Department of Plastic and Reconstructive Surgery, The Northern Hospital, Epping, Victoria, Australia.
Clin Anat. 2010 May;23(4):427-30. doi: 10.1002/ca.20952.
Flexor carpi ulnaris (FCU) is an ever-present muscle of the anterior flexor compartment of the forearm. Variations of FCU are uncommon, with additional slips or heads of muscles described, and only one reported case of an accessory muscle. We describe a unique clinical case report in which an accessory FCU was identified and describe the findings of 5,000 cadaveric dissections of the forearm, performed as part of an ongoing institutional study of anatomical variations. An aberrant accessory forearm flexor muscle was identified incidentally at the wrist during surgery for an anterior interosseous to ulnar nerve transfer for management of ulnar nerve palsy. This muscle was seen running superficial to the ulnar nerve and radial to the FCU proper, arising from the common flexor origin and inserting at the triquetral carpal bone. This was therefore suitably acknowledged as an "accessory FCU". The anomaly was identified as bilateral using ultrasound imaging, and was found to be anomalously innervated by the median nerve with nerve conduction studies. A subsequent review of 5,000 cadaveric dissections of the forearm did not identify any such variations related to FCU, despite identifying a range of variations of the other forearm flexor musculature. While the scarcity of this anomaly is thus highlighted, consideration of an accessory FCU, and its aberrant innervation is important in a range of surgical approaches.
尺侧腕屈肌 (FCU) 是前臂前屈肌间隔中始终存在的肌肉。FCU 的变异并不常见，有额外的滑液或肌肉头被描述，只有一例 accessory muscle 的报道。我们描述了一个独特的临床病例报告，其中鉴定出一个 accessory FCU，并描述了作为正在进行的解剖变异机构研究的一部分对前臂进行的 5000 具尸体解剖的发现。在因尺神经瘫痪而行正中神经至尺神经的骨间前神经转移术时，在手腕处意外发现了一个异常的 accessory 前臂屈肌。该肌肉位于尺神经浅面，FCU 固有肌的桡侧，发自共同屈肌起点，止于三角骨。因此，这被恰当地认为是一个“accessory FCU”。该异常通过超声成像被确认为双侧，并通过神经传导研究发现其由正中神经异常支配。随后对 5000 具前臂尸体解剖的回顾没有发现任何与 FCU 相关的变异，尽管发现了其他前臂屈肌的一系列变异。虽然这种异常的罕见性得到了强调，但在一系列手术方法中，考虑 accessory FCU 及其异常支配是很重要的。
