Anatomy cruciate ligament
The knee joint is the largest joint in the human body. The knee joint includes the femur, tibia, patella, meniscus, various capsule tissues, the ligamentous apparatus and many bursae. If we now take a closer look at the ligamentous apparatus, we must distinguish between the collateral ligaments, the internal ligaments and the cruciate ligaments, among other things.
The cruciate ligaments run from the middle of the head of the shinbone to the thigh bone and cross each other. The task of the cruciate ligaments is to stabilize the knee by preventing the lower leg from sliding forward over the thigh or the upper leg over the lower leg during walking, depending on whether the anterior or posterior cruciate ligament is involved. The rear cruciate ligament in particular prevents the thigh from moving forward, while the front cruciate ligament acts in exactly the opposite way.
Therapy
In general, a decision must be made between conservative and surgical treatment of a posterior cruciate ligament rupture. This must be considered and decided individually. It is also important to take into account the patient and his or her expectations.
While older, rather non-athletic people have different expectations regarding the load possibilities of their cruciate ligaments than, for example, competitive athletes, surgery for a torn posterior cruciate ligament is more likely to be induced in a competitive athlete than in a person who can be free of complaints even without surgery. From a medical point of view, there is no clear standard to date as to whether a posterior cruciate ligament rupture should be treated conservatively or surgically. The representatives of both points of view have their own opinions, which are discussed again and again.
For example, there are doctors among them who are convinced that arthrosis tends to occur earlier without surgery than with surgery. In the following, therefore, advantages and disadvantages are listed. However, for an assessment between conservative and operative therapy, nothing seems as important as the individual consideration and the individual contact of the patient with the treating physician.
Only the doctor can ultimately make an individual decision regarding the form of therapy. Important indications for the decision for the conservative therapy a posterior cruciate ligament rupture exists particularly in the case of stretching of the posterior cruciate ligament or partial rupture. If a patient with a total rupture of the posterior cruciate ligament is able to compensate for the instability by means of his muscles, the decision is also made here rather for the conservative form of therapy.
As a rule, surgery is not performed on patients who are not involved in competitive sports and are older than 50 years. Even if ligament injuries are already older than 14 days, conservative therapy is generally used. However, it is important to note that conservative therapy for a posterior cruciate ligament rupture can only be successful if the patient carries out the necessary training independently on a daily basis.
The motivation of the patient is therefore particularly important and must also be discussed with the patient before the decision regarding the form of therapy is made. The conservative form of therapy for a posterior cruciate ligament rupture usually begins immediately after the acute pain has subsided with full loading, but in conjunction with an individually adapted plastic splint and physiotherapy. The goal of conservative therapy is to improve muscle strength through exercises that are simultaneously designed to improve the stability of the affected knee joint.It is the muscles that are supposed to take over the function of the torn cruciate ligaments, so that the individual assistance and motivation of the patient discussed in the previous paragraph must be clarified here once again with regard to the success of the conservative therapy of the torn posterior cruciate ligament.
In addition to the actual therapy: can be integrated. Combinations of these treatment methods are also conceivable in the case of a posterior cruciate ligament rupture and are aimed at improving blood circulation and ultimately also reducing pain.
- Stimulation current,
- Ultrasound and or
- Ice treatment
Which tendon is ultimately used is multifactorial and can be seen individually.
The decisions depend on individual indications:
- Profession
- Sports Activity
- Complex knee ligament injury
- Bony tearing
- Overall status
- Additional Violations
- Cruciate ligament rupture with additional meniscus lesion close to the base
Even though the description of the surgical techniques may seem quite complicated, the success rates seem good to satisfactory, especially in cases without significant additional injuries. The surgical therapy form is usually followed by a consistent follow-up treatment (rehabilitation). These measures can take up an average of about 3 months, whereby a full load is usually only reached after 6 months.
A posterior cruciate ligament injury usually represents a serious injury. The prognosis for regaining full weight-bearing capacity must be considered rather unfavorable, regardless of the decision whether conservative or surgical treatment should be applied. Either way, the patient’s help and above all his patience is required.
The pictures show the procedure for cruciate ligament plastics. While patellar tendon plastic surgery usually involves removal of the middle third of the patellar tendon including adjacent bone blocks (left image), semitendinosus tendon and/or gracilis tendon are separated from the bone arthroscopically via a small skin opening and separated from the respective muscle belly by means of “strippers” (right image). The resulting remnants of the tendons scar with their respective surroundings without any significant loss of function.
As a result of serious accidents, partial ruptures of the anterior and posterior cruciate ligaments occur, so that operative both cruciate ligaments have to be replaced. See anterior cruciate ligament rupture. Usually, these two operations are then performed as part of a more complex surgery.
The reason for this is not only that only one operation has to be scheduled, but also that if the two operations were to be performed at different times, too much scar tissue would be formed in the meantime, which would make it unnecessarily difficult to perform another cruciate ligament operation. The risk of infection is also not insignificant. In most cases, both cruciate ligament plastic surgery using the patellar tendon (patellar tendon) and cruciate ligament plastic surgery using the middle semitendinosus or gracillis tendon are used.
As a rule, the anterior cruciate ligament is replaced with the patellar tendon, the posterior cruciate ligament with the quadruple semitendinosus tendon. To keep the scarring of an operation to a minimum, the operation should be performed arthroscopically if possible. Such operations use a highly sophisticated procedure.
