Post-operative Physiotherapy Previous Cruciate Ligament (ACL) Reconstruction


Knee anatomy and biomechanics

The knee joint is classified as a modified trochlear joint, located between two bones: the femur and the tibia. This joint allows for flexion and extension, as well as a small rotation of the leg. 12

It consists of the “connection” between two joints: one between the femur and the tibia and whose main function is to support body weight, whilst the joint between the kneecap and the femur promotes frictionless movement. 1

The Anterior Cruciate Ligament (ACL) is one of the ligaments that produces stability, restricting anterior slippage of the tibia over the femur and preventing hyperextension. 11

Injury mechanism and evaluation

Knee injuries are amongst the most frequent problems of the musculoskeletal system. In 9% of cases, there is damage to one or more ligaments and the Anterior Cruciate Ligament is the most injured. Since the ACL is a primary stabiliser of the knee, a rupture can lead to functional instability 6 and an increased risk of degeneration of the joint cartilage.5

There are several tools available to the Healthcare Professional to correctly assess the existence of a rupture, for example: 4

  1. Patient history

A rupture of the ACL should be suspected from the moment the patient claims that at some point they have performed a acceleration/deceleration mechanism (walking or running) in conjunction with a knee valgus. As a background, it should be verified if there is a type of degenerative injury that may have “dragged on” for some years.

  1. Clinical examination

There are several specific tests to detect an ACL rupture, including the Lachman Test and the Anterior Drawer Test.

  1. Magnetic Resonance Imaging

This examination is usually performed when there is difficulty in undertaking the physical examinations or where there is some doubt in the medical diagnosis.

The incidence of knee injuries in a period after 5 years after surgery is 17% in patients under 18 years of age and 7% in people between 18 and 25 years of age.10

subtitle: 1. previous drawer test8 2. LachmanTest8 3. magnetic resonance7

Surgery and post-surgical

There are two major methods of ligamentoplasty. The type of graft that has been used for the most time is the patellar tendon (bone – tendon – bone), which offers a greater stability of the joint – although there are not enough studies to prove this – and hamstring tendon grafts are also used. 2

After surgery, muscle weakness and atrophy (mainly of the quadriceps) are usually observed (when compared to the contra lateral limb) and, consequently, the knee functions are affected. Although the anterior cruciate ligamentoplasty offers a greater stability to the knee, the muscle strength necessary to extend the knee will be affected – differences being notices between the 2 lower limbs in the first weeks. In a period of 1 to 6 years, a weakness between 6% and 18% may occur. 9

For these reasons, it is important that rehabilitation takes place and it is crucial that the treatment includes exercises involving movement, balance, and proprioception, in open and closed kinetic chains. 10


Individual treatment plans should always be developed for each patient because several factors may have influenced the condition of the individual, such as a graft revascularisation and the techniques to fix it.3

The rehabilitation programme should, however, respect certain objectives in order to achieve a more favourable outcome:

  1. Range of Motion – it is important to try and obtain as much range as possible soon after surgery to maintain good knee mobility and avoid increased cartilage stress.
  2. Body Weight Support – it is important to adapt the knee to the weight of the patient, with gradual increase of the load applied, in order that it is not overloaded.
  3. Muscular Strengthening – one of the main objectives of treatments is to re-establish control of the quadriceps and strengthen them, using mainly neuromuscular electrical stimulation and exercise protocols.
  4. Neuromuscular/Proprioceptive Training – after surgery, there is a change in the notion of the person’s body, in relation to its centre of gravity and support base. For this reason, it is important to perform a program of dynamic exercises that promote balance.

Rehabilitation of an Anterior Cruciate Ligament injury is usually a lengthy and extremely demanding process. It should be multidisciplinary, with all health professionals involved working as a team in decision making during the rehabilitation (from the Surgeon, Physiatrist or Sports Medicine Doctor and the Physiotherapist and, also for discharge. It is, therefore, important to understand that the adoption of the strategies proposed here aim to correspond to the objectives of the person, being these specific not only for the purpose for which they are proposed, but also for the person themselves and their aspirations to continue physical activity after injury.

Adapted from the original:

1. Abulhasan, J. F., Michael J. Grey, M. J. (2017). Anatomy and Physiology of Knee Stability. Journal of Functional Morphology and Kinesiologia 2(3).


2. Biau, D. J., Tournoux, C., Katsahian, S., Schranz, P. J., Nizard, R. S. (2006). Bone-patellar tendon-bone autografts versus hamstring autografts for reconstruction of anterior cruciate ligament: meta-analysis. BMJ


3. Cavanaugh, J. T., Powers, M. (2017). ACL Rehabilitation Progression: Where Are We Now? Curr Rev Musculoskelet Medicine 10, 289–296


4. Filbay S. R., Grindem, H. Evidence-based recommendations for the management of anterior cruciate ligament (ACL) rupture. Best Practice & Research Clinical Rheumatology.


5. Frobell, R. B., Roos, E. M., Roos, H. P., Ranstam, J., & Lohmander, L. S. (2010). A Randomized Trial of Treatment for Acute Anterior Cruciate Ligament Tears. New England Journal of Medicine, 363(4), 331–342.


6. Grinsven, S. V., Cingel, R. E. H. V., Holla, C. J. M., Loon, C. J. M. V. (2010). Evidence-based rehabilitation following anterior cruciate ligament reconstruction. Knee Surgery and Sports Traumatology Arthrosc. 18, 1128- 1144.


7. Halinen, J., Koivikko, M., Lindahl, J. Hirvensalo, E. (2009). The efficacy of magnetic resonance imaging in acute multi-ligament injuries. International Orthopaedics (SICOT). 33. 1733–1738


8. Lubowitz, J. H., Bernardini, B. J., Reid, J. B. (2008). Comprehensive Physical Examination for Instability of the Knee. The American Journal of Sports Medicine. 36 (3). 578 – 579.


9. Kim, K. M., Croy, T., Hertel, J., Saliba, S. (2010). Effects of Neuromuscular Electrical Stimulation After Anterior Cruciate Ligament Reconstruction on Quadriceps Strength, Function, and Patient-Oriented Outcomes: A Systematic Review. Journal of Orthopaedic and Sports Physical Therapy. 40 (7), 383- 391.


10. Manske, R. C., Prohaska, D., Lucas, B. (2012). Recent advances following anterior cruciate ligament reconstruction: rehabilitation perspectives. Critical reviews in rehabilitation medicine. Curr Rev Musculoskeletical Medicine. 5, 59- 71


11. Marieswaran, M., Jain, I., Garg, B., Vijay Sharma, V.,Kalyanasundaram, D. (2018). A Review on Biomechanics of Anterior Cruciate Ligament and Materials for Reconstruction. Applied Bionics and Biomechanics  2018 (1)


12. Seeley, R. R., Stephens, T. D., Tate, P. (2003). Anatomia e Fisiologia. McGraw- Hill Higher Education. 6ª Edição


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