The aim of this study is to investigate the differences in graft failure between patients that underwent ACL reconstruction using allograft tendons and patients that underwent ACL reconstruction using autograft tendons in patients older than 40 y.o. and after at least 2 years of follow-up. The hypothesis of the study is that there will be a difference in graft failure and patient reported functional outcomes between allograft and autograft ACL reconstruction.

Inclusion Criteria:

• Participant is willing and able to give informed consent for participation in the study.
• Male and female patients of fertile age can be recruited
• Patients aged 40 years old and above, and 2 years minimum of follow-up
• Patients that underwent primary ACL reconstruction with allograft an autograft tendons

Exclusion Criteria:

• Multiligamentous lesion
• Meniscal tear leading to subtotal or total meniscectomy or meniscal graft
• Indication for major cartilage restoration or resurfacing
• Ipsilateral knee fractures
• History of ligament injury
• Concomitant extracapsular procedures
• Ipsilateral or contralateral knee surgeries

Patients that underwent ACL reconstruction using either allograft or autograft tendons, at least 2 years of follow-up, gender male and female, no comorbidities.

Group 1 are patients aged ≥ 40 y.o. that underwent ACL reconstruction using allograft tendons.

Group 2 are patients aged ≥ 40 y.o. that underwent ACL reconstruction using autograft tendons.