Reference Value for the Cross Sectional Area of Fibular Nerve Ultrasonography through the Anatomic Investigation in Korean

ABSTRACT

OBJECTIVE: To investigate the reference value for cross sectional area (CSA) of the fibular nerve in Koreans. METHOD: One musculoskeletal radiologist and one physiatrist performed fibular nerve ultrasonography (US) on 60 lower extremities of 30 asymptomatic Korean volunteers (16 males, 14 females). The mean age was 46.6 years (range: 21-75 years). We measured CSA of the fibular nerve at three sites: proximal portion (PP) at the bifurcation, mid-portion (MP), and an area just above the fibular head (FH). In addition, the fibular nerves of 7 lower extremities from 4 cadavers were cut from the fibular head to the proximal portion and divided into three sections (PP, MP, FH). They were subsequently fixed with 10% neutral buffered formalin and perpendicularly excised to 2 mm thickness. They were photographed by an operating microscope and CSA was measured. Using the Kruskal-Wallis test, measurements obtained from US images were compared between asymptomatic volunteers with a significance level of 0.05. RESULTS: In asymptomatic volunteers, the CSA of the three portions were PP: 13.8+/-1.2 mm2, MP: 11.1+/-1.0 mm2, FH: 10.9+/-0.6 mm2. The fibular nerves were well visualized with clear borders by US. In cadavers, the CSA of three portions were PP: 20.3+/-10.3 mm2, MP: 16.7+/-8.6 mm2, FH: 14.4+/-8.9 mm2. There was no significant difference between the three portions in asymptomatic volunteers and cadavers (p>0.05). CONCLUSION: In normal Korean adults, the area of fibular nerve at the fibular head is 10.9+/-0.6 mm2. Ultrasonographic evaluation of the fibular nerve can be helpful in diagnosing fibular nerve lesions.