Polyester fibre prosthetic anterior cruciate ligament implant rupture: necrosis of ingrown connective tissue.

AIMS: To describe the histopathological and microanalytical features in seven cases of ruptured Apex(R) polyester (Terylene(R)) fibre anterior cruciate ligament prosthesis.

METHODS AND

RESULTS

Transmitted and polarized light microscopy was performed in all cases; one case was investigated by immunohistochemistry, transmission electron microscopy and scanning electron microscopy, with backscatter and X-ray detectors for elemental microanalysis. For comparison we also studied synovial biopsy material and unused polyester fibres. In the excised ligaments there was much ingrowth of fibrous tissue accompanying a florid giant cell reaction to the individual intact polyester fibres throughout the ligaments. Phagocytosis of particles of prosthesis-derived material was demonstrated and a striking finding was of necrosis of the ingrown connective tissue in the central portions of the ligaments. Hyalinized areas and 'neoligament growth' were less striking. A consistent finding in the polyester fibres was of small particles containing antimony, used as a catalyst in the manufacturing process.

CONCLUSIONS

The pattern of reaction to the prosthetic material and the presence of necrosis differ from previous descriptions in animal and human explants of this and other prosthesis types. The mechanical effect of the necrosis is unlikely to be of significance with this ligament, which is load-bearing ab initio.