Uncemented intramedullary fixation of implants using polyethylene sleeves. A roentgenographic study

Forty-three prostheses with noncemented, high-molecular-weight, polyethylene-sleeved components were used in the treatment of bone tumors around the knee in growing children. The average age of the patients was 11 years. There were 27 boys and 16 girls. There were 17 sleeved components in the distal femur and 26 in the proximal tibia. The average follow-up time was 27 months. The roentgenograms were nominally obtained at three, six, 12, 18, and 24 months, and irregularly thereafter, and were assessed using a zonal evaluation scheme. A sclerotic interface around the polyethylene sleeves invariably developed and progressed in density up to 28 months postoperatively. There were significant zonal differences in sclerosis, particularly between the plateau and the mid-sleeve zone. Only in one patient did a sleeve become loose and require revision.