Background:

Time-dependent changes in lower extremity alignment after an opening-wedge high tibial osteotomy (OWHTO) have been poorly investigated. Moreover, few studies have investigated risk factors of postoperative alignment change.

Purposes:

To investigate time-dependent alignment changes and identify predictive factors for postoperative alignment change after OWHTO.

Study Design:

Case-control study; Level of evidence, 3.

Methods:

This study included patients who underwent OWHTO between March 2010 and September 2018. A total of 142 knees with a mean follow-up of 42 months were included and classified as the change group when the amount of hip-knee-ankle (HKA) angle change was >1°; if otherwise, then as the no-change group. HKA angle was obtained at 6 time points: preoperatively and at 3 months, 6 months, 1 year, 2 years, and final follow-up postoperatively. Multiple regression analysis was performed to identify the factors that were correlated with the changes in the HKA angle from 3 months to the final follow-up.

Results:

Among the 142 knees, 59 (42%) were included in the change group. The overall postoperative HKA angles progressed serially toward varus after OWHTO. The mean angles of the 6 time points were 8.5°, –3.7°, –3.6°, –3.3°, –3.1°, and –2.7°, respectively. The mean HKA angles of the change and no-change groups were 9.1°, –4.3°, –3.4°, –2.8°, –2.0°, and –1.4° and 8.1°, –3.3°, –3.8°, –3.6°, –3.8°, and –3.7°, respectively. Greater change in the HKA angle was predicted by preoperatively greater valgus stress joint line convergence angles and less medial joint space width.

Conclusion:

Of the cases of OWHTO, 42% showed correction loss of >1° at a mean follow-up of 42 months. The overall postoperative HKA angles progressed serially to varus angles after OWHTO. Preoperative greater valgus stress joint line convergence angles and less medial joint space width were predictive factors for greater change in alignment toward varus after OWHTO.

中文翻译：

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术前内侧紧实度和狭窄的内侧关节间隙是开放楔形高位胫骨截骨术后下肢向内翻变化的预测因素

背景：

开放楔形胫骨高位截骨术（OWHTO）后下肢对齐的时间依赖性变化尚未得到很好的研究。此外，很少有研究调查术后对线改变的危险因素。

目的：

调查随时间变化的对线变化，并确定 OWHTO 术后对线变化的预测因素。

学习规划：

病例对照研究；证据水平，3。

方法：

本研究纳入 2010 年 3 月至 2018 年 9 月期间接受 OWHTO 的患者。共纳入 142 只膝关节，平均随访 42 个月，当髋-膝-踝 (HKA) 角度变化量变化时归为变化组>1°；否则，作为不变组。在 6 个时间点获得 HKA 角：术前和术后 3 个月、6 个月、1 年、2 年和最终随访。进行多元回归分析以确定与HKA角从3个月到最终随访的变化相关的因素。

结果：

在 142 个膝关节中，59 个（42%）被包括在改变组中。在 OWHTO 后，整体术后 HKA 角度逐渐向内翻方向发展。6个时间点的平均角度分别为8.5°、–3.7°、–3.6°、–3.3°、–3.1°和–2.7°。变化组和未变化组的平均 HKA 角分别为 9.1°、–4.3°、–3.4°、–2.8°、–2.0°、–1.4° 和 8.1°、–3.3°、–3.8°、–3.6 °、–3.8° 和 –3.7° 分别。术前更大的外翻应力关节线会聚角和更小的内侧关节间隙宽度预测了 HKA 角的更大变化。

结论：

在 OWHTO 病例中，42% 的患者在平均 42 个月的随访中显示矫正损失 > 1°。OWHTO 后，整体术后 HKA 角度连续发展为内翻角度。术前较大的外翻应力关节线会聚角和较小的内侧关节间隙宽度是 OWHTO 后内翻对线变化较大的预测因素。