O. Robertsson, L. Borgquist, K. Knutson, S. Lewold, and L. Lidgren, “Use of unicompartmental instead of tricompart-mental prostheses for unicompartmental arthrosis in the knee is a cost-effective alternative: 15,437 primary tricompartmental prostheses were compared with 10,624 primary medial or lateral unicompartmental prostheses”, ActaO, vol. 70, no. 2, pp. 170–175, Jan. 1999.