Abstract

Background

Intra-articular venous malformations of the knee are an uncommon cause of unilateral knee pain in children. Timely diagnosis is important because lesions with intrasynovial involvement can lead to joint space hemorrhage and secondary cartilage damage.

Objective

To describe our tertiary center’s experience of diagnostics and typical magnetic resonance imaging (MRI) findings.

Materials and methods

A retrospective review of all patients ≤16 years of age managed for intra-articular venous malformations of the knee at our institution between 2002 and 2018.

Results

Of 14 patients (8 male), the mean age at presentation was 6 years (range: 0–14 years). The most common clinical findings were unilateral knee pain (93%), joint swelling (79%), quadriceps atrophy (50%) and a limited range of motion (29%). Cutaneous manifestations were present in four patients (29%). Contrast-enhanced MRI was available in all cases. After initial MRI, a vascular anomaly etiology had been identified in 11 cases (79%), and correctly reported as a venous malformation in 6 (55%). Three patients received entirely different diagnoses (arthritis, tumor or pigmented villonodular synovitis). Three of seven patients with intrasynovial lesions had established chondropathy at diagnosis. Two patients with lesions of the suprapatellar fat pad had intrasynovial involvement that was not visualised on MRI.

Conclusion

Although MRI usually permits the diagnosis, clinical awareness of these lesions is important for optimal imaging, accurate interpretation and timely diagnosis. Involvement of the intrasynovial cavity carries a risk of hemarthrosis and progressive chondropathy that may be underestimated by MRI.

中文翻译：

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儿童膝关节内静脉畸形：磁共振成像发现和滑膜受累的意义。

摘要

背景

膝关节内静脉畸形是儿童单侧膝关节疼痛的常见原因。及时诊断很重要，因为累及滑膜内病变可导致关节腔出血和继发性软骨损伤。

目的

描述我们的三级中心的诊断经验和典型的磁共振成像（MRI）发现。

材料和方法

回顾性分析2002年至2018年间我们机构中所有≤16岁的膝关节内静脉畸形患者。

结果

在14例患者（8例男性）中，出现时的平均年龄为6岁（范围：0-14岁）。最常见的临床表现是单侧膝关节疼痛（93％），关节肿胀（79％），股四头肌萎缩（50％）和运动受限（29％）。皮肤表现出现在四名患者中（29％）。在所有情况下都可以使用增强造影剂。初次MRI后，已确定11例（79％）的血管异常病因，并正确报告为6例（55％）的静脉畸形。三名患者得到了完全不同的诊断（关节炎，肿瘤或色素沉着的绒毛结节性滑膜炎）。在7例滑膜内病变患者中，有3例在诊断时出现软骨病。两名伴有rap上脂肪垫病变的患者有滑膜内受累，MRI上没有显示。

结论

尽管MRI通常可以诊断，但是对这些病变的临床认识对于最佳成像，准确解释和及时诊断很重要。滑膜内腔受累可能会引起血栓形成和进行性软骨病，而MRI可能低估了这种风险。