Autograft vs Allograft
Strong evidence supports that in patients undergoing ACL reconstructions, the practitioner should use either autograft or appropriately processed allograft tissue, because the measured outcomes are similar, although these results may not be generalizable to all allografts or all patients, such as young patients or highly active patients.

Rationale
This recommendation was built upon two high strength studies and seven moderate strength studies. 26, 39, 62, 63, 85, 111, 112, 113, 117 The preparation of allografts varies with respect to procurement, processing, storage, and implantation. Each of these steps can affect the mechanical properties and incorporation of the graft. Understanding these limitations, there were two high strength and six moderate strength studies available that compared ACL reconstruction with autograft and allograft tissues.
 
Combining the autograft and nonirradiated allograft data from two studies, there was a 6% failure rate with autograft and a 9% failure rate with nonirradiated allograft, which was not a statistically significant difference.111, 112 In contrast, there was a 34% failure rate with irradiated allograft (2.5 Mrad). The difference between failures in the autograft group and the irradiated allograft group was statistically significant.
 
Five moderate strength prospective comparative studies, similarly demonstrated that the clinical outcomes of ACL reconstruction with allograft were not significantly different from those with autograft.26, 62, 63, 84, 117
 
The allografts used in the study by Gorschewsky et al. were sterilized with osmotic treatment, oxidation, and solvent drying with acetone.39 In contrast, the other studies involved the use of fresh-frozen allografts or cryopreservation.  The patient-oriented outcomes, physical examination findings, instrumented laxity measurements, and complications in the allograft group in the study by Gorschewsky et al. were much worse than those in the other treatment arms of the other five prospective comparative studies. 26, 39, 62, 63, 84, 117

While outcomes following ACL reconstruction using autograft tissue and using non-irradiated allograft tissue are similar overall, these results may not be generalizable to specific subsets of patients with ACL rupture, such as athletes and young patients.  In fact, a longitudinal cohort study indicated a higher failure rate of allograft tissue in younger patients (Figure 3, Kaeding -- Sports Health 2011). 
 
Potential Harms of Implementation
As with all surgery procedures, there are surgical risks and complications including but not limited to graft failure, arthrofibrosis, infection, neurovascular injury, and anesthetic complications.  With ACL reconstruction using autograft tissue, there are specific additional risks of donor site morbidity, including risk of patellar fracture and long-term kneeling pain (with autograft bone-patellar tendon-bone) as well as risk of saphenous nerve trauma and long-term knee flexor strength deficit (with autograft hamstring tendon).  With ACL reconstruction using allograft tissue, there are specific additional risks of potential for disease transmission and limited availability.
 
Future Research
While outcomes following ACL reconstruction using autograft tissue and using non-irradiated allograft tissue are similar overall, these results may not be generalizable to specific subsets of patients with ACL rupture, such as elite athletes and very young patients.  Specifically, further research is needed to assess the outcomes following ACL reconstruction using autograft tissue and using non-irradiated allograft tissue in patients with specific activity levels (including elite athletes), ages (including the young and very young), and associated injuries.
 
Further research is needed to assess the outcomes following ACL reconstruction using autograft tissue and using non-irradiated allograft tissue in patients with specific activity levels (including elite athletes), ages (including the young and very young), and associated injuries.
 
 

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