Formation of new menisci after polycentric knee arthroplasty. Report of four cases, one with a bucket handle tear.

This paper presents four patients with polycentric artificial knee joints in whom reoperation revealed new menisci interposed between the artificial joint surfaces. One of the menisci had a bucket handle tear and was excised. Histological examination showed a fibrocartilage structure with the appearance of a newly formed meniscus. The artificial knees functioned well and the reoperations were performed because of trauma in one patient, because of femoro-patellar problems in one knee, and for conversion of a hemi-arthroplasty to an arthroplasty including all the compartments of the knee joint in two patients.