Department of Orthopaedic Surgery, Hospital for Special Surgery, New York, New York.
Department of Orthopaedic Surgery, University of Miami Hospital, Miami, Florida.
J Reconstr Microsurg. 2020 Jun;36(5):311-315. doi: 10.1055/s-0039-1701036. Epub 2020 Jan 27.
Optimizing axon count is essential for successful nerve transfer surgery, and a donor-to-recipient axon count ratio greater than 0.7:1 has been associated with improved outcomes. A gracilis free functioning muscle transfer (FFMT) is an option to restore elbow flexion, but its axon count has not been evaluated. Our aim was to quantify the axon count of the nerve to the gracilis muscle.
The nerve to the gracilis was dissected in 10 fresh frozen adult cadaveric hindquarter specimens (four females and six males). The length of the nerve to the gracilis was measured and a biopsy taken. A validated histologic preparation technique was utilized, and axons were counted. The mean length and axon counts were calculated.
The average axon count in the nerve to the gracilis was 818 (range = 684-1,000, standard deviation [SD] = 116). The average length was 98 mm (range = 81-115 mm, SD = 13 mm).
Our study found the average axon count in the nerve to the gracilis was 818. Prior literature suggests axon count ratio greater than 0.7:1 is associated with better clinical outcomes. Using data from prior studies, the spinal accessory, three intercostal, and two intercostal nerves are all sufficient for the transfer to the nerve to the gracilis with donor to recipient ratios of 1.7:1, 1.3:1, and 0.9:1, respectively.
优化轴突计数对于成功的神经转移手术至关重要，并且已经证实供体与受体的轴突计数比大于 0.7:1 与改善的结果相关。游离股薄肌功能性肌肉转移（FFMT）是恢复肘部弯曲的一种选择，但尚未对其轴突计数进行评估。我们的目的是量化股薄肌神经的轴突计数。
在 10 个新鲜冷冻的成人尸骸后肢标本（4 名女性和 6 名男性）中解剖股薄肌神经。测量股薄肌神经的长度并进行活检。采用经过验证的组织学准备技术，计数轴突。计算平均长度和轴突计数。
股薄肌神经中的平均轴突计数为 818（范围=684-1000，标准差[SD]=116）。平均长度为 98 mm（范围=81-115 mm，SD=13 mm）。
我们的研究发现股薄肌神经中的平均轴突计数为 818。先前的文献表明，轴突计数比大于 0.7:1 与更好的临床结果相关。使用先前研究的数据，副神经、三根肋间神经和两根肋间神经均足以转移到股薄肌神经，供体与受体的比例分别为 1.7:1、1.3:1 和 0.9:1。
