This week’s Orthopaedic Crossfire® debate was part of the 35th Annual Current Concepts in Joint Replacement® (CCJR®), Winter meeting, which took place in Orlando. This week’s topic is “Patella Resurfacing: Rarely, If Ever Necessary.” For is Robert L. Barrack, M.D., Washington University School of Medicine, St. Louis, Missouri. Opposing is Steven B. Haas, M.D., Hospital for Special Surgery, New York, New York. Moderating is Robert E. Booth, Jr., M.D., Jefferson Health 3B Orthopaedics, Philadelphia, Pennsylvania.
Dr. Barrack: Anterior knee pain is very common. Maybe the most common symptom after knee replacement. The misconception is that it’s from an unresurfaced patella. In my experience, it is far more common that this patient has a resurfaced patella that isn’t quite articulating well. Knee pain—this is something we see day in and day out and it’s usually with a resurfaced patella.
The bigger problem is when you go beyond just having asymmetric loading and anterior knee pain to where you get fragmentation of the patella. You look at the AP x-ray, the coronal alignment looks good. Something’s not quite right and because of that you get loosening on one side and fracture and fragmentation on the other side. This is the type of thing we see with regularity. These are very serious complications and the knee is never quite the same.
On CT, the knee is a little malrotated, but a fragmented, fractured patella—I see this on a regular basis.
The data I see on resurfacing studies is varied and contradictory. Dozens of studies say not resurfacing is equivalent, occasionally even better. Other studies say that routine resurfacing is equivalent or better. But they are usually underpowered, so you have to go to meta-analyses and registry data. If you look at the meta-analyses, you find that the reoperation rate is higher if you don’t resurface the patella. The incidence of anterior knee pain is contradictory.
The problem is the meta-analyses include old components that don’t do well with the non-resurfaced patella. Registry data says about the same. The reoperation rate is higher when the patella is not resurfaced. The clinical results of a subsequently resurfaced patella are generally unpredictable because there is an underlying problem. If you have malrotation, resurfacing the patella isn’t going to solve it.
Clinical results are similar. Indications for revision are unclear. If the patient has diffuse pain and you resurface their patella, it’s going to make your revision rate look higher, but they’re actually just problems with the indications.
What about the resurfaced patella? The problem is all the complications are not reported to a registry because they’re not implant related, in that you’re not putting in an implant. Usually you’re just taking out an implant. And the results vary by type.
A paper from the Mayo Clinic showed that lateral facet pain can require revision so they looked at 15-20 cases, but 99% of surgeons are not aware of this option (Nikolaus, et al., JOA). They don’t perform this procedure. If I re-operated on everyone who had lateral facet pain, the reoperation rate would go through the roof.
