(Osteochondral Autograft Transfer System)
The main knee joint compounds are femur extremity, tibia extremity and patella. To ensure a good flow in the movements, bone surfaces are covered with an elastic tissue called cartilage (its wear leads to arthrosis). In the joint, there is also a synovial fluid (anoil-like fluid that washes these areas, enabling better slipping).
Articular cartilage is a tissue with low regenerative capacities, and is impossible to be repaired. Wear and thinning of this cartilage form the arthrosis.
These cartilage lesions are often diagnosed through an MRI or scan
Sometimes these lesions are localized and circumscribed. They are the best indications for cartilage grafts.
Rehabilitation follows some general principles
In the first three weeks, mobilization without load, drainage, massage and cryotherapy. The closedchain functional exercises are encouraged in particular (apartment bike). All knee revolutions should be avoided, which is why during this period, wearing removable splints is advised (day and night).
After three weeks, once support is authorized, we can move on to muscle strengthening, knee stability and mobility improvement exercises. Muscle recovery will be progressive, with bike, treadmill or rowing. Proprioception is emphasized.
Leg muscle strengthening will continue gradually to avoid excessive knee loading that could damage the articular cartilage.
Duration of the sick leave is estimated at 6 to 8 weeks.
Cartilage lesions located in a bearing area of the femur can progress rapidly into an arthrosis.
Arthrosis can then progress and extend. To avoid total knee prosthesis implantation, we propose a joint cartilage graft, knowing that indications remain limited in patients with circumscribed lesions in the knee.
Then, with a suitable functional rehabilitation, we expect full recovery of physical performance.
This type of graft is donebytaking an osteochondral graft from an eccentric area of the femur; osteochondral graft is composed of a cartilage fragment on a bone fragment (“core” of cartilage surface on a bone support).
These interventions are often made arthroscopically, everything depending on the size and location of this loss of cartilage matter. If the loss of matteris low and easily accessible, we will perform an arthroscopic intervention; On the contrary, if the lesion is large, it requires more grafts. If the area with loss of cartilage lies in an area difficult to access by arthroscopy, we will obliged to perform open surgery.
Fragments of bones and cartilage are removed from the same knee, from eccentric areas. These areasare situated on the external or internal boundaries of femoral condyles or around the intercondylar indentation. “Cores” taken usually have a diameter between 6 and 11 mm. The number of “cores” taken depends on the wear size. Then, these “cores” taken are embedded into the area where there is loss of cartilage.
When multiple grafts are required, we will take more “cores”.
Depending on the technique used (arthroscopy or not), length of hospital stay varies from 1 to 3 days, with resumption of walking. The patient will not be able to resume support on the operated leg for about three weeks.
Then, walking will be resumed, with progressive support, using two crutches.