ABSTRACT
PURPOSE: To analyze the clinical and radiologic results after total knee arthroplasties using down-sizing femoral prosthesis for tight fitting in patients over 75 years old. SUBJECTS AND METHODS: The study tracked the histories of 99 elderly patients aged 75 and over who underwent total knee arthroplasties with at least five years of follow-up from January 1st, 2005 to December 31st, 2007. The average age of the 99 patients was 78.58 years, and 17 women an 82 men patients underwent 78 cases of total knee arthroplasties on the right and 77 cases of total knee arthroplasties on the left. The HSS score and VAS scoring systems were introduced for clinical analysis. We compared the results of the width of the radiolucent line in 7 sections around the femoral component, 7 sections around the tibia component and 5 sections in the patella component using the American Knee Society Radiographic Evaluation and Scoring system respectively. RESULT: The average period of postoperative follow-up study was 6.2 years. The average femoral prosthesis size in preoperative measurement was 2.41 while the size selected in surgery was 1.89. The average VAS score decreased from 8.15 in preoperative measurement to 2.85 in postoperative measurement. Clinical significant loosening or dislocation of femoral prosthesis was not observed. Although the radiolucent line was observed in 5 cases, the score was less than 4. CONCLUSION: Total knee arthroplasties using down-sizing femoral prosthesis does not increase osteolysis and dislocation of femoral prosthesis but does reduce pain and help patients return to normal activities. Therefore this study showed that total knee arthroplasties using down-sizing femoral prosthesis helped elderly patients aged 75 and over.