# Anthropometric Analysis of Brazilian and Imported Total Knee Arthroplasty Implants in the Brazilian Population

## TL;DR

This study compares Brazilian and imported knee implants to see how well they fit the knee anatomy of Brazilian men and women.

## Contribution

The study provides a detailed anthropometric comparison of TKA implants in the Brazilian population, identifying which implants best match local anatomical dimensions.

## Key findings

- The best implant adaptations for Brazilian knees were Medacta Sphere (female femurs) and Zimmer Persona (male tibias).
- Imported implants showed better customization for Brazilian patients compared to domestic ones.
- Some implants had differences exceeding 10 mm, emphasizing the need for careful implant selection by surgeons.

## Abstract

To evaluate the anatomical conformity of 25 total knee arthroplasty (TKA) implants to the knee morphology of the Brazilian female and male population.

We analyzed 500 magnetic resonance imaging (MRI) scans of knees from 250 women and 250 men. We collected data on anteroposterior (AP) and mediolateral (ML) measurements of femurs, tibias, and implants to assess their morphological correspondence.

The mean AP versus ML divergence between joint morphologies and the implants was as follows: 4.48 mm for female femurs; 4.89 mm for male femurs; 3.63 mm for female tibias; and 6.11 mm for male tibias. The implants with the best AP versus ML adaptation were: Medacta Sphere for female femurs; Stryker Triathlon for male femurs; Smith & Nephew Legion for female tibias; and Zimmer Persona for male tibias. When comparing the best femoral and tibial implant ratios for female subjects, the United Orthopedic U2 presented the best statistical score, followed by the Aesculap Columbus and Smith &Nephew Legion implants. For male patients, the implants with the highest scores were the Zimmer Persona, the Microport Advance, and the Smith & Nephew Legion. The worst ratios were found in the Peter Brehm BPK-S for female individuals and the Orthovasive Indus for male subjects.

The implants studied presented satisfactory results for bone coverage of the knees of Brazilian subjects of both genders undergoing TKA. However, we also found differences higher than 10 mm in most implants. This finding highlights that surgeons must carefully plan the TKA during implant selection. Imported implants proved to be more customizable than Brazilian ones in this population.