Today's News

Saturday, February 15, 1997

Early IDE results finds no difference in cemented and porous growth fixation

Early clinical and radiographic results of 240 randomized, primary total knee arthoplasties in patients with noninflammatory degenerative joint diseases found that cement fixation offers no advantage over fixation via bone ingrowth with respect to overall pain relief, function and knee score.

The results of an Investigational Device Exemption protocol of the Food and Drug Administration to compare the performance of cemented hydroxyapatite (HA)-coated and uncoated porous total knee arthroplasties were reported Friday in scientific paper 261.

Patients who had all components cemented served as the control group. The two investigational groups (HA and non-HA) received identical implants as the control group, but had the femoral and tibial components inserted without cement and with four cancellous screws in the tibial tray. One-year postoperatively, there was no significant difference in the knee score, pain score and functional score, said Paul H. Castello, MD, orthopaedic service, Fitzsimons Army Medical Center, Aurora, Colo.

"HA did not significantly improve the clinical performance of the press-fit prosthesis," Dr. Castello said. "Comparative radiographic evaluation revealed no significant differences in the alignment of the femoral or tibial components of the three groups. Also, no significant differences were identified in terms of the number or grade of radiolucencies."

Co-authors of the study from Fitzsimons Army Medical Center are Edward J. Lisecki, MD, chief, total joint and orthopaedic service, and William T. Pace, MD, orthopaedic service. Other authors are Bernard Stulberg, MD, Cleveland Center for Joint Reconstruction, Cleveland, and Peter Earnshaw, FRCSC, Guy's Hospital, London, England.