ACL Injuries 101 (Part II)

Surgical & Non-Operative Management of ACL Tears

*Disclaimer: This content is for educational and informational purposes only and is not intended as medical advice. It should not be used to diagnose, treat, or replace the guidance of a licensed healthcare provider. Always consult with your physician, physical therapist, or medical team before making decisions about your health, especially regarding injury management or surgery.

Introduction

In Part I, we explored what the ACL is, how it is commonly injured, and the initial steps for managing this injury. After a round of “prehab” and consulting with an orthopedist, the next step is deciding whether to continue with non-operative management or to undergo surgery. For many years, reconstruction surgery has been considered the standard of care, particularly for athletes. However, not every individual with an ACL injury requires surgery, and research increasingly supports non-operative rehabilitation as a viable pathway for certain patients. Choosing between surgery and non-operative care depends on your activity goals, knee stability, associated injuries, and personal circumstances. In this article, we will break down the key differences, benefits, and limitations of both options to help you make an informed choice about your recovery.

Non-Surgical Management of ACL tears

Surgery was once considered the only path forward after an ACL tear, but research now shows that non-operative care can be just as effective for many patients. A systematic review by de Jonge et al. (2024) found no strong evidence that ACL reconstruction was superior to rehabilitation alone. In fact, patients who did not undergo surgery had lower rates of knee osteoarthritis compared to those who did. Similarly, the Delaware-Oslo ACL cohort reported comparable outcomes between surgical and non-surgical groups in knee function, muscle strength, and return to sport. When adjusted for activity level, re-injury rates were also similar. While surgery provided better passive knee stability, this did not translate into better functional outcomes.

An exciting development in this space is the cross-bracing protocol, a non-operative strategy designed to promote natural ACL healing. The knee is immobilized at 90° of flexion for the first 4 weeks, then the brace is gradually unlocked by 10–15° each week until week 10, when full range of motion is restored. Patients remain non-weightbearing for the first 6–8 weeks while walking, though supervised exercise is allowed earlier. Early results are promising: at 12 weeks, 50% of participants showed an intact but thickened ACL (grade 1) on MRI. For context, grade 3 represents a complete rupture and grade 0 a normal ligament. This approach is still emerging and should only be pursued under the guidance of an orthopedic surgeon and a physical therapist, but it highlights the growing potential for ACL recovery without surgery.

What does Non-Operative Management look like?

Non-operative management will look extremely similar to the physical therapy someone would do after surgery. It includes the same focus on restoring strength, balance, coordination, and sport-specific movement. The only difference is that instead of recovering from a surgical procedure, you’re building the same stability and function through training alone. In both cases, a successful return to sport requires time, commitment, and structured progression.

Surgical Management of ACL Tears

ACL tears are most commonly treated with reconstruction, where a new ligament is created from donor tissue. In rare cases, if the tear occurs near the ligament’s attachment to bone, a repair may be performed by re-anchoring the torn end. Because reconstruction is overwhelmingly more common, this section will focus on that procedure.

Donor Options for ACL Reconstruction

There are four main graft choices for ACL reconstruction:

Bone–Patellar Tendon–Bone (BPTB)
Uses the middle third of the patellar tendon (just below the kneecap) along with small bone plugs from each end. This allows solid fixation but may cause kneeling pain or patellar tendon irritation.
Hamstring Tendon
Uses strands of hamstring tendon (often combined with a tendon from the inner thigh). This avoids bone removal but may result in some hamstring weakness.
Quadriceps Tendon
Taken from the tendon above the kneecap, sometimes with a small bone plug for fixation. This option is increasingly popular as a balance between strength and lower donor-site pain.
Allograft (Cadaver Tissue)
Donor tissue from a cadaver. Often chosen for revision surgeries or older patients with lower sport demands. It avoids harvesting from your own body but has a higher risk of graft failure in younger, high-level athletes.

Autografts (using your own tissue) are typically stronger and more common in younger athletes, though they do create some weakness or soreness at the harvest site. Graft choice depends on factors such as age, sport, prior surgeries, pain history, and surgeon preference.

Newer techniques like the BEAR® implant (Bridge-Enhanced ACL Repair) or additional procedures such as lateral extra-articular tenodesis (LET) may be considered in special cases. These options are still evolving and should be discussed with an orthopedic surgeon who specializes in ACL surgery.

Which Graft is the Best?

There is not strong evidence that supports one graft as being vastly superior, and the best choice depends on your own preferences, medical history (e.g. history of patellar tendon pain), and the surgeon’s preferences as well. However, for high level, competitive athletes, the bone-patellar tendon-bone graft is usually recommended due to its strong fixation and lower risk of graft elongation, which can be critical for returning to cutting and pivoting sports. Allografts do have the highest re-tear rates, so they are likely not the best choice for someone returning to a high level sport.

