All knee Topics

ACL Reconstruction (Hamstring Tendon Graft)

ACL reconstruction is a surgical procedure that is typically performed arthroscopically in order to replace a damaged ACL (anterior cruciate ligament) with graft material, either from the patient’s own body (autograft) or from a donor (allograft).

Key statistics about ACL Reconstruction

  • 100,000 – 200,000 ACL tears and severe sprains occur in the United States each year[1]
  • Approximately 100,000 ACL reconstruction procedures are performed in the United States each year[2]
  • 90% of patients who undergo ACL reconstruction have near-normal knee function restored[1]
  • 81% of patients who undergo ACL reconstruction return to some form of sport, 65% return to their preinjury level of sport, and 55% return to competitive sport following the procedure[3]

Expert Insights

Selecting the right types of ACL Graft - Daniel Cooper, MD

Why is ACL Reconstruction performed?

ACL reconstruction is often required to relieve pain and restore knee function after a sprain or tear to the ACL.

It is common to hear or feel a popping sensation when the ACL is torn, and the injury is often accompanied by rapid swelling, severe instability, intense pain, and loss of range of motion. An ACL tear also may increase the likelihood of sustaining further damage, such as a torn meniscus.

Who needs ACL Reconstruction?

The ACL is the most frequently damaged ligament in the knee.

A partial or complete ACL tear is a common injury that often occurs due to sports-related trauma, or from activities that involve sudden stops and changes in direction, or forceful twisting. Football, basketball, and soccer players, as well as skiers are among athletes most at-risk for ACL tears.

ACL reconstruction is necessary to address ACL tears that cannot be repaired or treated with nonsurgical measures.

Knee Anatomy

The knee joint is formed by three bones: the femur (thigh bone), the tibia (shin bone), and the patella (kneecap).

Ligaments connect bones to other bones and provide stability to the joint. There are two cruciate ligaments located inside the knee joint that connect the femur to the tibia: the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL). The ACL and PCL cross each other and work together to control the forward and backward movement and limit rotation of the knee.

3D rendering of knee with colorized regions highlighting the Femur, PCL, ACL, and Tibia

How is the Hamstring Tendon Graft prepared?

There are numerous graft material options available for ACL reconstruction, which are either autografts (from the patient) or allografts (from a donor). These include:

A hamstring autograft is one of the strongest grafts used in an ACL reconstruction. As this technique is considered to be better to prevent anterior knee pain, it is often indicated in patients who kneel on a regular basis.

The semitendinosus hamstring tendon is harvested and folded to create a 2-strand tendon graft during the reconstruction procedure. The graft is reinforced with sutures. In many cases, a portion of the nearby gracilis tendon is also harvested in order to create a 4-strand tendon graft.

3D rendering of the backside of the knee showing 2 and 4-strand hamstring grafts for Torn ACL reconstruction

How is ACL Reconstruction using a Hamstring Tendon Graft performed?

  • The surgeon will make small incisions around the knee joint and the arthroscope will be inserted into one of the incisions.
  • Saline solution is pumped into the joint to expand it and improve visualization.
  • Images from the arthroscope are sent to a video monitor where the surgeon can see inside the joint.
  • The damaged portions of the ACL are removed and the bones are prepared for the graft.
  • Using a drill, a bone tunnel is created in the femur and tibia.
  • After the graft is harvested and prepared, it is pulled up through the femoral and tibial tunnels and a plate or screws are used to anchor the femoral end of the graft in place.
  • The tibial end of the graft is secured with screws or other fixation devices.
  • Over time, the bone tunnels will fill in with new bone, incorporating the graft tissue.
  • Finally, the saline solution is drained, instruments are removed, and the incisions are closed using sutures.
Two 3D renderings of the knee juxtaposed where the left knee has a torn ACL and the right has a repaired ACL using a hamstring graft

What are the risks of ACL Reconstruction with a Hamstring Tendon Graft?

Risks associated with ACL reconstruction may include:

  • Infection
  • Blood clots
  • Knee stiffness
  • Limited range of knee joint motion

How long does it take to recover from ACL Reconstruction?

  • 24 hours after surgery: Physical therapy will begin and pain killers may be prescribed.
  • 1-3 days after surgery: Most patients are discharged from the hospital and will be able to walk with crutches. A physical therapy routine will be established by the surgeon and physical therapist.
  • 2 weeks after surgery: Any non-dissolvable sutures are removed, and bruising and swelling begin to subside.
  • 3-6 weeks after surgery: Most patients are able to return to work and resume driving and most daily activity.
  • 8-12 months after surgery: Most patients are fully recovered from ACL reconstruction.

What are the results of ACL Reconstruction?

ACL reconstruction is a safe and effective procedure performed to restore knee function following an ACL tear. 90% of patients who undergo ACL reconstruction return to near-normal knee joint function[1] and 81% return to some form of sport[3] following the procedure.

Evans, J., & Nielsen, J.L. (2022). Anterior Cruciate Ligament Injuries. StatPearls (Internet). Retrieved January 23, 2023 from
Csintalan, R.P., Inacio, M.C.S., & Funahashi, T.T. (2008). Incidence Rate of Anterior Cruciate Ligament Reconstructions. The Permanente Journal. 12(3), 17-21.
Ardern, C.L., Taylor, N.F., Feller, J.A., & Webster, K.E. (2014). Fifty-five per cent return to competitive sport following anterior cruciate ligament reconstruction surgery: an updated systematic review and meta-analysis including aspects of physical functioning and contextual factors. British Journal of Sports Medicine. 48, 1543-1552.
Last edited on February 7th, 2024 5:17 pm