Department of Anatomy, University of Western Brittany, Brest, France; Department of Plastic, Reconstructive and Aesthetic Surgery, Hand Surgery, Brest University Hospital, Brest, France.
LIEN, University of Western Brittany, Brest, France.
Orthop Traumatol Surg Res. 2024 May;110(3):103721. doi: 10.1016/j.otsr.2023.103721. Epub 2023 Oct 20.
High median nerve injuries can lead to poor distal recovery, especially poor functioning of median innervated thenar muscles involved in thumb opposition and palmar abduction. The palmaris brevis (PB) is a small subcutaneous muscle innervated by ulnar nerve. Innervation of the PB is in most of cases provided by the ulnar digital nerve to the little finger. The purpose of this study is to assess the feasibility of transferring the PB motor branch (PBMB) to the median nerve thenar motor branch (TMB), in order to allow for early restoration of thumb palmar abduction and opposition, through a preliminary cadaveric study.
Twenty-five cadaver upper limbs were dissected under magnification. The length of the PBMB and TMB, and their origin were recorded. Nerve transfer from PBMB to TMB was conducted, and evaluated on 2 parameters: surgical feasibility, and distance from the coaptation site to the recipient nerve muscle entry point. The PBMB and TMB were harvested, fixated in formalin, then embedded in paraffin. They were sectioned transversely, and stained with a combination of hematoxylin-eosin and Luxol fast blue. Myelinated axons were counted in each specimen and the donor-to-recipient axon ratio was recorded.
The PBMB was constant and originated from the ulnar digital nerve of the little finger in all cases. The transfer from PBMB to TMB was feasible in all cases. Mean myelinated axon counts of PBMB and TMB were 253±142 and 356±198, respectively (p=0.06). The donor-to-recipient axon ratio was 1:1.41. The mean distance from coaptation of the PBMB to the recipient thenar muscles was 23.1±3.0mm.
Based on our results, PBMB to TMB transfer is feasible. The PBMB has the advantage over other distal nerve transfer donors to be constant and superficial, allowing for an easier harvest. Moreover, this procedure does not sacrifice any intrinsic function of the hand, and the proximity of the PBMB with the carpal tunnel allows for a single incision procedure. Therefore, early restoration of the median innervated thenar muscles may be feasible by the PBMB to TMB transfer in cases of high median nerve lesions.
IV.
高位正中神经损伤可导致远端恢复不良，特别是与拇指对掌和掌心外展相关的正中神经支配的鱼际肌肉功能不良。掌短肌（PB）是一块细小的皮下肌肉，由尺神经支配。在大多数情况下，PB 由尺神经的小指指神经提供支配。本研究的目的是评估将 PB 运动支（PBMB）转移到正中神经鱼际运动支（TMB）的可行性，以便通过初步的尸体研究，早期恢复拇指掌心外展和对掌功能。
在放大倍数下解剖了 25 具尸体上肢。记录 PBMB 和 TMB 的长度及其起源。进行了从 PBMB 到 TMB 的神经转移，并通过 2 个参数进行评估：手术可行性和吻合部位到受神经肌肉进入点的距离。采集 PBMB 和 TMB，固定于福尔马林，然后嵌入石蜡。将其横向切片，并用苏木精-伊红和卢索快速蓝联合染色。对每个标本中的有髓神经轴突进行计数，并记录供体与受体的轴突比。
在所有情况下，PBMB 都是恒定的，起源于小指的尺神经指神经。从 PBMB 到 TMB 的转移在所有情况下都是可行的。PBMB 和 TMB 的平均有髓神经轴突计数分别为 253±142 和 356±198（p=0.06）。供体与受体的轴突比为 1:1.41。PBMB 与受鱼际肌肉吻合的平均距离为 23.1±3.0mm。
根据我们的结果，PBMB 到 TMB 的转移是可行的。与其他远端神经转移供体相比，PBMB 具有恒定且浅表的优势，便于采集。此外，该手术不会牺牲手部的任何固有功能，并且 PBMB 与腕管的接近允许进行单次切口手术。因此，在高位正中神经损伤的情况下，通过 PBMB 到 TMB 的转移可能可以早期恢复正中神经支配的鱼际肌肉。
IV。
