The anterior cruciate ligament (ACL) is one of the many structures in the knee joint that aids in the stability of the knee joint throughout movement. Mainly preventing excessive anterior (forward) translation of the tibia (lower leg bone) on the femur (thigh bone), as well as rotational forces.
The ACL is commonly torn in athletes with the mechanism of injury occurring being non-contact with your foot planted and a sudden change in direction or rapid stopping, or contact with a direct below to the side of your knee. You may experience hearing or feeling a “pop” in addition to the sensation of lack of stability or “giving way.”
It is of popular opinion that if an ACL is ruptured the only option is surgery, due to the belief that the ACL cannot heal naturally. However, there has been a big shift with new evidence surfacing concluding that ACL full thickness tears can in fact heal with conservative management, with no adverse effect on return to play*, and improved patient outcomes.
Filbay and colleagues (2022) analysed the data from The Knee Anterior Cruciate Ligament Nonsurgical vs Surgical Treatment (KANON) randomised control trial where participants either had rehabilitation alone or an optional delayed ACL reconstruction (ACLR). All measures were taken at baseline, three and six months, and one, two, and five years.
At the 2-year follow-up, 16 out of 54 (30%) of rehabilitation plus optional delayed ACLR participants displayed evidence of ACL healing on MRI. Compared to MRI showing evidence of ACL healing of 53% of rehabilitation alone participants at the 2 year follow-up and 58% at the 5-year follow-up for the same group.
Better sport/recreational function and knee-related quality of life was reported 2 years after injury by participants with evidence of ACL healing compared with the non-healed, delayed ACLR, and early ACLR groups.
Another reason for the pathway of surgery was due to the theory that an ACLR prevented the development of osteoarthritis (OA), however it is now being suggested that ACLR could increase the risk of OA. A 20 year follow-up study found that there was no difference in knee OA between operative versus nonoperative groups. This study found that the operative group demonstrated greater knee stability however subjective and objective functional outcomes were poorer despite this (Yperen et al. 2018).
It is important to note that in this post we are talking strictly on ACL ruptures alone. Everyone’s experiences and circumstances differ in what additional structures may or may not be implicated and a holistic approach is necessary for you and your allied health team to collectively choose what option may be best for you.
If you would like more information feel free to get in contact with one of our physiotherapists or exercise physiologists. Alternatively, book in for your rehab journey that we would be delighted to be a part of!
*It is important to know that electing to have surgery is not a necessity for return to sport and does not necessarily prevent further knee damage when returning to sport.
References:
Filbay, S, Roemer, F-W, Lohmander, S, Turkiewicz, A, Roos, E-M, Frobell, R & Englund, M, 2022, ‘Evidence of ACL healing on MRI following ACL rupture treated with rehabilitation alone may be associated with better patient-reported outcomes: a secondary analysis from the KANON trial,’ BMJ Journals, vol. 57, no. 2, pp 91-99.
Yperen, D, Reijman, M, Es, E, Bierma-Zeinstra, S & Meuffels, D-E, 2018, ‘Twenty-year follow up study comparing operative versus nonoperative treatment of anterior cruciate ligament ruptures in high-level athletes’, The American Journal of Sports Medicine, vol. 46, no. 5, pp. 1129-1136.