Predictive Reliability of the Phoenix Sign for the Outcome of Common Fibular (Peroneal) Nerve Decompression Surgery

• 作者: Adam Khan Erik Rosas Porscha Bailey Sequioa Du Casse Stephen L. Barrett Victoria Brown
• 来源期刊: 矫形学期刊(英文)
• 学科: 医学
• 关键词: Peripheral Nerve Block Drop Foot Ultrasound Guidance Common Peroneal Nerve Entrapment Common Fibular Nerve Entrapment
• 年，卷（期）: 2020,（9）
• 页码范围: 234-240
• 页数: 7页
• 分类号: R73

摘要

<span style="font-family:Verdana;">A positive Phoenix sign occurs when a patient, with a suspected focal nerve entrapment of the Common Fibular (Peroneal) Nerve (CFN) at the level of the fibular neck, demonstrates an improvement in dorsifexion after an ultrasound guided infiltration of a sub-anesthetic dose of lidocaine. Less than</span><span style="font-family:""> </span><span style="font-family:Verdana;">5 cc’s of 1% or 2% lidocaine is utilized and the effect is seen within minutes after the infiltration, but usually lasts only 10 minutes. This effect may be due to the vasodilatory action of lidocaine on the microcirculation in the area of infiltration. This nerve block has significant diagnostic utility as it is highly specific in the confirmation of true focal entrapment of the CFN, has high predictive value for a patient who may undergo surgical nerve decompression if they have demonstrated a positive Phoenix Sign, and may help in the surgical decision-making process in patients who have had a drop foot for many years but still may regain some motor function after decompression. In this retrospective review, 26 patients were tested, and 25</span><span style="font-family:""> </span><span style="font-family:""><span style="font-family:Verdana;">of this cohort demon</span><span style="font-family:Verdana;">strated a Positive Phoenix Sign (an increase in dorsiflexion strength of the</span><span style="font-family:Verdana;"> Extensor Hallucis Longus muscle (EHL)). One patient had no response to the </span><span style="font-family:Verdana;">peripheral nerve block. Of the 25 patients who demonstrated a positive</span><span style="font-family:Verdana;"> “Phoenix Sign” and underwent nerve decompression of the CFN, and 25 (100%) showed an increase in dorsiflexion strength of the EHL after nerve decom</span><span style="font-family:Verdana;">pression surgery of the CFN. The one patient in this cohort who did not</span><span style="font-family:Verdana;"> dem</span><span style="font-family:Verdana;">onstrate any im