This informative post was written by Olivia Huitson who was on placement with us in February 2025. At the time Olivia was a 3rd year physiotherapy student.
What is an Anterior Cruciate Ligament injury?
The anterior cruciate ligament (ACL) which is found in the knee, connects the thigh bone (femur) to the shinbone (tibia). An injury to this ligament occurs when it becomes stretched, partially torn or completely torn. After an ACL injury it is common to experience symptoms such as pain, a ‘cracking’ sound during the injury, instability of the knee, and swelling of the joint.
What is the Long-Term Impact of ACL Ruptures?
An ACL rupture isn’t just a short-term setback- it can have significant consequences years after the initial injury. Unfortunately, ACL ruptures can include increased risk of knee osteoarthritis, pain, reduced quality of life, and difficulty returning to previous activity levels, even with surgery. With these risks in mind, choosing the right treatment pathway is essential to ensure long-term knee health and function.
What are the objectives of ACL injury management?
There are many goals when it comes to the management of ACL injuries and can differ from patient-to-patient. However, there are primary goals that should be at the forefront of all ACL rehab plans including
- Restoring knee function- improving stability, strength, and movement control
- Addressing psychological barriers- helping individuals regain confidence in their knee and reduce fear of re-injury
- Preventing further injury- reducing the likelihood of secondary damage, such as meniscal or cartilage injuries
- Reducing the risk of future osteoarthritis- maintain knee joint health
- Optimising long-term quality of life- enabling individuals to return to their desired level of activity, wether that’s sport, work, or daily life
What does conservative management involve?
The conservative management of ACL injuries involves a structured rehab plan without immediate surgery. The first key component to expect is strength training. This is aimed to strengthen the muscles surrounding the knee called the quadriceps, hamstrings and glutes to compensate for the injured ACL and improve the overall stability of the knee. Neuromuscular training is then included to enhance balance, coordination, and movement patterns to reduce stress on the knee joint. The activities that are normally performed by the patient will then be modified such as making adjustments to sports to protect the knee while maintaining baseline fitness. In some cases, bracing can be used to provide additional knee support, particularly in the early stages of rehab.
So, how effective is conservative management?
Recent research has shown promising results for non-surgical treatment of ACL injuries.
A prospective cohort study found that starting non-operative treatment within four weeks of injury led to 91% of patients achieving low-grade ligament laxity and good knee stability. Those who began treatment with two weeks had even better outcomes.
The KANON trail, a high-quality randomised controlled study, found no significant difference in self-reported knee function between those who underwent early ACL surgery and those who followed structured rehabilitation with the option for delayed surgery.
Some studies suggest that at least 30% of individuals with ACL tears may show signs of natural ACL healing when following a high-quality rehabilitation program. This figure increases to 53% when excluding those who later chose to have ACL surgery.
Put simply, these findings indicate that surgery is not always necessary, and many people can achieve excellent recovery through physiotherapy-led rehabilitation alone.
The Cross Bracing Protocol: A New Approach to ACL Healing?
One emerging non-surgical treatment option is the Cross Bracing Protocol, developed by Dr Merv Cross. This approach aims to encourage ACL healing by holding the knee in a flexed position (90 degrees) for four weeks using a specialised knee brace. The rationale is that keeping the torn ACL fibres close together may promote natural tissue healing.
What is the process of bracing?
Step one: A knee brace is applied within the first 10 days after injury to immobilise the knee at 90 degrees.
Step two: For the first 4 weeks, the knee remains in this position 24/7 to allow the ACL fibres to reconnect.
Step three: After 4 weeks, the brace is gradually adjusted to allow increasing range of motion while maintains stability.
The protocol follows well-established orthapedic principles of tissue healing (reduction and mobilisation), similar to how broken bones are managed with casting. While research on this approach is still developing, it offers an exciting potential alternative to ACL surgery for select individuals.
Key takeaways
- ACL tears do not always require surgery! Many individuals can recover well with structured rehabilitation.
- Starting physiotherapy early (within the first two to four weeks) leads to better outcomes.
- High-quality rehabilitation can promote ACL healing in some cases and restore knee function effectively.
- The Cross Bracing Protocol is an emerging non-surgical approach that may further enhance healing.
- A personalised approach is essential- some people may still require surgery depending on their lifestyle, knee stability and personal goals.
Need help recovering from an ACL injury?
Here at North Yorkshire Physiotherapy we pride ourselves in delivering evidence-based ACL rehabilitation and can help guide you toward the best treatment plan for your needs. If you’ve recently suffered an ACL injury or are considering your options, book an appointment with us today to discuss your recovery pathway!