The LEAP: Why I Add an Extra Step to Your ACL Reconstruction

If you've been told you need ACL surgery, you may also hear your surgeon mention a "LEAP" — a lateral extra-articular procedure. It sounds like an add-on, and in a sense it is, but I think of it as one of the most important parts of getting your knee properly stable again.

Here's the idea in simple terms. Picture a wheel spinning on its axle. If you wanted to stop it from turning, would you grab it at the centre hub, or out at the rim? It's obviously much easier to control the spin at the rim, further from the middle. This is the same principle behind the LEAP, and it goes all the way back to Arthur Ellison, the American surgeon who first described this type of procedure in 1979: it's easier to control the rotation of a wheel at its rim than at its hub.¹ Your ACL sits deep in the centre of the knee — the hub. A LEAP works from the outside edge of the knee — the rim — which gives it real leverage over the twisting, pivoting motions that so often cause an ACL injury in the first place.

Why the outside of the knee matters

For a long time, ACL surgery focused purely on rebuilding the ligament in the middle of the knee. But we now understand that when the ACL tears, it's rarely acting alone. There's a band of tissue on the outer side of the knee called the anterolateral ligament (ALL), and it works together with the ACL to control rotation.

This structure was actually first hinted at back in 1879 by a French surgeon named Segond,² but it took until 2013 for Steven Claes and his colleagues to properly rediscover and describe it in detail — what's often called the modern rediscovery of the ALL.³ Once surgeons had a clear anatomical picture of it, interest in protecting it during ACL surgery took off. And when we look at MRI scans of knees with a fresh ACL tear, this structure is injured right alongside the ACL in the vast majority of cases — not the exception, but close to the rule.⁴

The evidence that changed my mind

The turning point for me — and for the field more broadly — was a major trial led by Alan Getgood and colleagues, known as the STABILITY trial, published in 2020.⁵ Nearly 620 young, active patients with ACL tears were randomly assigned to either a standard ACL reconstruction, or the same reconstruction plus a LEAP.

The results spoke for themselves. Patients who had the LEAP added were far less likely to re-tear their graft, and far less likely to have ongoing looseness or a "giving way" feeling in the knee two years down the line. Roughly speaking, adding the LEAP cut the risk of graft rupture by two-thirds.⁵ That's a big enough difference that it genuinely changes how I think about every ACL reconstruction I do.

The different ways to do a LEAP

There isn't just one way to do this, and the details matter less to you than the principle, but briefly:

• Some surgeons take a strip of the IT band (the tough band running down the outer thigh) and re-route it around the outside of the knee, fixing it near the top of the thigh bone — this is the modified Lemaire technique, the one used in the STABILITY trial.⁵
• Some reconstruct the ALL itself with a separate graft, more common among French surgical groups.
• Others use a variation that fixes the graft lower down, near the shin bone, which avoids some of the technical downsides of the other methods — this modern approach revives Ellison's original 1979 idea in a more refined form.⁶
• And then there's the over-the-top technique, which is the one I use. Rather than harvesting a separate piece of tissue and adding extra tunnels or hardware, it builds the lateral, rim-of-the-wheel control directly into the ACL graft construct itself.⁷

Does this cause other problems?

This is a fair question, and one I take seriously. For years there was a worry that tightening the outside of the knee might overload it and speed up arthritis. The best available evidence — a systematic review pulling together over 400 patients — doesn't support that concern.⁸ What it does show is that the strongest predictor of arthritis down the track isn't the LEAP at all, it's whether the meniscus (the knee's cartilage cushion) was already damaged at the time of surgery.⁸

Who really needs one?

Every surgery carries a cost — more operating time, and for some techniques, an extra incision or piece of hardware. So who benefits most? Based on the best current research, it's patients who are young, active in sports that involve pivoting and cutting (football, netball, basketball and the like), those with looser or more flexible joints, those with a high-grade pivot shift (a marker of significant rotational looseness), and anyone undergoing a repeat ACL reconstruction after a previous one has failed.⁹ Elite and professional athletes also do measurably better with a LEAP added, given how much is riding on getting back to full function the first time.¹⁰

My approach

As the evidence has built up, more surgeons — myself included — have moved toward simply offering this to everyone having an ACL reconstruction, not just the highest-risk patients. I use the over-the-top technique specifically because it gives you that rim-of-the-wheel rotational control without needing extra tunnels or implants. Every patient deserves the best shot at a knee that holds up the first time.

References

1. Ellison AE. Distal iliotibial-band transfer for anterolateral rotatory instability of the knee. Journal of Bone and Joint Surgery American. 1979;61(3):330-337.
2. Segond P. Recherches cliniques et expérimentales sur les épanchements sanguins du genou par entorse. 1879. (As reviewed in Morgan AM, et al. Knee Surgery & Related Research. 2022;34:45.)
3. Claes S, Vereecke E, Maes M, Victor J, Verdonk P, Bellemans J. Anatomy of the anterolateral ligament of the knee. Journal of Anatomy. 2013;223(4):321-328.
4. Ferretti A, Monaco E, Redler A, Argento G, De Carli A, Saithna A, Helito PVP, Helito CP. High Prevalence of Anterolateral Ligament Abnormalities on MRI in Knees With Acute Anterior Cruciate Ligament Injuries: A Case-Control Series From the SANTI Study Group. Orthopaedic Journal of Sports Medicine. 2019;7(6).
5. Getgood AMJ, Bryant DM, Litchfield R, et al. Lateral Extra-articular Tenodesis Reduces Failure of Hamstring Tendon Autograft Anterior Cruciate Ligament Reconstruction: 2-Year Outcomes From the STABILITY Study Randomized Clinical Trial. American Journal of Sports Medicine. 2020;48(2):285-297.
6. Al'Khafaji I, Devitt BM, Feller JA. The Modified Ellison Technique: A Distally Fixed Iliotibial Band Transfer for Lateral Extra-articular Augmentation of the Knee. Arthroscopy Techniques. 2022;11(2):e257-e262.
7. Zaffagnini S, Marcheggiani Muccioli GM, Grassi A, et al. Over-the-top ACL reconstruction plus extra-articular lateral tenodesis with hamstring tendon grafts: prospective evaluation with 20-year minimum follow-up. American Journal of Sports Medicine. 2017;45(14):3233-3242.
8. Devitt BM, Bouguennec N, Barfod KW, Porter T, Webster KE, Feller JA. Combined anterior cruciate ligament reconstruction and lateral extra-articular tenodesis does not result in an increased rate of osteoarthritis: a systematic review and best evidence synthesis. Knee Surgery, Sports Traumatology, Arthroscopy. 2017;25(4):1149-1160.
9. Firth AD, Bryant DM, Litchfield R, et al. Predictors of Graft Failure in Young Active Patients Undergoing Hamstring Autograft Anterior Cruciate Ligament Reconstruction With or Without a Lateral Extra-articular Tenodesis: The Stability Experience. American Journal of Sports Medicine. 2022;50(2):384-394.
10. Borque KA, Jones M, Laughlin MS, Balendra G, Willinger L, Pinheiro VH, Williams A. Effect of Lateral Extra-articular Tenodesis on the Rate of Revision Anterior Cruciate Ligament Reconstruction in Elite Athletes. American Journal of Sports Medicine. 2022.