Department of Radiology, British Columbia Children's Hospital, University of British Columbia, 4500 Oak St., Vancouver, BC, V6H 3N1, Canada.
Department of Orthopaedic Surgery, British Columbia Children's Hospital, University of British Columbia, Vancouver, BC, Canada.
Pediatr Radiol. 2021 Mar;51(3):435-440. doi: 10.1007/s00247-020-04866-z. Epub 2020 Nov 19.
Recent anatomical investigations have emphasized the variability in the knee extensor apparatus, with particular attention to a fifth component of the quadriceps femoris termed the tensor vastus intermedius or accessory "quinticeps femoris." Disorders of this structure have not been described in the pediatric imaging literature.
To review the clinical features, pathoanatomy and imaging findings of children presenting with derangement of the accessory quadriceps femoris, with a particular emphasis on the utility of early magnetic resonance imaging (MRI) of the thigh.
This is a retrospective analysis of 3 children, ages 3-10 years at presentation, who underwent imaging evaluation with subsequent surgically proven accessory quadriceps femoris muscles. Their clinical histories, including duration of symptoms, MRI findings, intervention and surgical outcomes, are reported.
All patients presented with progressive unilateral restricted knee flexion and had multiple imaging studies targeting the knee before diagnosis. Diagnosis in all patients was made on MRI of the thighs, which demonstrated a fusiform low signal intensity structure with muscle-like architecture arising from the anterior or anterolateral proximal femur and blending with the common quadriceps tendon distally. All patients underwent surgical release of the anomalous band with significant functional improvement.
In cases of progressive limited knee flexion without intrinsic pathology, an accessory quadriceps muscle should be considered as an extrinsic cause. Our experience demonstrated this to be readily identifiable on MRI, with symptomatic improvement following surgical release. Early recognition of this condition should prevent unnecessary intervention such as knee arthroscopy and the debilitating loss of flexion due to delayed diagnosis.
最近的解剖学研究强调了膝关节伸肌装置的可变性，特别关注股四头肌的第五个组成部分，称为中间股直肌或辅助“五头肌股四头肌”。这种结构的紊乱在儿科影像学文献中尚未描述。
回顾表现为辅助股四头肌紊乱的儿童的临床特征、病理解剖和影像学表现，特别强调早期大腿磁共振成像（MRI）的实用性。
这是对 3 名年龄在 3-10 岁的儿童进行的回顾性分析，这些儿童均经过影像学评估，并随后通过手术证实存在辅助股四头肌。报告了他们的临床病史，包括症状持续时间、MRI 结果、干预和手术结果。
所有患者均表现为进行性单侧膝关节屈曲受限，且在诊断前均进行了多次针对膝关节的影像学检查。所有患者均通过大腿 MRI 确诊，MRI 显示从股骨前或前外侧近端出现梭形低信号强度结构，具有类似肌肉的结构，并向远端与股四头肌肌腱融合。所有患者均接受了异常带的手术松解，功能显著改善。
在没有内在病变的进行性膝关节屈曲受限的情况下，应考虑辅助股四头肌作为外在原因。我们的经验表明，这种情况在 MRI 上很容易识别，手术松解后症状会改善。早期认识这种情况应可防止因延迟诊断而导致不必要的膝关节镜检查和因丧失活动度而导致的虚弱。
