Tear of meniscus

As a meniscal tear or Meniskusruptur is called a tear of one or both menisci of the knee joint. Medial meniscus injuries ( ie, the medial meniscus ) are significantly more likely than those of the lateral meniscus. The cracks are classified according to their course of direction in the longitudinal crack, Radiärriss and oblique view ( cloth tear). With regard to the spatial plane, a distinction is vertical cracks and horizontal cracks. Special forms are complex cracks, the bucket-handle tear and a "flipped meniscus ". Diagnosis is made by clinical examination, MRI and arthroscopy ( arthroscopy ).

Meniscal tears are quite common and usually there is no pain or restrictions. Not everyone meniscal tear needs to be treated.

• 3.1 meniscus repair ( meniscal repair )
• 3.2 Meniscectomy
• 3.3 meniscus replacement 3.3.1 Transplantation of a donor meniscus
• 3.3.2 implantation of an artificial meniscus

Frequency

There is a prospective study of 991 randomly selected people from Framingham, Massachusetts. Composition of the student participants:

• 57 % women
• 93 % white
• 11 % smokers

In 35 % of the participants, showed meniscal tears or serious degenerative meniscus lesions. The medial meniscus was affected in 28 % and the lateral meniscus in 12% of cases. Of the 308 participants (31%) with meniscal tear showed 66% to a tear of the medial meniscus, 24 % of the lateral meniscus and 10% of both menisci. In 66% of the dorsal horn was affected in 62 % of the DC area and only 11% in the anterior horn of the outer or inner meniscus. The crack was in 40 % of cases, horizontal, in 37 % complex, 12% at an angle and in 15% radially and longitudinally in 7%. A meniscus could have in this classification also several cracks.

In the age group 50 to 59 years, the incidence for women was only 19 %, whereas it was greater in men and with increasing age. In men 70-79 years it reached 56%.

In the presence of the radiograph secured osteoarthritis ( Kellgren - Lawrence grade 2 or higher) with knee pain or stiff, showed a meniscus injury in 63 %. In asymptomatic participants in 60 %. Without radiological signs of arthrosis were found in participants who had knee pain at least once in the year prior to the Untersuchugn at 32 % of the participants meniscus tears. Without complaints were seen in 23 % of participants meniscus tears. In no group found a correlation to knee discomfort.

Classification

The degenerative meniscus damage always start centrally in the meniscus. They are divided into four grades, with only from grade 3 and there is a tear in the meniscus:

Bucket-handle tear

A bucket-handle tear is the designation for a parallel to the main direction of the fibers extending meniscus tear. The meniscus is thereby split along its course along which front and rear ends of the fragment continues to maintain connection to the rest of the meniscus. The free edge displaced into the joint space, causing acute pain.

Diagnosis can be as a bucket-handle tear in the clinical examination cause problems, because sometimes the fragment again rests on its origin, then that is not to find " typical meniscus symptoms ".

Degenerative changes

Just as the cartilage surface of a joint degenerative changes over time, wear the menisci. Under load the meniscus tissue is rolled out, is getting thinner until it finally tears. These changes are collectively referred to as Meniscopathie and are a part of the action in the development of osteoarthritis. In case of accident injuries that should be considered as work-related accident, the histological examination of the meniscal tissue is crucial for the recognition of an accident context. Other degenerative changes can also be caused by an eversion angle other than zero degrees.

Therapy

How to treat a meniscus tear depends on several factors. Age, sportsmanship and the patient's pain play a big role, but usually a physiotherapy treatment is initially recommended.

Since most meniscus tears make no complaints, no treatment is then necessary and a demarcation must be made in case of complaints, how these are actually caused by the meniscus tear or any other problems, such as cartilage damage.

Severed meniscus parts can occasionally move ( " joint mouse ") is free in the joint and cause, for example, a joint lock. Meniscal tissue has the same surface hardness as the articular cartilage, so that permanent cartilage damage can be the result.

Symptoms of a torn meniscus are usually flexion and extension deficits, the knee can not be stretched so. In addition, severe pain behind the knee and on the sides above the respective meniscus that can pull up to the shin.

Before an operation, the diagnosis usually has to be confirmed by an MRI. Then, usually, a partial resection of the torn meniscus using arthroscopy knee ( arthroscopy ).

Of crucial importance in the treatment of meniscus damage is essential that the current stability situation of the affected knee joint. A meniscal repair or transplantation should not be performed without ( simultaneous ) stabilization operation at eg cruciate ligament tear, since the instability is primarily responsible for meniscal pathology.

Meniscus repair ( meniscal repair )

When meniscal repair torn meniscus of the share is mounted with special sutures or meniscal arrows of resorbable materials again. However, this is only possible with certain cracks and only when the meniscus is torn off at the capsule, so that it can be sewn there. In younger patients, a refixation is performed, because the consequences of meniscal resection on the joint time-dependent occur even in less grassroots cracks. To improve the healing of a freshening of the crack zone (so-called needling, or " needles " ) is performed next to the seams, so that the blood circulation is improved locally. Then the stitched meniscus must heal, a long post-treatment is necessary. The movement of the knee joint is not released in the initial phase after the operation. For this purpose, a stretching splint is worn. The stress can be built up quickly, as the meniscus is not loaded. After about three weeks, the movement of the knee joint can be increasingly released, a complete recording of sporting activities only after half a year, with a good course of healing, possibly even earlier. "Soft " sports activities such as weight training, swimming or cycling can be taken after about two months. After surviving the meniscal repair is the most successful treatment, with the best perspective for the knee joint.

