BLOG: Considerations for patellofemoral joint preservation vs patellofemoral arthroplasty
Many patients come into the office with complaints of anterior knee pain that they have had for years and when you look at the data, 24% of women have patellofemoral arthritis by the time they reach age 40 years. One of the goals I had when I co-founded the Patellofemoral Center at Hospital for Special Surgery was to encourage patients to seek treatment rather than completely change their lifestyle. During the years, I have met patients who have sold their two-story homes as they no longer were able to reciprocate stairs. I have seen countless patients who have modified their commute, decreased their activity level and sadly lived in pain with activities of daily living. There are many optionsfor treatment of patellofemoral arthritis, and these treatments were largely not available when I finished my training more than 15 years ago.
The first step in treating these patients is to find out if they have undergone adequate physical therapy (PT). It is a common story that patients have found therapy to either be a waste of time or to worsen their symptoms. A good patellofemoral PT program should at the very least help the patient get stronger, teach them effective ways to strengthen the quad without overloading the patellofemoral joint and perhaps, help them unlearn their compensatory behaviors that lead to other aches and pains.
While many practitioners use hyaluronic acid for end-stage osteoarthritis of the knee, we have found it to be effective for younger patients suffering from isolated patellofemoral arthritis. In combination with PT, this can be effective even for patients with longstanding symptoms.
For the younger patient with significant symptomatic chondromalacia, there are several good options available once they have failed physical therapy and injections. For the classic overloader with lateral patellar tilt, perhaps slight valgus and an elevated Q-angle, an anteromedializing tibial tubercle osteotomy can improve patellar tracking and decrease the contact stress at the lateral facet of the patella. In patients with chondral lesions of 2 cm2 and more, a cartilage restoration procedure can provide pain relief and reduce stress on the subchondral bone.
Depending on insurance approval and hospital budgets MACI (Vericel), DeNovo (Zimmer Biomet) and in rare cases, osteochondral allografts can be utilized. When kissing lesions are present, a bipolar surface replacement can be done with MACI or generally, I prefer an allograft on the trochlea and a MACI on the patella. These cases have a protracted recovery with 4 weeks of non-weight-bearing, 6 weeks in a hinged knee brace and CPM for the surface treatments.
The decision on whether to consider a patellofemoral arthroplasty (PFJ) can be difficult in patients between the ages of 40 and 50 years and generally is determined by the extent of chondral wear. In those patients with significant or central trochlear wear, the best option is a PFJ; however, those patients with significant lateral tracking and elevated tibial tubercle to trochlear groove may require anteromedializing osteotomy first to appropriately align the joint in preparation for arthroplasty. While onlay trochlear implants allow some lateralization and external rotation of the trochlear groove, there is a limited amount of correction that is possible.
In patients older than 50 years of age, a PFJ is the best option in almost all cases. After a PFJ, patients typically go home the same day, are allowed full weight-bearing and are back at work in 2 to 6 weeks.
Sabrina Strickland, MD, is co-founder of the Patellofemoral Center at Hospital for Special Surgery and is an associate professor at Weill Cornell Medical College.
Disclosure: Strickland reports she is a consultant for Vericel.