The ligaments of the knee allow to maintain its stability, joining it to the femur and tibia. ACL surgery is usually performed by arthroscopy, replacing the anterior cruciate ligament with a new one. In all cases of young people, surgery is recommended, since 80% of patients with a torn ligament and not operated on present degenerative signs, in addition to meniscal and cartilaginous lesions.
Anterior cruciate ligament of the knee: what is it?
The knee has four fundamental ligaments which are:
- Anterior Cruciate Ligament (ACL)
- Posterior Cruciate Ligament (PCL)
- Internal Lateral Ligament (ILL)
- External Lateral Ligament (ELE)
The knee joint communicates in its superior part the femur and in the inferior part the tibia. If it were not for the ligaments, the femur and tibia would move relative to each other and the stability of the knee would not be maintained.
Only the ACL and PCL are inside the joint and can therefore be operated on by arthroscopy. In contrast, injuries to the LCL and LLE can only be operated on in the traditional way, with open surgery.
The ACL, essential for knee stability
As the name suggests, the lateral ligaments are located on the sides of the knee and run from the femur to the tibia, each on its corresponding side.
The cruciate ligaments cross each other forming a kind of X inside the knee: one of them overlaps in front (anterior cruciate ligament) and the other crosses behind (posterior cruciate ligament). For example, the ACL is a “rope” that prevents the tibia from moving forward, while the PCL crosses behind and prevents the tibia from moving backward.
The most frequent injuries are those of the LLI because a valgus injury, knee inward and foot outward, with elongation or rupture of this ligament is more likely.
When a rupture of any of these structures occurs in an athlete, being a young patient with biomechanical and stability requirements of 100% for their sporting activity, the surgical indication is practically inevitable. In the case of an injured person who is not an athlete, a reasonable doubt arises:
1) Should I have surgery?
The clinic is the one that “rules”. That is to say, if your knee is unstable, it is advisable to operate. In people over 45 years of age, the indication must be qualified according to the degree of physical activity or the profession. Those who do not undergo surgery should be aware that the ACL does not “self-repair”, that they should reduce their physical activity (avoid contact sports, with changes of direction and rotation of the knee) and, in the event of any clinical manifestation of instability, they should undergo surgery. It should also be known that in 80% of patients with a torn cruciate ligament who have not undergone surgery, there are important degenerative signs with meniscal and cartilaginous lesions.
Once replacement surgery has been decided, other questions arise:
2) When do I have the surgery?
There is no consensus, but many scientific evidences indicate that it is convenient to perform the surgical intervention when the inflammation has disappeared and the arc of mobility of the knee is complete, a situation that usually occurs from the third week after the accident.
3) What does the operation consist of?
The entire procedure is performed arthroscopically, with the injured person conscious and watching the procedure on a monitor. The patient will leave the hospital on his own feet. In the surgery the torn ACL is replaced by a new one, which is “manufactured” with tendons that can be:
- Autologous: they are the patient’s own.
- Allograft: they come from another person, usually from a cadaver.
- Synthetic or animal grafts used to be used, but are no longer in use.
Factors that influence the success or not of the ACL operation
Either of the two options previously described has advantages and disadvantages. The use of one or the other will depend on the individual characteristics of the injured person, the experience of the surgeon and the availability of grafts in tissue banks. This is because, depending on the choice of one graft or another, there will be a greater or lesser risk of suffering a bad result, post-surgical discomfort in the donor area, infection, biocompatibility, and the process will be more or less expensive and more or less durable. The advice is that you trust the criteria of your knee specialist traumatologist, since he/she will offer the best option, whether or not surgery is indicated, as well as the technique to be performed and the graft to be placed.
Recovery from anterior cruciate ligament surgery
Although this surgery is currently performed by arthroscopy, it must be taken into account that the surgeon works inside a joint without being able to avoid manipulating its components (bone, cartilage, etc.). For this reason, it takes time for the knee to readapt and integrate the replacement plasty. Thus, at three months nerve endings are formed and at six months functional levels similar to those prior to ACL rupture are achieved. Even so, it should be noted that until one year has passed, the plasty does not behave like the “ideal” ACL. Knowing this allows us to schedule rehabilitation therapy.
The patient has to assume that the incorporation to daily activities and sports is progressive and slow. In addition, his “role” during rehabilitation is fundamental. All your efforts should be focused on achieving the following objectives:
– Regaining full mobility
– Achieving muscle power
– Gaining knee joint stability.
Rehabilitation should begin weeks before the operation so that the musculo-osteotendinous structures are in their best physical condition.
Early mobilization of the joint after ACL reconstruction can reduce pain, decrease adverse articular cartilage changes, promote joint nutrition, promote healing, and prevent joint capsule shrinkage.
Those patients with delayed goals, who do not reach full extension and/or flexion to 90° within two weeks, should be treated more aggressively, i.e., apply manual pressure or forced stretching.
Of course postoperative recovery will be in the hands of the rehabilitation and physical therapist specializing in knee pathology.
.