How is a torn ACL treated? When does it need surgery?
The major decision in treating a torn ACL is whether the patient would benefit from surgery to repair the injury. The surgeon and the patient need to discuss the level of activity that was present before the injury, what the patient expects to do after the injury has healed, the general health of the patient, and whether the patient is willing to undertake significant physical therapy and rehabilitation required after an operation.
Nonsurgical treatment may be appropriate for less active patients, who do not participate in activities that require running, jumping, or pivoting, and who would be interested in physical therapy to return range of motion and strength to match the uninjured leg.
The International Knee Documentation Committee, a collaboration of American and European orthopedic surgeons, developed a questionnaire to standardize the activity level assessment of patients before and after surgery to help guide surgeons and patients to decide whether surgery would be helpful. The activity levels were as follows:
- Level I: jumping, pivoting, and hard cutting
- Level II: heavy manual work or side-to-side sports
- Level III: light manual work and noncutting sports like running and bicycling
- Level IV: sedentary lifestyle without sports
Surgical repair is recommended for those who wish to return to Level I and II activities. This is generally not an emergency and is undertaken after understanding all treatment options.
Young athletes may require surgical repair of the ACL because of the potential for knee instability and inability to return to their level of competition.
A non-surgical approach might be considered for patients who have level III and level IV lifestyles.
Those who are candidates for nonoperative treatment benefit from physical therapy and exercise rehabilitation to return strength to the leg and range of motion to the injured knee. Even then, some patients might benefit from arthroscopic surgery to address associated cartilage damage and to debride or trim arthritic bony changes within the knee. Recovery from this type of arthroscopic surgery is measured in weeks, not months.
If surgery is planned, there is usually a waiting period of a few weeks after the injury so that pre-habilitation can occur to strengthen the muscles that surround the knee. The waiting period also decreases the risk of developing excess scar formation around the knee (arthrofibrosis) that might restrict knee motion after the operation.
Surgery is usually planned to occur within five months of injury.
The anterior cruciate ligament can be reconstructed by an orthopedic surgeon using arthroscopic surgery. There are a variety of techniques, depending on the type of tear and what other injuries may be associated. The decision as to what surgical option is appropriate is individualized and tailored to a patient’s specific situation. Because of its blood supply and other technical factors, the torn ACL ends are not usually sewn together, and instead, a graft is used to replace the ACL. Often an autograft, tissue taken from the patient’s own body, is a piece of hamstring or patellar tendon that is used to reconstruct the ACL.
Research is ongoing about the potential role of biologic enhancements to surgical repair, using stem cells, platelet-rich plasma, and growth factors to help promote healing and ligament regeneration.
Rehabilitation physical therapy and exercise program are often suggested to strengthen the quadriceps and hamstrings before surgery. It may take six to nine months to return to full activity after surgery to reconstruct an ACL injury.
The first three weeks concentrate on gradually increasing knee range of motion in a controlled way. The new ligament needs time to heal and care is taken not to rip the graft. The goal is to have the knee capable of being fully extended and flexing to 90 degrees.
By week six, the knee should have a full range of motion and a stationary bicycle or stair-climber can be used to maintain the range of motion and begin strengthening exercises of the surrounding muscles.
The next four to six months are used to restore knee function to what it was before the injury. Strength, agility, and the ability to recognize the position of the knee are increased under the guidance of the physical therapist and surgeon. There is a balance between exercising too hard and not doing enough to rehabilitate the knee and the team approach of patient and therapist is useful.