Ground reaction force comparison of canine cemented and cementless total hip replacement

Ground reaction forces were studied in the hindlimbs of ten dogs after cemented and cementless total hip replacement. The femoral components in five dogs were surgically press fitted into the medullary canal for porous ingrowth fixation (cementless) while the remaining five dogs had their femoral component cemented in place. Gait analysis was performed monthly for four postoperative months. Reductions in vertical ground reaction forces were observed in both cemented and cementless implanted hindlimbs one and two months after surgery. By three months postoperative, both groups had effectively returned to their preoperative vertical ground reaction force levels on the implanted hindlimb. At three and four months post implantation, the cemented group demonstrated equal load distribution between the operated and unoperated hindlimbs, whereas the cementless group showed a disparity in load distribution between the operated and unoperated hindlimbs which persisted for the four-month test period. We believe that the paired comparisons between operated and unoperated limbs are more descriptive of antalgic gait than comparisons with preoperative control values.