Can ACL Tear Heal on Its Own? An Explanation from OSC Bone Specialist

Can ACL Tear Heal on Its Own? An Explanation from OSC Bone Specialist

July 5, 2021

Doctor in Article:

Can ACL Tear Heal on Its Own? An Explanation from OSC Bone Specialist
Dr Gandhi Nathan Solayar

Can an ACL Tear Heal on Its Own? Here is an Explanation from OSC Bone Specialist

by Dr Gandhi Nathan Solayar FRCS (Tr&Orth)

Key Takeaways:

  • The short answer is NO (in the vast majority of cases)
  • ACL injuries are common, especially among those active in sports that involve pivoting and jumping (e.g., football, basketball, rugby, etc.).
  • The anterior cruciate ligament (ACL) plays a crucial role in maintaining the stability of the knee joint.

Can ACL Tear Really Heal by Its Own Without the Need of Surgery?

Over 800,000 ACL surgeries are performed by bone specialist doctors worldwide every year, and there is much interest in identifying the optimal way of treating patients with ACL injuries. The question here is: Can an ACL tear heal well without the need for surgery? In my view, the short answer is NO (in the vast majority of cases).


The Understanding of Torn Ligaments from Orthopedic Specialist

To understand the reason, we need to have a basic understanding of how torn ligaments heal. While the physiology of tissue recovery is complex, the basic chronology is as follows:

(1) a blood clot forms after initial bleeding;

(2) Inflammation occurs;

(3) new blood vessels form, which bring with it nutrients, new cells and oxygen required for healing;

(4) Fibrosis (scar tissue formation) occurs between the torn ends of the ligament;

(5) Over time, there is remodeling of the initial scar tissue into a structure similar to the ligament allowing it to resume its function – providing a stable connection between two bones.

When managing a ligament tear without surgery, it is vital that the limb is protected during the early phase – immobilizing it with a plaster cast or brace, for example – to prevent excessive movement, which would hinder proper recovery.

Good apposition (having both torn ends of the ligament close to each other) is also necessary during the crucial healing stage. Lack of proper apposition may result in elongation of the healed structure, thus negating its function as a restraining ligament.


What’s The Impact of ACL Tear?

In an ACL tear, however, there are a few factors that negatively impact the body’s innate ability for optimal recovery. In most cases, the ligament generally tears at its mid-point, which is mostly avascular – without a proper blood supply required for proper healing. The presence of joint fluid within the knee, which is vital for normal lubrication allowing movement, negatively affects the body’s capability of forming the ideal haematoma (blood clot).

A) Arthroscopic picture showing a torn ACL

A) Arthroscopic picture showing a torn ACL

B) The same patient showing the reconstructed ACL in the anatomical position

B) The same patient showing the reconstructed ACL in the anatomical position

Immobilizing the knee for long periods to treat an ACL tear without surgery (often for six weeks or more) in itself may cause other problems. With limited movement, the knee capsule tends to scar and stiffen, resulting in reduced movement – arthrofibrosis. Without adequate movement and use, the muscles around the knee – quadriceps, hamstrings, calf muscles – waste away, resulting in weakness and complicates the recovery.

Furthermore, most patients are also required to non-weight bear, i.e. avoid walking on the affected leg when in a cast. It slows overall recovery as proprioceptive feedback is curtailed. Proprioception is an essential concept in rehabilitation which, in basic terms, the body knows where the limb is in space. The lack of this crucial neuromuscular feedback impedes the patients’ normal walking (gait) pattern and may prolong their ability to return to their normal function.

The torn ACL ligament remnant left untreated can lead to other problems. The remnant stump (we sports surgeons and bone specialists refer to this as the “cyclops lesion”) may cause clicking and pain within the knee joint. In severe cases, even a locking phenomenon (meaning the inability of fully straightening the knee; my patients sometimes refer to this as the knee “jamming”). In the longer term, this results in worsening stiffness and loss of entire knee joint function.


C) Presence of a large “Cyclops” lesion in the knee joint

B) After removing the cyclops and reconstruction of the ACL

Apart from the ACL tear, it is common to have associated injuries to other components within the knee, namely the meniscus and cartilage. The meniscus is a vital structure that provides stability and ensures proper distribution of load-bearing within the knee joint (in laymen terms, it provides “suspension” to the knee). Damage to this structure is associated with early degeneration of the knee joint and as such, proper restoration of meniscal function is key in treating patients with these injuries. Unfortunately, with an ACL tear, the added instability results in shear forces which make meniscal healing difficult despite proper surgical repair and rehabilitation. In my practice, I am aggressive with meniscus injuries, and I believe that early restoration of this structure together with a stable knee (ACL reconstruction) significantly improves outcomes in my patients overall in terms of rehabilitation and return to function.

Understanding what happens biologically to a torn ACL, we turn our attention to management options available to us as orthopedic specialists and surgeons. Not all torn ACLs require surgery, and in my practice, patient selection is crucial to ensure the right person receives the appropriate treatment.


