Nishi Masanori, Okano Ichiro, Yoshikawa Yasushi, Tochio Hidenori, Usui Yuki, Inagaki Katsunori
Department of Orthopedic Surgery, Showa University School of Medicine, Shinagawa-ku, Tokyo, Japan.
Arthroplast Today. 2022 Jan 17;14:216-222.e1. doi: 10.1016/j.artd.2021.11.016. eCollection 2022 Apr.
The association between regional bone status around the acetabulum and the incidence of intraoperative acetabulum fractures has not been extensively studied. We investigated the association of Hounsfield unit (HU) values on computed tomography in the regions of the acetabulum with periprosthetic fractures.
We retrospectively reviewed records of 301 consecutive patients who underwent cementless total hip arthroplasty between October 2016 and December 2020. Using preoperative computed tomography taken in the 4 weeks preceding total hip arthroplasty, we measured HU values in 4 different acetabulum regions (anterior, medial, posterior, and superior). After identifying fracture cases, we identified a control group-matched in terms of sex, age, and preoperative diagnosis-selected in a 1:3 ratio among nonfracture patients treated in the same inclusive period. As the average HU values differed by region, we used the standardized value to compare fracture-site HUs. We ranked the standardized HU values for each acetabular site and compared the fracture site rank between the groups.
Intraoperative acetabular fractures were observed in 10 hips (3.2%), occurring most frequently in the superior region (40%). The standardized HU values of the fracture site were statistically lower in the fracture group ( = .039). We compared the ranks of the standardized HUs of the fractured parts with those of the corresponding parts in the control group; the fracture site had a significantly lower standardized HU rank, indicating that fractures tended to occur in the relatively "weaker-than-expected" parts.
Periprosthetic fractures tended to occur at relatively weak parts of the acetabulum.
髋臼周围局部骨状态与术中髋臼骨折发生率之间的关联尚未得到广泛研究。我们调查了髋臼区域计算机断层扫描中的亨氏单位（HU）值与假体周围骨折的关联。
我们回顾性分析了2016年10月至2020年12月期间连续301例行非骨水泥型全髋关节置换术患者的记录。使用全髋关节置换术前4周内拍摄的术前计算机断层扫描，我们测量了4个不同髋臼区域（前侧、内侧、后侧和上侧）的HU值。在确定骨折病例后，我们在同一纳入期内接受治疗的非骨折患者中，按照1:3的比例选择了一个在性别、年龄和术前诊断方面匹配的对照组。由于平均HU值因区域而异，我们使用标准化值来比较骨折部位的HU值。我们对每个髋臼部位的标准化HU值进行排名，并比较两组之间骨折部位的排名。
10例髋关节（3.2%）发生术中髋臼骨折，最常见于上侧区域（40%）。骨折组骨折部位的标准化HU值在统计学上较低（P = 0.039）。我们将骨折部位标准化HU的排名与对照组相应部位的排名进行比较；骨折部位的标准化HU排名明显较低，表明骨折倾向于发生在相对“比预期更弱”的部位。
假体周围骨折倾向于发生在髋臼相对薄弱的部位。