Since a posterior cruciate ligament injury is usually a severe injury, the prognosis for regaining full resilience under both conservative and surgical therapy is rather unfavorable. The conservative therapy consists of immobilizing the leg affected by a posterior cruciate ligament rupture with the help of a special splint in order to achieve a fusion of the parts of the injured cruciate ligament. This so-called PTS-splint (PTS = posterior tibial support) is a splint for the lower leg with a calf cushion which acts as a cushion to prevent the lower leg from sinking back.
This splint for immobilization after a torn posterior cruciate ligament must be worn for a total of six weeks, both during the day and at night. If the patient is free of pain, a load is possible, but bending movements must not be performed under any circumstances, as otherwise the torn cruciate ligament cannot grow together. At the end of these six weeks, after a torn posterior cruciate ligament, movement exercises should be performed without a splint in the prone position.
The purpose of this training is to strengthen the thigh extensor (quadriceps muscle).It is also important to limit flexion in the knee joint: a maximum of 60 to 70 degrees of flexion may be performed. From the ninth week on, wearing the splint at night is sufficient. From this point on, flexion is possible up to 90 degrees.
A complete healing of the posterior cruciate ligament usually takes about twelve weeks. The alternative to conservative therapy of a torn posterior cruciate ligament is surgical treatment. The indication for surgery is given in the case of bony tears of the posterior cruciate ligament, in the presence of concomitant injuries or in the case of severe instability of the knee.
The surgical procedure consists of an arthroscopic treatment, which means a mirror image of the joint (arthroscopy) with simultaneous surgical manipulation of the joint structures without complete opening of the joint. For this purpose, a few small incisions are made, as well as an approximately four cm long incision. A person affected by a posterior cruciate ligament rupture receives a posterior cruciate ligament plastic or PCL replacement plastic (PCL = posterior cruciate ligament).
Such a plastic is usually made from the patient’s own tendons. The tendons of the semitendinosus muscle or the gracilis muscle of the injured leg are the preferred material for treating a torn posterior cruciate ligament. This tendon is reinforced with sutures and inserted into predrilled channels in the lower leg and thigh at the attachment points of the original posterior cruciate ligament, where it is then fixed.
The fixation is done with screws and metal plates. Since these materials are resorbable, i.e. they dissolve by themselves after a certain time, metal removal at a later date is not necessary. If the body’s own tendons, which are used for cruciate ligament plastic surgery, have too low a tensile strength, artificially produced materials are used.
If there are other accompanying injuries to the knee joint in the case of a posterior cruciate ligament rupture, these are also treated in the same session. For example, posterior or lateral capsule-ligament structures can also be replaced by the body’s own tendon components. After the operation, a drainage is inserted into the knee joint, through which wound secretions and blood can drain away.
This drainage is usually removed the next day. Overall, surgery for a torn posterior cruciate ligament takes about one to two hours. After the operation, the further procedure consists of elevating and cooling the affected leg.
Stretching movements must not be performed and physiotherapy exercises to build up the leg muscles should be started. In addition, the surgeon must apply an extension splint for about six weeks. At the end of this period, he or she will receive a movable splint (PCL orthosis) and may begin with slow bending exercises in the prone position up to 60 to 70 degrees.
Furthermore, a training of coordination is useful. Sport should be avoided for a period of one year after surgery for a torn posterior cruciate ligament. If a rupture occurs in the cruciate ligament plastic surgery, the therapy consists of a revision cruciate ligament plastic surgery.
In this case, the material used is the tendon of the semitendinosus muscle of the other leg or the tendon of the quadriceps muscle. Sometimes the operation is performed in two stages. This means that in a first operation, the drill channels of the first cruciate ligament surgery are first filled with bone marrow from the iliac crest (cancellous bone grafting) and the actual cruciate ligament surgery is only performed in a second session after about three months, as it is then possible to drill again into the bone to anchor the surgery.
If chronic instability is already present after a posterior cruciate ligament rupture, treatment can be either conservative or surgical. The decision is based on the extent of the instability and the complaints in everyday life. The healing period of a torn posterior cruciate ligament is usually relatively time-consuming.
During the course of healing, however, the joint can usually be subjected to gradually increased stress. The duration of a complete healing process, which includes stability and functionality of the joint as before the trauma, depends crucially on the extent of the injury, individual factors of the affected person and the chosen treatment method. For simple injuries in young patients which are treated conservatively, complete healing can be achieved after about 12 weeks.
Surgical treatment of a torn posterior cruciate ligament is chosen when the injury is highly unstable. The healing time for surgical treatment of the injury is also influenced by individual factors.However, a healing period of at least 12 weeks can be assumed. The duration of a sick note written due to a torn posterior cruciate ligament usually varies depending on the activity performed.
For example, a person who performs heavy physical work during his or her job usually has to be written off sick longer than other affected persons. Since the beginning of the therapy is aimed at a strict protection of the joint, a sick leave of at least one to two weeks is to be assumed. In the course of healing the injury can be examined and the sick leave extended if necessary.
The resumption of sporting activities may be delayed beyond the specified times. This depends on the individual healing progress and the type of sport performed.
