Knee

By:

CP van der Hart 
Orthopedic surgeon 
Our Lady Hospital in Amsterdam

The reconstruction of the bands (ligaments) around the knee joint and in particular the injuries of the anterior cruciate ligament (ACL is now called) has always occupied an important place in the history of orthopedics. The torn anterior cruciate ligament usually leads to a debilitating knee instability with high risk of additional injury to the meniscus and cartilage. 
In the 50s, 60s and 70s, the surgical treatment of this injury meant a large incision (dissection). Infection and fibrosis (arthrofibrosis) were then known and accepted complications. 

Since the late 80's these operations are performed under arthroscopic guidance or completely arthroscopically. Infection and fibrosis are seen today hardly. The effects of ACL rupture are better understood by the greater knowledge in the field of biology and biomechanics of the knee joint and appreciated. The scar formation is now reduced to a minimum.

In this presentation the various aspects of arthroscopic anterior cruciate ligament reconstruction are discussed and the various stages of rehabilitation that are fully adapted to the biological changes of the knee joint and the stress-related changes of the graft.
Anatomy: 
Each joint is a compromise between mobility and stability. The decisive factor is the relationship between the bones, ligaments and muscles. The knee is, as the largest joint in the human body, a pivot hinge joint. The bending is carried out as a rolling and sliding movement. In a bent state is a rotation (rotation) is possible. 

Cup and bowl

At the knee joint to take the thighbone (femur), the shinbone (tibia) and the kneecap (patella) part. The ends thereof are covered with a layer of cartilage, so that the knee moves smoothly. In the knee joint, both condyles do femoris as a headline. These condyles are on the inside and outside are not uniform. 
The rest of their cartilaginous surfaces of the condyles and tibial bowl. The kneecap (patella) is an independent piece of bone, which in the tendon of the big thigh muscle has been recorded (musculus quadriceps femoris) and at the bottom is connected to the tibia. 

Menisci

Between the joint parts of the femur and tibia are the lateral meniscus and medial meniscus. They are crescent-shaped fibrocartilage disks.They are in cross-section from the outside to the inside wedge formation. The menisci increase the contact surfaces of the joint and thus helping to carry passed. Using these contact surfaces all forces They do this regardless of the position of the knee joint. Since the menisci with respect to the shinbone (tibia) are themselves mobile and deformable, will change the shape of the cup to that of the head at each position of the joint.

Capsule and ligaments:


The so-called joint capsule encloses the joint almost completely. It is not uniform in thickness, and especially on the outside can be interpreted as a number of different planes extending beams. The 
From the top of the kneecap runs the tendon of the kneecap (patellar ligament) to a bony prominence on the tibia (tibial tuberosity) as the last piece of the tendon. 
The main bands of the knee joint are:

  1. The outer ligament (ligamentum collateral fibulare): this band extends between the outer side of the thigh (lateral epicondyle femoris) to the outside of the fibula (caput fibula).
  2. The inner ligament (ligament tibial collateral): this band goes between the inside of the thigh (medial epicondyle femoris) to the inside of the shin.
  3. The anterior cruciate ligament (anterior cruciate ligament) (Fig. 4): this band is from the inside rear of outer epicondyle of the femur to the top of the tibia.
  4. The posterior cruciate ligament (posterior cruciate ligament): this band over the inner front of the inner epicondyle of the femur to the outside rear of the tibia.

The ligaments holding cup and bowl together. These are the bonds that stabilize the knee, without interfering. Flexion and extension The cruciate ligaments provide stability in anteroposterior direction and in rotation. The inner and outer ligaments provide stability in the lateral direction and in rotation. 
Of both cruciate ligaments is always a part of the fibers stretched.

The anterior cruciate ligament is located in the joint and prevents the lower leg during walking and turning movements, moving forward.

There are two distinct strands: the inside (anteromedial-) and the rear outer (posterolateral) bundle. The rear outer beam is tightly stretched position (extension), the inner beam bending, which is also important in the reconstruction with patellar tendon because (BPTB) (Figure 1) reconstructions, only the rear outer beam is restored. Because the rotating movement of the knee (pivot shift) occurs in almost extension is therefore achieved with rear outer beam replacement functional stability. 
The ACL is rich with blood This also means to be a damage to the ACL (70-75%) always initially thought to be a traumatic hematoma in the joint (haemarthrosis). In second place comes with haemarthrosis hairstyle terminal or peripheral meniscal tear, which sometimes occurs adhesion (meniscopexie) into consideration. 
There are located in the anterior cruciate ligament several neuronal receptors that are of interest to the incentives that are being sent. From the knee to the brains (proprioception) These incentives are the position in space, the speed and acceleration again around the knee joint occurs. Proprioception is closely linked to the coordination. 
The function of these receptors is dependent on the integrity of the anterior cruciate ligament. An extension (elongation) or partial rupture leads to dysfunction of the receptors. It is clear that this is also the co-ordination is adversely affected.

The United States is the anterior cruciate ligament injury in 1 in 5000 people. It mainly concerns the age group of 20 to 45 years. Total cracks in America each year approximately 100,000 people their cruciate ligament and slightly more than half is for surgery. In the Netherlands there are no exact figures are known but it is assumed that the numbers will not differ much.

Osgood Schlatter