A 10-year outcome study of patellar resurfacing during total knee arthroplasty (TKA) won the Surgical Techniques and Technologies Award during the recent meeting of The American Association of Hip and Knee Surgeons (AAHKS). This award recognizes outstanding advancement in surgical innovation within reconstructive surgery.
Lead author Jacob M. Wilson, M.D. teamed up with Mikaela H. Sullivan, M.D., Mark W. Pagnano, M.D. and senior author Robert T. Trousdale, M.D. to collect long term outcome data including implant survivorship, reoperation rates, complications and overall clinical outcomes for patients treated with patellar resurfacing of a thin native patella.
“We were honored to receive the AAHKS Surgical Techniques and Technologies Award for our paper on resurfacing the thin native patella.”
“Patients with a thin patella often have significant patellofemoral arthritis and prior data from our institution found higher revision rates in similar patients who were left un-resurfaced. For this reason, we sought to determine whether resurfacing was safe in this patient population. Our results suggest that this is a safe practice, and we hope these data will be useful to surgeons when encountering this clinical situation,” said Jacob M. Wilson, M.D.
Dr. Wilson, a hip and knee adult reconstruction surgeon at Vanderbilt University Medical Center, worked on the award-winning paper during his fellowship at Mayo Clinic in Rochester, Minnesota.
When OTW inquired as to the biggest controversy about this issue, Dr. Wilson said, “The question of whether to resurface the patella during primary total knee arthroplasty continues to be debated.”
“However, patients who have a thin native patella represent a clinical conundrum, regardless of surgeon philosophy. Prior data has demonstrated that patients with thin native patellae have a higher risk of revision when the patella is left unresurfaced when compared to resurfaced controls.”
“However, resurfacing patellae that are natively thin also has the theoretical risk of over resection and postoperative periprosthetic patella fracture. Prior literature is lacking regarding the safety of resurfacing these thin native patellae. This is what our paper addressed.”
Looking at data from 2000-2010, the team identified 11,333 patients undergoing primary TKA with patellar resurfacing. After 10 years, the percent of patients who did NOT experience a patella revision, patella-related reoperation, periprosthetic patella fracture, and/or a patella-related complication were 98%, 98%, 99% and 97%, respectively.
The research team noted three patella revisions among the study patients: one for patellar component aseptic loosening and two for prosthetic joint infection (PJI). “There were two additional patella-related reoperations, both arthroscopic synovectomies for patellar clunk,” wrote the authors. “Two patients underwent manipulation under anesthesia. There were three periprosthetic patella fractures managed nonoperatively, all with well-fixed components and intact extensor mechanisms. Radiographically, the patella appeared well fixed in all non-revised knees. Knee society scores improved from mean 36 preoperatively to mean 81 at 10-years postoperatively.”
“In our paper,” explained Dr. Wilson, “we describe the outcomes of 200 patients who had a native patellar thickness of ≤19mm who underwent patellar resurfacing during primary TKA. Median follow-up was 10 years.”
“Our primary finding was that overall, patella related complication and patellar revision were uncommon. Only three patients underwent revision of the patellar component: two for periprosthetic joint infection and one for patellar aseptic loosening. However, there were three periprosthetic patella fractures in our series. Fortunately, the extensor mechanism remained intact, and the component remained well fixed in all three and they were all, therefore, managed nonoperatively.”
Looking forward, he said, “While our data is informative and helpful for surgeons deciding whether to resurface a thin native patella during TKA, we still need prospective comparative data. Our data allows us to say that resurfacing appears to be a generally safe practice in this cohort, but we cannot comment on whether resurfacing or not resurfacing is a safer practice in this patient population. Prospective data could help clarify this.”
