COMPARISON OF CEMENTED AND NONCEMENTED ALLOGRAFTS IN DOGS WITH OSTEOSARCOMA

This study compares the radiographic and histological appearance of ce mented and non-cemented massive cortical allografts in dogs that under went a limb sparing procedure for osteosarcoma of the distal radius. T reatment consisted of removal of the affected bone and pancarpal arthr odesis using non-cemented (n = 13) or cemented (n = 47) fresh-frozen a llografts. Allografts were evaluated using a radiographic and histolog ical scoring system and compared statistically between groups. Allogra fts with better healing received a higher radiographic score and a low er histological score. The mean radiographic scores, for proximal unio n and distal union, were significantly greater in the non-cemented gro up at most evaluation periods. Complications after the operation inclu ded screw, plate, allograft and host bone failure, infection and local tumour recurrence. Screw failure in the allograft and allograft failu re were significantly more common in the non-cemented group. Histologi cal examination was performed on 44 dogs and cement increased the mean combined histological scores, and mean healing scores of the distal h ost-graft interface significantly. The use of cemented allografts sign ificantly decreases complications associated with implant loosening or allograft failure but may slightly delay allograft healing. At this p oint, the clinical relevance of the delay in healing is questionable a nd the benefits of intramedullary PMMA would appear to outweigh this r elative delay in healing.