Signs of an ACL Tear
ACL injuries usually happen in a single moment, and how that moment unfolded is an important part of the diagnosis.
A pivot, cut, or awkward landing
Often a non-contact injury with the foot planted as the knee twists or buckles.
A pop, then swelling
Many patients feel or hear a pop. Swelling typically develops within the first several hours.
The knee gives way
Once swelling settles, the knee may feel unstable or shift with pivoting, cutting, or stairs.
Meniscus or other ligaments
A meniscus tear, cartilage injury, or MCL sprain can occur at the same time.
What Shapes ACL Treatment
There is no single plan for every ACL tear. These factors guide the recommendation.
Athletes returning to sports such as soccer, basketball, football, or lacrosse are commonly evaluated for ACL reconstruction.
ACL reconstruction →Nonoperative PathLower-Demand ActivitiesSome patients who do not pivot or cut do well with rehabilitation and activity modification.
Treatment options →Young AthletesGrowing AthletesOpen growth plates change how ACL treatment is planned in children and adolescents.
Youth sports guide →Combined InjuryACL Plus Meniscus TearA meniscus tear with an ACL tear can influence the timing and type of surgery.
Meniscus tear guide →Knee SurgeryOther Knee InjuriesLigament, tendon, and kneecap injuries evaluated as part of comprehensive knee care.
Knee surgery overview →RecoveryACL Recovery TimelineMilestone-based rehabilitation through return-to-sport testing.
Recovery guide →A Measured, Conservative-First Approach
Every ACL plan starts with the knee you have and the activities you want to return to.
Accurate Diagnosis
Ligament stability testing, a check of the meniscus and other ligaments, and imaging to confirm the injury.
Restore the Knee First
Therapy begins by reducing swelling and regaining motion and quadriceps strength, whether or not surgery follows.
Surgery When Indicated
ACL reconstruction is considered for athletes in pivoting sports, recurrent giving way, or a combined injury that favors surgery.
Criteria-Based Return
Return to sport is guided by strength, motion, and functional testing rather than the calendar alone.
What to Expect at Your Evaluation
Your first visit is focused on understanding the problem and outlining clear options.
How the injury happened, whether you felt a pop, how quickly swelling appeared, and whether the knee has given way since.
X-rays are obtained to check for a fracture. MRI confirms an ACL tear and shows the meniscus, cartilage, and other ligaments.
Findings and options are explained in plain language, with time for your questions.
When to Have a Possible ACL Tear Evaluated
- A pop with swelling after a pivot or landing
- The knee giving way during activity
- Swelling that develops within hours of an injury
- Difficulty returning to sport after a knee injury
- New instability after a prior ACL injury
From Conservative Care to Surgical Options
Treatment is matched to your knee and your goals. Each surgical option is discussed along with its expected recovery.
Nonoperative Treatment
- Physical therapy to restore motion and quadriceps strength
- Neuromuscular and balance training
- Activity modification
- Bracing when indicated
This page is educational and does not replace an individual evaluation. Recovery varies with the procedure and healing; see the ACL surgery recovery timeline.
Read More Before Your Visit
In-depth guides written to help you understand your diagnosis and recovery.
Frequently Asked Questions
Often, yes. Many people can walk once the first swelling settles, but the knee may give way with pivoting, cutting, or quick changes of direction. Being able to walk does not rule out an ACL tear.
No. Some patients who do not take part in pivoting or cutting activities do well with rehabilitation and activity modification. ACL reconstruction is commonly considered for athletes who want to return to pivoting sports, for recurrent giving way, or when other injuries in the knee favor surgery.
An evaluation soon after the injury helps confirm the diagnosis, check for meniscus and other ligament injuries, and start therapy to restore motion and strength. Please ask about current appointment availability when you call.
ACL reconstruction replaces the torn ligament with a graft. ACL repair with internal brace reattaches the patient’s own ligament and is an option only in selected acute tears. Which approach fits depends on the tear pattern and timing.
Return to sport is based on strength, motion, and functional testing rather than a set date. The ACL surgery recovery timeline on this site outlines the phases.
Call (484) 526-1735 during office hours or schedule online through St. Luke’s. Please ask about current appointment availability when you call.
Referral requirements vary by insurance plan. Many plans allow direct access to orthopedic specialists, while others require a referral from your primary care physician. Office staff can verify your plan’s requirements when you call to schedule.
Questions About a Possible ACL Tear?
Visits are at 153 Brodhead Road, Rear Entrance, Bethlehem, PA 18017, for patients from Bethlehem, Allentown, and across the Lehigh Valley.
Schedule Online at St. Luke’sCall (484) 526-1735