Hamstring Tendon Autograft

History of Using Hamstring Tendon Autograft in ACL Surgery

The hamstring autograft has a long history of being a successful graft with minimal scarring and no loss of quadriceps or patellar strength in competitive and professional soccer, basketball, and volleyball players. Post-operative pain is significantly less compared to patellar tendon and quadriceps tendon harvesting.

What are the advantages of hamstring grafts?

The hamstring tendon is harvested through the same incision required to drill the tibial tunnel. Therefore no additional incisions are made. Thus, there is no additional scarring from using a hamstring tendon graft. Multiple large studies show a very low re-rupture rate with these grafts.

The graft is composed of the gracilis and semitendinosus tendons folded over. Therefore it is a “four-stranded” graft. Each knee has three hamstring tendons on either side of the knee for a total of six. Losing two tendons has not been shown to cause any long-term problems. In fact, multiple MRI studies show that the muscle bellies of the gracilis and semitendinosus fuse to the muscle belly of the remaining sartorius hamstring muscle.

Hamstring tendons are long and therefore they are folded over through the looped femoral fixation device. This is advantageous because failure does not occur on the femoral side of the construct. Therefore, for hamstring tendon ACL patients, there is only one site of concern of the construct (tibial side). This is in contrast to quadriceps and patellar tendon grafts which require fixation to be attached on both the femoral and tibial ends of the graft. Therefore, there is potential for failure of fixation at both the femoral and tibial side of the patellar tendon and quadriceps tendon grafts.

What are the disadvantages of hamstring grafts?

The hamstring graft diameter is not known until the surgeon harvests the tendons and sizes them during surgery through a measurement device. Ideally, a graft should be at least 8 mm in diameter. If the graft is smaller, there are many methods to make it larger in diameter, including weaving the four strands of the graft together. Additionally, reinforcing the graft with suture tape will make the graft stronger and thicker. If the graft is too small despite these techniques or if the graft is too short, the graft must be augmented with an allograft or it cannot be used.

There are a few studies showing that in elite-level hurdlers, there may be some slight loss of hamstring strength, so for a track and field athlete, this should be a consideration.

Read the Science Direct article by Dr. Chen and his colleagues about Four-Strand Hamstring Diamond Braid Technique for Anterior Cruciate Ligament Reconstruction

https://www.sciencedirect.com/science/article/pii/S2212628721000153

Watch Dr. Chen’s Video on Four Strand Diamond Braiding Technique for Hamstring Autograft in ACL Reconstruction

See Dr. Chen’s diamond braiding technique in which the four strands of the hamstrings are woven together like a braid, which increases the diameter by at least 1 mm.