What Happens If My ACL Graft Fails and I Need Revision Surgery?

Overview

Revision ACL reconstruction replaces a previously reconstructed ACL graft that has failed, whether from a new injury, a technical problem with the original surgery, or gradual stretching out over time. Dr. Raffo, a high-volume ACL surgeon and a second-opinion resource for patients throughout Bethesda and Montgomery County, evaluates the cause of the original failure, manages the old tunnels, chooses a graft suited to what's already been used, and adds a lateral extra-articular tenodesis in most revision cases because the data supporting it in this setting are strong.

Who this is for

• Patients whose ACL graft has re-torn, whether through a new pivoting injury or a fall, are the most straightforward revision candidates.
• Patients with a graft that has gradually stretched out, causing recurrent instability without a discrete re-injury, are also candidates after a full evaluation of tunnel position and graft integrity.
• Patients whose first surgery used tunnel positions that were not anatomic are candidates for revision even if the graft itself has not fully ruptured, since malpositioned tunnels are a common and correctable cause of persistent instability.
• Patients with well-preserved cartilage, adequate bone stock for tunnel management, and realistic expectations about a somewhat higher failure risk than a first-time reconstruction are the best candidates; patients with advanced arthritis or very poor remaining bone stock may need a staged approach or a different treatment path altogether.

How I approach it

The first job in any revision is figuring out why the first graft failed — a new injury, a technical problem with tunnel placement, or a graft that gradually attenuated — because that answer changes what I do next. If the old tunnels are badly malpositioned or widened, I stage the surgery: bone graft the old tunnels first, let them consolidate, then come back for the reconstruction itself, rather than trying to force new tunnels through compromised bone in a single setting.

I add a lateral extra-articular tenodesis to nearly every revision ACL reconstruction I do. A pooled analysis of 8 studies comparing revision ACL reconstruction with and without an added lateral procedure found failure rates of 11.7% without one versus 5.6% with one added — roughly half the failure rate — along with meaningfully less residual pivot shift (Grassi et al., AJSM 2024). Expert consensus lists revision ACL reconstruction as a "recommended" indication for a lateral procedure, not merely one to consider (Saithna, Geeslin, Sonnery-Cottet, Arthroscopy 2025). Graft choice in revision is also different from a first-time reconstruction — I don't default to whatever graft failed the first time, and I weigh what tissue is still available to harvest.

The operation

Revision surgery starts with a careful review of imaging to assess old tunnel position, tunnel widening, remaining bone stock, and the condition of the cartilage and menisci. If the existing tunnels are well-positioned and not overly widened, the revision graft can often be placed in a single stage, sometimes using the same tunnels or slightly offset ones. If tunnels are malpositioned or substantially widened, bone grafting of the old tunnels is performed first, and the ligament reconstruction is staged as a second procedure once the graft has incorporated. Graft choice depends on what was used previously and what tissue remains available — autograft, allograft, or a combination. A lateral extra-articular tenodesis is added in nearly all cases, given the strength of the revision-specific data. The knee is also re-evaluated for meniscal tears, since meniscal repair is performed in a meaningful share of revision cases.

Risks and honest tradeoffs

• Revision surgery carries a real failure risk even with a lateral procedure added. Pooled failure with a lateral procedure added is 5.6%, versus 11.7% without one — better, but not zero (Grassi et al., AJSM 2024).
• Surgical-site pain from an added lateral procedure can be prolonged. One series reported surgical-site pain in 72.1% of tenodesis patients versus 15.9% without, lasting a median of 3.2 versus 1.2 months (Grassi et al., AJSM 2024).
• Meniscal repair performed at the time of revision has its own failure rate. In the MARS cohort, 218 of 1,205 revision ACL reconstructions included a meniscal repair, with failure of 8.6% at 2 years — 8.8% for medial repairs versus 3.0% for lateral (Wright et al., MARS Group, AJSM 2020).
• Complication rates with an added lateral procedure did not differ significantly from revision without one (3.9% vs 2.0%, P=.19), though the comparison did not reach statistical significance (Grassi et al., AJSM 2024).
• Osteoarthritis risk is elevated in any ACL-injured knee, and revision knees have typically already sustained more cumulative joint damage. Roughly 36% of ACL-reconstructed knees have radiographic osteoarthritis at approximately 10 years, and meniscal status is the dominant driver of that risk (Webster & Hewett, Clin J Sport Med 2022).
• Staged bone grafting adds time to the overall treatment course when tunnels are malpositioned or widened, meaning some patients face two procedures rather than one before the reconstruction itself is complete.

Recovery and rehabilitation

Recovery after revision ACL reconstruction generally follows the same criteria-based framework as primary reconstruction, with two practical differences: patients who required staged bone grafting have a longer overall treatment timeline before the ligament reconstruction itself even begins, and postoperative pain in the first few months, particularly at a lateral tenodesis incision, can be more pronounced than after a first-time reconstruction.

• Staged cases: Bone graft incorporation is confirmed on imaging before the reconstruction is scheduled, typically requiring several months between the two procedures.
• Weeks 0–2: Early motion and weightbearing; more attention to soft-tissue healing given the additional lateral incision in most cases.
• Weeks 3–6: Progressive closed-chain quadriceps strengthening.
• Weeks 8–16: Return to running once pain, motion, and strength criteria are met (Rambaud et al., BJSM 2018).
• Month 9 and beyond: Return to pivoting sport only after passing a strength and hop-test battery, the same bar used after primary reconstruction (Grindem et al., BJSM 2016).

1. Weeks 0–2

   Early motion and weightbearing; more attention to soft-tissue healing given the additional lateral incision in most cases.

2. Weeks 3–6

   Progressive closed-chain quadriceps strengthening.

3. Weeks 8–16

   Return to running once pain, motion, and strength criteria are met (Rambaud et al., BJSM 2018).

4. Month 9 and beyond

   Return to pivoting sport only after passing a strength and hop-test battery, the same bar used after primary reconstruction (Grindem et al., BJSM 2016).

Alternatives I considered

For a patient with a low-demand lifestyle who has re-torn a graft but does not intend to return to pivoting sport, I discuss forgoing revision surgery in favor of continued bracing and activity modification, since the risks of a second reconstruction — including a nontrivial failure rate even with modern technique — are real and should be weighed against actual functional goals. For patients who are candidates but want to minimize additional surgical time, I discuss omitting the lateral tenodesis, understanding the tradeoff in failure risk described above.