1. Adams, R. D., Denny-Brown, D., Pearson, C. M.: Diseases of muscle. 2nd ed., pp. 503?508. New York: Harper and Brothers 1962
2. Engelbrecht, E., Siegal, A., Rottger, J., Bucholz, H. W.: Statistics of total knee replacement: Partial and total knee replacement, design St. Georg. Clin. Orthop. Rel. Res. 120, 54?63 (1976)
3. Freeman, P. A.: Walldius arthroplasty: A review of 80 cases. Clin. Orthop. Rel. Res. 94, 85?91 (1973)
4. Ritter, M. A., Vaughan, R. B.: Ectopic ossification after total hip arthroplasty. J. Bone Jt. Surg. 59-A/3, 345?351 (1977)