Accessibility Tools

What is Patellofemoral Arthritis?

Patellofemoral arthritis is an inflammatory condition characterized by loss of the smooth cartilage between the kneecap (patella) and the underlying femoral (thigh) bone in the knee joint. When the articular cartilage wears out, the underlying bones rub against each other, causing pain, swelling, stiffness, and restricted movement.

Causes of Patellofemoral Arthritis

Patellofemoral arthritis is caused by a wearing away of the cartilage under the kneecap. Some of the risk factors include the following:

  • Kneecap fracture or a history of knee trauma
  • Wear and tear due to aging
  • Dysplasia (abnormal bone cell and tissue growth)
  • Patella Alta (kneecap positioned higher than normal)
  • Inflammatory conditions such as gout and Paget’s disease

Symptoms of Patellofemoral Arthritis

The most common symptom of patellofemoral arthritis is a pain in the front of the knee that can be severe and may be present either at rest or during physical activity such as squatting or climbing. Other symptoms include:

  • Knee stiffness
  • Swelling
  • Knee crepitus (cracking sounds)
  • Valgus knee deformity (knock knees)

Diagnosis of Patellofemoral Arthritis

Your doctor will review your medical history and symptoms and perform a physical examination. Diagnostic tests can include the following:

  • X-rays: During this study, electromagnetic energy beams are used to produce images of the damaged bones.
  • CT scan: Detailed cross-sectional images are produced using multiplex-rays from different angles.
  • MRI Scan: Detailed images of the soft tissues and bones are produced by radio waves passing through the structures in a large magnetic field.

Treatment for Patellofemoral Arthritis

The main goal of treatment is to ease pain, improve joint movement, and prevent further damage to the knee joint. Patellofemoral arthritis can usually be managed by nonsurgical treatment methods including:

  • Weight loss: This can help reduce weight on the knee joint.
  • Exercises: Physical therapy or exercises such as swimming or walking help strengthen the muscles and reduce stiffness.
  • Rest: Avoid strenuous activities that trigger pain.
  • Non-steroidal anti-inflammatory drugs (NSAIDs): These drugs can help reduce swelling and pain.
  • Viscosupplementation: This involves the injection of a hyaluronic acid preparation into the knee joint to enhance lubrication.
  • Cortisone injection: This is injected into the knee joint to reduce inflammation.

If conservative treatment methods are unsuccessful, the following surgical approaches may be used:

  • Chondroplasty: This is an arthroscopic procedure in which instruments are inserted through small incisions into the joint to trim and smooth the rough cartilage, thereby reducing friction.
  • Cartilage Grafting: In this technique, healthy cartilage tissue is taken from other parts of the knee and grafted into the damaged areas.
  • Realignment Surgery: This method involves realigning the position of the kneecap by tightening or releasing the surrounding soft tissue attachments.
  • Partial Knee Replacement: The damaged articulating surfaces are replaced with prosthetic implants.
  • Tibial Tuberosity Transfer: This technique involves repositioning the tibial tubercle, a bony projection on the tibia to which the lower patellar ligament is attached. This helps realign the patella so that it traverses the center of the femoral groove, thereby reducing pressure on the damaged portions.
  • University of Arizona
  • Cal Poly Pomona
  • American Academy of Orthopaedic Surgeons
  • American Board of Orthopaedic Surgery
  • U.S. Ski & Snowboard
  • American Orthopaedic Society for Sports Medicine
  • University of California, Los Angeles
  • Stanford University
  • Biological Association
  • AANA Advancing the Scope