You might take your strong, sturdy knee joints for granted until you have torn ACL symptoms. Stability of your knees depends on ligaments that attach to your shin.
Two main ligaments — the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) crisscross inside your knee to prevent excessive forward and backward movement of the joint, according to Wheeless' Textbook of Orthopaedics. Torn ACL symptoms can worsen if you continue to walk on your injured knee.
Walking on a torn ACL too soon after injury can increase pain and cause further damage to your ligament.
Torn ACL Symptoms
According to an article published in the September 2017 edition of Current Reviews in Musculoskeletal Medicine_,_ more than 200,000 ACL injuries occur in the United States every year. These injuries are typically caused by trauma and often occur during sports activities that require quick turning, jumping or sudden stops.
Torn ACL symptoms are similar to other soft-tissue injuries — pain, swelling, stiffness and an inability to put weight on the affected leg usually occur right after this injury. In addition, a complete ACL tear often causes an audible "pop" at the time of the injury, according to the Mayo Clinic.
Walking too soon after an ACL injury can make your symptoms worse. If your ligament is partially torn, walking on it could potentially further damage the ligament.
Initial treatment for ACL tears include resting from aggravating activities, applying ice for 10 to 15 minutes every few hours for the first few days after injury, wrapping your knee with a compression bandage to help reduce swelling and elevating your knee above your heart. You will likely need to use crutches to avoid putting weight on your injured leg.
Once your pain and swelling have decreased, your knee will continue to feel unstable if your ACL is completely torn — even if you don't play sports. Everyday tasks such as walking on uneven surfaces will likely be difficult, and your knee might "give out" on you.
Diagnosis and Treatment
Ligament tears are diagnosed clinically by orthopedic doctors. Magnetic resonance imaging (MRI) is typically used to determine the extent of the tear.
The majority of people affected by an ACL tear elect to have it surgically repaired — particularly if they have physically demanding jobs, or if they plan to continue to play sports. However, people who lead a more sedentary life might chose to manage their injury with physical therapy and modification of certain daily activities.
Surgical repair of a torn ACL involves reconstruction of the ligament, often using a tendon graft from the hamstrings on the back of the knee or the patellar tendon at the front of the knee, according to the Cleveland Clinic. Grafts can also be taken from cadaver tissue.
ACL reconstruction surgery is performed arthroscopically — a camera and other surgical instruments are inserted through several very small incisions in the front of the knee. After surgery, physical therapy is necessarily for optimal recovery.
Rehab After ACL Reconstruction
After ACL reconstruction surgery, it's vital that you follow your surgeon's protocol to allow your knee to heal properly. Doing the wrong type of exercise too soon after surgery can cause your graft to re-tear or stretch out.
A knee brace is typically worn for up to six weeks after surgery. Initially, the brace is locked to keep your knee in a fully-straight position. As your quadriceps muscles become stronger, your therapist will unlock the brace.
Immediately after surgery, you will walk with crutches until you can tolerate full weight on your leg within your pain tolerance. However, in some cases, weight bearing might be delayed, depending on the source of your graft.
Range of motion exercises begin within the first week after surgery. You will remove your brace and gently work on bending your knee. If your knee is not fully straight, stretching will be performed to restore this motion as quickly as possible to prevent permanent stiffness.
Around three weeks after surgery, gentle strengthening exercises — such as mini-squats, step-ups and bridges — are added to the workout routine. A stationary bike is often used to improve circulation and increase range of motion, without putting significant pressure on your knee joint. Balance exercises, such as standing on one leg, also begin in this phase, according to University of Wisconsin Sports Medicine.
Cardio exercises, such as swimming or using an elliptical machine, are initiated six week after surgery. Strengthening exercises are progressively increased within your pain tolerance with one exception — hamstring strengthening exercises are delayed until 12 weeks if you've had a hamstring graft.
Return to Sports
You might be anxious to get back to your sport after ACL reconstruction. However, it's important not to rush the process. Returning too early can lead to re-injury.
Sports-specific training can begin as early as 12 weeks after surgery, as part of your physical therapy program. A return-to-running program will be initiated, beginning with run/walk intervals.
According to the Ohio State University Wexner Medical Center, an initial schedule might consist of three sessions, with at least one day of rest between workouts. You might begin by running for one minute, followed by three minutes of walking, repeated two to four times. Over time, your running intervals become longer than your walking intervals, until you are able to run continually.
Return to sports also requires dynamic balance and agility training. For example, a plyometric, or jumping program, might include the following progression:
- Two-footed hopping in place
- Two-footed hopping forward/backward
- Two-footed hopping side to side
- Single leg hopping in place
- Single leg hopping forward/backward
- Single leg hopping side to side
It will likely be at least six months after surgery before you are released to play sports without restrictions, due to the high risk of re-injury after ACL reconstruction. According to an article published in the January-March 2015 issue of the journal Joints, full return to sport depends on many factors, including range of motion, lower extremity strength, balance and proprioception. Additional factors include the type of graft and the stability of the knee joint after surgery.
- Current Reviews in Musculoskeletal Medicine: "Non-Operative Care of the Patient With an ACL-Deficient Knee"
- Mayo Clinic: "ACL Injury"
- Cleveland Clinic: "Anterior Cruciate Ligament (ACL) Injuries: Management and Treatment"
- Ohio State University Wexner Medical Center: "Basic Return to Running Rehabilitation Guideline"
- Wheeless' Textbook of Orthopaedics: "Anatomy of ACL"
- Joints: "Return to Sport After ACL Reconstruction: How, When and Why? A Narrative Review of Current Evidence"