Injury to the anterior cruciate ligament (ACL) is a common sports-related injury that we often talk about in young, athletic people. However, with individuals continuing athletic activities into their 40s, 50s, and even later in life, the same injuries are occurring more and more in an older population.

The question comes up as to whether or not an ACL tear in someone over the age of 40 is the same as someone who is in high school or college-aged? Are the treatments the same? Are the results of surgical intervention the same? What should a grown adult who sustains an ACL tear do to ensure they can resume their active lifestyle?

An Aging ACL

As we get older, it is natural to both fight and ignore signs of aging. By keeping active, eating well, and living a healthy lifestyle, we can continue to perform many activities well into our middle and later years. However, despite our best efforts, our body still shows signs of aging. We are accustomed to many of these signs, including graying hair, wrinkles in the skin, or other aspects of aging we do our best to cover up.

But there are also signs of aging that we do not see, as well. Even the ligaments within our bodies will change as we get older. By the time we have reached the age of 40, just about everyone shows some chronic degenerative changes within their anterior cruciate ligament. Specifically, the fibers that make up the ligament become less organized and show signs of deterioration. The number of stem cells within the ACL decreases over time and the cellular activity within the ligament begins to diminish.

All of these characteristics are normal, but they do lead to important changes within the ligament. Because of this, it’s important to think of people in their 40s and beyond a little differently from how we might consider the ACL of a teenager or 20-something.

ACL Injuries in Adults

Much like injuries in adolescence and young adults, most ACL tears in the adult population occur during sporting or athletic activities. Injuries can also occur as a result of falls, work accidents, and motor vehicle collisions. Typical symptoms of an ACL tear include:

  • Pain in the affected knee
  • Swelling of the joint
  • Symptoms of instability/giving out of the knee

People who are suspected of having torn their ACL should be evaluated by a medical provider. Specific information about the nature of the injury and examination maneuvers can help to determine if the ACL is damaged.

Specific tests are performed to evaluate the stability of the knee joint. If there is concern for a possible ACL tear, most often an imaging test will be obtained to confirm the diagnosis. The best test to evaluate the ACL is typically an MRI. In addition, X-rays are recommended as people who are over the age of 40 can often have associated arthritis, which may impact treatment decisions. For that reason, X-rays are routinely obtained to evaluate the overall health of the joint.

Rule of Thirds

Not all ACL tears require the same treatment, and not all people who sustain an ACL tear will have the same symptoms. For these reasons, there may be options when it comes to determining the best treatment for you. One way to think about ACL tears and the right treatment is the so-called “rule of thirds.”

While not scientifically based, the rule of thirds can help separate different categories of people who may benefit from different types of treatment for ACL injuries. The rule of thirds consists of three categories of individuals who have sustained an ACL tear:

  • Copers: A coper is an individual who is able to resume their usual activity level after sustaining an ACL tear without any type of surgical intervention. These individuals may not experience symptoms of severe instability or they may not participate in activities that cause them symptoms of instability. Either way, they are able to perform all of their activities without any type of surgical intervention.Adapters: An adapter is an individual who sustains an ACL tear and ends up adjusting their activity levels so that they no longer experience symptoms of instability of the knee joint. For example, an adapter might be someone who injured their knee playing recreational soccer and was unable to return to soccer, but decided that riding a bicycle for exercise was good enough. While they did not resume their preinjury level of activity, they were able to adapt their activities to remain healthy and active.Noncopers: A non-coper is somebody who ends up requiring surgical intervention because their sensations of knee instability persist with their chosen activity level. They are unable to remain healthy and active because their symptoms of knee joint instability interfere with their preferred lifestyle.

The rule of thirds suggests that about a third of all people who sustain an ACL injury will be in each of these three categories. As stated, this is not scientifically researched, but it is a reasonable way to consider the various options for treatment. Thinking about which category you might fit into may help you determine the most appropriate treatment path.

For people who are in their 40s and older, adaptation may be much more palatable than for a high school athlete who is trying to return to their sport. By thinking through your goals and your symptoms, you can help determine which category best fits your situation. If you find yourself able to cope or able to adapt, then nonsurgical treatment might be all that you need. If you are unable to cope with your limitations, then a surgical intervention might be a necessary treatment.

Nonsurgical Management

The goals of nonsurgical management are twofold—first, to reduce swelling, pain, and inflammation. Second, and most importantly, is to restore normal function and optimize stability and strength of the knee joint. Nonsurgical management should not be confused with nontreatment. In fact, nonsurgical management requires a significant amount of time, effort, and motivation, in order to be most effective.

Restoring mobility and strength are fairly straightforward, but improving the function and proprioception of the knee joint are critical elements to optimizing the nonsurgical treatment of ACL injuries of the knee. Numerous strengthening programs have been suggested, although no single rehabilitation program has been determined to be superior. Programs should focus not only on strength of the quadriceps and hamstrings but overall core strength and stability.

Surgical Treatment

It used to be the case that ACL reconstruction surgery was reserved for young athletes, and people over the age of 40 years old were recommended to undergo nonsurgical treatment. However, improved surgical techniques, and higher expectations of athletes in their middle and later years has led to an increase in the number of surgical reconstructions being performed in people’s 40s and 50s, and even beyond.

Individuals in this age group considering ACL reconstruction should have minimal arthritis in their knee joint. If they have more extensive arthritis, then ACL reconstruction is generally not beneficial.

Surgical treatment of a torn ACL in someone in their middle-aged years is similar to the treatment in a younger population. Options for surgical treatment are similar, including options for choosing the type of graft used to reconstruct the torn ACL. In younger patients, a much more significant difference between the use of someone’s own tissue and donor tissue has been noticed, but that has not been found in people who undergo ACL reconstruction in their 40s and older.

Recent research has led to the recommendation that young patients in their teens and 20s have ACL reconstruction using their own tissue, rather than donor grafts, because of a lower graft failure rate and lower infection rate. However, in people older than 40 years old, donor tissue has not been associated with an increase in re-tears of the ACL. For that reason, most patients in their 40s and older will choose donor tissue when having their ACL reconstructed.

The results of ACL reconstruction in people older than 40 years old have generally been favorable. When compared to people who chose nonsurgical treatment, those who have had their ACL reconstruction surgically were found to perform more athletic activity and had less ongoing knee discomfort. The complications and risks associated with ACL reconstruction are similar to those seen in young patients.

Older Patients

ACL treatment has been well-studied in the young, athletic population. Treatments have been carefully evaluated in high school and college-aged athletes. However, there is little data to guide the treatment of people who are in their 40s, 50s, and beyond. With people continuing high-intensity athletic activities well into these decades, surgical intervention definitely plays a role, but finding that role has been difficult.

Controversies in how to best manage ACL treatment in this older population remain. We know that nonsurgical treatment is often effective, but many active patients are reluctant to consider a trial of nonsurgical intervention, potentially delaying definitive treatment. There is also controversy about how much arthritis in the knee joint is too much to consider ACL reconstruction.

We know that mild arthritis is generally well-tolerated, whereas advanced bone-on-bone arthritis is a contraindication for ACL reconstruction. However, what to do for people in the middle ground of moderate degenerative arthritis remains unclear. Finally, the extent to which arthritis may progress as a result of ACL injury, and possibly because of ACL surgery, is also unclear.

A Word From Verywell

Determining the ideal treatment for individuals in their 40s, 50s, and beyond may be a little different than for a high school or college-aged athlete. Factoring in athletic expectations, the extent of arthritis in the joint, and the rehabilitation following surgery may all be factors that influence the treatment decision. Talking through these issues with your healthcare provider can help to guide the best treatment for your situation.