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

Medical Management of ACL Tear

For acute isolated ACL tears requiring surgery, early reconstruction within 3 months is strongly recommended to prevent additional cartilage and meniscal damage, while select patients with low activity demands may be managed conservatively with structured rehabilitation and activity modification. 1

Initial Management

Acute Symptom Relief

• Aspirate painful, tense knee effusions for immediate symptom relief in patients with acute ACL tears 1, 2
• MRI confirms diagnosis with 96% sensitivity and 97% specificity on 3T equipment 2

Treatment Decision Algorithm

Conservative (Non-Surgical) Management

Consider for:

• Patients with sedentary occupations and low activity demands 3
• Older patients (>40 years) with minimal instability symptoms 3
• Patients willing to permanently modify activities to avoid cutting, pivoting, and jumping 4

Conservative protocol includes:

• Structured physical therapy focusing on quadriceps strengthening and neuromuscular control 2, 4
• Activity modification to avoid pivoting and cutting movements 3
• Functional bracing during activities (though prophylactic bracing is not recommended for prevention) 1

Critical caveat: Younger patients (<30 years) have higher risk of progression to complete rupture and secondary meniscal injury with conservative treatment 5. Long-term studies show 90% of appropriately selected conservative patients rate outcomes as normal/almost normal at 27 years, but this requires permanent activity level reduction 6

Surgical Management

Indications for ACL Reconstruction

Strong indications:

• Younger patients (<30 years) desiring vigorous physical activity 2
• Active patients of any age wanting to return to jumping, cutting, or pivoting sports 2, 3
• Physically demanding occupations 3
• Patients who fail conservative management with persistent instability 3, 4
• To prevent future meniscus pathology, particularly in younger/active patients 1

Surgical Timing

Perform reconstruction within 3 months of acute isolated ACL tear - this is a strong recommendation because risk of additional cartilage and meniscal injury increases significantly after this timeframe 1, 2

Surgical Technique Decisions

Reconstruction vs. Repair:

• Always perform reconstruction rather than repair due to substantially lower revision surgery rates 1

Single-bundle vs. Double-bundle:

• Either technique is acceptable as outcomes are equivalent 1

Graft Selection for Skeletally Mature Patients:

• Bone-patellar tendon-bone (BTB) autograft reduces graft failure and infection risk but increases anterior/kneeling pain 1, 2
• Hamstring autograft reduces anterior/kneeling pain but has higher graft failure risk 1, 2
• Consider anterior lateral ligament (ALL) reconstruction or lateral extra-articular tenodesis (LET) when using hamstring autograft to reduce graft failure and improve short-term function 1
• Allograft is reasonable for older (>40 years) and less active patients 3

Management of Concomitant Injuries

Combined ACL/MCL tears:

• Treat MCL non-surgically - this results in good outcomes, though surgical MCL treatment may be considered in select cases 1, 2

Meniscal injuries:

• Prioritize meniscal repair over meniscectomy whenever technically possible, as repair results in similar clinical outcomes to isolated ACL injuries 2

Rehabilitation Protocol

Key Components

• Adequate preoperative rehabilitation improves postoperative quadriceps strength, knee range of motion, and potentially decreases time to return to sport 7
• Combine open and closed kinetic chain exercises for quadriceps strength recovery 2
• Integrate strength training with motor control exercises 2
• Continue rehabilitation for 9-12 months using criterion-based rather than purely time-based progression 7

Return to Sport Criteria

• Use functional evaluation (hop test) as one factor to determine return to sport readiness 1, 2
• Do not return to running before 12 weeks minimum to allow adequate graft remodeling 7
• Ensure no extension deficit preoperatively, as this is a major risk factor for postoperative extension problems 7

Long-Term Considerations

Osteoarthritis Prevention

• Address modifiable risk factors including weight control and quadriceps strengthening 2
• Patients remain at increased risk of knee osteoarthritis long-term even with successful surgical treatment 2
• Risk of contralateral ACL tear remains elevated 1

Primary Prevention

• Implement ACL injury prevention training programs for athletes in high-risk sports to reduce primary ACL injury risk 1, 2

Common Pitfalls to Avoid

• Do not delay surgery beyond 3 months in surgical candidates, as meniscal and cartilage damage risk increases 1
• Do not use functional knee braces routinely after isolated primary ACL reconstruction - they provide no clinical benefit 1
• Do not select conservative management for young, active patients without extensive counseling about permanent activity modification requirements 5
• Measure preoperative quadriceps strength deficits - deficits >20% negatively impact outcomes at 2 years 7