人工膝関節置換術における大腿骨骨軸と大腿骨コンポーネントのステム位置との比較―関節リウマチ患者のＸ線側面像における検討―

DOI 参考文献5件

書誌事項

タイトル別名
  • Comparison of the Anatomical Axis of the Distal Femur to the Position of the Femoral Stem for Total Knee Replacement, in Lateral Radiography of Rheumatoid Arthritis Patients

この論文をさがす

抄録

Objective: In this study we measured the position of the anatomical axis of the distal femur relative to the articular surface of the femoral condyle in lateral radiography, and compared the position of the anatomical axis to the position of the femoral stem for total knee arthroplasty.<BR>Methods: We studied 81 knees in 81 rheumatoid arthritis patients. The radiological grade of each knee joint was assessed by the Larsen method, and only knees for which Larsen grade was ≤III were included. The anatomical axis was defined as a line connecting the midpoints of femoral A/P diameter at 6 cm and 12 cm proximal from the distal end of the femur. The distances between that anatomical axis and the lines tangent to the anterior cortex and to the posterior condyle parallel to the anatomical axis were defined as A and B, respectively. The distances between the midline of the stem and the lines tangential to the inferior border of the anterior flange and to the posterior flange parallel to the midline of the stem were defined as a and b in 5 kinds of prostheses. The ratios A/B and a/b were calculated. Next, the proper size of each kind of prosthesis for each patient was determined by laying the template on the lateral radiograph. The distance between the midline of the stem and the anatomical axis was calculated as a minus A.<BR>Results: The mean value of A/B for all patients was 0.38 (SD 0.04) . The mean values of a/b were 0.36 (SD 0.02), 0.44 (SD 0.02), 0.54 (SD 0.03), 0.55 (SD 0.01) and 0.52 (SD 0.02) for models I, II, III, IV and V. The mean values of a minus A were 0.04 mm (SD 1.38), 1.42 mm (SD 1.44), 3.68mm (SD 1.48), 4.30 mm (SD 1.39) and 3.58 mm (SD 1.42) . The stem in models III, IV and V was located significantly posteriorly when compared to the stem in models I and II.<BR>Conclusion: Our results show that the position of the femoral stem in several kinds of components does not correspond to the position of the anatomical axis in most patients. In such cases, one should use an offset stem, However, the sizes of femoral condyles in Japanese patients are often smaller than those of many Western people. Therefore we sometimes cannot insert a femoral component with an offset stem because a portion of the offset would impinge on the posterior cortex of the posterior condyle. We should select prostheses with stems in the proper position.

収録刊行物

参考文献 (5)*注記

もっと見る

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