Graft Type	Source	Pros	Cons
Bone-Patellar Tendon -Bone (BPTB)	Middle third of your own patellar tendon	-Strong fixation -Used in high level athletes -Low failure rate	-Anterior knee pain -Pain with kneeling
Hamstring	Semitendinosus +/- gracilis tendon	-Smaller incision -Less post-op kneeling pain -Faster return of quadriceps strength	-Slower graft integration -Slightly higher risk of graft elongation -Possible hamstring weakness
Quadriceps	Top of quadriceps above the kneecap	-Strong, thick graft -Lower donor site pain than patellar	-Newer technique -Less long-term data in young athletes -Larger strength deficits
Allograft	Cadaver tissue	-No donor site pain -Shorter surgery -Quicker recovery during the early stage	-Higher failure rates in younger/active individuals -Rare chance of graft being absorbed

Why ACL Surgery Hurts

Even though ACL reconstruction is arthroscopic (minimally invasive), patients often experience significant pain and swelling. This happens because:

Tissue trauma: Small incisions and instrument manipulation inside the knee cause inflammation.
Graft harvesting: Taking tendon tissue from the patellar, hamstring, or quadriceps creates soreness in both the knee and donor site.
Bone tunnels: Drilling small tunnels in the femur and tibia to anchor the graft adds to discomfort.
Body’s healing response: Inflammation leads to swelling, warmth, and tenderness.

Most patients wake up with a knee brace and bandages and can usually begin walking with crutches as tolerated. Elevation, ice, and prescribed pain medications help manage discomfort. If other procedures (like a meniscus repair) were performed, weight-bearing or range of motion may be limited for several weeks.

Choosing a Pathway

Deciding on surgery can be a difficult choice, especially considering the cost, time commitment, and potential complications. Luckily, there are a few factors can may help in guiding your decision:

1. Presence of Recurrent Knee Instability

Frequent episodes of giving way or “buckling” during daily activities or sport.
Inability to control pivoting, cutting, or sudden directional changes.
Objective instability on physical exam (positive Lachman, pivot shift)
All these factors favor surgical management

2. Occupational and Sport Demands

High-demand sports requiring cutting, pivoting, or jumping (soccer, basketball, football, skiing) may favor surgery for return to pre-injury performance.
Occupations requiring full knee stability under load (military, firefighter, law enforcement, heavy labor) may also favor surgery.
Sedentary jobs and sports with lower need for cutting/pivoting (e.g. cycling, running, weight-lifting) may do better with non-surgical management

3. Associated Injuries

Meniscus tears (especially bucket-handle type) or cartilage damage may necessitate surgical intervention.
Multi-ligament injuries (ACL + MCL, PCL, or posterolateral corner) usually require reconstruction.
Chronic instability with secondary joint damage is a consideration for surgery.

4. Age and Activity Level

Younger, highly active patients are more likely to opt for surgery to protect the knee and resume sports.
Older or less active patients may successfully manage with structured rehabilitation alone.
Skeletally immature patients may require special surgical considerations.

5. Knee Function and Strength

Adequate quadriceps and hamstring strength, good neuromuscular control, and ability to perform dynamic movements without giving way can favor non-operative rehab.
Persistent weakness or functional deficits despite rehab may indicate need for reconstruction.

6. Psychological Readiness and Fear of Re-Injury

High fear, low confidence, or anxiety may slow rehab progress.
Patients seeking “security” or reassurance may lean toward reconstruction.
Motivation and willingness to adhere to rigorous rehab protocols are crucial in either pathway.

7. Timing and Lifestyle Considerations

Timing of the season in relation to the season is a huge factor for athletes
Lifestyle preferences, willingness to avoid surgery, or desire to minimize downtime may favor rehab.
Access to physical therapy and commitment to structured rehab is critical for non-operative success.

8. History of Prior Knee Injuries

Previous ACL tear in same or opposite knee
History of meniscus or cartilage surgery may influence decision-making.

9. Long-term Knee Health Considerations

Surgery may reduce instability episodes but doesn’t guarantee prevention of osteoarthritis.
Non-operative rehab can restore function but may carry higher risk of recurrent instability in high-demand activities.
Your personal medical history and risk-factors (e.g. previous injury history) will aid in making your decision.

10. Medical Comorbidities or Surgical Risk

Cardiovascular, metabolic, or other conditions that increase anesthesia or surgery risk may favor rehab
Contraindications to surgery make rehab the safer first-line approach.

Summary

Ultimately, the decision on how to manage your ACL injury depends on your knee stability, activity goals, other injuries, and personal preferences. Many people can do well with rehab alone, but surgery may be better for those with high-demand sports, instability, or complex knee injuries. Thankfully, if you are still unsure, you can always proceed with non-operative management, and then pivot to surgery at a later date if you are not happy with your progress.

Regardless of your choice, make sure you are working with a sports physical therapist who specializes in ACL recovery so you can safely rebuild strength and confidence in your knee. At Team Rally Sports PT, ACL recovery is our specialty, and you can call to schedule a free discovery call to see if we are the right fit for you as you start your ACL journey.

In part III, we will talk in depth about participating in “prehab” prior to ACL surgery, including pros and cons, what to expect, and how it impacts recovery after surgery.