PATELLAR INSTABILITY SURGERY
WHAT IS IT?
The medial patellofemoral ligament (or MPFL) is a ligament that attaches to the inner edge of the patella and the inner femoral condyle on the inner side of the femur. It stabilizes the patella by preventing it from dislocating outward during knee flexion.
After an episode of patellar dislocation, the MPFL is systematically torn. It is possible to reconstruct it to stabilize the patella and prevent the occurrence of new dislocations: this is the MPFL reconstruction.
In agreement with your surgeon and based on the benefit-risk balance, MPFL reconstruction was proposed to you. The surgeon has explained the other alternatives. It goes without saying that your surgeon may, if necessary and depending on the findings during surgery or a difficulty encountered, proceed with another technique deemed by him more beneficial to your specific case.
BEFORE THE TREATMENT:
An imaging assessment will be carried out by your surgeon to look for factors predisposing to patellar dislocation. This generally involves standard radiographs and a CT scan and/or MRI of the knee.
WHAT TREATMENT?
The surgical procedure is performed under general or regional anesthesia. A vertical incision of a few centimeters is made on the upper and inner side of the tibia. A hamstring tendon is harvested from the inner side of the tibia (semitendinosus or gracilis tendon).
The actual reconstruction of the MPFL requires one or two other incisions at the inner edge of the patella and the inner side of the femur. Tunnels may be created to pass the graft according to the technique used.
The new ligament is positioned and fixed to the femur and patella by various means (suture, staple, screw, anchor…). At the end of the procedure, the surgeon tests the patella, which should be stable and not dislocate outward.
AND AFTER?
The procedure is performed on an outpatient basis. Weight-bearing on the operated limb is allowed from the first day with crutches and a removable brace in extension. Rehabilitation starts immediately.
Flexion may be limited during the first few weeks. A preventive anticoagulant treatment for thrombosis may sometimes be prescribed.
EXPECTED RESULTS
MPFL reconstruction is a straightforward surgical procedure. It is very effective for patellar dislocation. It can often be combined with other treatments for dislocation (tibial tuberosity osteotomy, vastus medialis plasty, lateral retinacular release, trochleoplasty, etc.).
