ACL Graft Choice
Anterior Cruciate Ligament
Reconstruction
Graft Selection Options and Rationale
Richard B Jones, M.D.
Sports Medicine Orthopaedist
Southeastern Sports Medicine
The anterior cruciate ligament is a central stabilizer of the knee. It is one of the most frequently injured ligaments in the body, approaching epidemic rates. It is most commonly injured in athletes, but can be injured with various accidents from the home to the workplace. Injury to this ligament often requires surgical reconstruction to restore normal function of the knee and protect secondary structures within the knee.
Over the last three decades surgical procedures for the torn anterior cruciate ligament have advanced tremendously with most achieving success rates in the 85 to 90% range. Unfortunately, this structure is unable to be repaired after rupture. Therefore, the torn ACL must be replaced with another structure to function in its place. This involves making tunnels in the bone at the attachment sites of the previous ACL and passing the replacement tissue into its place. It then must be fixed to the bone with one of a variety of different fixation devices such as screws, pins or staples. Multiple tissues exist to serve this role with various pluses and minuses. This has been a topic of great debate amongst sports medicine orthopaedists as to which tissue constitutes the best reconstruction choice. It also has become a topic of lengthly discussions for patients as well.
It must first be pointed out that there is no definite right or wrong answer in deciding the proper choice of graft (replacement tissue) for ACL reconstruction. Many factors go into the decision such as surgeon preference and familiarity with the procedure, cost, and operating time. Many factors related to the patient also exist such as age, activity level, sport of choice, weight, concern with incision size, and concern with postoperative pain.
The most common tissues used as ACL grafts include the middle third of the patellar tendon (with a small piece of bone from the knee cap on one end and the tibia attachment on the other), the quadriceps tendon, hamstring tendons, or the iliotibial band. The tissues are all harvested from the patients operative leg (or in some cases the opposite leg) at the time of surgery. This is called autograft tissue. The other option is called allograft tissue. This is tissue from a human donor or “cadaver”. Common allograft tissues used are the patellar tendon, achilles tendon, and tibialis tendon (around the ankle). Believe it or not, for surgical reasons, an allograft ACL is not an option. There are infection risks with allograft tissues such as hepatitis and HIV, but these are extremely small. (HIV risk is about one in two thirds million).
Below are my pros and cons of common ACL reconstruction graft options.
Bone-patellar tendon-bone graft:
Pros:
-Probably the most commonly used graft overall
-Most orthopaedic surgeons familiar with the technique
-Well proven, long term clinical success
-strong early fixation (bone against bone)
-can comfortably rehab aggressively
Cons:
-Requires slightly larger incision
-higher incidence of pain in the front of the knee long term and difficulty kneeling
-may have more difficulty regaining motion after surgery
-may have residual weakness of quadriceps muscle
-risk of patella (knee cap) fracture after surgery
-slight increased pain initially after surgery(my personal observation)
Hamstring graft:
Pros:
-Smaller incision size
-Well proven clinical success (with more modern techniques)
-less initial pain and swelling after surgery(my personal observation)
-lower incidence of pain in the front of the knee and kneeling pain long term
Cons:
-Possibly weaker initial fixation until healing occurs (probably not so with newer techniques)
-More technically demanding procedure
-Less surgeon familiarity with procedure
-Longer operative time
-May need to rehab a little less aggressively
-May have residual hamstring muscle weakness
Allograft tibialis tendon:
Pros:
-most commonly used allograft tissue
-quick availability from tissue banks
-small incision size
-no residual effects from graft harvest
-similar benefits to hamstring tendon graft
-good for revision or redo procedures
Cons:
-risk of disease transmission
-more expensive
-some reports of slower incorporation(or healing) of graft to the body
-may need to slow rehab somewhat
Allograft Bone-Patellar tendon-Bone:
Pros:
-Benefits of strong bone to bone initial fixation
-small incision size
-ability to adjust bone block size in revision situations
Cons:
-risk of disease transmission
-more expensive
-some reports of slower incorporation(or healing) of graft to the body
-may need to slow rehab somewhat
Those discussed above are the most commonly used types of grafts. Certainly, every question has not been addressed and further discussion with your orthopaedic surgeon is always welcome.
Richard B. Jones, M.D.
Southeastern Sports Medicine
828-274-4555