Jones Lynee C, Wood Jil A, MacDessi Samuel J
Orthopaedics, Oceania University of Medicine, Apia, WSM.
Orthopaedics, Sydney Knee Specialists, Sydney, AUS.
Cureus. 2023 Jan 29;15(1):e34349. doi: 10.7759/cureus.34349. eCollection 2023 Jan.
Total knee arthroplasty (TKA) has become the treatment of choice for advanced osteoarthritis. Identifying malalignment is central to improving TKA outcomes and providing optimal management of TKA patients with post-operative pain and dissatisfaction. Computed tomography (CT) imaging has become increasingly popular as a more precise way of analysing post-TKA component alignment and the Perth CT protocol remains the current predominant assessment tool. This study aimed to analyse and compare inter- and intra-observer agreement of a post-operative multi-parameter quantitative CT assessment (Perth CT protocol) in TKA patients.
Post-operative CT images of 27 patients who underwent TKA were analysed retrospectively. Images were analysed by an experienced radiographer and a final-year medical student at least two weeks apart. Measurements for nine angles were collected: modified hip-knee-ankle (mHKA) angle, lateral distal femoral angle (LDFA) and medial proximal tibial angle (MPTA), femoral flexion and tibial slope, femoral rotation angle, femoral-tibial match rotational angle, tibial tubercle lateralisation distance, and Berger's tibial rotation. Intra-observer and inter-observer intraclass correlation coefficients (ICCs) were calculated.
Inter-observer reliability for the measurements of all variables varied from poor to excellent (ICC: -0.003 to 0.981). Five out of the nine angles demonstrated good to excellent reliability. Inter-observer reliability was highest for mHKA in the coronal plane and the poorest for the tibial slope angle in the sagittal plane. The intra-observer reliability for both reviewers was excellent (0.999 vs. 0.989).
This study demonstrates that the Perth CT protocol has excellent intra-observer reliability and good to excellent inter-observer reliability for five out of nine of the measured angles used to assess component alignment post-TKA, making it a useful tool for surgical outcome prediction and success.
全膝关节置换术（TKA）已成为晚期骨关节炎的首选治疗方法。识别力线不良对于改善TKA疗效以及为术后疼痛和不满意的TKA患者提供最佳管理至关重要。计算机断层扫描（CT）成像作为一种分析TKA术后假体组件力线的更精确方法越来越受欢迎，而珀斯CT方案仍然是当前主要的评估工具。本研究旨在分析和比较TKA患者术后多参数定量CT评估（珀斯CT方案）中观察者间和观察者内的一致性。
回顾性分析27例行TKA患者的术后CT图像。由一名经验丰富的放射技师和一名医学专业最后一年的学生至少间隔两周对图像进行分析。收集九个角度的测量值：改良髋-膝-踝（mHKA）角、股骨远端外侧角（LDFA）和胫骨近端内侧角（MPTA）、股骨屈曲和胫骨坡度、股骨旋转角、股胫匹配旋转角、胫骨结节外移距离和伯杰胫骨旋转。计算观察者间和观察者内组内相关系数（ICC）。
所有变量测量的观察者间可靠性从差到优不等（ICC：-0.003至0.981）。九个角度中有五个显示出良好到优秀的可靠性。冠状面mHKA的观察者间可靠性最高，矢状面胫骨坡度角最差。两位观察者的观察者内可靠性均为优秀（分别为0.999和0.989）。
本研究表明，珀斯CT方案对于用于评估TKA术后组件力线的九个测量角度中的五个具有优秀的观察者内可靠性和良好到优秀的观察者间可靠性，使其成为手术结果预测和成功评估的有用工具。
