Background:

Anterior closing wedge osteotomy of the proximal tibia may be considered in revision anterior cruciate ligament (ACL) reconstruction surgery for patients with excessive posterior tibial slope (PTS).

Purpose:

(1) To determine the ratio of wedge thickness to degrees of correction for supratubercle (ST) versus transtubercle (TT) osteotomies for anterior closing wedge osteotomies and (2) to evaluate the accuracy of ST and TT osteotomies in achieving slope correction.

Study Design:

Controlled laboratory study.

Methods:

The computed tomography (CT) scans of 38 knees in 37 patients undergoing revision ACL reconstruction were used to simulate both ST and TT osteotomies. A 10° wedge was simulated in all CT models. The height of the wedge along the anterior tibia was recorded for each of the 2 techniques. The ratio of wedge height to achieved degree of correction was calculated. ST and TT osteotomies were performed on 3-dimensional (3D)–printed tibias of the 12 patients from the study group with the greatest PTS, after the desired degree of correction was determined. Pre- and postosteotomy slopes were measured for each tibia, and the actual change in slope was compared with the intended slope correction.

Results:

According to CT measurements, the ratio of wedge height to degree of correction was 0.99 ± 0.07 mm/deg for the ST osteotomy and 0.83 ± 0.06 mm/deg for the TT osteotomy (P < .001). When these ratios were used to perform simulated osteotomies on the twelve 3D-printed tibias, the mean slope correction was within 1° to 2° of the intended slope correction, regardless of osteotomy location (ST or TT) or whether slope was measured on the medial or lateral plateau. The ST technique tended to undercorrect and the TT technique tended to overcorrect.

Conclusion:

When anterior tibial closing wedge osteotomies were removed to correct excessive PTS, removing a wedge with a ratio of 1 mm of wedge height for every 1° of intended correction for an ST technique and a ratio of 0.8 mm to 1° for a TT technique resulted in overall average slope correction within 1° to 2° of the target.

Clinical Relevance:

The calculated ratios will allow clinicians to more accurately correct PTS when performing anterior closing wedge tibial osteotomy.

中文翻译：

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确定胫骨前侧闭合楔形截骨术胫骨后倾角过大的楔形高度与矫正度数的比值

背景：

对于胫骨后倾（PTS）过大的患者，在翻修前交叉韧带（ACL）重建手术中可考虑胫骨近端前闭合楔形截骨术。

目的：

(1) 确定前闭合楔形截骨术的结节上 (ST) 截骨术与经结节 (TT) 截骨术的楔形厚度与矫正度数的比率，以及 (2) 评估 ST 和 TT 截骨术在实现斜度矫正方面的准确性。

学习规划：

受控实验室研究。

方法：

37 名接受翻修 ACL 重建的患者的 38 膝的计算机断层扫描 (CT) 扫描用于模拟 ST 和 TT 截骨术。在所有 CT 模型中都模拟了 10° 楔形。对于 2 种技术中的每一种，都记录了沿胫骨前部的楔形高度。计算楔形高度与达到的矫正程度的比率。在确定所需的矫正程度后，对来自研究组的 12 名 PTS 最大的患者的 3 维 (3D) 打印胫骨进行 ST 和 TT 截骨术。测量每个胫骨截骨前和截骨后的斜率，并将斜率的实际变化与预期的斜率校正进行比较。

结果：

根据 CT 测量，ST 截骨术的楔形高度与矫正程度的比率为 0.99 ± 0.07 mm/deg，TT 截骨术的楔形高度与矫正程度的比率为 0.83 ± 0.06 mm/deg ( P < .001)。当使用这些比率对 12 个 3D 打印胫骨进行模拟截骨时，无论截骨位置（ST 或 TT）如何或是否在胫骨上测量斜率，平均斜率校正在预期斜率校正的 1° 至 2° 范围内。内侧或外侧平台。ST 技术倾向于矫正不足，TT 技术倾向于过度矫正。

结论：

当去除胫骨前侧闭合楔形截骨术以矫正过度的 PTS 时，ST 技术每 1° 的预期矫正度与 0.8 mm 至 1° 的比率去除一个楔形物，导致楔形物高度为 1 mm在目标的 1° 到 2° 范围内的整体平均坡度校正。

临床相关性：

计算出的比率将使临床医生在进行前闭合楔形胫骨截骨术时更准确地纠正 PTS。