Background:There is still debate regarding the association between arthrometric knee laxity measurements and subjective knee outcome and revision surgery after primary anterior cruciate ligament reconstruction (ACLR).Purpose:To assess whether arthrometric knee laxity (measured with the KT-1000 arthrometer) 6 months after primary ACLR was associated with the 1-, 2-, and 5-year subjective knee outcomes or revision ACLR at a 5-year follow-up.Study Design:Cohort study, Level of evidence 3.Methods:Patients who underwent primary ACLR with a hamstring tendon autograft at the authors’ institution between January 1, 2005, and December 31, 2017, with no concomitant ligamentous injuries, were identified. Anterior knee laxity (KT-1000 arthrometer, 134 N) was assessed 6 months postoperatively. The Knee injury and Osteoarthritis Outcome Score (KOOS) was collected preoperatively and 1, 2, and 5 years postoperatively. Patients who underwent revision ACLR at any institution in the country within 5 years of primary surgery were identified through the Swedish National Knee Ligament Registry.Results:A total of 4697 patients (54.3% male) with available KT-1000 arthrometer measurements were included (normal: side-to-side [STS] ≤2 mm, 3015 [64.2%]; nearly normal: STS 3-5 mm, 1446 [30.8%]; abnormal: STS >5 mm, 236 [5.0%]). The only significant difference in subjective knee outcome between the groups was for the KOOS Symptoms subscale at the 1-year follow-up (STS ≤2 mm, 79.9 ± 16.2; STS 3-5 mm, 82.5 ± 14.8; STS >5 mm, 85.1 ± 14.2; P < .001). No other significant differences between the groups were found preoperatively or at 1, 2, or 5 years postoperatively for any of the KOOS subscales. The hazard for revision ACLR within 5 years of the primary surgery was significantly higher for the groups with an STS of 3 to 5 mm (6.6%; 95/1446) (hazard ratio [HR], 1.42; 95% CI, 1.07-1.87; P = .01) and an STS >5 mm (11.4%; 27/236) (HR, 2.61; 95% CI, 1.69-4.03; P < .001) compared with the group with an STS ≤2 mm (3.8%; 116/3015).Conclusion:A high grade of postoperative knee laxity (STS 3-5 mm and STS >5 mm) 6 months after primary ACLR was associated with an increased hazard of revision ACLR within 5 years, but it was not associated with an inferior subjective knee outcome.

中文翻译：

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术后膝关节高度松弛与翻修手术风险增加相关：一项针对 4697 名原发性 ACL 重建患者的队列研究


背景：关于关节测量膝关节松弛测量与主观膝关节结果和初次前交叉韧带重建 (ACLR) 后翻修手术之间的关联仍存在争议。目的：评估关节测量膝关节松弛（使用 KT-1000 关节计测量）是否需要 6 个月主要 ACLR 与 1 年、2 年和 5 年主观膝关节结果或 5 年随访时的修订 ACLR 相关。研究设计：队列研究，证据级别 3。方法：接受主要 ACLR 的患者2005 年 1 月 1 日至 2017 年 12 月 31 日期间，在提交人所在的机构进行了自体腿筋肌腱移植，未发现伴随韧带损伤。术后 6 个月评估膝关节前部松弛度（KT-1000 关节计，134 N）。术前和术后 1 年、2 年和 5 年收集膝关节损伤和骨关节炎结果评分 (KOOS)。通过瑞典国家膝关节韧带登记处确定了初次手术后 5 年内在国内任何机构接受过 ACLR 翻修的患者。结果：共有 4697 名患者（54.3% 男性）具有可用的 KT-1000 关节计测量结果（正常） ：边到边[STS] ≤2 mm，3015 [64.2%]；接近正常：STS 3-5 mm，1446 [30.8%]；异常：STS >5 mm，236 [5.0%]）。各组之间主观膝关节结果的唯一显着差异是 1 年随访时的 KOOS 症状分量表（STS ≤2 mm，79.9 ± 16.2；STS 3-5 mm，82.5 ± 14.8；STS > 5 mm， 85.1 ± 14.2；P < .001)。对于任何 KOOS 分量表，在术前或术后 1 年、2 年或 5 年时，各组之间均未发现其他显着差异。 对于 STS 为 3 至 5 mm 的组，初次手术后 5 年内进行 ACLR 翻修的风险显着更高 (6.6%; 95/1446)（风险比 [HR], 1.42; 95% CI, 1.07-1.87 ；P = .01) 且 STS > 5 mm (11.4%; 27/236) (HR, 2.61; 95% CI, 1.69-4.03; P < .001) 与 STS ≤ 2 mm (3.8) 的组相比%; 116/3015).结论：初次 ACLR 术后 6 个月的高度膝关节松弛（STS 3-5 mm 和 STS >5 mm）与 5 年内翻修 ACLR 的风险增加相关，但事实并非如此与较差的主观膝关节结果相关。