Patellofemoral joint replacement

FAQs Patellofemoral Joint Replacement in Arizona

 

Patellofemoral joint replacement is a viable treatment option for arthritis in kneecap and adjoining area. Though first used in 1950s, the replacement surgery is highly successful now with the availability of advanced implants. The procedure is widely recognized as a proven, breakthrough alternative for young patients with isolated arthritis affecting the kneecap and adjacent thighbone.

What is patellofemoral joint replacement?

Patellofemoral joint replacement is a surgical procedure to replace the patellofemoral surface – where femur of thighbone joins the rear of the patella or kneecap – of the knee with implants. The open procedure involves removing worn down patellofemoral component and resurfacing the area with metal and plastic prosthetics.

The knee joint has three compartments. The main knee joint is formed with femur meeting tibia. The inside part is known as medial and the outer part as lateral compartments. Patellofemoral, the third, lies on the front, between femur and the kneecap. Arthritis may impact any of the three compartments. Arthritis in the patellofemoral joint results in rubbing of femur and the backside of the kneecap. This leads to pain as you walk, kneel, do squatting, or climb up and down.

During patellofemoral joint replacement, surgeons remove damaged bone and cartilage. A metal surface is attached to the thighbone and a plastic surface is fixed to the posterior side of the kneecap. While dome-like plastic implant is attached to the kneecap, a metallic shield is placed around the trochlear groove. Bone cement is used to fix all implants.

What are conditions treated with patellofemoral joint replacement?

Patellofemoral joint replacement is a successful way to treat

  • isolated patellofemoral arthritis or arthritis impacting only the patellofemoral components
  • advanced chondromalacia or inflammation due to patellofemoral structural damage
  • failed microfracture, OATS, or arthroscopic lateral release to treat kneecap pain

Who is a candidate for patellofemoral joint replacement?

Patellofemoral joint replacement is suitable for those with

  • anterior osteoarthritis
  • cartilage damage and arthritis limited to the front knee compartment
  • chronic patellofemoral pain nonresponsive to non-surgical treatment
  • damaged patella, but no damage to other compartments of the knee
  • knee has normal stability and range of movement
  • no arthritic changes in other two compartments of the knee
  • no need for total knee replacement

However, the procedure is not for those with arthritis impacting the knee or requiring total knee replacement.

How is patellofemoral joint replacement performed?

Patellofemoral joint replacement is an open procedure. It focuses on partial replacement of worn out portion leaving as much part of the knee as possible intact.

The patient is placed under general anesthesia. An open incision is made in the midline on your front knee. Surgeons remove the worn out or damaged portions. A metal surface is attached to the thighbone and a plastic surface is fixed to the posterior side of the kneecap. While dome-like plastic implant is attached to the kneecap, a metallic shield is placed around the trochlear groove. Bone cement is used to fix all implants.

After an assessment of joint movement and stability, the cut is closed and the area is dressed. A small exhaust is created to allow draining out of excess fluid in the next 48 hours.

How long does patellofemoral joint replacement surgery take?

It takes between 1 and 2 hours.

Do I need to stay at the hospital after patellofemoral joint replacement?

Patients stay for 2 to3 days at the hospital. They are observed for side effects and also helped in achieving pain control and independence prior to being discharged. The drain is removed and tests are done to ensure all is well before the discharge.

Do I need rest after patellofemoral joint replacement?

Yes, patients need a week’s rest to ensure that there is no complication, including stress failure of implants.

What are the restrictions following patellofemoral joint replacement?

  • Keep the incision bandage clean and dry
  • No showering for 3 days
  • Rest for a 2 weeks
  • No driving for six weeks
  • RICE therapy (rest, ice, compression, and elevation) for a week
  • Use crutches for 6 to 12 weeks
  • Avoid weight bearing for 12 weeks
  • Use a brace after 6 weeks and continue using for 12 weeks
  • Avoid jumping or running for life

What kind of rehabilitation is needed following patellofemoral joint replacement?

For the first 10 days, do normal passive range of motions. After that, chalk out a physiotherapy strategy in consultation with your doctors and therapist. The aim is to gradually increase ROM without putting stress on the knee and preventing blood clotting. At least six to 8 months of progressive therapy is required.   

How long is the recovery period following patellofemoral joint replacement?

Return to work is decided by how physically demanding it is and your recovery level. It takes 2 to 3 weeks to return to sedentary jobs. But for labor-intensive jobs, wait until 12 weeks.

Total recovery takes 6 to 9 months. You can return to non-impact activities, including walking or swimming, without any problem in three months. Even you can ride bikes, join light gym workouts, or take to an elliptical trainer. But no high-level activity is allowed for 6 to 9 months, until you recovery fully. You can play golf in 3 months.

However, you have to avoid any high-impact activity with the potential to cause twisting or excessive knee rotation for life. It may lead to mechanical failure of the implants.

What are the potential complications of patellofemoral joint replacement?

  • Short-term knee stiffness and pain
  • Potential infection, bleeding, and nerve damage mostly attributed to surgical and medical care mistakes.
  • Blood clots are common and patients are advised anticoagulants to prevent them.
  • Loosening or early failure of implants

References

Cannon A, et al. Patellofemoral Resurfacing Arthroplasty: Literature Review and Description of a Novel Technique. Iowa Orthop J. 2008; 28: 42–48.

Dahm DL, et al. Patellofemoral arthroplasty versus total knee arthroplasty in patients with isolated patellofemoral osteoarthritis. Am J Orthop (Belle Mead NJ). 2010 Oct;39(10):487-91.

Lonner JH. Patellofemoral Arthroplasty, J Am Acad Orthop Surg, August 2007 vol. 15 no. 8; 495-506

Hofmann AA, et al. Patellofemoral replacement: The third compartment. Bone Joint J November 2013 vol. 95-B no. 11 Supple A 124-128

Blazina ME, et al. Patellofemoral replacement. Clin Orthop 1979;144:98-102

McKeever DC. Patellar prosthesis. J Bone Joint Surg [Am] 1955;37-A:1074-84

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