Department of Anatomical Dissection and Donation, Medical University of Lodz, Poland.
Institute of Functional and Clinical Anatomy, Friedrich Alexander University Erlangen-Nürnberg, Erlangen, Germany.
Folia Morphol (Warsz). 2022;81(2):451-457. doi: 10.5603/FM.a2021.0039. Epub 2021 Apr 26.
In adults, the fibularis tertius (FT) demonstrates great morphological variation. The present study classifies the types of FT insertion in human foetuses and compares their prevalence to the prevailing classification among adults.
Fifty spontaneously-aborted human foetuses (19 male, 31 female, 100 upper limbs in total) aged 18-38 weeks of gestation at death were examined. The foetuses were obtained from spontaneous abortion after parental consent. The study was performed in accordance with the legal procedures in force in Poland and with the Body Donation Programme for both adults and foetuses.
The most common type of FT found was type VI (32%), characterised by a bifurcated distal attachment: a main tendon inserting onto the base of the fourth metatarsal bone, and accessory bands inserting onto the fourth interosseous space. Five other types were observed: type IV (20%), with a single tendon inserting distally to the fascia covering the fourth interosseous space; type I (18%), with a single tendon inserting distally onto the shaft of the fifth metatarsal bone; type V (14%), with a bifurcated arrangement comprising a main tendon characterised by a very wide insertion onto the base of the fifth metatarsal bone and an accessory band inserting onto the base of the fourth metatarsal bone; and type III (12%) with a single tendon inserting distally onto the shaft of the fourth metatarsal bone and fascia covering the fourth interosseous space. Finally, type II (4%) was characterised by a single tendon inserting onto the base of the fifth metatarsal bone via a very wide distal insertion.
The FT demonstrates high morphological variability, with the most common configuration found in adults - a single insertion onto metatarsal 5 - being actually uncommonly found in foetuses.
在成年人中，第三腓骨（FT）表现出很大的形态变异。本研究对人胎儿 FT 的插入类型进行分类，并将其与成年人中流行的分类进行比较。
对 50 例自然流产的人胎儿（19 名男性，31 名女性，总共 100 只上肢）进行了检查。这些胎儿是在父母同意后因自然流产而获得的。该研究是按照波兰现行法律程序以及成人和胎儿遗体捐献计划进行的。
发现最常见的 FT 类型是 VI 型（32%），其特征为远端分叉附着：一个主要的肌腱插入第四跖骨的基部，辅助带插入第四骨间空间。还观察到其他五种类型：IV 型（20%），单一肌腱远端插入覆盖第四骨间空间的筋膜；I 型（18%），单一肌腱远端插入第五跖骨的骨干；V 型（14%），分叉排列包括一个主要的肌腱，其插入非常宽的第五跖骨基部和一个辅助带插入第四跖骨基部；以及 III 型（12%），单一肌腱远端插入第四跖骨的骨干和筋膜覆盖第四骨间空间。最后，II 型（4%）的特征是单一肌腱通过非常宽的远端插入插入第五跖骨基部。
FT 表现出很高的形态变异性，而在成年人中最常见的配置——单一插入到第五跖骨——实际上在胎儿中并不常见。
