When does an ACL tear need physiotherapy vs surgery?

Anterior Cruciate Ligament (ACL) tears are a common injury among individuals in their teens or early adulthood. They most often occur as a result of a non-contact pivoting or twisting injury. When the injury happens it is usually very apparent. Patients will feel or hear a ‘pop’ inside their knee and this will be accompanied by a pretty rapid onset of swelling or fluid buildup. What happens from here is that most patients will have an encounter with the healthcare system where individuals are told to start some physiotherapy and see a surgeon for a consultation.

Do I need surgery after an ACL tear?

So the questions arises: is surgery needed after an ACL tear? Which patients should be treated with physiotherapy? The answer is, it depends.

Initially, all patients with an ACL tear need physiotherapy. Even if surgery is a possible downstream scenario, patients will only be considered eligible for surgery once the swelling in the knee has been minimized, the muscles around the knee (i.e. the quadriceps) have been strengthened, and there is full range of motion. In the absence of more complex injuries (like displaced meniscus tears or other associated ligamentous injuries), this can take anywhere from 3-6 weeks.

After this initial period of recovery and rehabilitation following ACL injury, the decision making process of whether or not surgery is needed comes into play. If patients can modify their activities and rehabilitate to an extent (usually after 3-6 months) where their knee does not give way, then ongoing nonoperative care is suitable. This may involve the use of a custom ACL brace for pivoting and twisting activities. When patients have persistent knee instability despite appropriate neuromuscular rehabilitation or if their work/sports/recreational activities necessitate pivoting, twisting, acceleration and deceleration movement patterns, then surgery can be considered.

Based on the above, it is clear that surgery is required for patients who are symptomatic (with instability) despite an initial period of rehab. For patients who are competitive athletes, early surgical management is often suggested to obviate the risk of knee instability and secondary damage to other structures in the knee.

What will happen to my knee in the future?

Another question that patients often ask is “what will happen to my knee in the future?” This is a difficult question to answer. However, it is well known that a proportion patients with ACL tears develop osteoarthritis. Surgery does not in and of itself change this risk. The key element is that ongoing knee instability that can cause secondary damage to meniscus and cartilage. Reinjury becomes the main culprit and the risk of this needs to be minimized. So whether physiotherapy alone can prevent this or surgery is required, the important part is that patients should be able to pursue a life of activity and meaningful endeavours without symptoms.

Fore more information on how ACL surgery is performed and on ACL post-operative rehabilitation, please refer to Therapia Videos.