上腕骨大結節の解剖学的位置におけるX線的評価

抄録

Accurate reproduction of anatomic relationship is important in non-constrained prosthetic arthroplasty. However, the geometry of the glenohumeral joint for prosthetic components has not been established yet. In this study, we evaluated the relationship between the position of the greater tuberosity and various geometric measurement values in the glenohumeral joint. Radiographs of 519 shoulders without osseous lesions were reviewed. There were 296 males and 223 females, and the mean age was 49.7 years old. Four parameters were measured on true anteroposterior radiographs, including the distance between the greater tuberosity and the humeral head, and the neck shaft angle. There were significant differences in all parameters between the males and females. Especially, the distance between the greater tuberosity and the humeral head was significantly correlated with the neck shaft angle in both the males (P<0.01, r=-0.468) and females (P<0.01, r=-0.639). At replacement of the smaller neck shaft angle than the anatomical neck shaft angle observed in the patient, the replacement of the humeral head component in the same distance between the greater tuberosity and the humeral head as that before surgery, might not be considered to be the reproduction of the anatomical glenohumeral joint. Therefore, we concluded that the determination of the distance between the greater tuberosity and the humeral head, in consideration of its relationship with the neck shaft angle, is important for the prevention of postoperative subacromial impingement.