Anterior cruciate ligament (ACL) reconstruction requires a graft to replace the ligament that no longer functions. If the graft tears again after the first operation, revision ACL reconstruction raises an important question: what tissue can be used for the second reconstruction?

Many patients have already used their own hamstring tendon during the first operation, so the available autograft options for revision reconstruction may be limited.

The quadriceps tendon is one autograft that can be considered for ACL revision. In some operations, a small patellar bone block is preserved when the tendon is harvested, creating a quadriceps tendon-bone graft for the new ligament reconstruction.

The anterior cruciate ligament lies inside the knee joint and connects the femur to the tibia. It plays an important role in maintaining front-to-back and rotational stability of the knee.

When the ACL is severely torn and surgical reconstruction is needed, a suitable piece of tissue is usually used to recreate the ligament structure. This tissue is called a graft.

After fixation, the graft must gradually heal into the bone tunnels and take on the role of stabilizing the knee. For this reason, graft source, graft size, and fixation method are all important issues in ACL reconstruction.

If a certain tissue has already been used during the first ACL operation and another tear occurs later, graft choice during revision reconstruction becomes more complex.

The conditions in revision ACL reconstruction are different from those in the first reconstruction. The first operation may already have harvested part of the patient’s own tendon, while also leaving bone tunnels and fixation devices in the femur and tibia. During the next operation, the surgeon must address the previous tunnels and also find a suitable graft to rebuild the ACL.

For patients whose hamstring tendon has already been used on one side, the quadriceps tendon becomes another source of autologous tissue.

The quadriceps muscle is located at the front of the thigh and is the main muscle group that straightens the knee. It connects downward to the patella, or kneecap, through the quadriceps tendon.

For ACL reconstruction, part of the quadriceps tendon can be harvested as a graft. This graft can include tendon on one end and a bone block on the other, allowing it to be used for fixation in the bone tunnels during ACL revision.

If the first ACL reconstruction used an autologous hamstring tendon and revision surgery is being considered, patients can discuss which tendon was used the first time, what autograft options remain, whether a tendon needs to be harvested from the other leg, and whether the quadriceps tendon is an option.

If the surgeon recommends a quadriceps tendon-bone graft, it is reasonable to ask where the tendon and bone will be harvested, how anterior knee pain and knee extension function may be affected after surgery, and how quadriceps strength will be restored during rehabilitation.

The graft is only one part of the ACL revision plan. Previous tunnel position and size, meniscus and cartilage condition, knee stability, and other anatomical factors also influence the final treatment strategy.