[Alloplastic ligament replacement. A study of the biological fixation of 5 non-resorbable materials]

The long-term stability of alloplastic ligament prostheses depends on various parameters, on including the quality of the biologic fixation in the bone tissue. Biomechanical and histological tests were therefore performed to examine the stability obtained with five different alloplastic and non-resorbable ligament substitute materials following stress-free implantation into the distal femur and proximal tibia of Wistar rats. The materials were: a filament of the PTFE ligament prosthesis, PTFE suture material (Goretex), polyethylene terephthalate (Mersilene), polyethylene (Braun-Dexon) and polybutylene terephthalate (Miralene). The materials used were all of USP-1 quality. Extraction trials of the implants 32 weeks later did not show any differences between the PTFE materials, such as polyethylene and polyethylene terephthalate, whereas a significantly lower value was found for polybutylene terephthalate. The fixation involved connective tissue exclusively with all the materials tested except for PTFE. PTFE not only induced tight and direct bony contact externally, within the material itself extensive formation of new bone was also found. PTFE was found to be the most histocompatible material, while polyethylene terephthalate led to the most pronounced foreign-body-type reactions.