If I have an ACL reconstruction, does it matter whether the new ligament comes from my own tendon or from a donor?
It is one of the first questions patients ask once they have grasped that the torn ligament is replaced rather than repaired. Using a donor tendon, an allograft, means no second incision, no hamstring to weaken and no kneeling pain from a patellar tendon harvest, which is why this practice uses non-irradiated donor tendon often. The question is whether it lasts as well.
What the study looked at
The authors, from Ohio State University, searched for every comparative study of autograft against allograft in primary ACL reconstruction and kept only those that stated whether the donor tissue had been irradiated. Irradiation and chemical sterilisation weaken tendon, and much of the older evidence against allograft never separated processed from unprocessed tissue. Nine studies met the criteria. Six compared patellar tendon autograft with patellar tendon allograft, two compared hamstring with hamstring, and one compared hamstring autograft with tibialis allograft. The outcomes were graft failure, looseness of the knee on examination and on instrumented testing, and patient-reported knee scores.
What they found
- No study found a significant difference in graft failure between autograft and non-irradiated allograft.
- No study found a difference in knee laxity, on the examination table or on instrumented testing.
- No study found a difference in patient-reported knee scores.
- The mean age of patients was 24.5 to 32 years in seven of the nine studies.
The authors are explicit about the limit of that finding: “These findings apply to patients in their late 20s and early 30s. Caution is advised when considering extrapolation of these findings to younger, more active cohorts.”
What the companion papers add
The review is twelve years old, so it is read here alongside three later papers. The Kaiser Permanente registry compared 14,015 soft-tissue grafts and found that allografts irradiated at 1.8 Mrad or more carried 3.4 to 3.9 times the revision risk of hamstring autograft, chemically processed grafts 3.0 times, and non-processed allografts no different risk at all: processing, not donation, was the problem. A randomised trial in 99 mostly active-duty military patients with a median age of 26, followed for at least ten years, found 26.5% failure with fresh-frozen non-irradiated allograft against 8.3% with hamstring autograft: in young, high-demand patients the donor tendon did fail more, even unprocessed. And a 2026 meta-analysis of soft-tissue grafts found no difference in revision or re-tear, with a small advantage to autograft on two knee questionnaires.
What it means for you
Outside high-demand cohorts, a non-irradiated, non-chemically-processed donor tendon has not been shown to fail more often than the patient’s own, and it spares them a donor site. In this practice it is the mainstay for most patients, including recreational athletes at any age, and particularly for the patient whose hamstrings measure small, for whom a hamstring graft carries its own higher failure risk, and for the patient who needs to kneel. For the professional or high-level competitive athlete, the data from military and elite cohorts point the other way, and the graft is typically their own patellar tendon. The tissue bank’s processing method is the question to ask of any allograft, and the answer here is none.
This is background for the conversation with your surgeon, not a recommendation for an individual knee; the chapter on which graft is best sets out the whole picture.
A caveat worth knowing
A systematic review without pooling can only say that no included study found a difference, which is weaker than saying none exists, and nine small studies with short follow-up could miss a real one. The strongest contrary evidence, the ten-year randomised trial in young military patients, was published the year after this review and is not in it. The honest summary is that the answer depends on age, activity and processing, and the review’s own authors said so.