SINGLE-STAGE REVISION USING AN UNCEMENTED, POROUS-COATED, ANATOMIC ENDOPROSTHESIS IN 2 DOGS - CASE-REPORT

Objective-To describe the clinical and radiographic features of septic and aseptic failure of two femoral endoprostheses and their successfu l revision. Study Design-Case report. Animals or Sample Population-Two skeletally mature male research dogs. Methods-An uncemented porous-co ated anatomic (PCA) endoprosthesis was implanted in a single-stage rev ision procedure after thorough debridement and lavage of the femoral c anal. An autogenous cancellous bone graft was used in dog 2 (aseptic l oosening). Serial clinical and radiographic examinations were performe d postoperatively. The dogs were euthanatized 1 year (dog 1) and 2 yea rs (dog 2) after revision surgery, and necropsy was performed. High-re solution contact radiographs and histopathologic evaluation of femoral sections were obtained. Results-The cause of implant failure was sept ic loosening in dog 1 and aseptic loosening in dog 2. In both dogs, cl inical function returned to normal after revision. Serial radiographic assessment after revision documented disappearance of the bone pedest al and the periprosthetic lucency. Cancellous hypertrophy seen adjacen t to the proximal porous-coated region of the implants provided radiog raphic evidence of bony fixation. Histological evaluation of femoral s ections documented successful implant integration with bone and fibrou s tissue. Conclusion-Revision with an uncemented implant in a single-s tage procedure was successful in the two dogs described in this report . Clinical Relevance-This report provides a detailed description of th e clinical course and serial radiographic assessment of septic and ase ptic loosening of two femoral endoprostheses. Single-stage revision is a potential treatment for either condition as demonstrated by the suc cessful outcome in these two dogs. (C) Copyright 1998 by The American College of Veterinary Surgeons.