Lutz Rex W, Thalody Hope, Alexander Tia, Radack Tyler, Ong Alvin, Ponzio Danielle, Orozco Fabio, Post Zachary D
Orthopedic Surgery, Jefferson Health New Jersey, Stratford, USA.
Orthopedic Surgery, Rothman Orthopaedic Institute, Egg Harbor Township, USA.
Cureus. 2024 Jun 15;16(6):e62428. doi: 10.7759/cureus.62428. eCollection 2024 Jun.
Introduction The canal-to-calcar isthmus (CC) ratio has been previously correlated with proximal femur osteology, but its relationship with bone density is not well established. Our purpose was to assess the relationship between femoral bone density, measured on opportunistic quantitative CT in Hounsfield units (HU), and CC ratio. Methods A total of 148 THA patients were included. The CC ratio was measured on anteroposterior hip radiographs. Using perioperative CT scans, a 1 cm diameter area was identified on a single mid-coronal slice in the medial calcar just proximal to the intertrochanteric ridge. The mean HU was calculated in this region to represent calcar bone density. Results Twenty-four percent (n = 35) of patients were classified as Dorr A (average CC ratio 0.47 [0.45; 0.48]), 67% (n = 96) as Dorr B (0.62 [0.55; 0.68]), and 11% (n = 17) as Dorr C (0.78 [0.77; 0.80]). There was a significant difference between Dorr A and Dorr C femurs (769 (144) vs. 588 (154) HU) as well as between B and C femurs (718 (166) vs. 588 (154) HU). The CC ratio was correlated with calcar bone density on CT (-0.370). Conclusion CC ratio is correlated with bone density determined by HU measurements on an opportunistic quantitative computed tomography scan, and bone density HU values were able to accurately differentiate bone density in Dorr A and B from Dorr C femurs. These findings suggest that the CC ratio is a reliable measurement to predict bone density in Dorr C femurs. Therefore, arthroplasty surgeons can confidently use the Dorr classification for patients with Dorr C femurs when preoperatively planning for THA.
引言 此前已发现股骨颈峡部（CC）与股骨近端骨学相关，但其与骨密度的关系尚未明确。我们的目的是评估在机会性定量CT上以亨氏单位（HU）测量的股骨骨密度与CC比值之间的关系。方法 共纳入148例全髋关节置换（THA）患者。在髋关节前后位X线片上测量CC比值。利用围手术期CT扫描，在转子间嵴近端的内侧股骨距单一层面的中冠状面上确定一个直径1 cm的区域。计算该区域的平均HU值以代表股骨距骨密度。结果 24%（n = 35）的患者被归类为多氏A型（平均CC比值0.47 [0.45；0.48]），67%（n = 96）为多氏B型（0.62 [0.55；0.68]），11%（n = 17）为多氏C型（0.78 [0.77；0.80]）。多氏A型与多氏C型股骨之间（769（144）对588（154）HU）以及B型与C型股骨之间（718（166）对588（154）HU）存在显著差异。CC比值与CT上的股骨距骨密度相关（-0.370）。结论 CC比值与机会性定量计算机断层扫描上通过HU测量确定的骨密度相关，并且骨密度HU值能够准确区分多氏A型和B型股骨与多氏C型股骨的骨密度。这些发现表明CC比值是预测多氏C型股骨骨密度的可靠测量指标。因此，关节置换外科医生在为THA进行术前规划时，可以放心地将多氏分类用于多氏C型股骨的患者。
