Secondary Patellar Resurfacing in TKA: A Combined Analysis of Registry Data and Biomechanical Testing.

Leandra Bauer,Christoph Thorwächter,Thomas M Grupp,Patrick Weber,Arnd Steinbrück,Volkmar Jansson,Matthias Woiczinski,Oliver Melsheimer

doi:10.3390/jcm10061227

Leandra Bauer, Christoph Thorwächter + Show 6 more

Open Access

https://doi.org/10.3390/jcm10061227

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Abstract

The German Arthroplasty registry (EPRD) has shown that different prosthesis systems have different rates of secondary patellar resurfacing: four years after implantation, the posterior-stabilized (PS) Vega prosthesis has a 3.2% risk of secondary patellar resurfacing compared to the cruciate-retaining (CR) Columbus prosthesis at 1.0% (both Aesculap AG, Tuttlingen, Germany). We hypothesized that PS implants have increased retropatellar pressure and a decreased retropatellar contact area compared to a CR design, which may lead to an increased likelihood of secondary patellar resurfacing. Eight fresh frozen specimens (cohort 1) were tested with an established knee rig. In addition, a possible influence of the registry-based patient collective (cohort 2) was investigated. No significant differences were found in patient data–cohort 2-(sex, age). A generally lower number of PS system cases is noteworthy. No significant increased patella pressure could be detected with the PS design, but a lower contact area was observed (cohort 1). Lower quadriceps force (100°–130° flexion), increased anterior movement of the tibia (rollback), greater external tilt of the patella, and increasing facet pressure in the Vega PS design indicate a multifactorial cause for a higher rate of secondary resurfacing which was found in the EPRD patient cohort and might be related to the PS’ principle function.

Highlights

According to the German Arthroplasty registry (EPRD), 124,677 total knee arthroplasties (TKA) were performed in Germany in 2019 [1]
Flexion), increased anterior movement of the tibia, greater external tilt of the patella, and increasing facet pressure in the Vega PS design indicate a multifactorial cause for a higher rate of secondary resurfacing which was found in the EPRD patient cohort and might be related to the PS’
Follow-up of patients who may have been treated in a hospital without data capture for the EPRD is facilitated by hospitals providing mandatory billing data [1, 17]

Summary

Introduction

According to the German Arthroplasty registry (EPRD), 124,677 total knee arthroplasties (TKA) were performed in Germany in 2019 [1]. The main reason for implantation is degenerative joint wear. It can be assumed that the number of artificial joints required by the population will continue to increase. Total knee arthroplasty has developed rapidly in recent decades, up to 19% of patients are dissatisfied with their prosthesis [2,3,4,5]. In the United States (US), >90% of primary TKA are performed with patellar resurfacing [6,11]. The Swedish Registry reports a significantly lower number (2.9%) of patellar resurfacing for primary TKA [12].

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