The anterior cruciate ligament (ACL) of the knee is usually ruptured during the performance of a sporting activity in which an uncontrolled knee rotation mechanism occurs accidentally: the foot of the affected limb is usually fixed to the ground while a rotation of the rest of the body occurs, either by a fall or the same inertia of the body gesture that was being performed. Usually, in the mechanism of injury of the ACL also participate other forces apart from those of torsion, being for that reason frequent that its rupture is associated with injuries of the internal lateral ligament or of the meniscus.
It is a frequent injury in soccer players and all those contact sports in which there are sudden changes of direction such as rugby, basketball, handball, etc… sports in which there are contusions and unexpected falls. It is also common in skiing, where the foot can easily become locked while the rest of the body moves causing a sudden twisting of the knee in the course of a fall.
After the rupture of the anterior cruciate ligament the patient experiences a rapid swelling of the knee, because when the ligament ruptures there is bleeding inside the joint (this joint effusion is called hemarthrosis). This swelling causes pain and forces the patient to leave the knee immobilized in a position of slight flexion and to avoid resting the foot on the ground during walking. Occasionally, when the anterior cruciate ligament is already deteriorated by previous partial injuries or by a long sports history, it may rupture in the context of milder sports accidents and without generating such a clear symptomatology in the knee; in these cases, the severity of the injury may go unnoticed by the patient due to the absence of significant swelling or pain.
What is the most appropriate treatment for this type of tear?
It is an injury that usually occurs in the context of active patients from adolescence to age 50. In younger patients (from 15 to 30 years of age) the injury appears due to competitive sports activities and usually occurs after a sports accident of considerable intensity. In older patients (30 to 50 years of age), ACL rupture usually occurs during non-competitive sports activity or in the context of an accident during a physically demanding work activity.
Currently, the treatment of choice for anterior cruciate ligament rupture in active patients under 50 years of age is surgical reconstruction. In order to establish the surgical indication of the injury, it is essential to objectify the existence of rotational instability of the knee by means of the maneuvers of the physical examination in the consultation room and the realization of a magnetic resonance of the knee.
The anterior cruciate ligament surgical technique is arthroscopic and consists of reconstructing the ligament within the joint using a tendon (either the hamstring, patellar or quadricipital tendon); this tendon can be obtained from the patient himself (technique of choice) or from the tissue bank. In younger patients (under 25 years of age), an extracapsular anteroexternal reinforcement with the ileotibial strap is often associated with intrarticular ACL reconstruction (this technique is called Lemaire plasty).
What future consequences can this injury have for the affected person?
The main consequence of the rupture of the anterior cruciate ligament is rotational instability of the knee. Clinically, the patient expresses the subjective perception of instability as “I feel that my knee is going, that it cannot hold me”, especially when walking downhill, when going down a step or when making a change of direction in the direction of walking.
Evidently this generates difficulty and insecurity to develop physical activities of certain intensity. In addition, it may be accompanied by discomfort. These episodes of instability entail subluxations of the knee, and these subluxations or alterations of the contact between the bones of the knee precipitate with the years the appearance of an osteoarthritis of precocious form.
Thus, with the surgical treatment of the rupture of the cruciate ligament it is pretended to solve the rotational instability of the knee and at the same time, to prevent the appearance of an osteoarthritis in an early way. In addition, if there are associated meniscal or articular cartilage lesions they can also be treated during the same arthroscopic surgical procedure.