Finite element study of a partial meniscectomy of a complete discoid lateral meniscus in adults

•When the meniscus width dropped progressively in the range of 8-12 mm, the peak stress in the knee joint increased slowly.•The biomechanical environment of the knee joint is significantly deteriorated when the lateral meniscus is retained insufficiently (width <8 mm).•The peak stress position shifted from medial to lateral when the width of the residual lateral meniscus was reduced.•Impingement of the medial femoral intercondylar cartilage with the medial tibial eminence was observed when the meniscus width was reduced to 2 mm.