Meniscectomy

The other surgical option is arthroscopic partial meniscectomy, in this case the torn piece of the meniscus is removed. After a partial removal of the meniscus can already the day of surgery, a pain- oriented transition to full load carried. Supportive Unterarmgehstöcke can be used for several days. Accompanying physiotherapy is recommended during the first weeks after surgery. The ability to work is usually produced after 1 to 2 weeks. In knee stressful physically active patients, it may take several weeks until the patient can pursue his professional and sporting activities again. Partial resection carried out in particular with degenerative meniscal tears and remote from the base.

Before the age of arthroscopic partial resection usually accompanied by a complete Meniscectomy by arthrotomy, which was originally introduced in the 1970s by I. Smillie ( falsely assumed that the meniscus would form new). The more meniscus was resected, the early developed a knee joint osteoarthritis. In a follow-up Scottish average forty years after a complete resection of the medial or lateral meniscus in adolescence (mean 15.6 years ) had already 7 of 53 patients a knee prosthesis (13.2% ) and all other patients examined had marked to severe signs of osteoarthritis. In comparison to the data from the Scottish prosthetic register a 132- fold risk of early prosthesis implantation results after complete Meniscectomy without difference between the medial and lateral meniscus. The surgical treatment of meniscal tear on existing osteoarthritis has no advantages compared to physiotherapy.

Meniscus replacement

A so-called " meniscus replacement ", an implant made of polyurethane ( Actifit ), collagen ( CMI) or a human donor (allograft ) is used in place of the meniscus removed, so that, at best, an endogenous meniscus tissue can retrain. However, the insertion of the implant takes a longer treatment behind, athletes must here anticipate several months break. Long-term studies of the meniscus replacement or even clinical studies comparing the replacement with the pure partial resection, are still pending, the meniscus replacement does not represent a standard method

Transplantation of a donor meniscus

Patients who accidentally lose a meniscus at a young age, threatens the medium to long term, the development of early osteoarthritis. Often joined by early add an incipient painful cartilage damage of the femoral condyle and the tibial head. Pain and effusion in the knee joint are the first signs of osteoarthritis development and important indication of an early overloading of the joint portion. A major surgical procedure is in this situation, the transplantation of a donor meniscus dar. It can be replaced both the indoor and the lateral meniscus. The method presupposes an accurate diagnosis, according to the size must be determined individually and also side of the meniscus. The donor meniscus is usually appointed by internationally active banks and tissue donated by deceased accident victims. A rejection reaction as internal organs and a life-long medication, as after heart transplantation is necessary, for example, is not necessary here. The donor meniscus is removed under sterile operating conditions and then examined according to standard international criteria for pathogens. The risk of transmission of infectious diseases is negligible, but neither negligible as the unregulated legal situation for the surgeon in Germany. This is liable under current law only for the quality of the donor meniscus. After appropriate storage and transport elaborate the meniscus transplant is performed. The donor meniscus is used as part of an arthroscopy minimally invasive. After careful preparation of the donor of the meniscus is introduced through a small opening of about 1 cm into the knee joint and stitched in place stably. The disadvantage of a donor meniscus lies in the often months-long waiting time for a suitable transplant. Which substantially corresponds to the post-treatment after meniscus seam. The transplantation of a donor meniscus is primarily the prevention of early osteoarthritis and the elimination of pain. An intense exercise after the transplant needs to be clarified in consultation with the surgeon. Clinical studies show a significant reduction in pain and a very good ingrowth of Spendermenisci. In addition, long-term studies show only slow progression of osteoarthritis, but where there are no controlled clinical trials. The vast majority of patients cope well with the donor meniscus may have concomitant operations Beinachskorrektur necessary to achieve optimal relief of the damaged joint section with the donor meniscus.

Implantation of an artificial meniscus

In recent years, the importance of artificial meniscus implants has increased. If large parts of the meniscus must be removed are essentially two approaches to use, which differ in terms of their scientific research article as follows:

• Synthetic meniscus implant: using the plastic polyurethane, EU approval in 2008, to date, no published clinical trial results

• Biological meniscus implant: use of bovine collagen type 1, EU approval in 2000, more than 8 international clinical studies, over 12 peer reviewed technical publications of clinical results ( see bibliography)

For polyurethane meniscus implant, there are no clinical data in scientific journals, but only a few animal studies. Still running a European patient study, which has a very low level of evidence because of their small number of patients, lack of control group and has not been performed randomization. The clinical degradation behavior of the plastic polyurethane is not scientifically proven.

The existing literature on meniscus implants in regular clinical use for years is based mainly on the implant from bovine collagen type 1, over 400 patients were followed up with such an implant and ( up to eight years later ) documented their results in various international studies. The world's largest meniscus study ( level of evidence 1: a randomized, controlled) shows that patients benefit from the bovine collagen meniscus ( Rodkey et al JBJS 2008. ). Study results also show the complete removal of the bovine collagen within two years, which is in most cases replaced by a new, endogenous Meniskusregenerat.

After meniscus transplantation, the phase of the partial load extended to 5 to 6 weeks, otherwise there were no significant differences for meniscal repair result. Even with transplantation of a synthetic meniscal about six weeks partial weight bearing is necessary.