Treatment of ACL Injury in Adults
For isolated ACL tears in adults, ACL reconstruction should be performed as early as possible—ideally within 3 months of injury—using autograft tissue (bone-patellar tendon-bone or hamstring) to reduce the risk of additional meniscal and cartilage damage, graft failure, and long-term osteoarthritis. 1
Surgical vs. Non-Operative Management
When to Operate
- ACL reconstruction is strongly recommended to lower the risk of future meniscus pathology and procedures, particularly in younger and more active patients 1
- Surgery should be reconstruction rather than repair due to lower revision surgery rates 1
- The decision hinges on activity level: patients wanting to return to jumping, cutting, or pivoting sports require reconstruction 2
Non-Operative Option
- Non-operative management (rehabilitation, bracing, activity modification) can be considered for sedentary patients with low activity demands 2
- Recent evidence shows that at 11-year follow-up, early reconstruction versus initial rehabilitation with optional delayed reconstruction showed similar patient-reported outcomes, though 52% of the delayed group eventually required surgery 3
- Critical caveat: Non-operative treatment may trend toward lower osteoarthritis rates but results in significantly worse knee stability 4
Timing of Surgery
Early reconstruction (within 3 months) is strongly preferred because the risk of additional cartilage and meniscal injury starts to increase after this window 1
- Animal studies demonstrate that immediate reconstruction reduces meniscus degeneration, while delayed reconstruction (28 days) actually facilitates cartilage degeneration compared to no surgery 5
- Delayed reconstruction fails to protect the meniscus and may worsen cartilage outcomes through inflammatory reactions combined with mechanical stress from meniscus damage 5
- Recent murine models confirm that immediate ACLR mitigates posttraumatic osteoarthritis development compared to delayed reconstruction 6
Graft Selection
Autograft vs. Allograft
Surgeons should strongly favor autograft over allograft to improve patient outcomes and decrease graft failure rates, particularly in young and active patients 1
Autograft Type Selection
When using autograft in skeletally mature patients 1:
- Bone-patellar tendon-bone (BTB): Favor to reduce risk of graft failure or infection
- Hamstring: Favor to reduce risk of anterior knee pain or kneeling pain
Both options have similar overall outcomes, so the choice depends on weighing these specific risks 1
Surgical Technique
Single-bundle or double-bundle techniques can both be considered as outcomes are similar between the two approaches 1
Augmentation Procedures
- Anterior lateral ligament (ALL) reconstruction or lateral extra-articular tenodesis (LET) may be considered when performing hamstring autograft reconstruction in select patients to reduce graft failure and improve short-term function, though long-term outcomes remain unclear 1
Concomitant Injuries
Combined ACL/MCL Tears
- Non-surgical treatment of the MCL injury results in good outcomes when combined with ACL reconstruction 1
- Surgical treatment of the MCL may be considered in select cases 1
Post-Operative Management
Bracing
- Functional knee braces are NOT recommended for routine use after isolated primary ACL reconstruction as they provide no clinical benefit 1
- Prophylactic bracing is not a preferred option for preventing ACL injury 1
Return to Sport
- Functional evaluation (such as hop testing) should be considered as one factor—not the sole determinant—for return to sport decisions 1
- Approximately two-thirds of patients achieve patient-acceptable symptom states, though 44% develop radiographic osteoarthritis by 11 years regardless of treatment timing 3
Prevention
Training programs designed to prevent injury should be used to reduce the risk of primary ACL injuries in athletes participating in high-risk sports 1
Acute Management
Physicians may consider aspirating painful, tense effusions after knee injury with likely or confirmed ACL tear for symptom relief 1