Non-Invasive Treatment for Torn Ligament: An Orthopedic Perspective

Another focus of evolving strategies in dealing with ACL injuries without surgery is the use of biologics – stem cell therapy, in particular. This subject has received a lot of headlines in recent years, and many patients often ask my opinion regarding this option. I share the view taken by many sports surgeons worldwide in that the evidence supporting its use is still insufficient to justify the costs involved.

There is a tendency towards an industry-driven bias in the current literature, while some impartial observers do not report significant differences with patients treated with these. While there may be a role of augmenting ACL reconstructive surgery with the use of biologics, I am keen on seeing what the future holds in this field, particularly in orthopedics. One, in particular, is the future role of exosomes which are stem cell signaling molecules. These may mimic the role of biologics with lower costs. However, research in this area is still ongoing.

There are certain exceptions where I would consider non-surgical treatment in dealing with an active patient following an ACL rupture. In some cases where there is only a partial tear (confirmed on an MRI scan) without any related injuries to the knee joint, I believe functional rehabilitation alone is the ideal solution.

Close follow-up of their recovery with the help of physiotherapy is important in ensuring a successful outcome. The patient should be counselled on the possibility of delayed surgery if conservative management fails.


ACL Tear Injuries in Children and Teenagers

Another crucial area where non-surgical methods may be preferable is in cases of ACL injuries in children and adolescents. In the pediatrics ACL injury, we commonly see avulsions (where the bone is fractured or pulled off from its footprint) instead of mid-ligament tears, which are frequent in adults. In special circumstances, children can be treated in casts/braces alone with close follow-up by the orthopedic specialist.

The presence of a growth plate (in young, growing bones) presents its own set of unique challenges to the surgeon when dealing with injuries around the knee joint. In my hands, if surgery is required, I tend to perform minimally invasive repairs in children, as opposed to graft replacements in adults, or a modified reconstruction that minimizes injury to the growth plate in young adolescents.


Verdict from Bone Specialist Doctor on ACL Tear Treatment

In my view, the decision on how to manage ACL tears cannot simply be grouped into either surgical or non-surgical methods. The overall decision must be based on the individuality of every patient that presents to me with this injury. A careful history focusing on the patients’ needs, demands, and expectations are crucial in deciding on an appropriate management strategy. Similarly, the MRI scan will also help identify other critical structures that may be damaged (meniscus, cartilage, other ligaments etc.)

A personalized treatment plan is my method of choice as a sports surgeon and a bone specialist doctor. Among my mostly sedentary, elderly, low-demand patients and with comorbidities (other significant medical problems), I would mainly opt for a non-surgical approach. Conversely, in a young active individual, high demand activities (sports) and with injuries to other structures (commonly the meniscus), I would strongly advise for ACL reconstructive surgery. In my practice (especially in my cohort of elite, high-level athletes), I would perform surgery early. I believe this accelerates the patient’s recovery by minimizing muscle loss and reducing the “down-time” in terms of the period away from sports and an overall happier patient.


Proper Rehab with Physiotherapy For Torn ACL

There have been studies evaluating the role of rehabilitation alone without surgery in dealing with patients following ACL tears. Some researchers suggest that rehabilitation and physiotherapy without surgery may give rise to similar outcomes compared to patients undergoing early or delayed ACL reconstruction in terms of patient outcomes and overall function. Conversely, there is a large body of data that suggest otherwise, with the return-to-sports and favorable patient-reported results following ACL reconstructive surgery. How do we make sense of this?

Regardless of the options, properly supervised rehabilitation and physiotherapy treatment should be performed, emphasizing gradual movement recovery, muscular strength, and a return to function. Good communication between the bone specialist doctor and the physiotherapist is essential in the recovery period, especially in avoiding re-injury, monitoring progress and determining the appropriate time of return to high-level activity (in cases of athletes).


Consult with Orthopedic Specialist Centre (OSC) For Better Understanding

In summary, an ACL tear does NOT heal optimally on its own due to the reasons mentioned above. However, this does not necessarily mean that all cases of ACL tears require surgery and that an individual approach to each case is vital in deciding which patients would benefit from ACL reconstructive surgery. That being said, ACL surgery is a good option for most patients with a high likelihood of returning to pre-injury levels of function. Proper counselling of one’s options with the treating orthopedic specialist would help determine the ideal method of managing this common injury. Good luck! Contact us here for more info.


About OSC:

Orthopaedic Specialist Centre (OSC) is the brainchild of four highly-experienced Malaysian orthopaedic specialists, who have come together to create an innovative centre of excellence purely focused on bone and joint care. Using their decades of experience in practice, they have embarked on a new mission for Malaysian orthopaedics. At OSC, the patient’s journey from treatment to recovery is accompanied by elevated levels of personalised expertise and empathy, in order to make a real difference to our patients’ lives. In contrast to large, faceless hospitals, OSC is a uniquely intimate medical boutique, one that puts meticulous, tailored care at the heart of the patient experience. OSC aims to redefine orthopaedic care in Malaysia, by making world-class treatment comfortable, cost-effective and attainable for the whole community. For more information, please visit