Department of Anatomical Dissection and Donation, Medical University of Lodz, Lodz, Poland.
Department of Neurosurgery, Tulane University School of Medicine, New Orleans, Louisiana, USA.
Clin Anat. 2021 Jan;34(1):71-81. doi: 10.1002/ca.23646. Epub 2020 Sep 9.
The quadriceps femoris (QF) consists of four muscles: the rectus femoris; vastus medialis; vastus lateralis, and vastus intermediate. The tendons of all of these parts join together into a single tendon that attaches to the patella. The QF is a powerful extensor of the knee joint that is needed for walking. A growing number of publications have examined the fifth head of the QF muscle. There is no information about the possibility of other heads, and there is no correct classification of their proximal attachments. Further, the frequency of occurrence of additional heads/components of the QF remains unclear.
One hundred and six lower limbs (34 male and 18 female) fixed in 10% formalin solution were examined.
Additional heads of the QF were present in 64.1% of the limbs. Three main types were identified and included subtypes. The most common was Type I (44.1%), which had an independent fifth head. This type was divided into two subtypes (A-B) depending on its location relative to the vastus intermediate. The second most common type was Type II (30.8%), which originated from other muscles: IIA from the vastus lateralis; IIB from the vastus intermediate, and IIC from the gluteus minimus. In addition, Type III (25%) was characterized by multiple heads: IIIA-two heads with a single common tendon; IIIB-two heads with two separate tendons; IIIC-three heads (lateral, intermediate, medial), and IIID-four heads (bifurcated lateral and bifurcated medial).
The introduction of a new classification based on a proximal attachment is necessary. The presence of the fifth, sixth, seventh, or eighth head varies.
股四头肌（QF）由四块肌肉组成：股直肌、股内侧肌、股外侧肌和股中间肌。这些部分的肌腱都连接在一起形成一个单一的肌腱，附着在髌骨上。QF 是膝关节的强大伸肌，是行走所必需的。越来越多的出版物研究了 QF 肌肉的第五个头。目前还没有关于其他头的信息，也没有对其近端附着点进行正确的分类。此外，QF 的附加头/组成部分的出现频率仍不清楚。
检查了 106 条下肢（34 名男性和 18 名女性），这些下肢固定在 10%的福尔马林溶液中。
64.1%的肢体存在 QF 的附加头。确定了三种主要类型，包括亚型。最常见的是 I 型（44.1%），它有一个独立的第五个头。这种类型分为两个亚型（A-B），这取决于它相对于股中间肌的位置。第二种最常见的类型是 II 型（30.8%），它起源于其他肌肉：IIA 来自股外侧肌；IIB 来自股中间肌，IIC 来自臀小肌。此外，III 型（25%）的特点是多个头：IIIA-两个头共用一个单一的共同肌腱；IIIB-两个头有两个单独的肌腱；IIIC-三个头（外侧、中间、内侧），IID-四个头（分叉外侧和分叉内侧）。
有必要基于近端附着点引入一种新的分类。第五、第六、第七或第八个头的出现情况各不相同。
