The anterior cruciate ligament (ACL) is one of two cruciate ligaments in the knee and the most commonly injured knee ligament. ACL injuries occur predominantly in pivoting sports and in motor vehicle trauma. Once torn, the ACL does not heal, and the knee becomes unstable during activities that require pivoting, cutting, jumping, or landing. Dr. Chudik has developed arthroscopic techniques for pediatric and revision ACL reconstruction that are used by surgeons internationally.
What Is an ACL Injury?
The ACL is a rope-like ligament composed of strong collagen fibers that connects the femur (thigh bone) to the tibia (leg bone) inside the knee. It sits in the intercondylar notch and crosses the posterior cruciate ligament (PCL), forming an X-shape that keeps the tibia from sliding forward on the femur and controls rotational stability during sport-specific movements.
ACL injuries range from partial tears (grade 1 and 2) to complete tears (grade 3). Complete tears are the most common pattern in sports and are the typical indication for surgical reconstruction. About 50 percent of complete ACL tears are accompanied by an associated meniscus tear, and 10 to 20 percent involve additional ligament injury. The prognosis and recovery plan depend as much on these associated injuries as on the ACL itself.
Causes and Risk Factors
- Non-contact pivoting injuries during sport, especially with the knee in slight flexion and valgus (the most common mechanism)
- Direct contact to the knee with the foot planted
- Landing from a jump with poor knee mechanics
- Female athletes at higher risk than male athletes in the same sport, attributed to neuromuscular, anatomic, and hormonal factors
- Participation in high-risk sports such as soccer, basketball, football, skiing, lacrosse, and volleyball
- Prior knee injury, including a prior ACL tear on either side
Symptoms
- An audible pop at the time of injury
- Immediate swelling from bleeding into the joint (hemarthrosis), typically within the first few hours
- Inability to continue the activity at the time of injury
- Instability or giving-way with subsequent pivoting, cutting, or stair descent
- Pain varies, with some patients having minimal pain after the initial injury
Diagnosis
Dr. Chudik’s evaluation begins with the mechanism of injury and a detailed history. Physical examination includes the Lachman test (the most sensitive), the pivot shift test (which reproduces the instability pattern), and the anterior drawer test. Associated meniscus and ligament testing is always performed. X-rays rule out associated fractures, including the Segond fracture (a small avulsion of the lateral tibial plateau often associated with ACL tears). MRI confirms the ACL tear and characterizes associated injuries to the meniscus, cartilage, and other ligaments. The Westmont office has on-site high-field MRI and X-ray.
Treatment
Non-surgical treatment is reasonable for partial tears, for patients willing to modify activity to avoid pivoting sports, and for lower-demand patients who do not require full knee stability for their lifestyle. It involves a targeted physical therapy program for quadriceps and hamstring strengthening, neuromuscular retraining, and activity modification.
Surgical reconstruction is recommended for complete tears in active patients who want to return to pivoting sport, manual labor, or an active lifestyle. Dr. Chudik performs arthroscopic anatomic ACL reconstruction, replacing the torn ligament with a tendon graft (patellar tendon, quadriceps tendon, or hamstring tendon) placed in the native ACL footprints on the femur and tibia. Associated meniscus tears are repaired or trimmed at the same procedure when indicated.
Dr. Chudik has also developed:
- Arthroscopic Pediatric Growth-Plate-Sparing ACL Reconstruction for skeletally immature athletes, a technique used by surgeons internationally
- Arthroscopic Revision ACL Reconstruction for failed prior ACL surgeries
Recovery and Outcomes
Recovery after ACL reconstruction typically includes early motion beginning immediately after surgery, weight-bearing as tolerated within the first week, progressive strengthening and neuromuscular training over three to six months, and return to sport after objective return-to-play testing at six to nine months. Dr. Chudik uses an objective return-to-sport testing protocol to confirm readiness rather than relying on time alone.
Outcomes are very good in appropriately selected patients, with the majority returning to pre-injury sport. Factors that affect outcome include associated injuries, graft choice, surgical precision, and rehabilitation adherence.
When to See Dr. Chudik
Schedule an evaluation after any knee injury with a pop, immediate swelling, or sense of instability, or if prior ACL treatment has not restored confidence in the knee. Call 630-324-0402 or request an appointment online.