An ACL and MCL tear can sound like a two-surgery problem, but it isn’t always. The MCL has more healing potential than the ACL, so some combined injuries can be treated with bracing and rehabilitation for the MCL while the ACL gets its own treatment plan.
At Jonathan L. Glashow, MD Orthopedic Surgery & Sports Medicine on the Upper East Side, we’ll look at how each ligament was injured and how stable your knee feels before recommending surgery.
Why Can the ACL and MCL Tear at the Same Time?
Your ACL helps control front-to-back and rotational stability inside the knee. The MCL supports the inner side of the joint. A force that drives the knee inward while it twists, such as a collision, awkward landing, or skiing injury, can damage both.
With a combined ACL and MCL injury, knowing both ligaments are torn only tells part of the story. We also need to know how loose the knee is, where the MCL tore, whether motion is coming back, and whether the meniscus, cartilage, or another ligament was injured.
Why Doesn’t Every MCL Tear Need Surgery?
Lower-grade MCL injuries often heal without an operation. A 2025 review of combined ACL-MCL injuries explains that grade I and II MCL tears are commonly managed nonsurgically while ACL treatment depends on instability, activity demands, and the injury pattern.
For an athlete or active adult, that can mean wearing a brace, rebuilding motion and strength, and giving the MCL time to heal. Even with two injured ligaments, the MCL may regain enough stability without surgery.
When Could Both Ligaments Need Surgical Treatment?
A complete MCL tear deserves a closer look, especially when the inner side of the knee remains loose. Consensus guidance on combined ACL-MCL injuries also emphasizes tear location, persistent instability, and the overall injury pattern when deciding whether to operate on the MCL.
We may discuss MCL repair surgery or reconstruction when:
- A complete MCL tear leaves substantial medial instability
- The MCL has pulled away from its attachment in a pattern that may not heal reliably
- The knee stays loose after bracing and rehabilitation
- Other ligament damage makes the knee unstable in more than one direction
Persistent MCL instability can place more stress on an ACL reconstruction, so the medial side of the knee needs careful evaluation before the surgical plan is set.
How Do We Decide What Your Knee Needs?
We’ll examine ACL and MCL stability, range of motion, swelling, and tenderness. MRI can show the tear pattern and associated injuries, but your exam and how the knee functions are just as important.
When the MCL isn’t regaining dependable stability, we may discuss MCL repair surgery or reconstruction based on the tear pattern and tissue quality. If it’s healing well, treatment may focus on the ACL instead of operating on both ligaments.
Dr. Jonathan L. Glashow is a board-certified orthopedic surgeon and Clinical Associate Professor at NYU Grossman School of Medicine who specializes in sports orthopedic surgery.
Schedule an ACL and MCL Evaluation in NYC
If you’ve been diagnosed with an ACL and MCL tear, you deserve to know what each injury means before committing to surgery. Schedule an evaluation at our Upper East Side practice. We’ll explain what your exam and imaging show and whether your treatment should include MCL repair in NYC along with ACL treatment.
