Autograft Selection for ACL Reconstruction
For a 46-year-old woman requiring ACL reconstruction without allograft availability, you should use either bone-patellar tendon-bone (BTB) or hamstring tendon autograft, with the choice determined by whether you prioritize minimizing graft failure/infection risk (favor BTB) versus minimizing anterior knee and kneeling pain (favor hamstring). 1
Primary Recommendation Framework
The 2023 AAOS guidelines provide moderate-strength evidence for autograft selection in skeletally mature patients:
- Bone-Patellar Tendon-Bone (BTB): Favor this to reduce risk of graft failure or infection
- Hamstring Tendon: Favor this to reduce risk of anterior or kneeling pain
Clinical Decision Algorithm
Choose BTB if:
- Patient prioritizes lowest possible graft failure rate
- Patient has high activity demands or plans to return to pivoting sports
- Anterior knee pain/kneeling pain is not a major concern for patient's occupation or lifestyle
- Patient accepts donor site morbidity at the extensor mechanism
Choose Hamstring if:
- Patient's occupation involves frequent kneeling (e.g., construction, carpet laying, religious practices)
- Patient has concerns about anterior knee pain
- Patient wants to preserve the extensor mechanism
- Patient accepts potentially slightly higher revision rates and slower return to sport
Supporting Evidence Details
BTB advantages include fastest graft incorporation via bone-to-bone healing, lower revision rates, and greater return-to-sport rates compared to hamstring 2. However, donor-site morbidity includes anterior knee pain, kneeling pain, and small risks of patellar fracture or tendon rupture 2, 3.
Hamstring advantages include smaller incision, preserved extensor mechanism, and reduced anterior knee pain 2, 3. Disadvantages include potential knee flexion weakness, saphenous nerve injury risk, and possible graft loosening from bone tunnel widening 2.
Important Caveats
Age consideration: At 46 years old, this patient falls into a demographic where both grafts perform well. Research shows that in patients over 40, both autograft options return patients to preoperative Tegner activity levels with similar outcomes 4.
Quadriceps tendon: While not specifically mentioned in the AAOS moderate-strength recommendations, quadriceps tendon autograft is an emerging third option with minimally invasive harvest techniques and preservation of both patellar tendon and hamstrings 2. However, long-term outcomes are less established, and knee extension weakness has been documented 2.
Avoid common pitfall: Do not default to allograft in this age group simply because the patient is over 40. The 2023 AAOS guidelines represent a major shift from 2013, now recommending autograft over allograft even in older patients to improve outcomes and decrease graft failure rates 1.
Surgical Timing Note
Once you've selected the graft, perform reconstruction as soon as possible—the risk of additional cartilage and meniscal injury increases within 3 months of ACL tear 1.