Understanding ACL Graft Options: Autografts, Allografts, and the Role of Lateral Extra‑Articular Tenodesis

Introduction

The anterior cruciate ligament (ACL) is a crucial stabilizer in the knee. When it ruptures, reconstruction is often required, and the choice of graft material is a central decision. In this episode of the Complete Physio Podcast, Simon Moyes discusses the main graft types, their advantages and drawbacks, and the emerging practice of adding a lateral extra‑articular tenodesis (LEAT) to improve outcomes.

Main Types of ACL Grafts

1. Autografts (patient’s own tissue)

• Patellar Tendon (Bone‑Patellar‑Tendon‑Bone, BPTB)
• Technique: Middle third of the patellar tendon with a bone plug at each end.
• Pros: Considered the gold‑standard for strength; bone‑to‑bone healing promotes solid incorporation.
• Cons: Prominent anterior knee scar; 5‑10 % experience anterior knee pain, especially when kneeling; donor‑site morbidity.
• Hamstring Tendons
• Technique: Typically the semitendinosus, sometimes combined with gracilis; can be fashioned into double, triple, or quadruple bundles to achieve adequate thickness.
• Pros: Smaller incision, no bone plug needed, good functional outcomes comparable to BPTB.
• Cons: Potential hamstring weakness after harvest; rare risk of saphenous nerve irritation; donor‑site pain.
• Quadriceps Tendon (Distal Quad)
• Technique: Harvesting the distal portion of the quadriceps tendon, optionally with a small bone block.
• Pros: Large tendon size allows a thick graft; lower incidence of donor‑site pain compared with patellar tendon; early results are promising.
• Cons: Still relatively new; not universally adopted yet.

2. Allografts (donor tissue)

• Source: Cadaveric tendon, often processed to reduce disease transmission.
• Pros: Shorter operative time, no donor‑site morbidity, useful for older or low‑activity patients.
• Cons: Higher re‑rupture rates than autografts; therefore, generally reserved for low‑demand individuals.

Lateral Extra‑Articular Tenodesis (LEAT)

• Background: Originates from the 1980s Macintosh procedure, which used the fascia lata to control knee rotation. Modern LEAT is performed alongside ACL reconstruction.
• Why It’s Used: Reduces rotational instability and significantly lowers the risk of graft re‑rupture, especially in high‑demand, younger, or hyper‑mobile patients.
• Considerations:
• Adds an extra incision and scar.
• May slightly prolong rehabilitation and cause temporary stiffness or soreness, but the functional benefit often outweighs these drawbacks for active individuals.

Decision‑Making Factors

• Patient Profile: Age, activity level, sport demands, and personal preferences (e.g., tolerance for scar or anterior knee pain).
• Surgeon Expertise: Surgeons tend to favor the graft they are most comfortable with; most can perform several techniques.
• Risk of Re‑injury: High‑risk athletes may benefit from LEAT and a stronger graft (BPTB or quad tendon).
• Donor‑Site Morbidity: Concerns about knee pain or hamstring weakness influence graft choice.
• Second Opinions: Patients are encouraged to discuss options with multiple surgeons to align expectations.

Practical Tips for Patients

• Ask about the surgeon’s preferred graft and why.
• Inquire whether LEAT will be added and how it may affect recovery.
• Discuss potential complications such as anterior knee pain (BPTB) or hamstring weakness (hamstring graft).
• Consider long‑term activity goals when weighing autograft versus allograft.

Personal Insight

Simon, a recreational skier in his 60s, says he would likely choose either a hamstring autograft or an allograft if he ever needed ACL reconstruction, emphasizing that the decision ultimately rests on surgeon expertise and individual circumstances.

Summary of Pros and Cons

Conclusion

Choosing the right ACL graft is a nuanced decision that balances graft strength, healing potential, donor‑site morbidity, and patient lifestyle. While the patellar tendon remains the benchmark for strength, hamstring and quadriceps autografts offer comparable outcomes with different trade‑offs. Allografts serve a niche for low‑demand patients but carry a higher failure risk. Adding a lateral extra‑articular tenodesis can markedly reduce re‑rupture rates for active individuals, albeit with a modest increase in recovery time. Ultimately, informed discussion with a skilled surgeon—potentially supplemented by a second opinion—ensures the graft choice aligns with the patient’s goals and anatomy.

The optimal ACL graft depends on individual needs: patellar tendon offers maximal strength, hamstring and quadriceps autografts provide solid alternatives with fewer donor‑site issues, allografts suit low‑activity patients, and adding a lateral extra‑articular tenodesis can further protect high‑risk athletes from re‑injury.