What are the options for Anterior Cruciate Ligament (ACL) reconstruction after ACL graft failure?

ACL Reconstruction After Graft Failure

Revision ACL reconstruction should be performed using autograft tissue, with bone-patellar tendon-bone (BPTB) or quadriceps tendon (QT) preferred over hamstring tendon (HT) due to lower graft failure rates, though all three options produce similar functional outcomes. 1

Graft Selection for Revision Surgery

Primary Graft Choice

• BPTB and QT autografts are the preferred options for revision ACL reconstruction, with graft failure rates of approximately 10% for both, compared to 19% for hamstring tendon grafts 1
• Autografts remain the favored choice even in revision settings, despite the technical challenges 2
• When selecting between BPTB and hamstring grafts in any ACL reconstruction, surgeons should weigh that BPTB reduces graft failure and infection risk but increases anterior/kneeling pain 3

Graft Selection Based on Previous Failure

The choice of revision graft depends critically on what failed previously:

• For failed BPTB grafts: Either ipsilateral hamstring tendon OR contralateral BPTB are equivalent options for revision 4
• For failed hamstring grafts: Contralateral hamstring tendon is superior to ipsilateral BPTB for revision 4
• This strategy optimizes donor site recovery while maintaining strength rehabilitation potential 4

Surgical Approach: Single-Stage vs Two-Stage

Single-Stage Revision

• Single-stage revision can be successful when optimal tunnel placement is achievable 5
• This approach is preferred when previous tunnel position and size allow for anatomic graft placement 5

Two-Stage Revision

• A staged approach is indicated when optimal tunnel placement is not possible due to malposition or widening of previous tunnels 5
• The first stage addresses tunnel osteolysis with bone grafting, followed by definitive reconstruction once bone stock is restored 5, 6

Critical Preoperative Evaluation

Before proceeding with revision, identify the specific cause of failure:

Common Failure Mechanisms

• Traumatic rupture is the most common reason for graft failure 2
• Technical errors (tunnel malposition, graft tensioning issues) 2, 6
• Missed concomitant injuries at index surgery 2, 6
• Biological graft incorporation failure 2
• Young age and incomplete rehabilitation 6

Essential Diagnostic Workup

• Advanced imaging to assess tunnel position, tunnel widening/osteolysis, and concurrent pathology 5, 2
• Clinical examination for abnormal laxity and functional instability 5, 2
• Evaluation for limb malalignment requiring correction 5, 6

Concomitant Procedures

Address all contributing factors in the same surgical session when possible:

• Meniscal treatment for new or progressive tears 5
• Lateral extra-articular augmentation (ALL reconstruction or LET) to reduce re-rupture risk, particularly with hamstring grafts 3
• Corrective osteotomy for limb malalignment 5, 6
• Cartilage lesion management 5

Timing of Revision Surgery

• Early reconstruction is preferred to minimize risk of additional cartilage and meniscal injury, similar to primary ACL tears 3, 7
• The 3-month threshold where additional injury risk increases applies to revision scenarios as well 3

Expected Outcomes and Patient Counseling

Realistic Expectations

• Revision ACL reconstruction reliably restores knee stability and function, BUT clinical outcomes and reoperation rates are worse than primary reconstruction 5
• Return to sport rates are lower after revision compared to primary surgery 6
• Functional outcomes at 2 years show no significant difference between QT, HT, and BPTB grafts, with all patients returning to pre-injury activity levels 1

Strength Recovery

• Knee strength recovery (extensor and flexor) following revision surgery is similar to primary reconstruction when using the same graft technique 4
• Limb symmetry index at 4,6, and 9 months post-surgery shows no difference between revision and primary procedures 4

Common Pitfalls to Avoid

• Failing to identify the cause of initial graft failure leads to recurrent failure 2, 6
• Ignoring concurrent meniscal, ligamentous, or cartilage pathology compromises revision outcomes 5, 6
• Not addressing limb malalignment when present perpetuates abnormal loading 5, 6
• Attempting single-stage revision with inadequate bone stock or poor tunnel position increases failure risk 5
• Choosing hamstring autograft without considering lateral extra-articular augmentation in high-risk patients 3