Patients between 14-60 years of age who will undergo an anterior cruciate ligament (ACL) reconstruction between Nov 1, 2021- Dec 31, 2023, will have their charts reviewed be approached in clinic when the surgery is scheduled regarding their participation in this study. At the time of consent, patients will be randomized to a group via a computerized randomization process, either the experimental hybrid remnant repair (HRR) or traditional ACL reconstruction with ACL stump debridement. Routine postoperative data will be collected at regularly scheduled post-operative and physical therapy appointments including range of motion, pain, patient-reported outcomes, return-to-sport tests, and proprioceptive data. Additionally, patients will be asked to undergo a post-operative MRI between 9 and 15 months following the date of their surgery. Radiologists reading the MRIs will be blinded to which group the patient is in. The primary outcome measure is graft incorporation between the two groups.

The purpose of this study is to examine the efficacy of a hybrid remnant repair (HRR) anterior cruciate ligament reconstruction (ACLR) with a traditional ACLR. Orthopedic surgeons are consistently looking for ways to improve outcomes following ACLR. Previous research has focused on different graft harvesting techniques and selection as well as biological augmentation of the graft. Recently, as reconstruction techniques have improved the anatomic accuracy of the reconstruction, there has been a renewed interest in remnant-preserving techniques. Surgeons in the sports medicine department are trained and have been performing HRR for several months at this point. The investigators are interested in comparing the results of patients who underwent HRR ACLR compared to a traditional ACLR.

The specific aim of this investigation is to determine the efficacy of ACL reconstruction with HRR to the standard ACL reconstruction with stump debridement. This study will specifically focus on whether patients who underwent HRR ACLR achieve superior incorporation of the graft, proprioceptive abilities, and improved patient-reported outcomes compared to traditional ACLR. If this procedure provides superior outcomes, it will benefit patients who have an ACL tear with a vascularized remnant stump remaining. The investigators will access information in the Henry Ford electronic medical records and review patient charts to consent patients undergoing ACL reconstruction between June 1, 2021- Dec 31, 2023. The investigators will record intraoperative data including date of surgery, type of graft used, whether or not there was a prior surgery; post-operative data including strength, range of motion, and patient-reported outcomes; all of which are routinely collected or documented. Additionally, between 6 and 15 months postoperatively, patients will undergo postoperative magnetic resonance imaging (MRI) to determine the incorporation of the graft and ACL remnant.

The investigators hypothesize patients undergoing HRR ACLR will have better incorporation with improved vascularity compared to patients undergoing a traditional ACLR. The investigators hypothesize that this will lead to improved proprioceptive abilities and improved patient-reported outcomes, which may reduce the time required to be cleared to return to sport and resume usual activities of daily living.

Inclusion Criteria:

• Patients aged 14-65 will undergo an anterior cruciate ligament (ACL) reconstruction from June 1,2021-Dec 31,2023 will be chart reviewed and asked about participating in the study in Dr. Moutzouros's clinic at a routine pre-operative clinic appointment .

There will be 100 subjects who are consented, 50 in each group (Arm A- HRR ACLR; Arm B- traditional ACLR with stump debridement).

Exclusion Criteria:

• Patients will be excluded if they suffered concomitant medial collateral ligament (MCL), lateral collateral ligament (LCL), or posterior cruciate ligament (PCL) injury as well as patients who did not undergo HRR ACLR. Additional exclusion criteria includes poor follow-up to post-operative clinic appointments.

We do not foresee the need to share any individual participant data (IPD) at this time.