Geijer Mats, Kiernan Sverrir, Sundberg Martin, Flivik Gunnar
Department of Radiology, University of Gothenburg, Gothenburg, Sweden.
Department of Radiology, Sahlgrenska University Hospital, Gothenburg, Sweden.
Acta Radiol Open. 2020 Oct 8;9(10):2058460120964911. doi: 10.1177/2058460120964911. eCollection 2020 Oct.
Restoration of a correct biomechanical situation after total hip arthroplasty is important.
To evaluate proximal femoral symmetry of acetabular and femoral offset and femoral neck anteversion pre- and postoperatively in hip arthroplasty by semi-automated 3D-CT and to validate the software measurements by inter- and intraobserver agreement calculations.
In low-dose CT on 71 patients before and after unilateral total hip arthroplasty, two observers used a digital 3D templating software to measure acetabular offset, true and functional femoral offset, and femoral neck anteversion. Observer agreements were calculated using intraclass correlation. Hip measurements were compared in each patient and between pre- and postoperative measurements.
Preoperatively, acetabular offset (2.4 mm), true (2.2 mm), and functional global offset (2.7 mm) were significantly larger on the osteoarthritic side without side-to-side differences for true and functional femoral offset or femoral neck anteversion. Postoperatively, acetabular offset was significantly smaller on the operated side (2.1 mm) with a concomitantly increased true (2.5 mm) and functional femoral offset (1.5 mm), resulting in symmetric true and functional global offsets. There were no differences in postoperative femoral neck anteversion. Inter- and intraobserver agreements were near-perfect, ranging between 0.92 and 0.98 with narrow confidence intervals (0.77-0.98 to 0.94-0.99).
Acetabular and concomitantly global offset are generally increased in hip osteoarthritis. Postoperative acetabular offset was reduced, and femoral offset increased to maintain global offset. 3D measurements were reproducible with near-perfect observer agreements. 3D data sets should be used for pre- and postoperative measurements in hip arthroplasty.
全髋关节置换术后恢复正确的生物力学状态很重要。
通过半自动三维CT评估髋关节置换术前、后髋臼和股骨偏心距以及股骨颈前倾角的股骨近端对称性，并通过观察者间和观察者内一致性计算验证软件测量结果。
对71例单侧全髋关节置换术患者进行低剂量CT扫描，两名观察者使用数字三维模板软件测量髋臼偏心距、真实和功能性股骨偏心距以及股骨颈前倾角。使用组内相关系数计算观察者间的一致性。比较每位患者术前和术后的髋关节测量值。
术前，骨关节炎侧的髋臼偏心距（2.4毫米）、真实偏心距（2.2毫米）和功能性整体偏心距（2.7毫米）明显更大，而真实和功能性股骨偏心距或股骨颈前倾角无左右差异。术后，手术侧的髋臼偏心距明显变小（2.1毫米），同时真实股骨偏心距（2.5毫米）和功能性股骨偏心距增加（1.5毫米），导致真实和功能性整体偏心距对称。术后股骨颈前倾角无差异。观察者间和观察者内的一致性接近完美，范围在0.92至0.98之间，置信区间较窄（0.77 - 0.98至0.94 - 0.99）。
髋关节骨关节炎时髋臼及整体偏心距通常会增加。术后髋臼偏心距减小，股骨偏心距增加以维持整体偏心距。三维测量具有可重复性，观察者间一致性接近完美。三维数据集应用于髋关节置换术的术前和术后测量。
