Patellofemoral Replacement

Good candidates for patellofemoral replacement are individuals who have isolated patellofemoral arthritis or anterior knee pain due to degenerative changes, and for whom non-surgical treatments have not provided sufficient relief. This procedure is usually recommended for patients who do not have significant arthritis in other compartments of their knee.

Patellofemoral replacement surgery is typically done on an outpatient basis, where you’ll go home the same day. The procedure begins with the administration of anesthesia, which can be general (you are asleep) or regional (you are awake, but your lower body is numb). Your knee surgeon Dr. Mayo then makes an incision at the front of the knee to access the joint. The patella and trochlea are then prepared by removing the damaged surfaces. New, prosthetic surfaces are then placed. The trochlear component is typically made of metal, and the patellar component is usually plastic. These materials are designed to glide smoothly against each other, similar to normal cartilage.

Recovery timelines vary, but generally, patients are encouraged to stand and walk within 24 hours after surgery with the help of physical therapy. Most individuals return to their regular activities within 6-8 weeks. Full recovery, including a return to sports activities, typically occurs within 3-6 months.

After surgery, expect to spend some time in the recovery room under observation until you are able to go home. You will be in a knee brace, and allowed to walk with crutches. Pain can be managed with medications, and physical therapy will begin soon after surgery to help restore knee mobility and strength.

Physical therapy is a vital part of recovery from patellofemoral replacement and typically includes:

• Early Stage: The focus is on gentle exercises to improve range of motion and reduce swelling. Assisted walking and balance training may also begin.
• Middle Stage: Strengthening exercises are introduced to improve muscle function and support for the knee.
• Late Stage: Functional training, including stair climbing and potentially sport-specific activities, is introduced to help you return to normal activities.

Like any surgery, patellofemoral replacement comes with potential risks, including:

• Infection: Less than 1% of patients typically experience an infection. Antibiotics are given before surgery to help prevent this. If an infection does occur, it may require antibiotics, or if more severe, additional surgeries.
• Blood clots: The risk of developing a blood clot, such as deep vein thrombosis, is small but real. Measures are taken before, during, and after surgery to minimize this risk.
• Implant loosening or failure: Over time, the implant may loosen or wear out. The risk is relatively low, but it increases with heavy use and high-impact activities.
• Persistent pain or stiffness: Some patients may continue to experience pain or stiffness in the knee after surgery.

If patellofemoral arthritis is left untreated, potential risks include:

• Worsening pain: As the patellofemoral arthritis progresses, pain can increase and become more persistent.
• Reduced mobility: Advanced arthritis can make it difficult to perform activities that involve knee bending, such as walking, climbing stairs, or getting up from a seated position.
• Progression of arthritis: Arthritis may develop in other parts of the knee over time, potentially necessitating a total knee replacement in the future.