The anterior cruciate ligament (ACL) is a central pivot ligament of the knee that stabilises the knee by preventing anterior translation of the tibia relative to the femur. It plays an essential role in stabilising the knee during rotational movements under load. It is usually torn during a sprain in football, skiing, basketball, handball, tennis, badminton, etc. (pivot sports) or during road accidents (bicycle, motorbike, etc.).
The traumatic mechanism must be analysed. Traumatic movement is an uncontrolled and abrupt rotation of the knee, often causing a “snap”, severe pain and usually immediate joint effusion. Applying an ice pack helps to calm the pain and deflate the knee. Joint stiffness sets in quickly and the best thing to do is to keep moving with gentle flexion/extension movements of the knee in line, i.e. avoid twisting. Rigid splints are therefore not essential, but they are often comfortable and reassuring for the first few days. Crutches are necessary to make walking easier and put less strain on the knee until an appointment with a specialist is made.
After a severe sprain (cracking, effusion, pain and/or feeling of instability of the knee) it is necessary to consult an emergency centre quickly to have X-rays taken to exclude a fracture, and to be examined to determine clinically if the knee is lax. If this is the case, an MRI is necessary to confirm a ligament tear (in other words a tear of the anterior cruciate ligament) and especially to look for associated lesions such as a meniscal tear, a sprain of a peripheral ligament (LLI, LLE), or bone contusions. An appointment with an orthopaedic surgeon specialising in the knee is necessary to be re-examined and to discuss the best treatment for you, and in particular whether surgery is necessary. The choice between surgical and conservative treatment is made according to several criteria: the severity of the lesions in your knee, your current sporting activities and future ambitions, your professional activity, your age, your symptoms.
Conservative treatment consists of rehabilitation with a physiotherapist to restore the function of the knee and train the muscles to stabilise it under all circumstances. Conservative treatment is suitable for people whose knee is spontaneously relatively stable (e.g. in partial ACL tears), who practice activities in the axis (cycling, swimming), who have a rather sedentary professional activity (office work).
Surgical treatment is indicated in the presence of associated injuries (ACL tear + meniscal or collateral ligament tear), in patients practising and wishing to continue to practise pivotal sports activities, and in power workers. The goal of surgical treatment is to reconstruct the ACL and repair associated injuries. Once torn, the ACL does not heal and cannot be repaired, a new ACL must be grafted. To do this, a tendon graft is implanted into the knee in place of the torn ACL. This surgery is performed arthroscopically. Several small scars are made: two 5mm scars for the arthroscopy, one 3cm scar for the graft removal, two 2cm scars to make the bone tunnels that allow the graft to be introduced into the knee joint and fixed. Several types of graft are commonly used: the central 1/3 of the quadriceps tendon (tendon-bone), the central 1/3 of the patellar tendon (bone-tendon-bone), the hamstring tendons (DIDT = medial rectus semitendinosus = gracilis and semitendinosus) (purely tendonous). Allografts (tissue bank grafts) are never used as a first-line procedure in our practice because of the high risk of failure (4 times more re-ruptures). Our preferred graft is the central 1/3 of the quadricipital tendon, which allows us to harvest a graft of a size and length tailored to your knee and which has ideal biomechanical properties. After being inserted into the knee, this ACL graft is fixed in the bone tunnel of the femur and the tibia with absorbable interference screws. The scars are sutured with absorbable sutures or staples depending on your skin quality and aesthetic expectations.
The hospital stay lasts 2 to 3 days (1 to 2 nights). You come to the clinic on the morning of the operation, are operated on during the day, and begin mobilisation and walking the day after the operation. The criteria for returning home are: independent movement and walking, calm scars (no bleeding), manageable pain with simple medication (paracetamol, ibuprofen, tramadol). Prophylactic anticoagulation is necessary and is done by subcutaneous injections or by tablets per os, for a variable duration depending on the surgical procedure performed.
During the hospitalization, two physiotherapy sessions per day will allow you to regain your autonomy and will teach you the exercises to be performed at home on a daily basis. You can resume outpatient physiotherapy sessions twice a week from the week following the operation, ideally with a sports physiotherapist.
Walking is done with the help of walking sticks for a period of 4 to 6 weeks, allowing for a load adapted to the surgical procedure performed.
The objective of the first 10 days is to relax the knee by applying ice regularly (ideally 20 minutes every 2 hours), to heal the surgical wounds, to perform isometric contractions of the quadriceps, and to fully extend the knee.
Joint mobility should be recovered within the first 3 months: regain full extension as soon as possible, be able to flex to 90° 6 weeks after surgery, and have full mobility recovered 3 months after surgery.
The muscles atrophy rapidly and muscle stimulation is beneficial to regain voluntary control of the muscle, avoid too much amyotrophy and allow you to walk again without crutches.
All post-operative rehabilitation is carried out according to a protocol and in stages where the principle is to move on to the next stage when the objectives of the stage in question are achieved. To give you an idea of how long it takes to resume physical and sporting activities after the operation:
walking without canes after 4 to 6 weeks
Exercising on an exercise bike and in the swimming pool after 6 weeks
running (jogging) from 3-4 months
jumping from 4 months
resumption of pivotal sports after 9-12 months
At 6-7 months after the operation, a dynamic evaluation is carried out: evaluation of muscle strength on the isokinetic machine, evaluation of proprioception (balance) and plyometry (jumps). This test allows you to situate yourself and target your shortcomings in order to optimise your rehabilitation.
The return to pivotal sports will be authorised by your surgeon depending on the joint healing assessed during the follow-up appointments and on your functional recovery assessed during the tests.
Routine post-operative check-ups are done at :
The day before the operation an appointment with the anaesthetist will allow you to choose between general anaesthesia and spinal anaesthesia (a shot in the back that puts both lower limbs to sleep). In addition, a nerve block (femoral or adductor) will certainly be offered to you for pain relief. Translated with www.DeepL.com/Translator (free version)
In case of conservative treatment: having an unstable knee that dislocates and causes a meniscal tear;
In case of surgical treatment (ACL reconstruction): postoperative haemarthrosis requiring a puncture or surgical revision for arthroscopic washing of the knee, dysaesthesia, particularly in the saphenous nerve territory due to the scar of the tibial tunnel, recurrence of anterior laxity in case of non-integration or distension of the graft (risk in smokers or in case of poor post-operative rehabilitation), joint stiffness in case of lack of post-operative physiotherapy or in case of an inflammatory state of the knee, the extreme of which is algodystrophy (CRPS in English)