Sugiura Shiro, Matsuura Yusuke, Suzuki Takane, Nishikawa Satoru, Mori Chisato, Kuniyoshi Kazuki
Department of Orthopaedic Surgery, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba, 260-8670, Japan.
Nishikawa Orthopaedic Clinic, Chiba, Japan.
Surg Radiol Anat. 2018 Mar;40(3):345-347. doi: 10.1007/s00276-017-1923-y. Epub 2017 Nov 14.
According to the anatomical literature, the extensor pollicis brevis (EPB) tendon passes through the first compartment and enters the base of the proximal phalanx of the thumb. There have been a few reports on the different types of supernumerary EPB tendons; however, an unusual course of the EPB tendon is extremely rare.
During routine cadaveric dissection in the Department of Gross Anatomy, we detected an variant EPB muscle in a 96-year-old fresh female cadaver.
The EPB muscle originated from the posterior surface of the radius and interosseous membrane. However, the EPB tendon passed through the third compartment instead of the first compartment. It ran parallel to the extensor pollicis longus (EPL) tendon and entered the base of the thumb proximal phalanx. The EPL tendon was attached to the base of the first distal phalanx, as normally observed. Both EPB and EPL muscles were innervated by the posterior interosseous nerve.
We report a case of a variant course of the EPB tendon appearing in the third extensor compartment of the wrist with the EPL tendon. The knowledge of this anatomic variation will be helpful for accurate diagnosis and surgical planning.
根据解剖学文献，拇短伸肌（EPB）肌腱穿过第一腱鞘并进入拇指近节指骨基底。关于额外的EPB肌腱的不同类型已有一些报道；然而，EPB肌腱走行异常极为罕见。
在大体解剖学系进行常规尸体解剖时，我们在一名96岁的新鲜女性尸体中发现了一条变异的EPB肌。
EPB肌起自桡骨后面和骨间膜。然而，EPB肌腱穿过第三腱鞘而非第一腱鞘。它与拇长伸肌（EPL）肌腱平行走行并进入拇指近节指骨基底。EPL肌腱如正常所见附着于第一远节指骨基底。EPB和EPL肌均由骨间后神经支配。
我们报告了1例EPB肌腱走行变异的病例，该肌腱出现在腕部第三伸肌腱鞘并与EPL肌腱伴行。了解这种解剖变异将有助于准确诊断和手术规划。
