The great importance and value of the meniscus in the knee function has, by now, been fully understood by the whole scientific community, as well as by the general public. The knee has two crescent-shaped menisci (medial and lateral). Simply stated, each meniscus acts as a knee suspension, protecting the thigh and tibial cartilages.
In the event that a meniscus is severely injured (complex meniscus ruptures), usually no suturing with a high chance of success can be performed. In these cases, partial meniscectomy is necessarily selected. Without the protective property of the menisci (as “shock absorbers” of the joint), persistent pain, recurrent effusion and arthritis points may sometimes develop.
Regarding most patients, these symptoms develop over the age of 55 (and always depending on the patient's activities), total knee arthroplasty, unicompartmental knee replacement, or knee osteotomy, are the wisest choices. However, regarding young patients, the aforementioned procedures are usually disapproved. In these cases, the specialist orthopaedic surgeon should consider the option of meniscal transplantation.
The purpose of meniscal transplantation is to replace the removed meniscal segment (usually from a previous operation) with the meniscal graft (easily found on the market, by a company), in order to delay further degeneration of the knee cartilage.

The basic criteria to be observed for a patient to be eligible for this procedure are:

• Young age (under 55 years) and non-obese (with a BMI less than 30)
• Persistent effusion and pain, which does not subside conservatively, for more than 6 months
• Lack of more than 50% of the mass of the meniscus to be transplanted
• Stable knee, without any ruptures of the anterior and / or posterior cruciate or other ligaments. If such a rupture exists, it should also be treated simultaneously, or in a preceding surgery to that of the meniscal transplantation.
• Correct knee structure. In the case of knee deformities (genu varum or valgum) the option of a knee osteotomy should also be discussed with the patient
• Normal cartilage. In addition, if cartilage damages exist, they should be treated together with the meniscal transplantation.

Nowadays, meniscal transplantation is performed arthroscopically (without cutting the knee joint open) unless we need a meniscal transplant with bone blocks to also replace the roots of the meniscus to be transplanted. In this rare case, we perform a mini arthrotomy, so that the bone blocks can enter the joint. The meniscal transplant is fixed through a special technique (outside-in, inside-out, or all-inside) depending on the anatomical region of the meniscus which has been transplanted.
The meniscal roots should be properly and reliably evaluated by an experienced orthopedic surgeon in the magnetic resonance imaging, in order for a right choice of a meniscal transplant to be made. One of the most common errors is the wrong choice of a meniscal transplant for transplantation, due to poor quality of the magnetic resonance imaging, or its incorrect evaluation.
The chances of complications following meniscal transplantation are extremely rare. They are about stiffness, resurgery due to incomplete integration, heamatoma, infection, and nerve damage. Modern regenerative medicine, in conjunction with orthopaedic surgery also offers us the possibility of meniscal transplantation combined with the use of stem cells by the patient themselves. This option seems to improve the integration of the meniscus transplant into the knee and is beneficial regarding pain control. The transplantation of the meniscal scaffold acts as a substrate, so that the body can regenerate meniscal tissue within the porous scaffold, and, ultimately, a meniscus.
In addition to the robust and proper surgical technique, the complete and reliable physiotherapeutic approach of the patient is perhaps the most important part of this surgery. The key to success in recovering after such a surgery is progress, based on the criteria and patience. Effusion and pain control, full motion range and the recovery of the power of the quadriceps and other muscles are the main factors a physiotherapist should place under supervision, to safely lead the patient to full recovery.