MRI of meniscal allografts

To illustrate the techniques and the MRI appearance of meniscal transplants. Three patients underwent MRI of the knee between 2 weeks and 14 months after meniscal transplantation. Although postoperative artifacts were present, in all three patients the position, signal intensity, and morphology of the postoperative menisci could be easily characterized with standard spin-echo techniques. In the early postoperative period in the patients with clinically acceptable surgical results, the meniscal allograft had an MR appearance indistinguishable from the native meniscus; follow-up MRI showed increasing signal intensity in the periphery of the menisci on double-echo spin-echo imaging. In one case complicated by a joint effusion developing 6 weeks after surgery, MRI showed displacement and deformity of the allograft. Although preliminary, these results demonstrate that MRI can readily show the morphology and position of the transplanted meniscus and suggest it may prove useful in the identification of both immediate and long-term complications of the procedure.