Kneecap Dislocation Specialist

Are you an athlete who participates in sports that requires a rapid change of direction? If so, you may be at risk of developing a patella (kneecap) dislocation. Symptoms of a kneecap dislocation are rapid, acute swelling and severe knee pain until the kneecap is relocated to its original position. Kneecap dislocation specialist, Doctor Benedict Nwachukwu provides diagnosis as well as surgical and nonsurgical treatment options for patients in Manhattan, New York City, NY who have sustained a patella dislocation. Contact Dr. Nwachukwu’s team today!

What is a patella dislocation?

A patella or kneecap dislocation is a knee injury that occurs when the patella slips out of its normal position on the knee. A kneecap can dislocate with an unnatural twist, or when the knee is bent, and the patella is hit. A patella dislocation can cause extreme pain, stiffness and swelling. When a kneecap dislocates, the supporting soft tissue can weaken and contribute to the chance of further dislocations and knee instability. Manhattan, New York City and the surrounding New York boroughs orthopedic knee specialist, Dr. Benedict Nwachukwu specializes in treating various knee injuries, including patella dislocation.

What is the trochlear groove?

The trochlear groove is a component of the knee that is not as well known or discussed as the other parts of the joint. When the knee is bent, the undersurface of the patella lies in an area known as the trochlear groove. The patella moves smoothly up and down in the trochlear groove, as if on a track. This is important because the patella serves as a fulcrum to increase the overall strength and efficiency of the quadriceps muscles of the thigh. A patella dislocation forces the kneecap out of this groove and severe dislocations can cause tearing of the ligaments that hold the patella in place on the trochlea.

How is a patella dislocated?

A patellar dislocation is quite common, especially in young athletes. A kneecap dislocation typically occurs when the knee is straight, and the lower leg is bent outward while twisting, as seen with sports that require a rapid change of direction. A patella dislocation can also occur when the knee is bent and the patella is hit as seen in an accident or fall. In some patients however, underlying knee abnormalities can cause a patella dislocation with very little force and may occur repeatedly.  After a patella dislocation is experienced, it is critical for the kneecap to be relocated (reduced) back to its original anatomical position in the trochlear groove. This can happen spontaneously as the patient extends the knee, or in more difficult dislocations, by a qualified orthopedic specialist in a medical setting.

What are the symptoms of a patella dislocation?

Symptoms of a patella dislocation are often accompanied by rapid, acute swelling and severe knee pain until the kneecap is relocated to its original anatomic position. Other common symptoms include:

  • Hearing a popping sound at the time of injury or dislocation
  • Feeling the knee give way or buckle
  • Visual deformity of the knee
  • Pain along the inside ligaments which continues even after relocation
  • Instability in the knee joint
  • Locking or catching sensation (may be from loose bodies)

How is a patella dislocation diagnosed?

Even if the kneecap has slipped back into place on its own, patients in New York should still visit Dr. Nwachukwu as soon as possible. If the kneecap is persistently displaced, an immediate ER visit is critical. Once the kneecap is back in place, Dr. Nwachukwu will perform a thorough exam of the affected knee and obtain a medical history, including the events that led up to the dislocation. He will use diagnostic tests, such as x-rays and an MRI scan to evaluate the cartilage, surrounding ligaments and to determine if there are loose bodies.

What is the treatment for a dislocated kneecap?

Non-Surgical Treatment:

First and foremost, a patella dislocation requires an immediate relocation. Once the initial treatment is complete, the knee will need to be immobilized for a period of time, as determined by Dr. Nwachukwu. Bracing the joint protects the knee as well as increases patella stabilization and decreases swelling. A physical therapy program is recommended once the knee has begun to heal. Specific exercises will help strengthen the thigh muscles and reduce the inflammation to the tendons in the knee, reducing the risk of additional dislocations.

Surgical Treatment:

If non-surgical methods fail to decrease pain or if the patient experiences further dislocations, surgery may be recommended. Surgical procedures performed by Dr. Nwachukwu for patellar dislocation may include:

  • Lateral release: Loosens the structures pulling the kneecap out of place, while tightening the medial side of the knee.
  • MPFL Reconstruction: Reconstructs the ligament called the medial patellofemoral ligament which is the stabilizing tether between the end of the femur and the inner side of the patella.
  • Medical Imbrication also called Reefing: tightens the tissues on the inner side of the knee.
  • Bone Realignment: If the reason for the dislocation is a shallow trochlear groove, this procedure realigns the knee by positioning the tibial tubercle (large oblong bump) on the shin bone. This pulls the patella more to the inner side of the knee.

For more information on patella dislocation and recurrent patella instability, and the treatment options available, please contact the office of Benedict Nwachukwu, MD, orthopedic knee specialist serving Manhattan, New York City and the surrounding New York boroughs.   


HSS  Sports Medicine Institute West Side
610 W 58th Street
New York, NY 10019

HSS Brooklyn
148 39th Street, 7th Floor
Brooklyn, NY 11232

Fax: 646-885-8252

Office Hours

HSS Sports Medicine Institute West Side
Monday: 8:00 am – 5:00 pm
Tuesday: 8:00 am – 5:00 pm
Wednesday: 8:00 am – 5:00 pm
Thursday: 8:00 am – 5:00 pm

HSS Brooklyn
Friday: 8:00 am – 5:00 pm