Mhaskar Vikram Arun, Saggar Rachit, Karan Satyabrat, Maheshwari Jitendra
Sitaram Bhartia Institute of Science and Research, New Delhi, India.
Max Super Speciality Hospital, Delhi, India.
Arch Orthop Trauma Surg. 2024 Dec 28;145(1):102. doi: 10.1007/s00402-024-05743-2.
Achieving precise postoperative alignment is critical for the long-term success of total knee arthroplasty (TKA). Long-leg standing radiograph (LLR) at 6 weeks post-op is the gold standard for assessing alignment, but its reliance on weight-bearing and positioning makes it less practical in the early postoperative period. Supine computed tomography scanogram (CTS) offers a potential alternative. This study compares CTS and LLR in patients undergoing TKA with patient-specific valgus correction angles (VCA).
A prospective study of 108 knees from 57 patients undergoing primary TKA was conducted. CTS was performed on postoperative day three in a supine non-weight-bearing position, and LLR at six weeks in an upright standing position. Coronal alignment was assessed using hip-knee-ankle angle (HKA) and compared using Bland-Altman plots, paired-samples t-tests, and Cohen's d.
CTS showed 57% of knees were within 3° of neutral alignment, while LLR showed 61%. The mean difference between modalities was 0.52° (SD, 3.56°; p = 0.07). Inter-observer reliability was excellent for both CTS and LLR (all ICCs > 0.9).
While CTS provides a useful alternative for early postoperative alignment assessment-particularly in situations where a standing LLR is not feasible-the observed variability suggests that LLR remains the more reliable modality when precise alignment is critical. Surgeons should therefore consider CTS as an adjunct tool for early decision-making or non-ambulatory patients in the immediate postoperative setting.
Level II, Prospective Comparative Study.
实现精确的术后对线对于全膝关节置换术（TKA）的长期成功至关重要。术后6周的长腿站立位X线片（LLR）是评估对线的金标准，但其对负重和体位的依赖使其在术后早期不太实用。仰卧位计算机断层扫描扫描图（CTS）提供了一种潜在的替代方法。本研究比较了接受TKA且有患者特异性外翻矫正角度（VCA）的患者的CTS和LLR。
对57例接受初次TKA的患者的108个膝关节进行了一项前瞻性研究。术后第三天在仰卧非负重位进行CTS检查，术后六周在直立站立位进行LLR检查。使用髋-膝-踝角（HKA）评估冠状面的对线情况，并使用Bland-Altman图、配对样本t检验和Cohen's d进行比较。
CTS显示57%的膝关节处于中立对线的3°范围内，而LLR显示为61%。两种检查方式之间的平均差异为0.52°（标准差，3.56°；p = 0.07）。CTS和LLR的观察者间可靠性均极佳（所有组内相关系数均>0.9）。
虽然CTS为术后早期对线评估提供了一种有用的替代方法，特别是在无法进行站立位LLR检查的情况下，但观察到的变异性表明，当精确对线至关重要时，LLR仍然是更可靠的检查方式。因此，外科医生应将CTS视为术后即刻早期决策或非步行患者的辅助工具。
II级，前瞻性比较研究。
