What is the quadriceps tendon?
The quadriceps tendon is the strong tendon that inserts on the top of the patella (kneecap), and it is a convergence of the four quadricep muscles that function to extend the knee and leg. All four of these muscles come together just above the patella and form a strong, thick tendon. The quadriceps tendon is important, and if injured or torn, the patient will not be able to extend their knee.
What causes a quadriceps tendon tear?
A rupture of the quadriceps tendon occurs relatively infrequently, and is usually seen in patients older than 40 years old. Injuries to the quadriceps tendon can be very disabling, and if not treated appropriately, can have many negative long-term effects. Common causes include:
- Injury – A very strong force is required to tear the quadriceps tendon. Tears are commonly caused by a traumatic injury like a harsh landing from a jump or impact from a fall.
- Tendon weakness – Tendon rupture can also occur if the individual already suffers from tendon pain and weakness prior to the injury
What are the symptoms?
When a quadriceps tendon tears, there is often a tearing or popping sensation. Pain and swelling typically follow, and you may not be able to straighten your knee. Additional symptoms include:
- An indentation at the top of your kneecap where the tendon tore
- Bruising and tenderness
- Your kneecap may sag or droop because the tendon is torn
- Difficulty walking due to the knee buckling or giving way
- Inability to extend the leg (if complete rupture)
How is a quadriceps tendon rupture diagnosed?
Initially a patient who presents with pain and swelling in the knee should undergo x-rays of the affected knee, since the kneecap moves out of place when the quadriceps tendon tears. This is often very obvious on a "side view" x-ray of the knee. Dr. Potts may also order an MRI scan of the knee to evaluate all of the soft tissue structures in the knee and help distinguish between a complete and partial tear.
What is the treatment for quadriceps tendon tears?
- Partial tears – In some cases, partial tears can sometimes be treated non-operatively. In order for a partial tear to be treated without surgery, the patient must be able to perform a straight-leg raise. If this is the case, treatment consists of immobilization and eventual physical therapy.
- Complete tears – similar to the treatment of partial tears, surgery is necessary if the patient is unable to perform a straight-leg raise. Without surgical repair of the tendon, the patient will be unable to extend their knee and will ultimately have significant long-term disability. Surgery is recommended within a few days to a week following the injury.