Ligamys is an implant used to treat ruptures of the anterior cruciate ligament (ACL ruptures).
Ligamys fulfils two functions:
- The knee is mechanically supported or stabilised, respectively, for a sufficient period of time.
- This stabilisation enables the torn anterior cruciate ligament to heals up.
Ligamys enables preservation of the patient’s own cruciate ligament. No removal of a tendon from the patient’s body is required.
The robust thread temporarily assumes the functions of the injured cruciate ligament. It is pulled through two very small tunnels that are drilled through the femur (thigh bone) and tibia (shinbone). The thread is positioned to run in the same direction as the patient’s anterior cruciate ligament.
A small metal plate made of titanium (the flip anchor) secures the polyethylene thread on the outside of the femur and keeps the thread tensioned.
The pivotal component of the system is the so-called monobloc. It comprises a spring system and is inserted into the tibial plateau obliquely from below. The monobloc holds the other end of the polyethylene thread elastically.
The monobloc with the polyethylene thread provides a dynamic connection between the femur and tibia, which stabilises the joint and relieves the injured cruciate ligament.
This allows the cruciate ligament to grow back together again, while the spring system ensures knee stability in every phase of movement.
A look inside the joint
For the procedure, special instruments are inserted through small incisions into the knee joint. One of them is a camera that shows the situation inside the joint on a monitor.
Under camera view, the diagnosis previously established by examination and imaging (e.g. X-ray, MRI) must now be confirmed. Ligamys can be used only if the anterior cruciate ligament is torn in such a way that healing is possible.
Implantation of the monobloc
The monobloc is then implanted into the tibial plateau, and then the small boreholes for the polyethylene thread are drilled. The latter is then pulled through the drill holes in the femur and tibial plateau to the metal sleeve (monobloc).
Microfracturing for regeneration
The next step is a microfracture To this end, small holes are punched into the bone next to the cruciate ligament insertion site, which trigger natural repair mechanisms in the joint. With the leaking blood, stem cells surface, which induce formation of new tissue and thus support the regeneration in case of joint injuries.
Stabilisation of the knee
Finally, the polyethylene thread is fixated in the spring system under predetermined tension. It can stabilise the injured knee and give the torn cruciate ligament the necessary rest to allow it to heal up.
The two cruciate ligament stumps are not sutured. Thin threads which later dissolve are intended to align the two ends in such a way that they can grow together without tensile stress.