What is an ACL injury?
An ACL injury is a tear or sprain of the anterior cruciate ligament (ACL) one of the major ligaments in your knee. ACL injuries most commonly occur during sports that involve sudden stops or changes in direction, jumping, and landings.
- downhill skiing
- A loud “pop” or a “popping” sensation in the knee
- Severe pain and inability to continue the activity
- Rapid swelling
- Loss of range of motion
- A feeling of instability or “giving way” with weight-bearing
How to diagnose an ACL injury
During the physical exam, your doctor will check your knee for swelling and tenderness. They may also move your knee into a variety of positions to assess the range of motion and overall function of the joint.
Usually, an examination for an ACL tear can’t be diagnosed with a physical exam alone to determine the severity of the injury. These tests may include:
ACL Injury pre-disposing factors
Like with any injury, it cannot be blamed on one thing. Injuries are multi-factorial as well as non-preventable. Injuries will always happen. The only thing that we can do is to decrease the frequency or incidence of them. Luckily, as we continue to learn more about the mechanism of injury, we have developed some strategies to reduce your chance of ACL injuries.
ACL Case study
Hewett et al after screening 205 female collegiate athletes with a drop-jump task, 9 athletes went on to suffer an ACL injury during the following season. The 9 athletes in this study had several important factors in common in comparison to those who did not suffer an injury:
• Knee abduction angle at landing was 8° or greater
• Knee abduction moment was 2.5 times greater
• Ground reaction force was 20% higher
• Female athletes – 4-5 x more likely to tear an ACL compared to their male counterparts.
Looking at the data
A case series of elite collegiate athletes who suffered ACL injuries prior to and during their college careers continually found difficulty returning to sports participation (Kamath et al., 2014). Of the 35 athletes who had undergone ACLR prior to enrollment in college, the rate of re-operation on the involved limb was 51.4%, the rate of re-rupture of the ACL graft was 17.4%, and the contralateral ACL rupture was 20.0% within this population of athletes. Similarly, those who underwent ACLR during college had a 20.4% re-operation rate, 1.9% suffered re-rupture of the ACL graft, and 11.1% of these athletes underwent ACLR on the contralateral limb.
Unfortunately, these findings are not isolated to collegiate athletes; professional (Busfield et al., 2009) and high school athletes (McCullough et al., 2012) alike have similar statistics. Considering these numbers, it points to inadequate or premature return to athletic participation, which may be because we are overlooking important aspects of athletic competition.
Treatment for an ACL injury
Medical treatment for an ACL injury begins with several weeks of rehabilitation. A physical therapist will create a plan depending on your ACL injury. They will teach you how to do exercises on your own as well as provide a brace and crutches to help with stability. The goal of rehabilitation is to reduce pain and swelling, restore your knee’s full range of motion, and strengthen muscles.
Your doctor may recommend surgery if:
- You’re an athlete and want to continue in your sport
- More than one ligament in your knee is also injured
- The injury is causing your knee to buckle during everyday activities
Returning to your sport after an ACL injury
The decision of an athlete returning to the sport should be a collaborative effort between the athlete, parents, coach, and surgeon. Athletes tend to get antsy when return to sports discussions start occurring. Over the many years of testing athletes, we have seen that this collaboration is crucial in the return to sport decision. RTS decisions should be based on objective performance testing criteria that must be met by the athlete.
We have recently updated our ACL Return to Sport (RTS) Exam that takes the athlete through research-based physical and functional testing items that have high specificity. The rules of this exam are: Athletes must be 9 months post-op to be eligible, Surgeons must sign off on the exam, and every test item needs to be a “Yes” to be considered a “Pass”.
The decision to return an athlete before 9 months may be an aggressive move that could be costly in the end. The time component for optimal grafting is a significant consideration in the RTS decision. Through communications with orthopedic surgeon experts, sophisticated protocols, and research, 9 months post-op for safe return to sport is a minimum time requirement and is based on the extent of damage as well as tissue quality.
The RTS decision should rely minimally on subjective eyeballing and alternatively rely more heavily on objective physical and functional testing criteria. These objective criteria will likely expose concerns with the ACLR knee. Before functional testing occurs on the RTS Exam, a fatigue protocol should not be overlooked in creating a realistic environment for analysis. Equally important in the RTS decision is the collaboration of the DPT, Surgeon, Athlete, Coach, and Parent.
Failing to follow a criteria-based exam for RTS could lead to what Grindem et al found in their research. In summary of those findings, of the athletes that did not meet the specific objective criteria, 38% of them re-tore their ACL.
Please email firstname.lastname@example.org or call us at any of our 6 Magic Valley locations with any questions you may have regarding ACL rehabilitation and return to sport decision making. We look forward to collaborating with you in helping your athletes return safely and swiftly to their sport.