[Indication and limitations of meniscus replacement]

Meniscal lesions are among the most important musculoskeletal disorders and are the most common indication for knee joint arthroplasty. However, the structural integrity and function is rarely retained, and a loss of tissue results. Thus, there is a huge demand for meniscal replacement options.

Autografts were used in the past but did not fulfill expectations. Meniscus allografts have been developed to be a viable treatment option. However, availability is limited and evidence of a long-term chondroprotective effect scarce. Artificial scaffolds made from either collagen or PCU foam are available, which aid the regeneration of meniscal tissue and are rather intended as a partial replacement with an intact peripheral rim. Those implants thus have a limited spectrum of indication. While they seem to be symptomatically effective, it remains unclear whether they can reduce secondary cartilage damage. Newer developments aim at a permanent replacement of lost meniscal tissue.

In summary, there is currently no meniscal replacement available for a broad range of indications and with a solid scientific foundation. Prophylactic use should be limited to cases with a high chance of progression to osteoarthritis, like a lateral total meniscectomy. Otherwise meniscal replacement should be considered in younger, symptomatic patients with mild to moderate secondary changes. Potential causes of the initial meniscal injury like instability or deformities should be carefully assessed and addressed. In many cases, osteotomy might be a viable alternative to meniscus replacement.