What is the meniscus?
Each knee joint has two menisci, an inner and an outer. They are the link between the thigh and the shin. The meniscus consists of fibrocartilage and has many functions.
1. Last- und Druckverteiler
4. Bestandteil des Gelenkschmiermechanismus
A damaged meniscus due to trauma (injury) or degeneration (abrasion) needs, with a few exceptions, a surgical treatment as a torn meniscus can cause further damage after a short time, due to attrition of the joint cartilage, even if the alarm signal of pain is missing.
The operation should be undertaken as soon as possible to repair, or to possibly avoid the damage to the articular cartilage.
The aim of arthroscopic meniscus surgery is to save as much meniscal tissue as possible and to remove only as much as is absolutely necessary.
A torn meniscus or grated part has not only lost its function, but also represents a stimulus factor that can lead to harmful joint effusion, and therefore must be removed.
By a partial meniscectomy the meniscus will be smaller, but retains much of its function, so that the early osteoarthritis (Gelenkabnützung), as was the rule after previously performed total meniscectomy, must not be feared.
If the fracture is close to the joint capsule, i.e. in the well-perfused area, the meniscus may be sewn in young patients arthroscopically and thus saved even entirely, a fact which improves the prognosis for the knee joint again.
On the day of surgery, the patient may wake up with a full load. Forearm crutches are needed only in exceptional cases.
After the first day of surgery, intensive physiotherapy and therapeutic exercise is undertaken.
The hospital stay amounts to a few days.
Under ideal conditions, the operation can be performed on an ambulant basis.
This surgery requires immobilization of the knee joint with a removable splint and load removal with two forearm crutches for three weeks.
In the splint isometric strength exercises can be performed.
After four weeks, full weight bearing is allowed, with intensive physiotherapy and therapeutic exercises done.
Some plan designs of the meniscus:
a,b. Longitudinal tear
c Cartilage tear
d basket-handle tear luxated,
e, f, g. cloth cracks
h Radial tear
i Near joint capsule tear
i suitable for a meniscal repair
a to h are treated by partial removal
Ability to work
in the case of office work after a few days
heavy physical labor after about two to four weeks
office work after about two to three weeks
heavy physical labor after about six to eight weeks
Sports can be resumed, in the absence of additional injuries to articular cartilage, and depending on the age, muscle performance and sport as follows: In the case of partial meniscectomy after two to three weeks, in the case of meniscal repair after about two to three months.
In partial meniscus removal without significant damage to the articular cartilage (stage I and II, see below), good results can be expected in 98 percent of cases. The introduction of high-frequency surgery succeeded in improving the success rate. In the case of meniscal sutures, about 92 percent of the cases are getting good results.
Patients with severe cartilage damage can demonstrate a poorer success rate, however, this is independent of the meniscus surgery.
In about 5 percent of cases postoperative joint effusions occur, that do indeed need an aspiration, but do not adversely affect the end result.
Other complications occur in the following percentages:
Infections in 0.08 percent, thrombosis in 1.6 percent, pulmonary embolism in 0.02 percent of the cases.
In 10 percent of meniscal suture cases sensory disturbances occur below the knee joint, which disappear usually after one to two years.