The quadriceps tendon and patella tendon are the large tendons that connect the quadriceps (thigh muscle) to the patella (kneecap) and the leg. Their function to allow knee extension for functions such as walking, running, and kicking. Without a quadriceps or patella tendon, it is extremely difficult to walk, let alone run or participate in sports.
Ruptures of the quadriceps and patella tendon are relatively infrequent. They usually occur in patients older than 40 years of age during an activity with forced flexion of the knee, such as falling down the stairs. Sometimes, patients will have prior injuries to the quadriceps or patella tendon such as patellar tendonitis. Patella tendon ruptures are less common than quadriceps tendon ruptures.
Patients with patella or quadriceps tendon ruptures will typically have a painful, swollen knee after a fall. They will have difficulty walking and cannot straighten their leg against gravity or resistance. There is often a palpable defect where the rupture occurred.
Radiographs will show a patella that is sitting either too high (in the case of a patella tendon rupture) or too low (with a quadriceps tendon rupture).
The treatment of most quadriceps and patella tendon ruptures is surgery within 4 weeks after the injury. These tendons rarely heal on their own, and surgery is needed to put the ends of the tendon together. The surgery is usually an outpatient procedure under general or regional anesthesia. An incision is made on the front of the knee and heavy, non breakable sutures are used to repair the ruptured tendon to the patella.
After the surgery, it typically takes between 6 and 8 weeks for the tendon to heal. During that time, the knee is kept straight in a brace for a majority of the time to allow the repair to heal without stretching out. Once the surgeon has determined that the repair is healed, physical therapy begins in order to regain motion of the knee and strength in the quadriceps.
Over time, patients with quadriceps and patella ruptures regain their motion and strength and can return to sports and regular activities. It can often take up to a year for patients to fully recover from this difficult injury.