successful surgical treatment. Additionally, restoring knee

stability with surgical reconstruction protects the meniscus and other structures which

are damaged during episodes of instability, and may prevent the progression of arthritis.

ACL surgery entails arthroscopy (insertion of a 4 mm camera into the knee through

small incisions), repair of associated meniscal, ligament, or articular cartilage injury, and

reconstruction (replacement) of the ACL with a tendon taken from another part of the

knee or from a tissue donor (allograft). The tendon is placed into bone tunnels in the

femur and tibia, which are drilled in an arthroscopic-assisted fashion, where the ACL

previously existed. The tendon graft may be fixed with a variety of devices, usually

small screws, placed in the bone arthroscopically. These hold the graft in place until

your body converts it into a new ACL, which takes about 6-12 months. The screws are

generally left in place permanently. The tendon graft is usually taken from the middle

1/3 of the patellar tendon (tendon connecting knee cap to tibia), medial hamstrings

(tendon along inner thigh), or from a tissue donor. When a tissue donor is used, better

functional results are seen with fresh-frozen non-irradiated patellar tendon grafts.

Allografts which are irradiated have impaired biomechanical function, and soft tissue

allografts (hamstrings/tibialis anterior/achilles) have shown inferior clinical results in

medical literature. I would not recommend using these at this time. Quadriceps tendon

autograft may be a reasonable alternative, but there is insufficient clinical data to

compare it to the above grafts. Stem cell augmentation is unproven at this time, is

expensive, and has been shown to impair function in some studies. There are risks and

benefits to each graft, and choice usually depends on age, prior knee injury status, level

of athletic expectation, cosmesis, and rehab expectations/capacity in terms of pain.

Your surgeon should be able to guide you to the choice which best suits your individual

expectations.

The surgery is usually done on an outpatient basis, with the patient going home the

same day as the procedure. Rehab involves aggressive exercises performed on a daily

basis, emphasizing knee flexibility and strengthening, usually overseen by a physical

therapist. Patients can often begin running at 2 months after surgery. In general, ACL

reconstruction is one of the most successful procedures we perform as orthopaedic

surgeons, with 90-95% of patients being able to return to cutting/pivoting sports at 6

months after surgery. Be sure that your surgeon has adequate training in this technique

(fellowship training in orthopaedic sportsmedicine is helpful), and if you have

unanswered questions seek a second opinion.

Please give us a call with any questions you may have: 205-971-1750