ACL Injuries Non-Surgical Treatment

The decision between nonoperative and surgical treatment depends on how the knee behaves, what the patient wants to return to, and whether other structures in the knee were injured. Nonoperative treatment may be appropriate for patients who:

• Have lower physical demands: Patients whose activities are primarily straight-line, such as walking, cycling, swimming, jogging, or weight training, often do well without an ACL.
• Do not experience instability in daily life: A knee that does not buckle during routine activities after the initial swelling resolves is more likely to function well with rehabilitation.
• Are willing to modify activities: Avoiding or limiting sports that require cutting, pivoting, and jumping lowers the risk of further injury.
• Have no associated injuries requiring surgery: A repairable meniscus tear, a displaced tear causing locking, or injury to multiple ligaments generally favors surgical treatment.
• Have a partial ACL tear: Some partial tears leave enough intact ligament to keep the knee stable and can be managed with rehabilitation alone.

Nonoperative treatment is generally not recommended for skeletally immature children and adolescents who wish to stay active in sports, as an unstable knee in this age group carries a high rate of subsequent meniscus and cartilage injury. In these patients, Dr. Rynecki Baker will discuss growth plate–sparing surgical options.

High-quality research supports rehabilitation as a reasonable first step for select patients. The KANON trial, a randomized study of adults with acute ACL tears, compared early reconstruction with a structured rehabilitation program that allowed delayed reconstruction if needed. Roughly half of the patients in the rehabilitation group never required surgery. The patients who did poorly with rehabilitation tended to be those with ongoing instability. Each episode of giving way puts the meniscus and cartilage at risk, and a knee that repeatedly buckles is at higher risk of developing arthritis. This is why careful patient selection and close follow-up are central to Dr. Rynecki Baker’s approach.

Nonoperative treatment is an active process, not simply rest. It is carried out with a physical therapist and progresses through several phases:

Calming the knee

In the first weeks after injury, the focus is on reducing swelling, restoring full knee extension, regaining motion, and reactivating the quadriceps. Ice, compression, elevation, and a short period of crutches may be used, and neuromuscular electrical stimulation can help the quadriceps fire again.

Rebuilding strength

Progressive strengthening of the quadriceps, hamstrings, hips, and core is the foundation of a stable knee. Strong hamstrings in particular help resist the forward sliding of the tibia that the ACL normally prevents.

Neuromuscular and perturbation training

Balance, agility, and perturbation exercises, in which the therapist introduces unexpected shifts to a standing surface, train the muscles around the knee to react quickly and protect the joint. This type of training helps the body compensate for the missing ligament.

Functional testing and return to activity

Before returning to more demanding activities, patients complete objective testing, including quadriceps and hamstring strength comparisons with the uninjured leg, single-leg hop tests, and validated questionnaires. Patients who meet these benchmarks and have no episodes of giving way are more likely to succeed without surgery.

A functional ACL brace may give some patients added confidence during activity, although bracing alone does not restore normal knee stability and does not replace strengthening and neuromuscular training. Dr. Rynecki Baker will discuss whether a brace makes sense for your activities.

Choosing nonoperative treatment is not a permanent decision. Dr. Rynecki Baker follows patients closely during rehabilitation and afterward. Reconstruction may be recommended if a patient:

• Continues to experience giving way or instability despite completing rehabilitation
• Develops locking, catching, or new pain suggesting a meniscus tear
• Decides to return to cutting, pivoting, or contact sports
• Is unable to meet the strength and functional benchmarks needed for safe activity

Delayed reconstruction can produce excellent results, particularly when it is performed before repeated instability has damaged the meniscus and cartilage. The goal is always to protect the long-term health of the knee.