Anterior Cruciate Ligament Surgery | Knee Surgery Department

	Anterior Cruciate Ligament Surgery

	The anterior cruciate ligament or ACL is made up of elastic fibers situated in the middle of the knee and are stretched between the femur and the tibia. Its name comes from the fact that it is situated in front of another ligament and crosses it. "Cruciate" comes from the Latin "crux" which means "cross". Thus its name anterior cruciate ligament as opposed to posterior cruciate ligament or PCL. The orientation of these fibers explains that its essential role is to keep the tibia from advancing in relationship to the femur (the inverse of the posterior cruciate ligament) the same goes with regard to its rotation.

	The translation and the rotation towards the front of the tibia are no longer checked. When this translation is brutal (abrupt movement, rotation of a blocked foot, certain gestures during sports …) this is felt as a sensation of loosing one’s knees and after a while insecurity and apprehension will set in. A muscular compensation is only possible just to a certain limit. Daily life is for the most part normal but major sports activities will raise the risks of instability (in particular team and combat sports). On the more or less long term, the anterior instability by a ACL rupture has for consequence a risk of meniscuses and cartilage lesions. After several years, it can lead to an accrued risk of a knee arthrosis, that is to say wear and tear of the cartilage.

	REPARATION PRINCIPLES OF ACL The simple suture of the anterior cruciate ligament is not sufficient for once the ligament is ruptured necrosis sets in and it will lose it’s mechanical qualities, even if the fragments are brought together and sutured. The ligament must be replaced by an equivalent structure. Artificial tendons have proven inefficient. A natural tendon taken from the knee itself must be used : ligamentoplasty.

	Most often a fragment of the patellar tendon is used because its properties come the closest to those of an ACL. One third of the patellar tendon is withdrawn along with the bony zones corresponding to the tendinous ties (the tendon heals over afterwards). Thus one is able to obtain a bone-tendon-bone transplant of about 10 mm in diameter. The intervention continues with an arthroscopy. Two orifices are used in order to introduce the arthroscope ( an optic system connected to a monitor allowing one to visualise the inside of the knee) and the instruments necessary for a ligamentoplasty. This arthroscopy permits the surgeon to verify the state of the meniscuses and cartilage. The remains of the anterior cruciate ligament are respected in order to liberate the central space of the knee for the future transplant.

	It begins at the exterior of the articulation and ends in the habitual tibial zone of the ACL insertion. The femoral insertion zone is then located and it is starting from here that a femoral tunnel is realised. These tunnels are realised with the aid of special wicks mounted on a rotating motor. A long thin pin is introduced in the two tunnels by penetrating the tibial tunnel. It perforates the femoral tunnel fundus and exits at the skin level of the thigh. The bone-tendon-bone transplant is fixed by a thread to the extreme inferior part of the pin then pulled upwards (this method avoids a second external incision cut for the passage of the transplant). One of the bony blocks will be lodged in the femoral tunnel and another in the tibial tunnel. The fixation of the bony blocks is effectuated with the help of headless screws that will play the role of a peg or a wedge by jamming the bony block in its tunnel. Thus, a neo-ligament is reconstructed in place and in the place of the former ruptured ligament. When knee laxity is an important, it will be necessary to realise a additional gesture. A sample of the fascia lata band, large external aponeurosis of the knee, will be taken. This band, will be left attached to the tibia and fixed to the femur so that it can control the overhanging of the external portion of the tibia.

	POSTOPERATIVE FOLLOW-UP Hospitalisation is five days. The knee is immobilised in a splint but a support is quickly authorised in the form of crutches. After the third day walking is progressively allowed and rehabilitation is precoce. During the first three weeks, walking should be done with the aid of crutches. The articulated splint, permits the flexion and the extension of the knee, but prevents any harmful lateral movement. It should be kept for a minimum of three weeks but makes more sense to keep it until the end of the sixth week, when the transplant has healed in the bone tunnels. Beyond the first six weeks, walking without crutches and splint is possible. Driving the car is allowed and often a little before the first six weeks are up. However driving a two wheel vehicle is strictly forbidden.