Background

Irreducible knee dislocations (IKD) are rare and can often be missed or misdiagnosed. The incidence of knee dislocation is quoted between 0.01% and 0.2% of all orthopaedic injuries, with up to 4% of these dislocations sub-classified as irreducible. The primary aim of this systematic review was to analyse cases of IKD described in the literature, with a secondary aim of producing a streamlined approach for managing these patients.

Patients and methods

A systematic review of the literature was conducted on 1st September 2021 in accordance with the PRISMA guidelines using the online databases Medline and EMBASE. The review was registered prospectively in the PROSPERO database. Case reports or clinical studies or reporting on IKD were included. The studies were appraised using the Methodological Index for Non-Randomized Studies (MINORS) tool and Newcastle-Ottawa quality assessment scale.

Results

The search strategy identified 60 studies eligible for inclusion, giving a total of 114 cases of IKD. Posterolateral dislocation was most common, seen in 85% of cases. The dimple sign was present in 70%. All cases required surgical intervention to achieve joint reduction. The most commonly involved structure blocking reduction was the medial collateral ligament (MCL) ± medial structures, seen in 52.4%. MCL reconstruction or repair was carried out in 32.3% cases. The overall incidence of neurovascular injury was 9% and the overall complication rate was 14.4%.

Conclusion

Based on the findings of this SR we conclude that: the most common type of IKDs are PL dislocations, and the MCL, medial retinaculum and capsule and vastus medialis oblique form the most common structures involved in block to reduction and often will require open reduction and repair in acute setting if arthroscopic reduction fails. The most common pattern of injury to ligament is likely to be ACL, PCL, MCL ± other structures but the MCL will be the most commonly repaired ligament. The dimple sign is often present and is highly pathognomonic of IKD. The incidence of neurovascular injury is uncommon. The most common post-operative complications likely to be encountered is medial skin necrosis and postoperative knee stiffness. Therefore, patients should be mobilised as early as possible with ROM in hinge brace.

Level of evidence

IV.

中文翻译：

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不可复位膝关节脱位的处理和结果的系统评价

背景

不可复位膝关节脱位 (IKD) 很少见，经常会被漏诊或误诊。膝关节脱位的发生率在所有骨科损伤中占 0.01% 至 0.2%，其中高达 4% 的脱位被归类为不可复位的。本系统评价的主要目的是分析文献中描述的 IKD 病例，其次要目的是制定一种简化的方法来管理这些患者。

患者和方法

2021 年 9 月 1 日，根据 PRISMA 指南，使用在线数据库 Medline 和 EMBASE 对文献进行了系统回顾。该评论在 PROSPERO 数据库中进行了前瞻性注册。包括病例报告或临床研究或 IKD 报告。使用非随机研究方法学指数 (MINORS) 工具和纽卡斯尔-渥太华质量评估量表对这些研究进行了评估。

结果

搜索策略确定了 60 项符合纳入条件的研究，总共提供了 114 例 IKD 病例。后外侧脱位最常见，见于 85% 的病例。70% 出现酒窝征。所有病例都需要手术干预以实现关节复位。最常涉及的结构阻塞复位是内侧副韧带 (MCL)  ± 内侧结构，见于 52.4%。32.3% 的病例进行了 MCL 重建或修复。神经血管损伤总发生率为9%，总并发症发生率为14.4%。

结论

基于此 SR 的发现，我们得出结论：最常见的 IKD 类型是 PL 脱位，MCL、内侧支持带和关节囊以及股内侧斜肌形成阻滞复位最常见的结构，通常需要切开复位和如果关节镜复位失败，则在急性情况下进行修复。最常见的韧带损伤模式可能是 ACL、PCL、MCL  ± 其他结构，但 MCL 将是最常修复的韧带。经常出现酒窝征，是 IKD 的高度特征性表现。神经血管损伤的发生率并不常见。可能遇到的最常见的术后并发症是内侧皮肤坏死和术后膝关节僵硬。因此，患者应尽早活动，并在铰链支具中使用 ROM。

证据等级

四、