What is the treatment for an Anterior Cruciate Ligament (ACL) tear?

Treatment of ACL Tear

For young, active patients (<30 years) who participate in cutting/pivoting sports, ACL reconstruction should be performed within 3 months of injury to prevent secondary meniscal and cartilage damage and enable return to sport. 1

Treatment Decision Algorithm

Surgical Reconstruction (Preferred)

Indications for surgery:

• Age <30 years with any activity level 2, 1
• Active patients of any age wanting to return to jumping, cutting, or pivoting sports 2, 1
• Physically demanding occupations 3
• Symptomatic instability after trial of conservative management 2
• Concomitant repairable meniscal tears 1

Timing:

• Perform reconstruction within 3 months of acute injury, as risk of additional cartilage and meniscal damage increases after this timeframe 1
• Ensure adequate preoperative range of motion and absence of flexion contracture, as preoperative extension deficit is a major risk factor for postoperative problems 4

Graft Selection:

• Bone-patellar tendon-bone (BPTB) autograft reduces graft failure and infection risk but increases anterior/kneeling pain 4, 1
• Hamstring tendon autograft reduces anterior knee pain but has higher graft failure rates 1
• Allograft is reasonable for patients >40 years with lower activity levels 2, 3
• Consider lateral extra-articular augmentation with hamstring grafts to reduce re-rupture risk 4

Surgical Technique:

• Single-bundle or double-bundle techniques have similar outcomes 1
• Repair any concomitant meniscal tears rather than performing meniscectomy, as repair results in similar clinical outcomes to isolated ACL injuries 1
• MCL injuries can be treated non-surgically with good outcomes 1

Conservative Management (Selected Cases)

Indications for non-operative treatment:

• Age >30 years with low activity levels and sedentary occupation 2
• Patients without symptomatic instability 2
• Presence of minor osteoarthritic changes (does not influence decision if no instability) 2
• Patient preference after informed discussion of risks 2

Conservative Protocol:

• Supervised physical therapy focusing on quadriceps strengthening and neuromuscular control 1
• Activity modification to avoid cutting/pivoting movements 2
• Consider aspiration of painful, tense effusions for symptom relief 1
• Monitor for development of instability, which would prompt delayed reconstruction 2

Risks of Conservative Approach:

• High risk of symptomatic instability in cutting/pivoting sports 2
• Increased risk of subsequent meniscal and cartilage damage 2
• May require delayed reconstruction after ineffective conservative care 2

Post-Reconstruction Rehabilitation

Early Phase (0-12 weeks):

• Immediate range of motion training and weight bearing within first week 5
• Open and closed kinetic chain exercises for quadriceps strength recovery 1
• Combined strength and motor control training 1
• Aquatic therapy may be added 3-4 weeks postoperatively once wound healed 2
• Core stability exercises to improve functional outcomes 2

Return to Running Criteria (minimum 12 weeks):

• 95% knee flexion ROM and full extension 2
• No effusion or trace effusion only 2
• Limb symmetry index >80% for quadriceps strength 2
• LSI >80% eccentric impulse during countermovement jump 2
• Pain-free aqua jogging, Alter-G running, and repeated single-leg hopping 2

Return to Sport Criteria (9-12 months):

• No pain or swelling 2
• Full knee ROM and stable knee on examination 2
• Normalized subjective knee function and psychological readiness 2
• Functional hop testing may be considered as one factor 1
• Use criterion-based rather than purely time-based progression 4

Return to Driving:

• Right-sided reconstruction: 4-6 weeks 2
• Left-sided reconstruction: 2-3 weeks 2

Critical Pitfalls to Avoid

• Delaying reconstruction beyond 3 months in surgical candidates increases risk of secondary injuries 1
• Operating with flexion contracture significantly worsens postoperative outcomes 4
• Quadriceps strength deficits >20% preoperatively negatively impact 2-year outcomes 4
• Returning to sport before 9-12 months or without meeting functional criteria increases reinjury risk 2, 4
• Performing meniscectomy instead of repair when technically feasible worsens long-term outcomes 1

Long-Term Considerations

• Even with successful surgical treatment, patients have increased risk of knee osteoarthritis long-term (up to 90% of patients) 1, 6
• Address modifiable risk factors: weight control and quadriceps strengthening 1
• Implement injury prevention programs for athletes in high-risk sports to reduce primary ACL injury risk 1