Olson Brendan, Wakeland William, Olson Jayden, Zoghi Sara, Hubbard John K
Texas A&M University College of Medicine, Bryan, TX, USA.
Texas A&M Health Science Center, Medical Research and Education Building II, 8447 John Sharp Pkwy, Bryan, TX, 77807, USA.
Surg Radiol Anat. 2025 Feb 13;47(1):78. doi: 10.1007/s00276-025-03591-2.
The extensor digitorum longus (EDL) and fibularis (peroneus) tertius (FT), muscles of the anterior compartment of the leg, synergistically work to dorsiflex and evert the foot. The EDL additionally extends the lateral four toes, while the FT normally lacks this ability. Anatomical variations of the variably present FT are common, but infrequently involve the EDL. The FT has been known to give off additional accessory tendons which may alter its role in ankle and foot movement. Documentation of unique anatomical variations of the FT and EDL can assist not only anatomists, but clinicians and surgeons as well.
During routine cadaveric dissection, a rare and unique bilateral presentation of the extensor digitorum longus and fibularis tertius was discovered.
The extensor digitorum longus was found to be missing its lateral-most tendon that would normally insert on the 5th digit. A large, overriding FT split into three tendons, with the medial-most tendon inserting to the phalanges of the 5th digit, effectively replacing the missing EDL tendon. All findings were present bilaterally.
To our knowledge, despite previous literature of unilateral presentations like this case, a bilateral EDL and FT variation as seen here has never been reported in humans. The use of accessory fibularis muscles in tendon graft procedures, especially the FT, makes awareness of leg anatomical variations critical for surgeons operating in the area. The present case is discussed alongside other documented anatomical variations, highlighting potential clinical implications for tendon grafting and preoperative imaging.
趾长伸肌（EDL）和第三腓骨肌（FT）是小腿前侧肌群，协同作用使足部背屈和外翻。EDL还可伸展外侧四个脚趾，而FT通常没有此功能。FT出现与否存在可变的解剖变异很常见，但很少涉及EDL。已知FT会发出额外的副腱，这可能会改变其在踝关节和足部运动中的作用。记录FT和EDL独特的解剖变异不仅有助于解剖学家，也有助于临床医生和外科医生。
在常规尸体解剖过程中，发现了一种罕见且独特的双侧趾长伸肌和第三腓骨肌表现。
发现趾长伸肌最外侧的肌腱缺失，该肌腱通常插入第5趾。一条粗大的、占主导地位的FT分成三条肌腱，最内侧的肌腱插入第5趾的趾骨，有效地替代了缺失的EDL肌腱。所有发现均为双侧存在。
据我们所知，尽管之前有关于像本病例这样的单侧表现的文献报道，但像此处所见的双侧EDL和FT变异在人类中从未被报道过。在肌腱移植手术中使用副腓骨肌，尤其是FT，使得了解小腿解剖变异对于在该区域进行手术的外科医生至关重要。本文将本病例与其他已记录的解剖变异一起讨论，强调了肌腱移植和术前成像的潜在临床意义。
