Department of Orthopedics and Traumatology, Faculty of Medicine, Pamukkale University, Denizli, Turkey.
J Knee Surg. 2022 Sep;35(11):1260-1267. doi: 10.1055/s-0040-1722628. Epub 2021 Jan 20.
There is a tendency of orthopaedic surgeons to elevate joint line (JL) in revision total knee arthroplasty (RTKA). Here, we ascertain the use of the spacer block tool (SBT) to determine JL more accurately for less experienced RTKA surgeons. To perform more precise restoration of JL, an SBT with markers was developed and produced using computer software and three-dimensional printers. The study was planned prospectively to include patients who received either condylar constrained or rotating hinge RTKA between January 2016 and December 2019. To determine JL, distance from fibular head (FH), adductor tubercle (AT), and medial epicondyle (ME) were measured on contralateral knee preoperative radiographs and on operated knee postoperative radiographs. Patients were randomized and grouped according to the technique of JL reconstruction. In Group 1, conventional methods by evaluating aforementioned landmarks and preoperative contralateral knee measurements were used to determine JL, whereas in Group 2, the SBT was used. The main outcome measure was the JL change in revised knee postoperatively in contrast to contralateral knee to compare effective restoration of JL between the groups. Twenty-five patients in Group 1 (3 males, 22 females, 72 years, body mass index [BMI] 32.04 ± 4.45) and 20 patients (7 males, 13 females, 74 years, BMI 30.12 ± 5.02) in Group 2 were included in the study. JL measurements for the whole group were FH-JL = 18.3 ± 3.8 mm, AT-JL = 45.8 ± 4.6 mm, and ME-JL = 27.1 ± 2.8 mm preoperatively, and FH-JL = 20.7 ± 4.2 mm, AT-JL = 43.4 ± 5.2 mm, and ME-JL = 24.7 ± 3.1 mm postoperatively. JL level differences in reference to FH, AT, and ME in Group 1 were 3.6 ± 3.1, 3.6 ± 3.5, and 3.4 ± 3.1 mm, respectively, and in Group 2 were 1.0 ± .0.9, 1.3 ± 1.3, and 1.1 ± 1.3 mm, respectively. There were statistically significant differences between the two groups in JL changes referenced to all of the specific landmarks ( < 0.05). The use of the SBT helped restore JL effectively in our cohort of RTKA patients. Therefore, this tool may become a useful and inexpensive gadget for less experienced and low-volume RTKA surgeons.
骨科医生在进行翻修全膝关节置换术（RTKA）时往往会抬高关节线（JL）。在这里，我们使用垫块工具（SBT）来确定 JL，以帮助经验较少的 RTKA 医生更准确地进行手术。为了更精确地恢复 JL，我们使用计算机软件和三维打印机开发并生产了带有标记的 SBT。该研究计划前瞻性地纳入 2016 年 1 月至 2019 年 12 月期间接受髁限制或旋转铰链 RTKA 的患者。为了确定 JL，我们测量了对侧膝关节术前 X 线片和手术膝关节术后 X 线片上腓骨头（FH）、收肌结节（AT）和内上髁（ME）的距离。根据 JL 重建技术将患者随机分组。在第 1 组中，使用评估上述解剖标志和术前对侧膝关节测量值的常规方法来确定 JL，而在第 2 组中使用 SBT。主要的观察指标是术后修订膝关节的 JL 变化与对侧膝关节相比，以比较两组之间 JL 的有效恢复。第 1 组 25 例患者（3 名男性，22 名女性，72 岁，体重指数 [BMI]32.04±4.45）和第 2 组 20 例患者（7 名男性，13 名女性，74 岁，BMI30.12±5.02）纳入研究。整个组的 JL 测量值为 FH-JL=18.3±3.8mm、AT-JL=45.8±4.6mm 和 ME-JL=27.1±2.8mm，术后 FH-JL=20.7±4.2mm、AT-JL=43.4±5.2mm 和 ME-JL=24.7±3.1mm。第 1 组相对于 FH、AT 和 ME 的 JL 水平差异分别为 3.6±3.1、3.6±3.5 和 3.4±3.1mm，而第 2 组分别为 1.0±0.9、1.3±1.3 和 1.1±1.3mm。两组在所有特定解剖标志参考的 JL 变化方面存在统计学显著差异（<0.05）。SBT 的使用有助于我们的 RTKA 患者群体有效地恢复 JL。因此，对于经验较少和低容量的 RTKA 医生来说，该工具可能成为一种有用且廉价的工具。
