Cartilage reconstruction using self-anchoring implant with functional gradient

Karen Cristina Laurenti,Carlos Alberto Fortulan,Lourdes Cristina De Albuquerque Haach,Arnaldo Rodrigues Dos Santos Jr,Rodrigo Bezerra De Menezes Reiff,João Manuel Domingos De Almeida Rollo,Ana Maria Minarelli Gaspar,Benedito De Moraes Purquerio

doi:10.1590/s1516-14392014005000030

Abstract

This study presents an innovative and original biomaterial designed to substitute for articular cartilage and mimic its mechanical behavior, including elastic cushioning and the characteristics of fiber-reinforced gel. The material was composed of polyurethane and bioglass microfiber 45S5. It was designed to present a tribological surface to the cartilage of the tibial plateau, and to convert over a functional gradient to an osteointegrable region for self-anchorage to the subchondral bone. The biomaterial samples showed no toxicity and promoted cell spreading. Subsequent in vivo studies in rabbits demonstrated the formation of a rigid structure similar to bone trabeculae in the distal region of the tribological surface of the implant. The tribological surface of the proximal region showed a fibrocartilaginous tissue with highly vascularized chondrocytes, thus validating the proposed concept for the design of the implant incorporating a functional gradient and auto-stability.

Highlights

Articular cartilage is a highly resilient connective tissue covering the bone joint surfaces
In order to achieve this goal, implants composed of bioglass microfiber and porous polyurethane were produced using available and reproducible manufacturing techniques
In injuries extending into the wellvascularized subchondral bone, all three stages naturally occur[21]

Summary

Introduction

Articular cartilage is a highly resilient connective tissue covering the bone joint surfaces. Articular cartilage is a tribological and lubricated surface that promotes movement without considerable friction. This type of cartilage is hyaline and is mainly composed of chondrocytes surrounded by extracellular matrix[1,2]. The biomechanical properties of articular cartilage depend largely on the composition and integrity of the extracellular matrix. Because it is an avascular tissue, articular cartilage has a low regeneration capacity. The cartilage lesions are healed by the formation of scar tissue composed mostly of fibrocartilage, which has weaker mechanical and biological properties than the original hyaline cartilage and which gradually degenerates over time, resulting in permanent loss of structure and function and leading to severe pain[1,3,4]

Methods

Results

Discussion

Conclusion