Quadriceps and Patellar Tendon Ruptures
Quadriceps and patellar tendon ruptures are significant injuries that affect the extensor mechanism of the knee. This mechanism includes the quadriceps muscles, the quadriceps tendon, the patella (kneecap), and the patellar tendon. This group of structures works together to allow us to straighten our knee and is critical for activities such as walking, running, and jumping. A rupture in this system is a serious injury that requires prompt medical attention.
A quadriceps tendon rupture occurs when the tendon that connects the quadriceps muscles to the patella tears. This typically happens at the point where the quadriceps tendon inserts into the kneecap.
Causes
These injuries most commonly occur in middle-aged people (after age 40), males more than females, who have weakened tendons due to chronic diseases like rheumatoid arthritis, diabetes, obesity, or chronic renal failure. They can also occur as a result of direct or indirect trauma, such as a direct fall onto the knee or from jumping/landing activities or a spontaneous rupture. A quadriceps tendon rupture after a total knee replacement typically affects men between the ages of 50 and 65. Intra-articular injections carry a 20-33% risk of a quadriceps tendon rupture.
Symptoms
Patients often report a popping sensation and immediate pain above the kneecap. There may be a palpable gap above the patella where the tendon has ruptured. The patient usually has difficulty walking due to the inability to straighten the knee.
Diagnosis
Dr. Reynolds will review the history of the injury and you symptoms and perform a physical exam. This may be sufficient to diagnose a quadriceps tendon rupture. Ultrasound imaging is the modality of choice to detect a tear.
Treatment
Initial management of a suspected rupture involves rest, icing, compression and elevation, and knee immobilization and physical therapy. A partial rupture may be able to be managed nonsurgically. Surgery to repair the tendon is usually required and involves reattaching a completely torn tendon to the kneecap. This is followed by a period of immobilization and then intensive physical therapy.
A patellar tendon rupture occurs when the tendon that connects the kneecap to the tibia (shinbone) tears. A patellar tendon rupture involves a complete tear of the tendon. This often happens at the point where the patellar tendon inserts into the tibia or the lower pole of the kneecap. These ruptures are classified as acute or chronic tears. This type of injury requires prompt diagnosis and surgical repair because this tendon is crucial to the function of the legs.
Causes
These injuries are most commonly seen in men between the ages of 30 and 40, who engage in running and jumping activities. Ruptures are usually the result of longstanding tendon degeneration due to chronic overuse and inflammation. They can occur after a direct blow to the front of the knee or during activities where the knee is bent and the foot planted, such as jumping, bounding up the stairs, landing from a jump or stopping and changing directions suddenly.
Symptoms
Patients often describe a tearing or popping sensation, followed by pain and swelling. A palpable gap may be present below the patella, and difficulty with weight bearing and standing on the leg. They usually can’t straighten the knee or walk normally.
Diagnosis
Dr. Reynolds will review the history of the injury and you symptoms and perform a physical exam looking for swelling and tenderness. These patients will have decreased range of motion, and a palpable defect below the kneecap. X-rays will be ordered to check for fractures, and an MRI is important to differential a partial from a complete rupture.
Treatment
Patellar tendon ruptures typically require surgical repair. Surgical intervention depends on timing and the location of the tear. Prompt repair surgery for acute ruptures is recommended to prevent the need for tendon reconstruction. Chronic ruptures usually require tendon reconstruction with an autograft or allograft. Surgical outcomes ae good to excellent.
The torn tendon is reattached to the patella or tibia with sutures. After surgery, the knee is usually immobilized for a period of time, followed by intensive physical therapy.
When you or a loved one has a knee injury, contact Dr. Masi Reynolds at Masi Orthopedics with offices in Santa Cruz, Fremont, Los Gatos and Menlo Park.
