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

Treatment of Anterior Cruciate Ligament (ACL) Tear

The treatment of ACL tears should be tailored based on patient age, activity level, and functional demands, with surgical reconstruction recommended for younger, active patients and non-surgical management appropriate for older, less active individuals with no functional instability. 1

Initial Assessment and Non-Surgical Management

• Standard knee X-rays are the first-line imaging study for knee instability, with MRI useful for confirming ACL tear and evaluating associated injuries 1
• Non-surgical treatment options include:
  • Supervised rehabilitation program (rated as "Appropriate" with score of 7/9) 2
  • Self-directed exercise program (rated as "Appropriate" with score of 7/9) 2
  • Activity modification (rated as "Appropriate" with score of 7/9) 2
  • ACL functional knee brace (rated as "May Be Appropriate" with score of 5/9) 2

Surgical Management Indications

Recommended for:

• Younger patients (especially under 30 years) 2, 1
• Highly active individuals 1
• Patients with functional instability during daily activities 1
• Patients with associated meniscal injuries 1
• Athletes wishing to return to pivoting sports 3

Not typically recommended for:

• Older patients with lower activity demands 2, 1
• Patients without functional instability 1
• Those with significant medical comorbidities 1
• Patients willing to modify activity levels 1

Surgical Options and Considerations

• ACL reconstruction is preferred over repair due to lower risk of revision surgery 1
• Graft selection options:
  • Autografts are recommended over allografts, particularly in young and active patients 1
  • Bone-patellar tendon-bone (BTB) grafts reduce risk of graft failure 1
  • Hamstring autografts reduce risk of anterior/kneeling pain 1
  • Allograft may be reasonable for older patients 2
• Either single-bundle or double-bundle techniques can be used with similar outcomes 1, though double-bundle arthroscopic ACL reconstruction has been recognized as the gold standard by some 4

Rehabilitation Protocol

Complete rehabilitation typically requires 9-12 months with structured progression 1:

1. Maximum Protection Phase (0-12 weeks)

   • Early healing period: Control forces to prevent disruption of the surgical site 5
   • Controlled motion period: Gradual increase in range of motion while protecting the graft 5

2. Moderate Protection Phase (12-24 weeks)

   • Focus on crutch-weaning and preparation for walking 5
   • Balance quadriceps and hamstring strengthening 5
   • Begin full weightbearing around 16 weeks 5

3. Minimum Protection Phase (24-48 weeks)

   • Protected activity period (24-36 weeks) 5
   • Light activity period (37-48 weeks) 5
   • Restrictions include no running, no jumping, and brace use 5

4. Return to Activity Phase (48-60 weeks)

   • Advanced rehabilitation to achieve maximum strength 5
   • Begin running when operated leg has at least 75% strength of normal leg 5

5. Return to Sport Criteria

   • No pain or swelling 1
   • Full knee range of motion 1
   • Stable knee on examination 1
   • Normalized subjective knee function and psychological readiness 1
   • Limb symmetry index >90% for quadriceps strength 1
   • Completion of sport-specific training program 1

Common Pitfalls and Caveats

• Psychological factors: Fear of reinjury is a significant contributor to not returning to sport; regular assessment of psychological factors is recommended 1, 6
• Delayed reconstruction: Patients who initially choose non-surgical management but experience persistent instability can undergo delayed ACL reconstruction 2
• Osteoarthritis risk: ACL tears, even with reconstruction, may increase risk of future osteoarthritis 4
• Rehabilitation protocol variation: Despite recent trends toward more accelerated protocols, there is little consensus among practitioners 6
• Avoiding early return to sport: Returning to sport too early increases risk of re-injury; complete rehabilitation typically requires 9-12 months 1

Recent Advances in Rehabilitation

• Early weight bearing and open kinetic chain exercises are now emphasized in newer protocols 6
• Alternative modalities such as neuromuscular electrical stimulation and blood flow restriction are being incorporated 6
• Clinical milestones rather than time-based progression are increasingly used to determine readiness for next rehabilitation phase 6