A tendon graft is a piece of tendon taken from a donor site and then used to reconstruct a damaged tendon. When tendons undergo severe damage, such as complete tearing, tendon grafts are often the only way to heal them. Less serious tendon injuries, on the other hand, can frequently be addressed with non-surgical approaches such as prolonged rest, immobilization, and anti-inflammatory medication.
Tendons are strong yet flexible fibrous tissue bands that attach muscles to bones. Ligaments are closely-related structures connecting bones to other bones. Due to the anatomical similarities between tendons and ligaments, tendon grafting is not only used to repair tendons; it is also employed to repair some damaged ligaments.
Perhaps the most common use of tendon grafts is in anterior cruciate ligament (ACL) reconstruction. The ACL is the main supporting ligament of the knee, and it is one of the most frequently injured ligaments in sports. In ACL reconstruction, tendon grafts are generally taken from either patellar tendons or hamstring tendons. Both of these tendons are good candidates for ACL reconstruction because of their width and length. Normally, a tendon graft should come from a tendon with similar shape and size to the tendon undergoing reconstruction.
Some instances of tendon replacement require a two-stage repair process. This approach employs temporary prosthetic grafts that are left in place for up to several months. The temporary grafts give the body time to prepare a healthy environment for the final tendon graft. Surgeons consider two-stage repair based on the specific circumstances of an injury. For example, if a patient has damaged flexor tendons in his or her hands and a lot of time has passed since the initial injury, then a two-stage process may be indicated.
Tissue for a tendon graft can be harvested from one of two main sources: autogenous tissue or donor tissue. Autogenous tissue refers to tissue taken from somewhere in the patient’s own body. Donor tissue for grafts comes most frequently from a deceased person who made his or her tissues available for medical purposes. Medical grafts consisting of autogenous tissue are known as autografts, while those consisting of donor tissue are known as allografts.
Typically, the first choice for a tendon graft will be an autograft. The reason that autografts are usually preferred is that allografts can bring additional risks. These risks include transmission of diseases from donor to patient and a potential immune rejection response. While allograft preparations, such as freezing to eliminate rejection-causing fibroblasts, greatly decrease these risks, the preparations themselves also have drawbacks. One drawback is that the preparations can cause tendon allografts to be weaker than autografts.
Despite their disadvantages, allografts are still suggested in many situations. If a patient has multiple injuries, then there may not be enough available tendons in his or her own body to address each one. Additionally, an autogenous tendon graft might be impossible if a patient has already had one or more prior tendon replacements. In the face of severe tendon injuries, whether or not to employ a tendon graft depends on the extent of the damage. Subsequent decisions about where to harvest the graft from are generally made jointly by doctors and patients after thorough discussion.