The type of graft that the surgeon chooses for ACL reconstruction has evolved over the past few decades. In the 1970s, Erickson popularized the patellar tendon graft autograft that Jones had originally described in 1960. This became the most popular graft choice for the next three decades. In fact, in a survey of American Academy of Orthopaedic Surgeon members done in 2000, 80% still favored the use of the patellar tendon graft.
In the light of harvest site morbidity and postoperative stiffness associated with the patellar tendon graft, many surgeons began to look at other choices, such as semitendinosus grafts, allografts, and synthetic grafts. Fowler and then Rosenberg popularized the use of the semi-tendinosus. However, even Fowler was not convinced of the strength of the graft. Then, Kennedy and Fowler developed the ligament augmentation device (LAD) to supplement the semitendinosus graft. Gore-Tex (Flagstaff,AZ), Leeds-Keio, and Dacron (Stryker, Kalamazoo, MI) were choices for an alternative synthetic graft to try to avoid the morbidity of the patellar tendon graft. The initial experience was usually satisfactory, but the results gradually deteriorated with longer follow-up.
Allograft was another choice that avoided the problem of harvest site morbidity. The initial allograft that was sterilized with ethylene oxide had very poor results. Today the freeze-dried, fresh-frozen, and cryo-preserved are the most popular methods of preservation of allografts. The allograft has become a popular alternative to the autograft because it reduces the harvest site morbidity and operative time. However, Noyes has reported a 33% failure with the use of allografts for revision ACL reconstruction.
The aggressive postoperative rehabilitation program advocated by Shelbourne in the 1990s greatly diminished the problems associated with the patellar tendon graft. Before that, the patient had to be an athlete just to survive the operation and rehabilitation program. The aggressive program emphasized no immobilization, early weight bearing, and extension exercises.
There was renewed interest in the semitendinosus during the mid-1990s. Biomechanical testing on the multiple-bundle semitendinosus and gracilis grafts demonstrated them to be stronger and stiffer than other options. This knowledge combined with improved fixation devices such as the Endo-button gave surgeons more confidence with no-bone, soft tissue grafts. The Endo-button made the procedure endoscopic, thereby eliminating the need for the second incision.
Fulkerson, Staubli, and others popularized the use of the quadriceps tendon graft. This again reduced the harvest morbidity, especially when only the tendon portion was harvested.
Shelbourne has described the use of the patellar tendon autograft from the opposite knee. He claims that this divides the rehabilitation between two knees and reduces the recovery time. With the contralateral harvest technique, the average return to sports for his patients was four months.
With both the patellar tendon and the semitendinosus added to the list of graft choices, the need for the use of an allograft is minimized.
The latest evolution is to use an interference fit screw to fixate the graft at the tunnel entrance. This produces a graft construct that is strong, short, and stiff. It means that the surgeon now has to learn just one technique for drilling the tunnels and can chose whatever graft he or she wishes: hamstring, patellar tendon, quadriceps tendon, or allograft.
Successful ACL reconstruction depends on a number of factors, including patient selection, surgical technique, postoperative rehabilitation, and associated secondary restraint ligamentous instability. Errors in graft selection, tunnel placement, tensioning, or fixation methods may also lead to graft failure. Comparative studies in the literature show that the outcome is almost the same regardless of the graft choice. The only significant fact from the metaanalysis, as confirmed by Yunes, is that the patellar tendon group had an 18% higher rate of return to sports at the same level. The most important aspect of the operation is to place the tunnels in the correct position. The choice of graft is really incidental. Studies by Aligetti, Marder, and O'Neill show that the only significant differences among the grafts is that the patellar tendon graft has more postoperative kneeling pain.
Was this article helpful?