Tendon transfers are common in anterior cruciate ligament, or ACL reconstruction. Tendons are taken from other body parts and used to replace the ACL. The ACL functions to keep the tibia in proper position and prevents the knee from giving way during physical activity. Two types of tissue can be used to reconstruct the ACL; an autograft, which is the patient's own tissue, and an allograft, which is tissue from a cadaver.
Patellar Tendon Autograft
In this type of tendon transfer, the middle third of the patellar tendon with a bone plug from the patella and the tibia is used. According to the American Academy of Orthopaedic Surgeons, this type of tendon transfer is referred to as the gold standard and is recommended to athletes and to patients whose jobs do not require a significant amount of kneeling. The patellar tendon graft has been shown to have a low incidence of failure, but patients have complained about pain behind the kneecap and pain with kneeling.
Hamstring Tendon Autograft
The semitendinosis hamstring tendon on the inside of the knee is used to create this autograft. The benefits to this type of graft include fewer problems with anterior knee pain and kneecap pain, as well as a smaller incision. However, there are drawbacks as well to this type of graft. According to the American Academy of Orthopaedic Surgeons, The graft may be limited by the strength of the tendon and the type of fixation, as it does not utilize bone plugs like the patellar tendon autograft.
Quadriceps Tendon Autograft
The middle one third of the quadriceps tendon along with a bone plug from the patella are used in this autograft. This type of tendon transfer is most often used for patients who have a failed ACL graft, or for taller and heavier patients, as it is a larger graft. This type of graft is not as solid as the patellar tendon graft, due to the use of only one bone plug, as opposed to two, according to the American Academy of Orthopaedic Surgeons. There is also a high association with anterior knee pain with this type of tendon transfer.
Allografts
Allografts are tendons taken from cadavers and, according to the American Academy of Orthopaedic Surgeons, are becoming increasingly popular. These grafts are often used for patients who have a failed ACL reconstruction or require repair of more than one ligament in the knee. This type of graft decreases the surgery time and eliminates the pain from harvesting the tendon from the patient. It also affords a smaller incision and a strong bony fixation. Allografts, however, have been associated with infection despite careful screening.
