What is the recommended treatment plan for a patient with an anterior cruciate ligament (ACL) tear?

Treatment Plan for ACL Tear

The treatment approach for an ACL tear depends critically on patient age and activity level: young, active patients (<30 years) participating in cutting/pivoting sports should undergo early ACL reconstruction with autograft to protect menisci and provide knee stability, while older, less active patients should initially pursue nonsurgical management with supervised physical therapy and activity modification. 1, 2

Initial Decision-Making Algorithm

For Young, Active Patients (<30 years, cutting/pivoting sports):

• Early ACL reconstruction is appropriate to provide knee stability and protect menisci from subsequent injury 1, 2
• When surgery is indicated for acute isolated ACL injury, early reconstruction is preferable as the risk of additional cartilage and meniscus injuries begins to increase after 3 months 2
• ACL reconstruction with autograft receives the highest appropriateness rating (median score 8/9) for this population 1

For Older Patients (>30-40 years, lower activity levels):

• Nonsurgical management is the first-line approach, consisting of supervised physical therapy and activity modification 1, 3
• Lower activity levels are better tolerated in ACL-deficient patients, and the consequence of subsequent meniscus tears is less severe as postmeniscectomy osteoarthritis is unlikely to manifest in their lifetime 1
• Delayed ACL reconstruction remains an option if persistent instability develops despite adequate nonsurgical measures 1

Preoperative Management (When Surgery is Planned)

Prehabilitation is essential and improves self-reported knee function up to 2 years after reconstruction. 1

Critical Preoperative Assessments:

• Measure preoperative range of motion (ROM): A preoperative extension deficit is a major risk factor for postoperative extension deficit 1
• Measure quadriceps and hamstring strength: A preoperative quadriceps strength deficit >20% has significant negative consequences for self-reported outcomes 2 years after reconstruction 1
• Refer to physical therapist when necessary to optimize preoperative function 1

Surgical Approach

Graft Selection:

• For skeletally mature patients, patellar tendon (BPTB) autograft may be favored to reduce the risk of graft failure or infection 2
• Hamstring tendon grafts may be preferred to reduce the risk of anterior knee pain or kneeling pain 2
• Allograft is a reasonable option for older patients (>40 years) with lower activity levels 1, 4
• Single or double bundle reconstruction techniques present similar results 2

Concomitant Meniscal Injury Management:

• Meniscal repair should be the first option whenever technically possible, as it results in similar clinical outcomes to isolated ACL injuries, unlike meniscectomy 2
• Partial meniscectomy increases osteoarthritis risk (OR=1.87), while total medial meniscectomy presents even higher risk (OR=3.14) 2

Postoperative Rehabilitation Protocol

Rehabilitation should continue for 9-12 months, depending on the patient's return-to-work or play goals. 1

Week 1 (Immediate Postoperative):

• Immediate weight bearing is appropriate if there is correct gait pattern (with crutches if necessary) and no pain, effusion, or temperature increase when walking 1
• Immediate weight bearing does not affect knee laxity and decreases the incidence of anterior knee pain 1
• Cryotherapy can be applied in the first postoperative week to reduce pain 1
• Start isometric quadriceps exercises in the first week for reactivating quadriceps muscles when they provoke no pain 1
• Electrostimulation can be useful as an addition to isometric strength training for re-educating voluntary quadriceps contraction 1

Weeks 2-3:

• Closed kinetic chain (CKC) exercises can be performed from week 2 postoperative 1
• When the quadriceps is reactivated, concentric and eccentric exercises should replace isometric exercises, provided the knee does not react with effusion or increased pain 1

Weeks 4-8 (Progressive Open Kinetic Chain Training):

• For BPTB grafts: Open kinetic chain (OKC) exercises can start from week 4 in restricted ROM of 90-45°, and extra resistance is allowed (e.g., leg extension machine) 1
• For hamstring grafts: OKC exercises can start from week 4 in restricted ROM of 90-45°, but no extra weight should be added in the first 12 weeks to prevent graft elongation 1
• Progressive ROM expansion: 90-30° in week 5,90-20° in week 6,90-10° in week 7, and full ROM in week 8 for both graft types 1

Throughout Rehabilitation:

• Neuromuscular training should be added to strength training to optimize self-reported outcomes and prevent reinjuries 1
• Altered neuromuscular function and biomechanics after reconstruction could be a risk factor for second ACL injury (graft rerupture or contralateral rupture) 1
• Pay attention to correct quality of movement for prevention of reinjuries 1
• Functional knee orthoses are not recommended for routine use in patients who received primary isolated ACL reconstruction, as they do not confer clinical benefit 2

Rehabilitation Supervision:

• Minimally supervised rehabilitation may result in successful outcomes in highly motivated patients who live far from a physical therapist 1
• When comparing 19-week versus 32-week rehabilitation programs, there are no differences in laxity, ROM, self-reported function, single-leg hop test, or isokinetic strength 1

Nonsurgical Management Protocol (For Appropriate Candidates)

Core Components:

• Supervised rehabilitation program focusing on quadriceps strengthening exercises, balance and proprioception training, and functional exercises to improve stability 1, 3
• Activity modification to avoid high-risk cutting and pivoting movements 1
• Weight control to reduce stress on the injured knee joint 2, 3
• ACL functional knee brace may be considered if the patient experiences instability during daily activities 1, 3

Monitoring for Surgical Conversion:

• If significant functional instability persists despite adequate nonsurgical treatment, delayed ACL reconstruction should be considered 1, 3

Critical Pitfalls to Avoid

• Do not delay surgery beyond 3 months in young, active patients with acute isolated ACL injury, as the risk of additional cartilage and meniscus injuries increases 2
• Do not perform unnecessary meniscectomy: Always attempt meniscal repair when technically possible to reduce osteoarthritis risk 2
• Do not rush weight bearing: Only allow immediate weight bearing if correct gait pattern is maintained without pain, effusion, or temperature increase 1
• Do not add extra weight to OKC exercises for hamstring grafts in the first 12 weeks to prevent graft elongation 1
• Do not neglect neuromuscular training: Strength training alone is insufficient; neuromuscular training is essential for preventing reinjuries 1
• Do not perform unnecessary surgery in older patients who can be adequately managed with conservative treatment 1, 3

Long-Term Considerations

• Address modifiable risk factors for osteoarthritis (weight control, quadriceps strengthening) after knee injuries 2, 3
• The presence of minor osteoarthritic changes does not influence treatment decision-making 1, 2
• Even with successful surgical treatment, patients with ACL and medial meniscus injuries have increased risk of developing knee osteoarthritis long-term 2